arch: define CONFIG_PAGE_SIZE_*KB on all architectures

Most architectures only support a single hardcoded page size. In order
to ensure that each one of these sets the corresponding Kconfig symbols,
change over the PAGE_SHIFT definition to the common one and allow
only the hardware page size to be selected.

Acked-by: Guo Ren <guoren@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Stafford Horne <shorne@gmail.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

mm, arch: add generic implementation of pfn_valid() for FLATMEM

Every architecture that supports FLATMEM memory model defines its own
version of pfn_valid() that essentially compares a pfn to max_mapnr.

Use mips/powerpc version implemented as static inline as a generic
implementation of pfn_valid() and drop its per-architecture definitions.

[rppt@kernel.org: fix the generic pfn_valid()]
Link: https://lkml.kernel.org/r/Y9lg7R1Yd931C+y5@kernel.org
Link: https://lkml.kernel.org/r/20230129124235.209895-5-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Guo Ren <guoren@kernel.org> [csky]
Acked-by: Huacai Chen <chenhuacai@loongson.cn> [LoongArch]
Acked-by: Stafford Horne <shorne@gmail.com> [OpenRISC]
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Reviewed-by: David Hildenbrand <david@redhat.com>
Tested-by: Conor Dooley <conor.dooley@microchip.com>
Cc: Brian Cain <bcain@quicinc.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch, mm: remove stale mentions of DISCONIGMEM

There are several places that mention DISCONIGMEM in comments or have
stale code guarded by CONFIG_DISCONTIGMEM.

Remove the dead code and update the comments.

Link: https://lkml.kernel.org/r/20210608091316.3622-7-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS

There are many platforms with exact same value for VM_DATA_DEFAULT_FLAGS
This creates a default value for VM_DATA_DEFAULT_FLAGS in line with the
existing VM_STACK_DEFAULT_FLAGS. While here, also define some more
macros with standard VMA access flag combinations that are used
frequently across many platforms. Apart from simplification, this
reduces code duplication as well.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Chris Zankel <chris@zankel.net>
Link: http://lkml.kernel.org/r/1583391014-8170-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

xtensa: add XIP kernel support

XIP (eXecute In Place) kernel image is the image that can be run
directly from ROM, using RAM only for writable data.

XIP xtensa kernel differs from regular xtensa kernel in the following
ways:
- it has exception/IRQ vectors merged into text section. No vectors
relocation takes place at kernel startup.
- .data/.bss location must be specified in the kernel configuration,
its content is copied there in the _startup function.
- .init.text is merged with the rest of text and is executed from ROM.
- when MMU is used the virtual address where the kernel will be mapped
must be specified in the kernel configuration. It may be in the KSEG
or in the KIO, __pa macro is adjusted to be able to handle both.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: rework {CONFIG,PLATFORM}_DEFAULT_MEM_START

Drop PLATFORM_DEFAULT_MEM_START from the platform/hardware.h headers.
Provide definition of CONFIG_DEFAULT_MEM_START always, allow changing it
only in noMMU configurations when PLATFORM_WANT_DEFAULT_MEM is selected.
Change prompt and description so that it's clear that it controls
PAGE_OFFSET and PHYS_OFFSET.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: move fixmap and kmap just above the KSEG

The virtual address space between the page table and the VMALLOC region
is big enough to host KASAN shadow map and there's enough space between
the VMALLOC area and KSEG for the fixmap and kmap.
Move fixmap and kmap to the gap between VMALLOC area and KSEG, just
above the KSEG. Reorder entries in the kernel memory layout printing
code. Drop duplicate PGTABLE_START definition, use
XCHAL_PAGE_TABLE_VADDR instead.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: make __pa work with uncached KSEG addresses

When __pa is applied to virtual address in uncached KSEG region the
result is incorrect. Fix it by checking if the original address is in
the uncached KSEG and adjusting the result. It looks better than masking
off bits because pfn_valid would correctly work with new __pa results
and it may be made working in noMMU case, once we get definition for
uncached memory view.

This is required for the dma_common_mmap and DMA debug code to work
correctly: they both indirectly use __pa with coherent DMA addresses.
In case of DMA debug the visible effect is false reports that an address
mapped for DMA is accessed by CPU.

Cc: stable@vger.kernel.org
Tested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: minimize use of PLATFORM_DEFAULT_MEM_{ADDR,SIZE}

Now that the kernel load address and KSEG physical base address have
their own Kconfig symbols PLATFORM_DEFAULT_MEM seems redundant. It makes
little sense to use it in MMU configurations instead of KSEG_PADDR.
In noMMU configurations there's no explicit KSEG, so it's still useful
for the early cache initialization and definition of ARCH_PFN_OFFSET,
which affects mem_map size.

- limit it to noMMU; MMU variants have XCHAL_KSEG_PADDR and
XCHAL_KSEG_SIZE;
- don't use it to define TASK_SIZE or MAX_LOW_PFN: first doesn't make
any difference in noMMU, second is meaningless as there's no high
memory;
- don't add default physical memory region: memory layout should come
from the DT, bootloader tags, or memmap= command line parameter.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: cleanup MMU setup and kernel layout macros

Make kernel load address explicit, independent of the selected MMU
configuration and configurable from Kconfig. Do not restrict it to the
first 512MB of the physical address space.

Cleanup kernel memory layout macros:

- rename VECBASE_RESET_VADDR to VECBASE_VADDR, XC_VADDR to VECTOR_VADDR;
- drop VIRTUAL_MEMORY_ADDRESS and LOAD_MEMORY_ADDRESS;
- introduce PHYS_OFFSET and use it in __va and __pa definitions;
- synchronize MMU/noMMU vectors, drop unused NMI vector;
- replace hardcoded vectors offset of 0x3000 with Kconfig symbol.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: add alternative kernel memory layouts

MMUv3 is able to support low memory bigger than 128MB.
Implement 256MB and 512MB KSEG layouts:

- add Kconfig selector for KSEG layout;
- add KSEG base address, size and alignment definitions to
arch/xtensa/include/asm/kmem_layout.h;
- use new definitions in TLB initialization;
- add build time memory map consistency checks.

See Documentation/xtensa/mmu.txt for the details of new memory layouts.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: move kernel mapping addresses into kmem_layout.h

Create a header dedicated to memory layout definitions. Include it from
places where these definitions are needed.
Express vmalloc area address, VIRTUAL_MEMORY_ADDRESS and KERNELOFFSET
through KSEG address.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: nommu: clean up memory map dump

noMMU configuration doesn't use special area for vmalloc allocations,
don't print it in the memory map.
PAGE_OFFSET is fixed to 0 in noMMU, use min_low_pfn and max_low_pfn for
lowmem range display.
Make all XCHAL_KSEG_* constants unsigned long for consistency with other
addresses.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: nommu: don't build most of the cache flushing code

Most cache flushing code is only relevant for MMU. Don't build it for
nommu configuration.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: support aliasing cache in k[un]map_atomic

Map high memory pages at virtual addresses with color that match color
of their physical address. Existing cache alias management mechanisms
may be used with such pages.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: implement clear_user_highpage and copy_user_highpage

Existing clear_user_page and copy_user_page cannot be used with highmem
because they calculate physical page address from its virtual address
and do it incorrectly in case of high memory page mapped with
kmap_atomic. Also kmap is not needed, as most likely userspace mapping
color would be different from the kmapped color.

Provide clear_user_highpage and copy_user_highpage functions that
determine if temporary mapping is needed for the pages. Move most of the
logic of the former clear_user_page and copy_user_page to
xtensa/mm/cache.c only leaving temporary mapping setup, invalidation and
clearing/copying in the xtensa/mm/misc.S. Rename these functions to
clear_page_alias and copy_page_alias.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

xtensa: clean up files to make them code-style compliant

Remove heading and trailing spaces, trim trailing lines, and wrap lines
that are longer than 80 characters.

Signed-off-by: Chris Zankel <chris@zankel.net>

xtensa/mm: remove WANT_PAGE_VIRTUAL

This is not useful: it provides page->virtual and is used with highmem.
xtensa has no support for highmem and those HIGHMEM bits which are found
by grep are partly implemented. The interesting functions like kmap() are
missing. If someone actually implements the complete HIGHMEM support he
could use HASHED_PAGE_VIRTUAL like most others do.

Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Chris Zankel <chris@zankel.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

asm-generic: rename page.h and uaccess.h

The current asm-generic/page.h only contains the get_order
function, and asm-generic/uaccess.h only implements
unaligned accesses. This renames the file to getorder.h
and uaccess-unaligned.h to make room for new page.h
and uaccess.h file that will be usable by all simple
(e.g. nommu) architectures.

Signed-off-by: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

xtensa: nommu support

Add support for !CONFIG_MMU setups.

Signed-off-by: Johannes Weiner <jw@emlix.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

xtensa: cope with ram beginning at higher addresses

The current assumption of the memory code is that the first RAM PFN in
the system is 0.

Adjust the relevant code to play well with setups where memory starts
at higher addresses, indicated by PLATFORM_DEFAULT_MEM_START.

The new memory model looks like this:

+----------+--+----------------------+----------------+
| | | | |
| | | RAM | |
| | | | |
+----------+--+----------------------+----------------+
| | | | |
+- PFN 0 | +- min_low_pfn +- max_low_pfn +- max_pfn
|
+- ARCH_PFN_OFFSET
+- PLATFORM_DEFAULT_MEM_START >> PAGE_SIZE

The memory map contains pages starting from pfn ARCH_PFN_OFFSET up to
max_low_pfn. The only zone used right now will span exactly the same
region.

Usually, ARCH_PFN_OFFSET and min_low_pfn are the same value. Handle
them separately for robustness. Gapping pages will be in the memory
map but marked as reserved and won't be touched.

Signed-off-by: Johannes Weiner <jw@emlix.com>
Signed-off-by: Chris Zankel <chris@zankel.net>

xtensa: move headers files to arch/xtensa/include

Move all header files for xtensa to arch/xtensa/include and platform and
variant header files to the appropriate arch/xtensa/platforms/ and
arch/xtensa/variants/ directories.

Moving the files gets also rid of all uses of symlinks in the Makefile.

This has been completed already for the majority of the architectures
and xtensa is one out of six missing.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Chris Zankel <chris@zankel.net>