riscv: Fix loading 64-bit NOMMU kernels past the start of RAM

commit 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear
mapping") added logic to allow using RAM below the kernel load address.
However, this does not work for NOMMU, where PAGE_OFFSET is fixed to the
kernel load address. Since that range of memory corresponds to PFNs
below ARCH_PFN_OFFSET, mm initialization runs off the beginning of
mem_map and corrupts adjacent kernel memory. Fix this by restoring the
previous behavior for NOMMU kernels.

Fixes: 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240227003630.3634533-3-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: Update mmap_rnd_bits_max

ARCH_MMAP_RND_BITS_MAX is based on Sv39, which leaves a few
potential bits of mmap randomness on the table if we end up enabling
4/5-level paging. Update mmap_rnd_bits_max to take the final address
space size into account. This increases mmap_rnd_bits_max from 24 to
33 with Sv48/57.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20230929211155.3910949-6-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv, crash: wrap crash dumping code into crash related ifdefs

Now crash codes under kernel/ folder has been split out from kexec
code, crash dumping can be separated from kexec reboot in config
items on risc-v with some adjustments.

Here wrap up crash dumping codes with CONFIG_CRASH_DUMP ifdeffery, and
use IS_ENABLED(CONFIG_CRASH_RESERVE) check to decide if compiling
in the crashkernel reservation code.

Link: https://lkml.kernel.org/r/20240124051254.67105-13-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Pingfan Liu <piliu@redhat.com>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Michael Kelley <mhklinux@outlook.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arm64, powerpc, riscv, s390, x86: ptdump: refactor CONFIG_DEBUG_WX

All architectures using the core ptdump functionality also implement
CONFIG_DEBUG_WX, and they all do it more or less the same way, with a
function called debug_checkwx() that is called by mark_rodata_ro(), which
is a substitute to ptdump_check_wx() when CONFIG_DEBUG_WX is set and a
no-op otherwise.

Refactor by centrally defining debug_checkwx() in linux/ptdump.h and call
debug_checkwx() immediately after calling mark_rodata_ro() instead of
calling it at the end of every mark_rodata_ro().

On x86_32, mark_rodata_ro() first checks __supported_pte_mask has _PAGE_NX
before calling debug_checkwx(). Now the check is inside the callee
ptdump_walk_pgd_level_checkwx().

On powerpc_64, mark_rodata_ro() bails out early before calling
ptdump_check_wx() when the MMU doesn't have KERNEL_RO feature. The check
is now also done in ptdump_check_wx() as it is called outside
mark_rodata_ro().

Link: https://lkml.kernel.org/r/a59b102d7964261d31ead0316a9f18628e4e7a8e.1706610398.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg KH <greg@kroah.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Phong Tran <tranmanphong@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steven Price <steven.price@arm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

riscv: mm: execute local TLB flush after populating vmemmap

The spare_init() calls memmap_populate() many times to create VA to PA
mapping for the VMEMMAP area, where all "struct page" are located once
CONFIG_SPARSEMEM_VMEMMAP is defined. These "struct page" are later
initialized in the zone_sizes_init() function. However, during this
process, no sfence.vma instruction is executed for this VMEMMAP area.
This omission may cause the hart to fail to perform page table walk
because some data related to the address translation is invisible to the
hart. To solve this issue, the local_flush_tlb_kernel_range() is called
right after the sparse_init() to execute a sfence.vma instruction for this
VMEMMAP area, ensuring that all data related to the address translation
is visible to the hart.

Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem")
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20240117140333.2479667-1-vincent.chen@sifive.com
Fixes: 7a92fc8b4d20 ("mm: Introduce flush_cache_vmap_early()")
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Fix build error on rv32 + XIP

commit 66f1e6809397 ("riscv: Make XIP bootable again") restricted page
offset to the sv39 page offset instead of the default sv57, which makes
sense since probably the platforms that target XIP kernels do not
support anything else than sv39 and we do not try to find out the
largest address space supported on XIP kernels (ie set_satp_mode()).

But PAGE_OFFSET_L3 is not defined for rv32, so fix the build error by
restoring the previous behaviour which picks CONFIG_PAGE_OFFSET for rv32.

Fixes: 66f1e6809397 ("riscv: Make XIP bootable again")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Closes: https://lore.kernel.org/linux-riscv/344dca85-5c48-44e1-bc64-4fa7973edd12@infradead.org/T/#u
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/r/20240118212120.2087803-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Use hugepage mappings for vmemmap

This will allow better TLB utilization and then should be more performant.

Before:

---[ vmemmap start ]---
0xffff8d8002000000-0xffff8d8012000000 0x000000046ec00000 256M PTE . .. .. D A G . . W R V
---[ vmemmap end ]---

After:

---[ vmemmap start ]---
0xffff8d8002000000-0xffff8d8012000000 0x000000046ec00000 256M PMD . .. .. D A G . . W R V
---[ vmemmap end ]---

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20231214132935.212864-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Make XIP bootable again

Currently, the XIP kernel seems to fail to boot due to missing
XIP_FIXUP and a wrong page_offset value. A superfluous XIP_FIXUP
has also been removed.

Signed-off-by: Frederik Haxel <haxel@fzi.de>
Link: https://lore.kernel.org/r/20231212130116.848530-2-haxel@fzi.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Don't use PGD entries for the linear mapping

Propagating changes at this level is cumbersome as we need to go through
all the page tables when that happens (either when changing the
permissions or when splitting the mapping).

Note that this prevents the use of 4MB mapping for sv32 and 1GB mapping for
sv39 in the linear mapping.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20231108075930.7157-2-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

RISC-V: Provide pgtable_l5_enabled on rv32

A few of the other page table level helpers are defined on rv32, but not
pgtable_l5_enabled. This adds the definition as a constant and converts
pgtable_l4_enabled to a constant as well.

Link: https://lore.kernel.org/r/20230830044129.11481-2-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: kdump: use generic interface to simplify crashkernel reservation

With the help of newly changed function parse_crashkernel() and generic
reserve_crashkernel_generic(), crashkernel reservation can be simplified
by steps:

1) Add a new header file <asm/crash_core.h>, and define CRASH_ALIGN,
CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX and
DEFAULT_CRASH_KERNEL_LOW_SIZE in <asm/crash_core.h>;

2) Add arch_reserve_crashkernel() to call parse_crashkernel() and
reserve_crashkernel_generic();

3) Add ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION Kconfig in
arch/riscv/Kconfig.

The old reserve_crashkernel_low() and reserve_crashkernel() can be
removed.

[chenjiahao16@huawei.com: fix crashkernel reserving problem on RISC-V]
Link: https://lkml.kernel.org/r/20230925024333.730964-1-chenjiahao16@huawei.com
Link: https://lkml.kernel.org/r/20230914033142.676708-9-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Chen Jiahao <chenjiahao16@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

crash_core: change the prototype of function parse_crashkernel()

Add two parameters 'low_size' and 'high' to function parse_crashkernel(),
later crashkernel=,high|low parsing will be added. Make adjustments in
all call sites of parse_crashkernel() in arch.

Link: https://lkml.kernel.org/r/20230914033142.676708-3-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Jiahao <chenjiahao16@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

riscv: Introduce virtual kernel mapping KASLR

KASLR implementation relies on a relocatable kernel so that we can move
the kernel mapping.

The seed needed to virtually move the kernel is taken from the device tree,
so we rely on the bootloader to provide a correct seed. Zkr could be used
unconditionnally instead if implemented, but that's for another patch.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Song Shuai <songshuaishuai@tinylab.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20230722123850.634544-2-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: kdump: Implement crashkernel=X,[high,low]

On riscv, the current crash kernel allocation logic is trying to
allocate within 32bit addressible memory region by default, if
failed, try to allocate without 4G restriction.

In need of saving DMA zone memory while allocating a relatively large
crash kernel region, allocating the reserved memory top down in
high memory, without overlapping the DMA zone, is a mature solution.
Here introduce the parameter option crashkernel=X,[high,low].

One can reserve the crash kernel from high memory above DMA zone range
by explicitly passing "crashkernel=X,high"; or reserve a memory range
below 4G with "crashkernel=X,low".

Signed-off-by: Chen Jiahao <chenjiahao16@huawei.com>
Acked-by: Guo Ren <guoren@kernel.org>
Acked-by: Baoquan He <bhe@redhat.com>
Link: https://lore.kernel.org/r/20230726175000.2536220-2-chenjiahao16@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: convert alloc_{pmd, pte}_late() to use ptdescs

As part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents, convert various page table functions to use ptdescs.

Some of the functions use the *get*page*() helper functions. Convert
these to use pagetable_alloc() and ptdesc_address() instead to help
standardize page tables further.

Link: https://lkml.kernel.org/r/20230807230513.102486-27-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Guo Ren <guoren@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

riscv: mm: fix 2 instances of -Wmissing-variable-declarations

I'm looking to enable -Wmissing-variable-declarations behind W=1. 0day
bot spotted the following instance in ARCH=riscv builds:

arch/riscv/mm/init.c:276:7: warning: no previous extern declaration
for non-static variable 'trampoline_pg_dir'
[-Wmissing-variable-declarations]
276 | pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
| ^
arch/riscv/mm/init.c:276:1: note: declare 'static' if the variable is
not intended to be used outside of this translation unit
276 | pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
| ^
arch/riscv/mm/init.c:279:7: warning: no previous extern declaration
for non-static variable 'early_pg_dir'
[-Wmissing-variable-declarations]
279 | pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
| ^
arch/riscv/mm/init.c:279:1: note: declare 'static' if the variable is
not intended to be used outside of this translation unit
279 | pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
| ^

These symbols are referenced by more than one translation unit, so make
sure they're both declared and include the correct header for their
declarations. Finally, sort the list of includes to help keep them tidy.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/llvm/202308081000.tTL1ElTr-lkp@intel.com/
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20230808-riscv_static-v2-1-2a1e2d2c7a4f@google.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Start of DRAM should at least be aligned on PMD size for the direct mapping

So that we do not end up mapping the whole linear mapping using 4K
pages, which is slow at boot time, and also very likely at runtime.

So make sure we align the start of DRAM on a PMD boundary.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reported-by: Song Shuai <suagrfillet@gmail.com>
Fixes: 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping")
Tested-by: Song Shuai <suagrfillet@gmail.com>
Link: https://lore.kernel.org/r/20230704121837.248976-1-alexghiti@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: fix truncation warning on RV32

lkp reports below sparse warning when building for RV32:
arch/riscv/mm/init.c:1204:48: sparse: warning: cast truncates bits from
constant value (100000000 becomes 0)

IMO, the reason we didn't see this truncates bug in real world is "0"
means MEMBLOCK_ALLOC_ACCESSIBLE in memblock and there's no RV32 HW
with more than 4GB memory.

Fix it anyway to make sparse happy.

Fixes: decf89f86ecd ("riscv: try to allocate crashkern region from 32bit addressible memory")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202306080034.SLiCiOMn-lkp@intel.com/
Link: https://lore.kernel.org/r/20230709171036.1906-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: move memblock_allow_resize() after linear mapping is ready

The initial memblock metadata is accessed from kernel image mapping. The
regions arrays need to "reallocated" from memblock and accessed through
linear mapping to cover more memblock regions. So the resizing should
not be allowed until linear mapping is ready. Note that there are
memblock allocations when building linear mapping.

This patch is similar to 24cc61d8cb5a ("arm64: memblock: don't permit
memblock resizing until linear mapping is up").

In following log, many memblock regions are reserved before
create_linear_mapping_page_table(). And then it triggered reallocation
of memblock.reserved.regions and memcpy the old array in kernel image
mapping to the new array in linear mapping which caused a page fault.

[ 0.000000] memblock_reserve: [0x00000000bf01f000-0x00000000bf01ffff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[ 0.000000] memblock_reserve: [0x00000000bf021000-0x00000000bf021fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[ 0.000000] memblock_reserve: [0x00000000bf023000-0x00000000bf023fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[ 0.000000] memblock_reserve: [0x00000000bf025000-0x00000000bf025fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[ 0.000000] memblock_reserve: [0x00000000bf027000-0x00000000bf027fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[ 0.000000] memblock_reserve: [0x00000000bf029000-0x00000000bf029fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[ 0.000000] memblock_reserve: [0x00000000bf02b000-0x00000000bf02bfff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[ 0.000000] memblock_reserve: [0x00000000bf02d000-0x00000000bf02dfff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[ 0.000000] memblock_reserve: [0x00000000bf02f000-0x00000000bf02ffff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[ 0.000000] memblock_reserve: [0x00000000bf030000-0x00000000bf030fff] early_init_fdt_scan_reserved_mem+0x28c/0x2c6
[ 0.000000] OF: reserved mem: 0x0000000080000000..0x000000008007ffff (512 KiB) map non-reusable mmode_resv0@80000000
[ 0.000000] memblock_reserve: [0x00000000bf000000-0x00000000bf001fed] paging_init+0x19a/0x5ae
[ 0.000000] memblock_phys_alloc_range: 4096 bytes align=0x1000 from=0x0000000000000000 max_addr=0x0000000000000000 alloc_pmd_fixmap+0x14/0x1c
[ 0.000000] memblock_reserve: [0x000000017ffff000-0x000000017fffffff] memblock_alloc_range_nid+0xb8/0x128
[ 0.000000] memblock: reserved is doubled to 256 at [0x000000017fffd000-0x000000017fffe7ff]
[ 0.000000] Unable to handle kernel paging request at virtual address ff600000ffffd000
[ 0.000000] Oops [#1]
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.4.0-rc1-00011-g99a670b2069c #66
[ 0.000000] Hardware name: riscv-virtio,qemu (DT)
[ 0.000000] epc : __memcpy+0x60/0xf8
[ 0.000000] ra : memblock_double_array+0x192/0x248
[ 0.000000] epc : ffffffff8081d214 ra : ffffffff80a3dfc0 sp : ffffffff81403bd0
[ 0.000000] gp : ffffffff814fbb38 tp : ffffffff8140dac0 t0 : 0000000001600000
[ 0.000000] t1 : 0000000000000000 t2 : 000000008f001000 s0 : ffffffff81403c60
[ 0.000000] s1 : ffffffff80c0bc98 a0 : ff600000ffffd000 a1 : ffffffff80c0bcd8
[ 0.000000] a2 : 0000000000000c00 a3 : ffffffff80c0c8d8 a4 : 0000000080000000
[ 0.000000] a5 : 0000000000080000 a6 : 0000000000000000 a7 : 0000000080200000
[ 0.000000] s2 : ff600000ffffd000 s3 : 0000000000002000 s4 : 0000000000000c00
[ 0.000000] s5 : ffffffff80c0bc60 s6 : ffffffff80c0bcc8 s7 : 0000000000000000
[ 0.000000] s8 : ffffffff814fd0a8 s9 : 000000017fffe7ff s10: 0000000000000000
[ 0.000000] s11: 0000000000001000 t3 : 0000000000001000 t4 : 0000000000000000
[ 0.000000] t5 : 000000008f003000 t6 : ff600000ffffd000
[ 0.000000] status: 0000000200000100 badaddr: ff600000ffffd000 cause: 000000000000000f
[ 0.000000] [<ffffffff8081d214>] __memcpy+0x60/0xf8
[ 0.000000] [<ffffffff80a3e1a2>] memblock_add_range.isra.14+0x12c/0x162
[ 0.000000] [<ffffffff80a3e36a>] memblock_reserve+0x6e/0x8c
[ 0.000000] [<ffffffff80a123fc>] memblock_alloc_range_nid+0xb8/0x128
[ 0.000000] [<ffffffff80a1256a>] memblock_phys_alloc_range+0x5e/0x6a
[ 0.000000] [<ffffffff80a04732>] alloc_pmd_fixmap+0x14/0x1c
[ 0.000000] [<ffffffff80a0475a>] alloc_p4d_fixmap+0xc/0x14
[ 0.000000] [<ffffffff80a04a36>] create_pgd_mapping+0x98/0x17c
[ 0.000000] [<ffffffff80a04e9e>] create_linear_mapping_range.constprop.10+0xe4/0x112
[ 0.000000] [<ffffffff80a05bb8>] paging_init+0x3ec/0x5ae
[ 0.000000] [<ffffffff80a03354>] setup_arch+0xb2/0x576
[ 0.000000] [<ffffffff80a00726>] start_kernel+0x72/0x57e
[ 0.000000] Code: b303 0285 b383 0305 be03 0385 be83 0405 bf03 0485 (b023) 00ef
[ 0.000000] ---[ end trace 0000000000000000 ]---
[ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
[ 0.000000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---

Fixes: 671f9a3e2e24 ("RISC-V: Setup initial page tables in two stages")
Signed-off-by: Woody Zhang <woodylab@foxmail.com>
Tested-by: Song Shuai <songshuaishuai@tinylab.org>
Link: https://lore.kernel.org/r/tencent_FBB94CE615C5CCE7701CD39C15CCE0EE9706@qq.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: init: Pass a pointer to virt_to_page()

Functions that work on a pointer to virtual memory such as
virt_to_pfn() and users of that function such as
virt_to_page() are supposed to pass a pointer to virtual
memory, ideally a (void *) or other pointer. However since
many architectures implement virt_to_pfn() as a macro,
this function becomes polymorphic and accepts both a
(unsigned long) and a (void *).

Fix this in the RISCV mm init code, so we can implement
a strongly typed virt_to_pfn().

Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

riscv: mm: Pre-allocate PGD entries for vmalloc/modules area

The RISC-V port requires that kernel PGD entries are to be
synchronized between MMs. This is done via the vmalloc_fault()
function, that simply copies the PGD entries from init_mm to the
faulting one.

Historically, faulting in PGD entries have been a source for both bugs
[1], and poor performance.

One way to get rid of vmalloc faults is by pre-allocating the PGD
entries. Pre-allocating the entries potientially wastes 64 * 4K (65 on
SV39). The pre-allocation function is pulled from Jörg Rödel's x86
work, with the addition of 3-level page tables (PMD allocations).

The pmd_alloc() function needs the ptlock cache to be initialized
(when split page locks is enabled), so the pre-allocation is done in a
RISC-V specific pgtable_cache_init() implementation.

Pre-allocate the kernel PGD entries for the vmalloc/modules area, but
only for 64b platforms.

Link: https://lore.kernel.org/lkml/20200508144043.13893-1-joro@8bytes.org/ # [1]
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230531093817.665799-1-bjorn@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Check the virtual alignment before choosing a map size

We used to only check the alignment of the physical address to decide
which mapping would fit for a certain region of the linear mapping, but
it is not enough since the virtual address must also be aligned, so check
that too.

Fixes: 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping")
Reported-by: Song Shuai <songshuaishuai@tinylab.org>
Link: https://lore.kernel.org/linux-riscv/tencent_7C3B580B47C1B17C16488EC1@qq.com/
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230607125851.63370-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Fix kfence now that the linear mapping can be backed by PUD/P4D/PGD

RISC-V Kfence implementation used to rely on the fact the linear mapping
was backed by at most PMD hugepages, which is not true anymore since
commit 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear
mapping").

Instead of splitting PUD/P4D/PGD mappings afterwards, directly map the
kfence pool region using PTE mappings by allocating this region before
setup_vm_final().

Reported-by: syzbot+a74d57bddabbedd75135@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=a74d57bddabbedd75135
Fixes: 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230606130444.25090-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: Ensure prot of VM_WRITE and VM_EXEC must be readable

Commit 8aeb7b17f04e ("RISC-V: Make mmap() with PROT_WRITE imply PROT_READ")
allows riscv to use mmap with PROT_WRITE only, and meanwhile mmap with w+x
is also permitted. However, when userspace tries to access this page with
PROT_WRITE|PROT_EXEC, which causes infinite loop at load page fault as
well as it triggers soft lockup. According to riscv privileged spec,
"Writable pages must also be marked readable". The fix to drop the
`PAGE_COPY_READ_EXEC` and then `PAGE_COPY_EXEC` would be just used instead.
This aligns the other arches (i.e arm64) for protection_map.

Fixes: 8aeb7b17f04e ("RISC-V: Make mmap() with PROT_WRITE imply PROT_READ")
Signed-off-by: Hsieh-Tseng Shen <woodrow.shen@sifive.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230425102828.1616812-1-woodrow.shen@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Fix unused variable warning when BUILTIN_DTB is set

commit ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap
region") wrongly moved the #ifndef CONFIG_BUILTIN_DTB surrounding the pa
variable definition in create_fdt_early_page_table(), so move it back to
its right place to quiet the following warning:

../arch/riscv/mm/init.c: In function ‘create_fdt_early_page_table’:
../arch/riscv/mm/init.c:925:12: warning: unused variable ‘pa’ [-Wunused-variable]
925 | uintptr_t pa = dtb_pa & ~(PMD_SIZE - 1);

Fixes: ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap region")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230519131311.391960-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: remove redundant parameter of create_fdt_early_page_table

create_fdt_early_page_table() explicitly uses early_pg_dir for
32-bit fdt mapping and the pgdir parameter is redundant here.
So remove it and its caller.

Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Song Shuai <suagrfillet@gmail.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Fixes: ef69d2559fe9 ("riscv: Move early dtb mapping into the fixmap region")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230426100009.685435-1-suagrfillet@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Allow to downgrade paging mode from the command line

Add 2 early command line parameters that allow to downgrade satp mode
(using the same naming as x86):
- "no5lvl": use a 4-level page table (down from sv57 to sv48)
- "no4lvl": use a 3-level page table (down from sv57/sv48 to sv39)

Note that going through the device tree to get the kernel command line
works with ACPI too since the efi stub creates a device tree anyway with
the command line.

In KASAN kernels, we can't use the libfdt that early in the boot process
since we are not ready to execute instrumented functions. So instead of
using the "generic" libfdt, we compile our own versions of those functions
that are not instrumented and that are prefixed so that they do not
conflict with the generic ones. We also need the non-instrumented versions
of the string functions and the prefixed versions of memcpy/memmove.

This is largely inspired by commit aacd149b6238 ("arm64: head: avoid
relocating the kernel twice for KASLR") from which I removed compilation
flags that were not relevant to RISC-V at the moment (LTO, SCS). Also
note that we have to link with -z norelro to avoid ld.lld to throw a
warning with the new .got sections, like in commit 311bea3cb9ee ("arm64:
link with -z norelro for LLD or aarch64-elf").

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230424092313.178699-2-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Introduce CONFIG_RELOCATABLE

This config allows to compile 64b kernel as PIE and to relocate it at
any virtual address at runtime: this paves the way to KASLR.
Runtime relocation is possible since relocation metadata are embedded into
the kernel.

Note that relocating at runtime introduces an overhead even if the
kernel is loaded at the same address it was linked at and that the compiler
options are those used in arm64 which uses the same RELA relocation
format.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230329045329.64565-4-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Move DTB_EARLY_BASE_VA to the kernel address space

The early virtual address should lie in the kernel address space for
inline kasan instrumentation to succeed, otherwise kasan tries to
dereference an address that does not exist in the address space (since
kasan only maps *kernel* address space, not the userspace).

Simply use the very first address of the kernel address space for the
early fdt mapping.

It allowed an Ubuntu kernel to boot successfully with inline
instrumentation.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20230203075232.274282-4-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Use PUD/P4D/PGD pages for the linear mapping

During the early page table creation, we used to set the mapping for
PAGE_OFFSET to the kernel load address: but the kernel load address is
always offseted by PMD_SIZE which makes it impossible to use PUD/P4D/PGD
pages as this physical address is not aligned on PUD/P4D/PGD size (whereas
PAGE_OFFSET is).

But actually we don't have to establish this mapping (ie set va_pa_offset)
that early in the boot process because:

- first, setup_vm installs a temporary kernel mapping and among other
things, discovers the system memory,
- then, setup_vm_final creates the final kernel mapping and takes
advantage of the discovered system memory to create the linear
mapping.

During the first phase, we don't know the start of the system memory and
then until the second phase is finished, we can't use the linear mapping at
all and phys_to_virt/virt_to_phys translations must not be used because it
would result in a different translation from the 'real' one once the final
mapping is installed.

So here we simply delay the initialization of va_pa_offset to after the
system memory discovery. But to make sure noone uses the linear mapping
before, we add some guard in the DEBUG_VIRTUAL config.

Finally we can use PUD/P4D/PGD hugepages when possible, which will result
in a better TLB utilization.

Note that:
- this does not apply to rv32 as the kernel mapping lies in the linear
mapping.
- we rely on the firmware to protect itself using PMP.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Acked-by: Rob Herring <robh@kernel.org> # DT bits
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20230324155421.271544-4-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Move the linear mapping creation in its own function

No change intended, it just splits the linear mapping creation from
setup_vm_final: this prepares for upcoming additions to the linear
mapping creation.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20230324155421.271544-3-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Get rid of riscv_pfn_base variable

Use directly phys_ram_base instead, riscv_pfn_base is just the pfn of
the address contained in phys_ram_base.

Even if there is no functional change intended in this patch, actually
setting phys_ram_base that early changes the behaviour of
kernel_mapping_pa_to_va during the early boot: phys_ram_base used to be
zero before this patch and now it is set to the physical start address of
the kernel. But it does not break the conversion of a kernel physical
address into a virtual address since kernel_mapping_pa_to_va should only
be used on kernel physical addresses, i.e. addresses greater than the
physical start address of the kernel.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20230324155421.271544-2-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: No need to relocate the dtb as it lies in the fixmap region

We used to access the dtb via its linear mapping address but now that the
dtb early mapping was moved in the fixmap region, we can keep using this
address since it is present in swapper_pg_dir, and remove the dtb
relocation.

Note that the relocation was wrong anyway since early_memremap() is
restricted to 256K whereas the maximum fdt size is 2MB.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230329081932.79831-4-alexghiti@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Move early dtb mapping into the fixmap region

riscv establishes 2 virtual mappings:

- early_pg_dir maps the kernel which allows to discover the system
memory
- swapper_pg_dir installs the final mapping (linear mapping included)

We used to map the dtb in early_pg_dir using DTB_EARLY_BASE_VA, and this
mapping was not carried over in swapper_pg_dir. It happens that
early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is
setup otherwise we could allocate reserved memory defined in the dtb.
And this function initializes reserved_mem variable with addresses that
lie in the early_pg_dir dtb mapping: when those addresses are reused
with swapper_pg_dir, this mapping does not exist and then we trap.

The previous "fix" was incorrect as early_init_fdt_scan_reserved_mem()
must be called before swapper_pg_dir is set up otherwise we could
allocate in reserved memory defined in the dtb.

So move the dtb mapping in the fixmap region which is established in
early_pg_dir and handed over to swapper_pg_dir.

Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob")
Fixes: 8f3a2b4a96dc ("RISC-V: Move DT mapping outof fixmap")
Fixes: 50e63dd8ed92 ("riscv: fix reserved memory setup")
Reported-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/all/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230329081932.79831-2-alexghiti@rivosinc.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: call best_map_size many times during linear-mapping

Modify the best_map_size function to give map_size many times instead
of only once, so a memory region can be mapped by both PMD_SIZE and
PAGE_SIZE.

Signed-off-by: Qinglin Pan <panqinglin2020@iscas.ac.cn>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20221128023643.329091-1-panqinglin2020@iscas.ac.cn
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Move cast inside kernel_mapping_[pv]a_to_[vp]a

Before commit 44c922572952 ("RISC-V: enable XIP"), these macros cast
their argument to unsigned long. That commit moved the cast after an
assignment to an unsigned long variable, rendering it ineffectual.
Move the cast back, so we can remove the cast at each call site.

Reviewed-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20221126060920.65009-2-samuel@sholland.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: fix reserved memory setup

Currently, RISC-V sets up reserved memory using the "early" copy of the
device tree. As a result, when trying to get a reserved memory region
using of_reserved_mem_lookup(), the pointer to reserved memory regions
is using the early, pre-virtual-memory address which causes a kernel
panic when trying to use the buffer's name:

Unable to handle kernel paging request at virtual address 00000000401c31ac
Oops [#1]
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.0.0-rc1-00001-g0d9d6953d834 #1
Hardware name: Microchip PolarFire-SoC Icicle Kit (DT)
epc : string+0x4a/0xea
ra : vsnprintf+0x1e4/0x336
epc : ffffffff80335ea0 ra : ffffffff80338936 sp : ffffffff81203be0
gp : ffffffff812e0a98 tp : ffffffff8120de40 t0 : 0000000000000000
t1 : ffffffff81203e28 t2 : 7265736572203a46 s0 : ffffffff81203c20
s1 : ffffffff81203e28 a0 : ffffffff81203d22 a1 : 0000000000000000
a2 : ffffffff81203d08 a3 : 0000000081203d21 a4 : ffffffffffffffff
a5 : 00000000401c31ac a6 : ffff0a00ffffff04 a7 : ffffffffffffffff
s2 : ffffffff81203d08 s3 : ffffffff81203d00 s4 : 0000000000000008
s5 : ffffffff000000ff s6 : 0000000000ffffff s7 : 00000000ffffff00
s8 : ffffffff80d9821a s9 : ffffffff81203d22 s10: 0000000000000002
s11: ffffffff80d9821c t3 : ffffffff812f3617 t4 : ffffffff812f3617
t5 : ffffffff812f3618 t6 : ffffffff81203d08
status: 0000000200000100 badaddr: 00000000401c31ac cause: 000000000000000d
[<ffffffff80338936>] vsnprintf+0x1e4/0x336
[<ffffffff80055ae2>] vprintk_store+0xf6/0x344
[<ffffffff80055d86>] vprintk_emit+0x56/0x192
[<ffffffff80055ed8>] vprintk_default+0x16/0x1e
[<ffffffff800563d2>] vprintk+0x72/0x80
[<ffffffff806813b2>] _printk+0x36/0x50
[<ffffffff8068af48>] print_reserved_mem+0x1c/0x24
[<ffffffff808057ec>] paging_init+0x528/0x5bc
[<ffffffff808031ae>] setup_arch+0xd0/0x592
[<ffffffff8080070e>] start_kernel+0x82/0x73c

early_init_fdt_scan_reserved_mem() takes no arguments as it operates on
initial_boot_params, which is populated by early_init_dt_verify(). On
RISC-V, early_init_dt_verify() is called twice. Once, directly, in
setup_arch() if CONFIG_BUILTIN_DTB is not enabled and once indirectly,
very early in the boot process, by parse_dtb() when it calls
early_init_dt_scan_nodes().

This first call uses dtb_early_va to set initial_boot_params, which is
not usable later in the boot process when
early_init_fdt_scan_reserved_mem() is called. On arm64 for example, the
corresponding call to early_init_dt_scan_nodes() uses fixmap addresses
and doesn't suffer the same fate.

Move early_init_fdt_scan_reserved_mem() further along the boot sequence,
after the direct call to early_init_dt_verify() in setup_arch() so that
the names use the correct virtual memory addresses. The above supposed
that CONFIG_BUILTIN_DTB was not set, but should work equally in the case
where it is - unflatted_and_copy_device_tree() also updates
initial_boot_params.

Reported-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>
Reported-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Link: https://lore.kernel.org/linux-riscv/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/
Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Evgenii Shatokhin <e.shatokhin@yadro.com>
Link: https://lore.kernel.org/r/20221107151524.3941467-1-conor.dooley@microchip.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

RISC-V: Add modules to virtual kernel memory layout dump

Modules always live before the kernel, MODULES_END is fixed but
MODULES_VADDR isn't fixed, it depends on the kernel size.
Let's add it to virtual kernel memory layout dump.

As MODULES is only defined for CONFIG_64BIT, so we dump it when
CONFIG_64BIT=y.

eg,
MODULES_VADDR - MODULES_END
0xffffffff01133000 - 0xffffffff80000000

Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220811074150.3020189-5-xianting.tian@linux.alibaba.com
Cc: stable@vger.kernel.org
Fixes: 2bfc6cd81bd1 ("riscv: Move kernel mapping outside of linear mapping")
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv/mm: enable ARCH_HAS_VM_GET_PAGE_PROT

This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports
standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT,
which looks up a private and static protection_map[] array. Subsequently
all __SXXX and __PXXX macros can be dropped which are no longer needed.

Link: https://lkml.kernel.org/r/20220711070600.2378316-17-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

riscv: mm: init: make pt_ops_set_[early|late|fixmap] static

These three functions are only used in init.c, so make them static.
Fix W=1 warnings like below:

arch/riscv/mm/init.c:721:13: warning: no previous prototype for function
'pt_ops_set_early' [-Wmissing-prototypes]
void __init pt_ops_set_early(void)
^

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20220516143204.2603-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Improve virtual kernel memory layout dump

With the arrival of sv48 and its large address space, it would be
cumbersome to statically define the unit size to use to print the different
portions of the virtual memory layout: instead, determine it dynamically.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

RISC-V: Fix the XIP build

A handful of functions unused functions were enabled during XIP builds,
which themselves didn't build correctly. This just disables the
functions entirely.

Fixes: e8a62cc26ddf ("riscv: Implement sv48 support")
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20220420184056.7886-5-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

RISC-V: Avoid empty create_*_mapping definitions

These trigger a handful of build warnings.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: 677b9eb8810e ("riscv: mm: Prepare pt_ops helper functions for sv57")
Link: https://lore.kernel.org/r/20220420184056.7886-2-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: add memory-type errata for T-Head

Some current cpus based on T-Head cores implement memory-types
way different than described in the svpbmt spec even going
so far as using PTE bits marked as reserved.

Add the T-Head vendor-id and necessary errata code to
replace the affected instructions.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/20220511192921.2223629-13-heiko@sntech.de
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

swiotlb: make the swiotlb_init interface more useful

Pass a boolean flag to indicate if swiotlb needs to be enabled based on
the addressing needs, and replace the verbose argument with a set of
flags, including one to force enable bounce buffering.

Note that this patch removes the possibility to force xen-swiotlb use
with the swiotlb=force parameter on the command line on x86 (arm and
arm64 never supported that), but this interface will be restored shortly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

RISC-V: relocate DTB if it's outside memory region

In case the DTB provided by the bootloader/BootROM is before the kernel
image or outside /memory, we won't be able to access it through the
linear mapping, and get a segfault on setup_arch(). Currently OpenSBI
relocates DTB but that's not always the case (e.g. if FW_JUMP_FDT_ADDR
is not specified), and it's also not the most portable approach since
the default FW_JUMP_FDT_ADDR of the generic platform relocates the DTB
at a specific offset that may not be available. To avoid this situation
copy DTB so that it's visible through the linear mapping.

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Link: https://lore.kernel.org/r/20220322132839.3653682-1-mick@ics.forth.gr
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Fixes: f105aa940e78 ("riscv: add BUILTIN_DTB support for MMU-enabled targets")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

RISC-V: mm: Fix set_satp_mode() for platform not having Sv57

When Sv57 is not available the satp.MODE test in set_satp_mode() will
fail and lead to pgdir re-programming for Sv48. The pgdir re-programming
will fail as well due to pre-existing pgdir entry used for Sv57 and as
a result kernel fails to boot on RISC-V platform not having Sv57.

To fix above issue, we should clear the pgdir memory in set_satp_mode()
before re-programming.

Fixes: 011f09d12052 ("riscv: mm: Set sv57 on defaultly")
Reported-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: Set sv57 on defaultly

This patch sets sv57 on defaultly if CONFIG_64BIT. And do fallback to try
to set sv48 on boot time if sv57 is not supported in current hardware.

Signed-off-by: Qinglin Pan <panqinglin2020@iscas.ac.cn>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: Prepare pt_ops helper functions for sv57

This patch prepare some pt_ops helper functions which will be used in
creating sv57 mappings during boot time.

Signed-off-by: Qinglin Pan <panqinglin2020@iscas.ac.cn>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: Control p4d's folding by pgtable_l5_enabled

To determine pgtable level at boot time, we can not use helper functions
in include/asm-generic/pgtable-nop4d.h and must implement these
functions. This patch uses pgtable_l5_enabled variable instead of
including pgtable-nop4d.h to controle p4d's folding, and implements
corresponding helper functions.

Signed-off-by: Qinglin Pan <panqinglin2020@iscas.ac.cn>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: init: mark satp_mode __ro_after_init

satp_mode is never modified after init, so it can be marked as
__ro_after_init.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: init: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef

Replace the conditional compilation using "#ifdef CONFIG_KEXEC_CORE" by a
check for "IS_ENABLED(CONFIG_KEXEC_CORE)", to simplify the code and
increase compile coverage.

Link: https://lkml.kernel.org/r/20211206160514.2000-3-jszhang@kernel.org
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

riscv: Move high_memory initialization to setup_bootmem

high_memory used to be initialized in mem_init, way after setup_bootmem.
But a call to dma_contiguous_reserve in this function gives rise to the
below warning because high_memory is equal to 0 and is used at the very
beginning at cma_declare_contiguous_nid.

It went unnoticed since the move of the kasan region redefined
KERN_VIRT_SIZE so that it does not encompass -1 anymore.

Fix this by initializing high_memory in setup_bootmem.

------------[ cut here ]------------
virt_to_phys used for non-linear address: ffffffffffffffff (0xffffffffffffffff)
WARNING: CPU: 0 PID: 0 at arch/riscv/mm/physaddr.c:14 __virt_to_phys+0xac/0x1b8
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 5.17.0-rc1-00007-ga68b89289e26 #27
Hardware name: riscv-virtio,qemu (DT)
epc : __virt_to_phys+0xac/0x1b8
ra : __virt_to_phys+0xac/0x1b8
epc : ffffffff80014922 ra : ffffffff80014922 sp : ffffffff84a03c30
gp : ffffffff85866c80 tp : ffffffff84a3f180 t0 : ffffffff86bce657
t1 : fffffffef09406e8 t2 : 0000000000000000 s0 : ffffffff84a03c70
s1 : ffffffffffffffff a0 : 000000000000004f a1 : 00000000000f0000
a2 : 0000000000000002 a3 : ffffffff8011f408 a4 : 0000000000000000
a5 : 0000000000000000 a6 : 0000000000f00000 a7 : ffffffff84a03747
s2 : ffffffd800000000 s3 : ffffffff86ef4000 s4 : ffffffff8467f828
s5 : fffffff800000000 s6 : 8000000000006800 s7 : 0000000000000000
s8 : 0000000480000000 s9 : 0000000080038ea0 s10: 0000000000000000
s11: ffffffffffffffff t3 : ffffffff84a035c0 t4 : fffffffef09406e8
t5 : fffffffef09406e9 t6 : ffffffff84a03758
status: 0000000000000100 badaddr: 0000000000000000 cause: 0000000000000003
[<ffffffff8322ef4c>] cma_declare_contiguous_nid+0xf2/0x64a
[<ffffffff83212a58>] dma_contiguous_reserve_area+0x46/0xb4
[<ffffffff83212c3a>] dma_contiguous_reserve+0x174/0x18e
[<ffffffff83208fc2>] paging_init+0x12c/0x35e
[<ffffffff83206bd2>] setup_arch+0x120/0x74e
[<ffffffff83201416>] start_kernel+0xce/0x68c
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<0000000000000000>] 0x0
softirqs last enabled at (0): [<0000000000000000>] 0x0
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace 0000000000000000 ]---

Fixes: f7ae02333d13 ("riscv: Move KASAN mapping next to the kernel mapping")
Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv/mm: Add XIP_FIXUP for riscv_pfn_base

This manifests as a crash early in boot on VexRiscv.

Signed-off-by: Myrtle Shah <gatecat@ds0.me>
[Palmer: split commit]
Fixes: 44c922572952 ("RISC-V: enable XIP")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv/mm: Add XIP_FIXUP for phys_ram_base

This manifests as a crash early in boot on VexRiscv.

Signed-off-by: Myrtle Shah <gatecat@ds0.me>
[Palmer: split commit]
Fixes: 6d7f91d914bc ("riscv: Get rid of CONFIG_PHYS_RAM_BASE in kernel physical address conversion")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: fix boolconv.cocci warnings

arch/riscv/mm/init.c:48:11-16: WARNING: conversion to bool not needed here

Remove unneeded conversion to bool

Semantic patch information:
Relational and logical operators evaluate to bool,
explicit conversion is overly verbose and unneeded.

Generated by: scripts/coccinelle/misc/boolconv.cocci

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Implement sv48 support

By adding a new 4th level of page table, give the possibility to 64bit
kernel to address 2^48 bytes of virtual address: in practice, that offers
128TB of virtual address space to userspace and allows up to 64TB of
physical memory.

If the underlying hardware does not support sv48, we will automatically
fallback to a standard 3-level page table by folding the new PUD level into
PGDIR level. In order to detect HW capabilities at runtime, we
use SATP feature that ignores writes with an unsupported mode.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Introduce functions to switch pt_ops

This simply gathers the different pt_ops initialization in functions
where a comment was added to explain why the page table operations must
be changed along the boot process.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Split early kasan mapping to prepare sv48 introduction

Now that kasan shadow region is next to the kernel, for sv48, this
region won't be aligned on PGDIR_SIZE and then when populating this
region, we'll need to get down to lower levels of the page table. So
instead of reimplementing the page table walk for the early population,
take advantage of the existing functions used for the final population.

Note that kasan swapper initialization must also be split since memblock
is not initialized at this point and as the last PGD is shared with the
kernel, we'd need to allocate a PUD so postpone the kasan final
population after the kernel population is done.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Move KASAN mapping next to the kernel mapping

Now that KASAN_SHADOW_OFFSET is defined at compile time as a config,
this value must remain constant whatever the size of the virtual address
space, which is only possible by pushing this region at the end of the
address space next to the kernel mapping.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: init: try best to remove #ifdef CONFIG_XIP_KERNEL usage

Currently, the #ifdef CONFIG_XIP_KERNEL usage can be divided into the
following three types:

The first one is for functions/declarations only used in XIP case.

The second one is for XIP_FIXUP case. Something as below:
|foo_type foo;
|#ifdef CONFIG_XIP_KERNEL
|#define foo (*(foo_type *)XIP_FIXUP(&foo))
|#endif

Usually, it's better to let the foo macro sit with the foo var
together. But if various foos are defined adjacently, we can
save some #ifdef CONFIG_XIP_KERNEL usage by grouping them together.

The third one is for different implementations for XIP, usually, this
is a #ifdef...#else...#endif case.

This patch moves the pt_ops macro to adjacent #ifdef CONFIG_XIP_KERNEL
and group first type usage cases into one.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: init: try IS_ENABLED(CONFIG_XIP_KERNEL) instead of #ifdef

Try our best to replace the conditional compilation using
"#ifdef CONFIG_XIP_KERNEL" with "IS_ENABLED(CONFIG_XIP_KERNEL)", to
simplify the code and to increase compile coverage.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: init: remove _pt_ops and use pt_ops directly

Except "pt_ops", other global vars when CONFIG_XIP_KERNEL=y is defined
as below:

|foo_type foo;
|#ifdef CONFIG_XIP_KERNEL
|#define foo (*(foo_type *)XIP_FIXUP(&foo))
|#endif

Follow the same way for pt_ops to unify the style and to simplify code.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: init: try best to use IS_ENABLED(CONFIG_64BIT) instead of #ifdef

Try our best to replace the conditional compilation using
"#ifdef CONFIG_64BIT" by a check for "IS_ENABLED(CONFIG_64BIT)", to
simplify the code and to increase compile coverage.

Now we can also remove the __maybe_unused used in max_mapped_addr
declaration.

We also remove the BUG_ON check of mapping the last 4K bytes of the
addressable memory since this is always true for every kernel actually.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: init: remove unnecessary "#ifdef CONFIG_CRASH_DUMP"

The is_kdump_kernel() returns false for !CRASH_DUMP case, so we don't
need the #ifdef CONFIG_CRASH_DUMP for is_kdump_kernel() checking.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: fix wrong phys_ram_base value for RV64

Currently, if 64BIT and !XIP_KERNEL, the phys_ram_base is always 0,
no matter the real start of dram reported by memblock is.

Fixes: 6d7f91d914bc ("riscv: Get rid of CONFIG_PHYS_RAM_BASE in kernel physical address conversion")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: try to allocate crashkern region from 32bit addressible memory

When allocating crash kernel region without explicitly specifying its
base address/size, memblock_phys_alloc_range will attempt to allocate
memory top to bottom (memblock.bottom_up is false), so the crash
kernel region will end up in highmem on 64bit systems. This way
swiotlb can't work on the crash kernel, since there won't be any
32bit addressible memory available for the bounce buffers.

Try to allocate 32bit addressible memory if available, for the
crash kernel by restricting the top search address to be less
than SZ_4G. If that fails fallback to the previous behavior.

I tested this on HiFive Unmatched where the pci-e controller needs
swiotlb to work, with this patch it's possible to access the pci-e
controller on crash kernel and mount the rootfs from the nvme.

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Fixes: e53d28180d4d ("RISC-V: Add kdump support")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: mm: Enable PMD split page table lock for RV64

After commit 1355c31eeb7e ("asm-generic: pgalloc: provide generic
pmd_alloc_one() and pmd_free_one()"), the main part to support
PMD split page table lock is in asm-generic/pgalloc.h.

The only change is add pgtable_pmd_page_ctor() into alloc_pmd_late(),
then we could enable ARCH_ENABLE_SPLIT_PMD_PTLOCK for RV64.

Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: remove .text section size limitation for XIP

Currently there's a limit of 8MB for the .text section of a RISC-V
image in the XIP case. This breaks compilation of many automatic
builds and is generally inconvenient. This patch removes that
limitation and optimizes XIP image file size at the same time.

Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Support allocating gigantic hugepages using CMA

This patch adds support to allocate gigantic hugepages using CMA by
specifying the hugetlb_cma= kernel parameter. This is only supported on
RV64.

Reviewed-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: fix the global name pfn_base confliction error

RISCV uses a global variable pfn_base for page/pfn translation. But this
is a common name and will be used elsewhere. In those cases, the
page-pfn macros which refer to this name will be referred to the
local/input variable instead. (such as in vfio_pin_pages_remote). This
make everything wrong.

This patch changes the name from pfn_base to riscv_pfn_base to fix
this problem.

Signed-off-by: Kenneth Lee <liguozhu@hisilicon.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Move early fdt mapping creation in its own function

The code that handles the early fdt mapping is hard to read and does not
create the same mapping size depending on the kernel:

- for 64-bit, 2 PMD entries are used which amounts to a 4MB mapping
- for 32-bit, 2 PGDIR entries are used which amounts to a 8MB mapping

So keep using 2 PMD entries for 64-bit and use only one PGD entry for
32-bit needed to cover 4MB. Move that into a new function called
create_fdt_early_page_table which, using the same naming as
create_kernel_page_table.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Simplify BUILTIN_DTB device tree mapping handling

__PAGETABLE_PMD_FOLDED defines a 2-level page table that is only used in
32-bit kernel, so there is no need to check for CONFIG_64BIT in #ifndef
__PAGETABLE_PMD_FOLDED and vice-versa.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Use __maybe_unused instead of #ifdefs around variable declarations

This allows to simplify the code and make it more readable.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Get rid of map_size parameter to create_kernel_page_table

The kernel must always be mapped using PMD_SIZE, and this is already the
case, this just simplifies create_kernel_page_table.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Introduce va_kernel_pa_offset for 32-bit kernel

va_kernel_pa_offset was only used for 64-bit as the kernel mapping lies
in the linear mapping for 32-bit kernel and then only the offset between
the PAGE_OFFSET and the kernel load address is needed.

But this distinction complexifies the code with #ifdefs and especially
with a separate definition of the address conversions macros.

Simplify the code by defining this variable for both 32-bit and 64-bit.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

memblock: make memblock_find_in_range method private

There are a lot of uses of memblock_find_in_range() along with
memblock_reserve() from the times memblock allocation APIs did not exist.

memblock_find_in_range() is the very core of memblock allocations, so any
future changes to its internal behaviour would mandate updates of all the
users outside memblock.

Replace the calls to memblock_find_in_range() with an equivalent calls to
memblock_phys_alloc() and memblock_phys_alloc_range() and make
memblock_find_in_range() private method of memblock.

This simplifies the callers, ensures that (unlikely) errors in
memblock_reserve() are handled and improves maintainability of
memblock_find_in_range().

Link: https://lkml.kernel.org/r/20210816122622.30279-1-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Acked-by: Kirill A. Shutemov <kirill.shtuemov@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [ACPI]
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Nick Kossifidis <mick@ics.forth.gr> [riscv]
Tested-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

riscv: Remove non-standard linux,elfcorehdr handling

RISC-V uses platform-specific code to locate the elf core header in
memory. However, this does not conform to the standard
"linux,elfcorehdr" DT bindings, as it relies on a reserved memory node
with the "linux,elfcorehdr" compatible value, instead of on a
"linux,elfcorehdr" property under the "/chosen" node.

The non-compliant code can just be removed, as the standard behavior is
already implemented by platform-agnostic handling in the FDT core code.

Fixes: 5640975003d0234d ("RISC-V: Add crash kernel support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/41c75d6ee3114ae6304f8afe0051895af91200ee.1628670468.git.geert+renesas@glider.be

riscv: Fix comment regarding kernel mapping overlapping with IS_ERR_VALUE

The current comment states that we check if the 64-bit kernel mapping
overlaps with the last 4K of the address space that is reserved to
error values in create_kernel_page_table, which is not the case since it
is done in setup_vm. But anyway, remove the reference to any function
and simply note that in 64-bit kernel, the check should be done as soon
as the kernel mapping base address is known.

Fixes: db6b84a368b4 ("riscv: Make sure the kernel mapping does not overlap with IS_ERR_VALUE")
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Get rid of CONFIG_PHYS_RAM_BASE in kernel physical address conversion

The usage of CONFIG_PHYS_RAM_BASE for all kernel types was a mistake:
this value is implementation-specific and this breaks the genericity of
the RISC-V kernel.

Fix this by introducing a new variable phys_ram_base that holds this
value at runtime and use it in the kernel physical address conversion
macro. Since this value is used only for XIP kernels, evaluate it only if
CONFIG_XIP_KERNEL is set which in addition optimizes this macro for
standard kernels at compile-time.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Tested-by: Emil Renner Berthing <kernel@esmil.dk>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Fixes: 44c922572952 ("RISC-V: enable XIP")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Make sure the kernel mapping does not overlap with IS_ERR_VALUE

The check that is done in setup_bootmem currently only works for 32-bit
kernel since the kernel mapping has been moved outside of the linear
mapping for 64-bit kernel. So make sure that for 64-bit kernel, the kernel
mapping does not overlap with the last 4K of the addressable memory.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Fixes: 2bfc6cd81bd1 ("riscv: Move kernel mapping outside of linear mapping")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Make sure the linear mapping does not use the kernel mapping

For 64-bit kernel, the end of the address space is occupied by the
kernel mapping and currently, the functions to populate the kernel page
tables (i.e. create_p*d_mapping) do not override existing mapping so we
must make sure the linear mapping does not map memory in the kernel mapping
by clipping the memory above the memory limit.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Fixes: c9811e379b21 ("riscv: Add mem kernel parameter support")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Fix memory_limit for 64-bit kernel

As described in Documentation/riscv/vm-layout.rst, the end of the
virtual address space for 64-bit kernel is occupied by the modules/BPF/
kernel mappings so this actually reduces the amount of memory we are able
to map and then use in the linear mapping. So make sure this limit is
correctly set.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Fixes: 2bfc6cd81bd1 ("riscv: Move kernel mapping outside of linear mapping")
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Fix 32-bit RISC-V boot failure

Commit dd2d082b5760 ("riscv: Cleanup setup_bootmem()") adjusted
the calling sequence in setup_bootmem(), which invalidates the fix
commit de043da0b9e7 ("RISC-V: Fix usage of memblock_enforce_memory_limit")
did for 32-bit RISC-V unfortunately.

So now 32-bit RISC-V does not boot again when testing booting kernel
on QEMU 'virt' with '-m 2G', which was exactly what the original
commit de043da0b9e7 ("RISC-V: Fix usage of memblock_enforce_memory_limit")
tried to fix.

Fixes: dd2d082b5760 ("riscv: Cleanup setup_bootmem()")
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Introduce structure that group all variables regarding kernel mapping

We have a lot of variables that are used to hold kernel mapping addresses,
offsets between physical and virtual mappings and some others used for XIP
kernels: they are all defined at different places in mm/init.c, so group
them into a single structure with, for some of them, more explicit and concise
names.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Map the kernel with correct permissions the first time

For 64-bit kernels, we map all the kernel with write and execute
permissions and afterwards remove writability from text and executability
from data.

For 32-bit kernels, the kernel mapping resides in the linear mapping, so we
map all the linear mapping as writable and executable and afterwards we
remove those properties for unused memory and kernel mapping as
described above.

Change this behavior to directly map the kernel with correct permissions
and avoid going through the whole mapping to fix the permissions.

At the same time, this fixes an issue introduced by commit 2bfc6cd81bd1
("riscv: Move kernel mapping outside of linear mapping") as reported
here https://github.com/starfive-tech/linux/issues/17.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Add mem kernel parameter support

The memblock_enforce_memory_limit() could change the memblock
range, so move the dram_end assignment after it in bootmem_init(),
then support mem= cmdline.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Only initialize swiotlb when necessary

The SWIOTLB buffer is not needed unless the physical address space
is beyond the limit of dma, only initialize swiotlb when swiotlb_force
is true or not all system memory is DMA-able.

Also move the swiotlb_init() into mem_init().

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: fix typo in init.c

Commit 010623568222 introduced a typo in "__initdata" spelling
which led to build breakage for XIP. Fix that.

Fixes: 010623568222 ("riscv: mm: init: Consolidate vars, functions")
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: mm: init: Consolidate vars, functions

Consolidate the following items in init.c

Staticize global vars as much as possible;
Add __initdata mark if the global var isn't needed after init
Add __init mark if the func isn't needed after init
Add __ro_after_init if the global var is read only after init

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: mm: Drop redundant _sdata and _edata declaration

The _sdata/_edata is already in sections.h, drop redundant
declaration.

Also move _xiprom/_exiprom declarations at the beginning of
the file, cleanup one CONFIG_XIP_KERNEL.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Move setup_bootmem into paging_init

Make setup_bootmem() static.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: mm: Remove setup_zero_page()

The empty_zero_page sits at .bss..page_aligned section, so will be
cleared to zero during clearing bss, we don't need to clear it again.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: mm: Fix W+X mappings at boot

When the kernel mapping was moved the last 2GB of the address space,
(__va(PFN_PHYS(max_low_pfn))) is much smaller than the .data section
start address, the last set_memory_nx() in protect_kernel_text_data()
will fail, thus the .data section is still mapped as W+X. This results
in below W+X mapping waring at boot. Fix it by passing the correct
.data section page num to the set_memory_nx().

[ 0.396516] ------------[ cut here ]------------
[ 0.396889] riscv/mm: Found insecure W+X mapping at address (____ptrval____)/0xffffffff80c00000
[ 0.398347] WARNING: CPU: 0 PID: 1 at arch/riscv/mm/ptdump.c:258 note_page+0x244/0x24a
[ 0.398964] Modules linked in:
[ 0.399459] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-rc1+ #14
[ 0.400003] Hardware name: riscv-virtio,qemu (DT)
[ 0.400591] epc : note_page+0x244/0x24a
[ 0.401368] ra : note_page+0x244/0x24a
[ 0.401772] epc : ffffffff80007c86 ra : ffffffff80007c86 sp : ffffffe000e7bc30
[ 0.402304] gp : ffffffff80caae88 tp : ffffffe000e70000 t0 : ffffffff80cb80cf
[ 0.402800] t1 : ffffffff80cb80c0 t2 : 0000000000000000 s0 : ffffffe000e7bc80
[ 0.403310] s1 : ffffffe000e7bde8 a0 : 0000000000000053 a1 : ffffffff80c83ff0
[ 0.403805] a2 : 0000000000000010 a3 : 0000000000000000 a4 : 6c7e7a5137233100
[ 0.404298] a5 : 6c7e7a5137233100 a6 : 0000000000000030 a7 : ffffffffffffffff
[ 0.404849] s2 : ffffffff80e00000 s3 : 0000000040000000 s4 : 0000000000000000
[ 0.405393] s5 : 0000000000000000 s6 : 0000000000000003 s7 : ffffffe000e7bd48
[ 0.405935] s8 : ffffffff81000000 s9 : ffffffffc0000000 s10: ffffffe000e7bd48
[ 0.406476] s11: 0000000000001000 t3 : 0000000000000072 t4 : ffffffffffffffff
[ 0.407016] t5 : 0000000000000002 t6 : ffffffe000e7b978
[ 0.407435] status: 0000000000000120 badaddr: 0000000000000000 cause: 0000000000000003
[ 0.408052] Call Trace:
[ 0.408343] [<ffffffff80007c86>] note_page+0x244/0x24a
[ 0.408855] [<ffffffff8010c5a6>] ptdump_hole+0x14/0x1e
[ 0.409263] [<ffffffff800f65c6>] walk_pgd_range+0x2a0/0x376
[ 0.409690] [<ffffffff800f6828>] walk_page_range_novma+0x4e/0x6e
[ 0.410146] [<ffffffff8010c5f8>] ptdump_walk_pgd+0x48/0x78
[ 0.410570] [<ffffffff80007d66>] ptdump_check_wx+0xb4/0xf8
[ 0.410990] [<ffffffff80006738>] mark_rodata_ro+0x26/0x2e
[ 0.411407] [<ffffffff8031961e>] kernel_init+0x44/0x108
[ 0.411814] [<ffffffff80002312>] ret_from_exception+0x0/0xc
[ 0.412309] ---[ end trace 7ec3459f2547ea83 ]---
[ 0.413141] Checked W+X mappings: failed, 512 W+X pages found

Fixes: 2bfc6cd81bd17e43 ("riscv: Move kernel mapping outside of linear mapping")
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Consistify protect_kernel_linear_mapping_text_rodata() use

The various uses of protect_kernel_linear_mapping_text_rodata() are
not consistent:
- Its definition depends on "64BIT && !XIP_KERNEL",
- Its forward declaration depends on MMU,
- Its single caller depends on "STRICT_KERNEL_RWX && 64BIT && MMU &&
!XIP_KERNEL".

Fix this by settling on the dependencies of the caller, which can be
simplified as STRICT_KERNEL_RWX depends on "MMU && !XIP_KERNEL".
Provide a dummy definition, as the caller is protected by
"IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)" instead of "#ifdef
CONFIG_STRICT_KERNEL_RWX".

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Only extend kernel reservation if mapped read-only

When the kernel mapping was moved outside of the linear mapping, the
kernel memory reservation was increased, to take into account mapping
granularity. However, this is done unconditionally, regardless of
whether the kernel memory is mapped read-only or not.

If this extension is not needed, up to 2 MiB may be lost, which has a
big impact on e.g. Canaan K210 (64-bit nommu) platforms with only 8 MiB
of RAM.

Reclaim the lost memory by only extending the reserved region when
needed, i.e. depending on a simplified version of the conditional logic
around the call to protect_kernel_linear_mapping_text_rodata().

Fixes: 2bfc6cd81bd17e43 ("riscv: Move kernel mapping outside of linear mapping")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Alexandre Ghiti <alex@ghiti.fr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: enable XIP

Introduce XIP (eXecute In Place) support for RISC-V platforms.
It allows code to be executed directly from non-volatile storage
directly addressable by the CPU, such as QSPI NOR flash which can
be found on many RISC-V platforms. This makes way for significant
optimization of RAM footprint. The XIP kernel is not compressed
since it has to run directly from flash, so it will occupy more
space on the non-volatile storage. The physical flash address used
to link the kernel object files and for storing it has to be known
at compile time and is represented by a Kconfig option.

XIP on RISC-V will for the time being only work on MMU-enabled
kernels.

Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
[Alex: Rebase on top of "Move kernel mapping outside the linear mapping" ]
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
[Palmer: disable XIP for allyesconfig]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Add crash kernel support

This patch allows Linux to act as a crash kernel for use with
kdump. Userspace will let the crash kernel know about the
memory region it can use through linux,usable-memory property
on the /memory node (overriding its reg property), and about the
memory region where the elf core header of the previous kernel
is saved, through a reserved-memory node with a compatible string
of "linux,elfcorehdr". This approach is the least invasive and
re-uses functionality already present.

I tested this on riscv64 qemu and it works as expected, you
may test it by retrieving the dmesg of the previous kernel
through /proc/vmcore, using the vmcore-dmesg utility from
kexec-tools.

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Add kdump support

This patch adds support for kdump, the kernel will reserve a
region for the crash kernel and jump there on panic. In order
for userspace tools (kexec-tools) to prepare the crash kernel
kexec image, we also need to expose some information on
/proc/iomem for the memory regions used by the kernel and for
the region reserved for crash kernel. Note that on userspace
the device tree is used to determine the system's memory
layout so the "System RAM" on /proc/iomem is ignored.

I tested this on riscv64 qemu and works as expected, you may
test it by triggering a crash through /proc/sysrq_trigger:

echo c > /proc/sysrq_trigger

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv/mm: Use BUG_ON instead of if condition followed by BUG.

BUG_ON() uses unlikely in if(), which can be optimized at compile time.

Signed-off-by: zhouchuangao <zhouchuangao@vivo.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Mark some global variables __ro_after_init

All of these are never modified after init, so they can be
__ro_after_init.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: add __init section marker to some functions

They are not needed after booting, so mark them as __init to move them
to the __init section.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Move kernel mapping outside of linear mapping

This is a preparatory patch for relocatable kernel and sv48 support.

The kernel used to be linked at PAGE_OFFSET address therefore we could use
the linear mapping for the kernel mapping. But the relocated kernel base
address will be different from PAGE_OFFSET and since in the linear mapping,
two different virtual addresses cannot point to the same physical address,
the kernel mapping needs to lie outside the linear mapping so that we don't
have to copy it at the same physical offset.

The kernel mapping is moved to the last 2GB of the address space, BPF
is now always after the kernel and modules use the 2GB memory range right
before the kernel, so BPF and modules regions do not overlap. KASLR
implementation will simply have to move the kernel in the last 2GB range
and just take care of leaving enough space for BPF.

In addition, by moving the kernel to the end of the address space, both
sv39 and sv48 kernels will be exactly the same without needing to be
relocated at runtime.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
[Palmer: Squash the STRICT_RWX fix, and a !MMU fix]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Add support for memtest

The riscv [rv32_]defconfig enabled CONFIG_MEMTEST,
but memtest feature is not supported in RISCV.

Add early_memtest() to support for memtest.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

mm: move mem_init_print_info() into mm_init()

mem_init_print_info() is called in mem_init() on each architecture, and
pass NULL argument, so using void argument and move it into mm_init().

Link: https://lkml.kernel.org/r/20210317015210.33641-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86]
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> [powerpc]
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Anatoly Pugachev <matorola@gmail.com> [sparc64]
Acked-by: Russell King <rmk+kernel@armlinux.org.uk> [arm]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

riscv: Cleanup setup_bootmem()

After the following patches,

commit de043da0b9e7 ("RISC-V: Fix usage of memblock_enforce_memory_limit")
commit 1bd14a66ee52 ("RISC-V: Remove any memblock representing unusable memory area")
commit b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()")

some logic is useless, kill the mem_start/start/end and unneeded code.

Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Get rid of MAX_EARLY_MAPPING_SIZE

At early boot stage, we have a whole PGDIR to map the kernel, so there
is no need to restrict the early mapping size to 128MB. Removing this
define also allows us to simplify some compile time logic.

This fixes large kernel mappings with a size greater than 128MB, as it
is the case for syzbot kernels whose size was just ~130MB.

Note that on rv64, for now, we are then limited to PGDIR size for early
mapping as we can't use PGD mappings (see [1]). That should be enough
given the relative small size of syzbot kernels compared to PGDIR_SIZE
which is 1GB.

[1] https://lore.kernel.org/lkml/20200603153608.30056-1-alex@ghiti.fr/

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Covert to reserve_initrd_mem()

Covert to the generic reserve_initrd_mem() function.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: add BUILTIN_DTB support for MMU-enabled targets

Sometimes, especially in a production system we may not want to
use a "smart bootloader" like u-boot to load kernel, ramdisk and
device tree from a filesystem on eMMC, but rather load the kernel
from a NAND partition and just run it as soon as we can, and in
this case it is convenient to have device tree compiled into the
kernel binary. Since this case is not limited to MMU-less systems,
let's support it for these which have MMU enabled too.

While at it, provide __dtb_start as a parameter to setup_vm() in
BUILTIN_DTB case, so we don't have to duplicate BUILTIN_DTB specific
processing in MMU-enabled and MMU-disabled versions of setup_vm().

Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Add numa support for riscv64 platform

Use the generic numa implementation to add NUMA support for RISC-V.
This is based on Greentime's patch[1] but modified to use generic NUMA
implementation and few more fixes.

[1] https://lkml.org/lkml/2020/1/10/233

Co-developed-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Separate memory init from paging init

Currently, we perform some memory init functions in paging init. But,
that will be an issue for NUMA support where DT needs to be flattened
before numa initialization and memblock_present can only be called
after numa initialization.

Move memory initialization related functions to a separate function.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Fix builtin DTB handling

All SiPeed K210 MAIX boards have the exact same vendor, arch and
implementation IDs, preventing differentiation to select the correct
device tree to use through the SOC_BUILTIN_DTB_DECLARE() macro. This
result in this macro to be useless and mandates changing the code of
the sysctl driver to change the builtin device tree suitable for the
target board.

Fix this problem by removing the SOC_BUILTIN_DTB_DECLARE() macro since
it is used only for the K210 support. The code searching the builtin
DTBs using the vendor, arch an implementation IDs is also removed.
Support for builtin DTB falls back to the simpler and more traditional
handling of builtin DTB using the CONFIG_BUILTIN_DTB option, similarly
to other architectures.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Fixup pfn_valid error with wrong max_mapnr

The max_mapnr is the number of PFNs, not absolute PFN offset.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Fixes: d0d8aae64566 ("RISC-V: Set maximum number of mapped pages correctly")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Set current memblock limit

Currently, linux kernel can not use last 4k bytes of addressable space
because IS_ERR_VALUE macro treats those as an error. This will be an issue
for RV32 as any memblock allocator potentially allocate chunk of memory
from the end of DRAM (2GB) leading bad address error even though the
address was technically valid.

Fix this issue by limiting the memblock if available memory spans the
entire address space.

Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Fix usage of memblock_enforce_memory_limit

memblock_enforce_memory_limit accepts the maximum memory size not the
maximum address that can be handled by kernel. Fix the function invocation
accordingly.

Fixes: 1bd14a66ee52 ("RISC-V: Remove any memblock representing unusable memory area")
Cc: stable@vger.kernel.org
Reported-by: Bin Meng <bin.meng@windriver.com>
Tested-by: Bin Meng <bin.meng@windriver.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Protect all kernel sections including init early

Currently, .init.text & .init.data are intermixed which makes it impossible
apply different permissions to them. .init.data shouldn't need exec
permissions while .init.text shouldn't have write permission. Moreover,
the strict permission are only enforced /init starts. This leaves the
kernel vulnerable from possible buggy built-in modules.

Keep .init.text & .data in separate sections so that different permissions
are applied to each section. Apply permissions to individual sections as
early as possible. This improves the kernel protection under
CONFIG_STRICT_KERNEL_RWX. We also need to restore the permissions for the
entire _init section after it is freed so that those pages can be used
for other purpose.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Enable CMA support

riscv has selected HAVE_DMA_CONTIGUOUS, but doesn't call
dma_contiguous_reserve(). This calls dma_contiguous_reserve(), which
enables CMA.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Add kernel image sections to the resource tree

This patch (previously part of my kexec/kdump series) populates
/proc/iomem with the various sections of the kernel image. We need
this for kexec-tools to be able to prepare the crashkernel image
for kdump to work. Since resource tree initialization is not
related to memory initialization I added the code to kernel/setup.c
and removed the original code (derived from the arm64 tree) from
mm/init.c.

Signed-off-by: Nick Kossifidis <mick@ics.forth.gr>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Use non-PGD mappings for early DTB access

Currently, we use PGD mappings for early DTB mapping in early_pgd
but this breaks Linux kernel on SiFive Unleashed because on SiFive
Unleashed PMP checks don't work correctly for PGD mappings.

To fix early DTB mappings on SiFive Unleashed, we use non-PGD
mappings (i.e. PMD) for early DTB access.

Fixes: 8f3a2b4a96dc ("RISC-V: Move DT mapping outof fixmap")
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Remove any memblock representing unusable memory area

RISC-V limits the physical memory size by -PAGE_OFFSET. Any memory beyond
that size from DRAM start is unusable. Just remove any memblock pointing
to those memory region without worrying about computing the maximum size.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

memblock: use separate iterators for memory and reserved regions

for_each_memblock() is used to iterate over memblock.memory in a few
places that use data from memblock_region rather than the memory ranges.

Introduce separate for_each_mem_region() and
for_each_reserved_mem_region() to improve encapsulation of memblock
internals from its users.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org> [x86]
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> [MIPS]
Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> [.clang-format]
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Emil Renner Berthing <kernel@esmil.dk>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20200818151634.14343-18-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch, drivers: replace for_each_membock() with for_each_mem_range()

There are several occurrences of the following pattern:

for_each_memblock(memory, reg) {
start = __pfn_to_phys(memblock_region_memory_base_pfn(reg);
end = __pfn_to_phys(memblock_region_memory_end_pfn(reg));

/* do something with start and end */
}

Using for_each_mem_range() iterator is more appropriate in such cases and
allows simpler and cleaner code.

[akpm@linux-foundation.org: fix arch/arm/mm/pmsa-v7.c build]
[rppt@linux.ibm.com: mips: fix cavium-octeon build caused by memblock refactoring]
Link: http://lkml.kernel.org/r/20200827124549.GD167163@linux.ibm.com

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Emil Renner Berthing <kernel@esmil.dk>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20200818151634.14343-13-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

riscv: drop unneeded node initialization

RISC-V does not (yet) support NUMA and for UMA architectures node 0 is
used implicitly during early memory initialization.

There is no need to call memblock_set_node(), remove this call and the
surrounding code.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Emil Renner Berthing <kernel@esmil.dk>
Cc: Hari Bathini <hbathini@linux.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20200818151634.14343-7-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

RISC-V: Make sure memblock reserves the memory containing DT

Currently, the memory containing DT is not reserved. Thus, that region
of memory can be reallocated or reused for other purposes. This may result
in corrupted DT for nommu virt board in Qemu. We may not face any issue
in kendryte as DT is embedded in the kernel image for that.

Fixes: 6bd33e1ece52 ("riscv: add nommu support")
Cc: stable@vger.kernel.org
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Add EFI runtime services

This patch adds EFI runtime service support for RISC-V.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
[ardb: - Remove the page check]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Implement late mapping page table allocation functions

Currently, page table setup is done during setup_va_final where fixmap can
be used to create the temporary mappings. The physical frame is allocated
from memblock_alloc_* functions. However, this won't work if page table
mapping needs to be created for a different mm context (i.e. efi mm) at
a later point of time.

Use generic kernel page allocation function & macros for any mapping
after setup_vm_final.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Add early ioremap support

UEFI uses early IO or memory mappings for runtime services before
normal ioremap() is usable. Add the necessary fixmap bindings and
pmd mappings for generic ioremap support to work.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Move DT mapping outof fixmap

Currently, RISC-V reserves 1MB of fixmap memory for device tree. However,
it maps only single PMD (2MB) space for fixmap which leaves only < 1MB space
left for other kernel features such as early ioremap which requires fixmap
as well. The fixmap size can be increased by another 2MB but it brings
additional complexity and changes the virtual memory layout as well.
If we require some additional feature requiring fixmap again, it has to be
moved again.

Technically, DT doesn't need a fixmap as the memory occupied by the DT is
only used during boot. That's why, We map device tree in early page table
using two consecutive PGD mappings at lower addresses (< PAGE_OFFSET).
This frees lot of space in fixmap and also makes maximum supported
device tree size supported as PGDIR_SIZE. Thus, init memory section can be used
for the same purpose as well. This simplifies fixmap implementation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Add sfence.vma after early page table changes

This invalidates local TLB after modifying the page tables during early init as
it's too early to handle suprious faults as we otherwise do.

Fixes: f2c17aabc917 ("RISC-V: Implement compile-time fixed mappings")
Reported-by: Syven Wang <syven.wang@sifive.com>
Signed-off-by: Syven Wang <syven.wang@sifive.com>
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
[Palmer: Cleaned up the commit text]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

mm/sparse: cleanup the code surrounding memory_present()

After removal of CONFIG_HAVE_MEMBLOCK_NODE_MAP we have two equivalent
functions that call memory_present() for each region in memblock.memory:
sparse_memory_present_with_active_regions() and membocks_present().

Moreover, all architectures have a call to either of these functions
preceding the call to sparse_init() and in the most cases they are called
one after the other.

Mark the regions from memblock.memory as present during sparce_init() by
making sparse_init() call memblocks_present(), make memblocks_present()
and memory_present() functions static and remove redundant
sparse_memory_present_with_active_regions() function.

Also remove no longer required HAVE_MEMORY_PRESENT configuration option.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20200712083130.22919-1-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/sparsemem: enable vmem_altmap support in vmemmap_populate_basepages()

Patch series "arm64: Enable vmemmap mapping from device memory", v4.

This series enables vmemmap backing memory allocation from device memory
ranges on arm64. But before that, it enables vmemmap_populate_basepages()
and vmemmap_alloc_block_buf() to accommodate struct vmem_altmap based
alocation requests.

This patch (of 3):

vmemmap_populate_basepages() is used across platforms to allocate backing
memory for vmemmap mapping. This is used as a standard default choice or
as a fallback when intended huge pages allocation fails. This just
creates entire vmemmap mapping with base pages (PAGE_SIZE).

On arm64 platforms, vmemmap_populate_basepages() is called instead of the
platform specific vmemmap_populate() when ARM64_SWAPPER_USES_SECTION_MAPS
is not enabled as in case for ARM64_16K_PAGES and ARM64_64K_PAGES configs.

At present vmemmap_populate_basepages() does not support allocating from
driver defined struct vmem_altmap while trying to create vmemmap mapping
for a device memory range. It prevents ARM64_16K_PAGES and
ARM64_64K_PAGES configs on arm64 from supporting device memory with
vmemap_altmap request.

This enables vmem_altmap support in vmemmap_populate_basepages() unlocking
device memory allocation for vmemap mapping on arm64 platforms with 16K or
64K base page configs.

Each architecture should evaluate and decide on subscribing device memory
based base page allocation through vmemmap_populate_basepages(). Hence
lets keep it disabled on all archs in order to preserve the existing
semantics. A subsequent patch enables it on arm64.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Jia He <justin.he@arm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Link: http://lkml.kernel.org/r/1594004178-8861-1-git-send-email-anshuman.khandual@arm.com
Link: http://lkml.kernel.org/r/1594004178-8861-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

riscv: Fix build warning for mm/init

Add static keyword for resource_init, this function is only used in this
object file.

Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Parse all memory blocks to remove unusable memory

Currently, maximum physical memory allowed is equal to -PAGE_OFFSET.
That's why we remove any memory blocks spanning beyond that size. However,
it is done only for memblock containing linux kernel which will not work
if there are multiple memblocks.

Process all memory blocks to figure out how much memory needs to be removed
and remove at the end instead of updating the memblock list in place.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Do not rely on initrd_start/end computed during early dt parsing

Currently, initrd_start/end are computed during early_init_dt_scan
but used during arch_setup. We will get the following panic if initrd is used
and CONFIG_DEBUG_VIRTUAL is turned on.

[ 0.000000] ------------[ cut here ]------------
[ 0.000000] kernel BUG at arch/riscv/mm/physaddr.c:33!
[ 0.000000] Kernel BUG [#1]
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.8.0-rc4-00015-ged0b226fed02 #886
[ 0.000000] epc: ffffffe0002058d2 ra : ffffffe0000053f0 sp : ffffffe001001f40
[ 0.000000] gp : ffffffe00106e250 tp : ffffffe001009d40 t0 : ffffffe00107ee28
[ 0.000000] t1 : 0000000000000000 t2 : ffffffe000a2e880 s0 : ffffffe001001f50
[ 0.000000] s1 : ffffffe0001383e8 a0 : ffffffe00c087e00 a1 : 0000000080200000
[ 0.000000] a2 : 00000000010bf000 a3 : ffffffe00106f3c8 a4 : ffffffe0010bf000
[ 0.000000] a5 : ffffffe000000000 a6 : 0000000000000006 a7 : 0000000000000001
[ 0.000000] s2 : ffffffe00106f068 s3 : ffffffe00106f070 s4 : 0000000080200000
[ 0.000000] s5 : 0000000082200000 s6 : 0000000000000000 s7 : 0000000000000000
[ 0.000000] s8 : 0000000080011010 s9 : 0000000080012700 s10: 0000000000000000
[ 0.000000] s11: 0000000000000000 t3 : 000000000001fe30 t4 : 000000000001fe30
[ 0.000000] t5 : 0000000000000000 t6 : ffffffe00107c471
[ 0.000000] status: 0000000000000100 badaddr: 0000000000000000 cause: 0000000000000003
[ 0.000000] random: get_random_bytes called from print_oops_end_marker+0x22/0x46 with crng_init=0

To avoid the error, initrd_start/end can be computed from phys_initrd_start/size
in setup itself. It also improves the initrd placement by aligning the start
and size with the page size.

Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code")
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Set maximum number of mapped pages correctly

Currently, maximum number of mapper pages are set to the pfn calculated
from the memblock size of the memblock containing kernel. This will work
until that memblock spans the entire memory. However, it will be set to
a wrong value if there are multiple memblocks defined in kernel
(e.g. with efi runtime services).

Set the the maximum value to the pfn calculated from dram size.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Register System RAM as iomem resources

Add System RAM to /proc/iomem, various tools expect it such as kdump.
It is also needed for page_is_ram API which checks the specified address
whether registered as System RAM in iomem_resource list.

Signed-off-by: Zong Li <zong.li@sifive.com>
[Palmer: check MEMBLOCK_NOMAP]
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Don't mark init section as non-executable

The head text section (i.e. _start, secondary_start_sbi, etc) and the
init section fall under same page table level-1 mapping.

Currently, the runtime CPU hotplug is broken because we are marking
init section as non-executable which in-turn marks head text section
as non-executable.

Further investigating other architectures, it seems marking the init
section as non-executable is redundant because the init section pages
are anyway poisoned and freed.

To fix broken runtime CPU hotplug, we simply remove the code marking
the init section as non-executable.

Fixes: d27c3c90817e ("riscv: add STRICT_KERNEL_RWX support")
Cc: stable@vger.kernel.org
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

mm: consolidate pte_index() and pte_offset_*() definitions

All architectures define pte_index() as

(address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)

and all architectures define pte_offset_kernel() as an entry in the array
of PTEs indexed by the pte_index().

For the most architectures the pte_offset_kernel() implementation relies
on the availability of pmd_page_vaddr() that converts a PMD entry value to
the virtual address of the page containing PTEs array.

Let's move x86 definitions of the PTE accessors to the generic place in
<linux/pgtable.h> and then simply drop the respective definitions from the
other architectures.

The architectures that didn't provide pmd_page_vaddr() are updated to have
that defined.

The generic implementation of pte_offset_kernel() can be overridden by an
architecture and alpha makes use of this because it has special ordering
requirements for its version of pte_offset_kernel().

[rppt@linux.ibm.com: v2]
Link: http://lkml.kernel.org/r/20200514170327.31389-11-rppt@kernel.org
[rppt@linux.ibm.com: update]
Link: http://lkml.kernel.org/r/20200514170327.31389-12-rppt@kernel.org
[rppt@linux.ibm.com: update]
Link: http://lkml.kernel.org/r/20200514170327.31389-13-rppt@kernel.org
[akpm@linux-foundation.org: fix x86 warning]
[sfr@canb.auug.org.au: fix powerpc build]
Link: http://lkml.kernel.org/r/20200607153443.GB738695@linux.ibm.com

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-10-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: don't include asm/pgtable.h if linux/mm.h is already included

Patch series "mm: consolidate definitions of page table accessors", v2.

The low level page table accessors (pXY_index(), pXY_offset()) are
duplicated across all architectures and sometimes more than once. For
instance, we have 31 definition of pgd_offset() for 25 supported
architectures.

Most of these definitions are actually identical and typically it boils
down to, e.g.

static inline unsigned long pmd_index(unsigned long address)
{
return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}

static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}

These definitions can be shared among 90% of the arches provided
XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined.

For architectures that really need a custom version there is always
possibility to override the generic version with the usual ifdefs magic.

These patches introduce include/linux/pgtable.h that replaces
include/asm-generic/pgtable.h and add the definitions of the page table
accessors to the new header.

This patch (of 12):

The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the
functions involving page table manipulations, e.g. pte_alloc() and
pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h>
in the files that include <linux/mm.h>.

The include statements in such cases are remove with a simple loop:

for f in $(git grep -l "include <linux/mm.h>") ; do
sed -i -e '/include <asm\/pgtable.h>/ d' $f
done

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org
Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

riscv: support DEBUG_WX

Support DEBUG_WX to check whether there are mapping with write and execute
permission at the same time.

[akpm@linux-foundation.org: replace macros with C]
Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Link: http://lkml.kernel.org/r/282e266311bced080bc6f7c255b92f87c1eb65d6.1587455584.git.zong.li@sifive.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: use free_area_init() instead of free_area_init_nodes()

free_area_init() has effectively became a wrapper for
free_area_init_nodes() and there is no point of keeping it. Still
free_area_init() name is shorter and more general as it does not imply
necessity to initialize multiple nodes.

Rename free_area_init_nodes() to free_area_init(), update the callers and
drop old version of free_area_init().

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com> [arm64]
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-6-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

riscv: Fix print_vm_layout build error if NOMMU

arch/riscv/mm/init.c: In function ‘print_vm_layout’:
arch/riscv/mm/init.c:68:37: error: ‘FIXADDR_START’ undeclared (first use in this function);
arch/riscv/mm/init.c:69:20: error: ‘FIXADDR_TOP’ undeclared
arch/riscv/mm/init.c:70:37: error: ‘PCI_IO_START’ undeclared
arch/riscv/mm/init.c:71:20: error: ‘PCI_IO_END’ undeclared
arch/riscv/mm/init.c:72:38: error: ‘VMEMMAP_START’ undeclared
arch/riscv/mm/init.c:73:20: error: ‘VMEMMAP_END’ undeclared (first use in this function);

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Allow device trees to be built into the kernel

Some systems don't provide a useful device tree to the kernel on boot.
Chasing around bootloaders for these systems is a headache, so instead
le't's just keep a device tree table in the kernel, keyed by the SOC's
unique identifier, that contains the relevant DTB.

This is only implemented for M mode right now. While we could implement
this via the SBI calls that allow access to these identifiers, we don't
have any systems that need this right now.

Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Remove unused code from STRICT_KERNEL_RWX

This patch removes the unused functions set_kernel_text_rw/ro.
Currently, it is not being invoked from anywhere and no other architecture
(except arm) uses this code. Even in ARM, these functions are not invoked
from anywhere currently.

Fixes: d27c3c90817e ("riscv: add STRICT_KERNEL_RWX support")
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: set max_pfn to the PFN of the last page

The current max_pfn equals to zero. In this case, I found it caused users
cannot get some page information through /proc such as kpagecount in v5.6
kernel because of new sanity checks. The following message is displayed by
stress-ng test suite with the command "stress-ng --verbose --physpage 1 -t
1" on HiFive unleashed board.

# stress-ng --verbose --physpage 1 -t 1
stress-ng: debug: [109] 4 processors online, 4 processors configured
stress-ng: info: [109] dispatching hogs: 1 physpage
stress-ng: debug: [109] cache allocate: reducing cache level from L3 (too high) to L0
stress-ng: debug: [109] get_cpu_cache: invalid cache_level: 0
stress-ng: info: [109] cache allocate: using built-in defaults as no suitable cache found
stress-ng: debug: [109] cache allocate: default cache size: 2048K
stress-ng: debug: [109] starting stressors
stress-ng: debug: [109] 1 stressor spawned
stress-ng: debug: [110] stress-ng-physpage: started [110] (instance 0)
stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd34de000 in /proc/kpagecount, errno=0 (Success)
stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd32db078 in /proc/kpagecount, errno=0 (Success)
...
stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd32db078 in /proc/kpagecount, errno=0 (Success)
stress-ng: debug: [110] stress-ng-physpage: exited [110] (instance 0)
stress-ng: debug: [109] process [110] terminated
stress-ng: info: [109] successful run completed in 1.00s
#

After applying this patch, the kernel can pass the test.

# stress-ng --verbose --physpage 1 -t 1
stress-ng: debug: [104] 4 processors online, 4 processors configured stress-ng: info: [104] dispatching hogs: 1 physpage
stress-ng: info: [104] cache allocate: using defaults, can't determine cache details from sysfs
stress-ng: debug: [104] cache allocate: default cache size: 2048K
stress-ng: debug: [104] starting stressors
stress-ng: debug: [104] 1 stressor spawned
stress-ng: debug: [105] stress-ng-physpage: started [105] (instance 0) stress-ng: debug: [105] stress-ng-physpage: exited [105] (instance 0) stress-ng: debug: [104] process [105] terminated
stress-ng: info: [104] successful run completed in 1.01s
#

Cc: stable@vger.kernel.org
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Yash Shah <yash.shah@sifive.com>
Tested-by: Yash Shah <yash.shah@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: add STRICT_KERNEL_RWX support

The commit contains that make text section as non-writable, rodata
section as read-only, and data section as non-executable.

The init section should be changed to non-executable.

Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: Fix range looking for kernel image memblock

When looking for the memblock where the kernel lives, we should check
that the memory range associated to the memblock entirely comprises the
kernel image and not only intersects with it.

Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: mm: use __pa_symbol for kernel symbols

__pa_symbol is the marcro that should be used for kernel symbols. It is
also a pre-requisite for DEBUG_VIRTUAL which will do bounds checking.

Signed-off-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

RISC-V: Add address map dumper

Add support for dumping the kernel address space layout to the console.
User can enable CONFIG_DEBUG_VM to dump the virtual memory region into
dmesg buffer during boot-up.

Signed-off-by: Yash Shah <yash.shah@sifive.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
[paul.walmsley@sifive.com: dropped .init/.text/.data/.bss prints;
added PCI legacy I/O region display]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

riscv: add nommu support

The kernel runs in M-mode without using page tables, and thus can't run
bare metal without help from additional firmware.

Most of the patch is just stubbing out code not needed without page
tables, but there is an interesting detail in the signals implementation:

- The normal RISC-V syscall ABI only implements rt_sigreturn as VDSO
entry point, but the ELF VDSO is not supported for nommu Linux.
We instead copy the code to call the syscall onto the stack.

In addition to enabling the nommu code a new defconfig for a small
kernel image that can run in nommu mode on qemu is also provided, to run
a kernel in qemu you can use the following command line:

qemu-system-riscv64 -smp 2 -m 64 -machine virt -nographic \
-kernel arch/riscv/boot/loader \
-drive file=rootfs.ext2,format=raw,id=hd0 \
-device virtio-blk-device,drive=hd0

Contains contributions from Damien Le Moal <Damien.LeMoal@wdc.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
[paul.walmsley@sifive.com: updated to apply; add CONFIG_MMU guards
around PCI_IOBASE definition to fix build issues; fixed checkpatch
issues; move the PCI_IO_* and VMEMMAP address space macros along
with the others; resolve sparse warning]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

riscv: Use PMD_SIZE to replace PTE_PARENT_SIZE

The PMD_SIZE is equal to PGDIR_SIZE when __PAGETABLE_PMD_FOLDED is
defined.

Signed-off-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[paul.walmsley@sifive.com: fixed spelling in commit summary]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

riscv: init: merge split string literals in preprocessor directive

sparse complains loudly when string literals associated with
preprocessor directives are split into multiple, separately quoted
strings across different lines:

arch/riscv/mm/init.c:341:9: error: Expected ; at the end of type declaration
arch/riscv/mm/init.c:341:9: error: got "not use absolute addressing."
arch/riscv/mm/init.c:358:9: error: Trying to use reserved word 'do' as identifier
arch/riscv/mm/init.c:358:9: error: Expected ; at end of declaration
[ ... ]

It turns out this doesn't compile. The existing Linux practice for
this situation is simply to use a single long line. So, fix by
concatenating the strings.

This patch should have no functional impact.

This version incorporates changes based on feedback from Luc Van
Oostenryck <luc.vanoostenryck@gmail.com>.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Reviewed-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/linux-riscv/CAAhSdy2nX2LwEEAZuMtW_ByGTkHO6KaUEvVxRnba_ENEjmFayQ@mail.gmail.com/T/#mc1a58bc864f71278123d19a7abc083a9c8e37033
Fixes: 387181dcdb6c1 ("RISC-V: Always compile mm/init.c with cmodel=medany and notrace")
Cc: Anup Patel <anup.patel@wdc.com>

riscv: add prototypes for assembly language functions from head.S

Add prototypes for assembly language functions defined in head.S,
and include these prototypes into C source files that call those
functions.

This patch resolves the following warnings from sparse:

arch/riscv/kernel/setup.c:39:10: warning: symbol 'hart_lottery' was not declared. Should it be static?
arch/riscv/kernel/setup.c:42:13: warning: symbol 'parse_dtb' was not declared. Should it be static?
arch/riscv/kernel/smpboot.c:33:6: warning: symbol '__cpu_up_stack_pointer' was not declared. Should it be static?
arch/riscv/kernel/smpboot.c:34:6: warning: symbol '__cpu_up_task_pointer' was not declared. Should it be static?
arch/riscv/mm/fault.c:25:17: warning: symbol 'do_page_fault' was not declared. Should it be static?

This change should have no functional impact.

Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

riscv: Fix undefined reference to vmemmap_populate_basepages

Using CONFIG_SPARSEMEM_VMEMMAP instead of CONFIG_SPARSEMEM to fix
following build issue.

riscv64-linux-ld: arch/riscv/mm/init.o: in function 'vmemmap_populate':
init.c:(.meminit.text+0x8): undefined reference to 'vmemmap_populate_basepages'

Cc: Logan Gunthorpe <logang@deltatee.com>
Fixes: d95f1a542c3d ("RISC-V: Implement sparsemem")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

riscv: Fix memblock reservation for device tree blob

This fixes an error with how the FDT blob is reserved in memblock.
An incorrect physical address calculation exposed the FDT header to
unintended corruption, which typically manifested with of_fdt_raw_init()
faulting during late boot after fdt_totalsize() returned a wrong value.
Systems with smaller physical memory sizes more frequently trigger this
issue, as the kernel is more likely to allocate from the DMA32 zone
where bbl places the DTB after the kernel image.

Commit 671f9a3e2e24 ("RISC-V: Setup initial page tables in two stages")
changed the mapping of the DTB to reside in the fixmap area.
Consequently, early_init_fdt_reserve_self() cannot be used anymore in
setup_bootmem() since it relies on __pa() to derive a physical address,
which does not work with dtb_early_va that is no longer a valid kernel
logical address.

The reserved[0x1] region shows the effect of the pointer underflow
resulting from the __pa(initial_boot_params) offset subtraction:

[ 0.000000] MEMBLOCK configuration:
[ 0.000000] memory size = 0x000000001fe00000 reserved size = 0x0000000000a2e514
[ 0.000000] memory.cnt = 0x1
[ 0.000000] memory[0x0] [0x0000000080200000-0x000000009fffffff], 0x000000001fe00000 bytes flags: 0x0
[ 0.000000] reserved.cnt = 0x2
[ 0.000000] reserved[0x0] [0x0000000080200000-0x0000000080c2dfeb], 0x0000000000a2dfec bytes flags: 0x0
[ 0.000000] reserved[0x1] [0xfffffff080100000-0xfffffff080100527], 0x0000000000000528 bytes flags: 0x0

With the fix applied:

[ 0.000000] MEMBLOCK configuration:
[ 0.000000] memory size = 0x000000001fe00000 reserved size = 0x0000000000a2e514
[ 0.000000] memory.cnt = 0x1
[ 0.000000] memory[0x0] [0x0000000080200000-0x000000009fffffff], 0x000000001fe00000 bytes flags: 0x0
[ 0.000000] reserved.cnt = 0x2
[ 0.000000] reserved[0x0] [0x0000000080200000-0x0000000080c2dfeb], 0x0000000000a2dfec bytes flags: 0x0
[ 0.000000] reserved[0x1] [0x0000000080e00000-0x0000000080e00527], 0x0000000000000528 bytes flags: 0x0

Fixes: 671f9a3e2e24 ("RISC-V: Setup initial page tables in two stages")
Signed-off-by: Albert Ou <aou@eecs.berkeley.edu>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

RISC-V: Implement sparsemem

Implement sparsemem support for Risc-v which helps pave the
way for memory hotplug and eventually P2P support.

Introduce Kconfig options for virtual and physical address bits which
are used to calculate the size of the vmemmap and set the
MAX_PHYSMEM_BITS.

The vmemmap is located directly before the VMALLOC region and sized
such that we can allocate enough pages to populate all the virtual
address space in the system (similar to the way it's done in arm64).

During initialization, call memblocks_present() and sparse_init(),
and provide a stub for vmemmap_populate() (all of which is similar to
arm64).

[greentime.hu@sifive.com: fixed pfn_valid, FIXADDR_TOP and fixed a bug
rebasing onto v5.3]
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andrew Waterman <andrew@sifive.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Michael Clark <michaeljclark@mac.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Zong Li <zong@andestech.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
[paul.walmsley@sifive.com: updated to apply; minor commit message
reformat]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

riscv: Using CSR numbers to access CSRs

Since commit a3182c91ef4e ("RISC-V: Access CSRs using CSR numbers"),
we should prefer accessing CSRs using their CSR numbers, but there
are several leftovers like sstatus / sptbr we missed.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

RISC-V: Setup initial page tables in two stages

Currently, the setup_vm() does initial page table setup in one-shot
very early before enabling MMU. Due to this, the setup_vm() has to map
all possible kernel virtual addresses since it does not know size and
location of RAM. This means we have kernel mappings for non-existent
RAM and any buggy driver (or kernel) code doing out-of-bound access
to RAM will not fault and cause underterministic behaviour.

Further, the setup_vm() creates PMD mappings (i.e. 2M mappings) for
RV64 systems. This means for PAGE_OFFSET=0xffffffe000000000 (i.e.
MAXPHYSMEM_128GB=y), the setup_vm() will require 129 pages (i.e.
516 KB) of memory for initial page tables which is never freed. The
memory required for initial page tables will further increase if
we chose a lower value of PAGE_OFFSET (e.g. 0xffffff0000000000)

This patch implements two-staged initial page table setup, as follows:
1. Early (i.e. setup_vm()): This stage maps kernel image and DTB in
a early page table (i.e. early_pg_dir). The early_pg_dir will be used
only by boot HART so it can be freed as-part of init memory free-up.
2. Final (i.e. setup_vm_final()): This stage maps all possible RAM
banks in the final page table (i.e. swapper_pg_dir). The boot HART
will start using swapper_pg_dir at the end of setup_vm_final(). All
non-boot HARTs directly use the swapper_pg_dir created by boot HART.

We have following advantages with this new approach:
1. Kernel mappings for non-existent RAM don't exists anymore.
2. Memory consumed by initial page tables is now indpendent of the
chosen PAGE_OFFSET.
3. Memory consumed by initial page tables on RV64 system is 2 pages
(i.e. 8 KB) which has significantly reduced and these pages will be
freed as-part of the init memory free-up.

The patch also provides a foundation for implementing strict kernel
mappings where we protect kernel text and rodata using PTE permissions.

Suggested-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
[paul.walmsley@sifive.com: updated to apply; fixed a checkpatch warning]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

riscv: remove free_initrd_mem

The RISC-V free_initrd_mem is identical to the default one, except
that it doesn't poison the freed memory. Remove it so that the
default implementations gets used instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

RISC-V: Fix memory reservation in setup_bootmem()

Currently, the setup_bootmem() reserves memory from RAM start to the
kernel end. This prevents us from exploring ways to use the RAM below
(or before) the kernel start hence this patch updates setup_bootmem()
to only reserve memory from the kernel start to the kernel end.

Suggested-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 this program is distributed
in the hope that it will be useful but without any warranty without
even the implied warranty of merchantability or fitness for a
particular purpose see the gnu general public license for more
details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 97 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

riscv: switch over to generic free_initmem()

The riscv version of free_initmem() differs from the generic one only in
that it sets the freed memory to zero.

Make ricsv use the generic version and poison the freed memory.

Link: http://lkml.kernel.org/r/1550515285-17446-5-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

RISC-V: Fix Maximum Physical Memory 2GiB option for 64bit systems

The Maximum Physical Memory 2GiB option for 64bit systems is currently
broken because kernel hangs at boot-time when this option is enabled
and the underlying system has more than 2GiB memory.

This issue can be easily reproduced on SiFive Unleashed board where
we have 8GiB of memory.

This patch fixes above issue by removing unusable memory region in
setup_bootmem().

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

RISC-V: Always compile mm/init.c with cmodel=medany and notrace

The Linux RISC-V 32bit kernel is broken after we moved setup_vm() from
kernel/setup.c to mm/init.c because Linux RISC-V 32bit kernel by default
uses cmodel=medlow which results in a non-position-independent setup_vm().

This patch fixes Linux RISC-V 32bit kernel booting by:
1. Forcing cmodel=medany for mm/init.c
2. Moving remaing MM-related stuff va_pa_offset, pfn_base and
empty_zero_page from kernel/setup.c to mm/init.c

Further, the setup_vm() cannot handle GCC instrumentation for FTRACE so
we disable it for mm/init.c by not using "-pg" compiler flag.

Fixes: 6f1e9e946f0b ("RISC-V: Move setup_vm() to mm/init.c")
Suggested-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

RISC-V: Free-up initrd in free_initrd_mem()

We should free-up initrd memory in free_initrd_mem() instead
of doing nothing.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>

RISC-V: Implement compile-time fixed mappings

This patch implements compile-time virtual to physical mappings. These
compile-time fixed mappings can be used by earlycon, ACPI, and early
ioremap for creating fixed mappings when FIX_EARLYCON_MEM=y.

To start with, we have enabled compile-time fixed mappings for earlycon.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>

RISC-V: Move setup_vm() to mm/init.c

The setup_vm() is responsible for setting up initial page table hence
should be placed in mm/init.c.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>

RISC-V: Move setup_bootmem() to mm/init.c

The setup_bootmem() mainly populates memblocks and does early memory
reservations. The right location for this function is mm/init.c. It
calls setup_initrd() so we move that as well.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>

riscv: fixup max_low_pfn with PFN_DOWN.

max_low_pfn should be pfn_size not byte_size.

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Signed-off-by: Mao Han <mao_han@c-sky.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

mm: remove include/linux/bootmem.h

Move remaining definitions and declarations from include/linux/bootmem.h
into include/linux/memblock.h and remove the redundant header.

The includes were replaced with the semantic patch below and then
semi-automated removal of duplicated '#include <linux/memblock.h>

@@
@@
- #include <linux/bootmem.h>
+ #include <linux/memblock.h>

[sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h]
Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au
[sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h]
Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au
[sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal]
Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au
Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

memblock: rename free_all_bootmem to memblock_free_all

The conversion is done using

sed -i 's@free_all_bootmem@memblock_free_all@' \
$(git grep -l free_all_bootmem)

Link: http://lkml.kernel.org/r/1536927045-23536-26-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

RISC-V: Add conditional macro for zone of DMA32

The DMA32 is for 64-bit usage.

Signed-off-by: Zong Li <zong@andestech.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

riscv: don't read back satp in paging_init

init_mm.pgd (aka swapped_pgd) gets relocated like all other kernel
symbols by the elf loader, so there is no need to reload it from satp.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

riscv: add ZONE_DMA32

This patch allows devices that require memory that can be addressed
using 32-bit addresses to work easily on RISC-V systems. The newly
improved dma-direct ops will tap into this pool automatically for
32-bit addressing.

Based on an earlier patch from Wesley W. Terpstra.

CC: Wesley W. Terpstra <terpstra@sifive.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

RISC-V: Init and Halt Code

This contains the various __init C functions, the initial assembly
kernel entry point, and the code to reset the system. When a file was
init-related this patch contains the entire file.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>