MIPS: of: Introduce helper function to get DTB

Selection of the DTB to be used was burried in more or less readable
code in head.S. Move this code into a inline helper function and
use it.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>

MIPS: Loongson-3: Enable COP2 usage in kernel

Loongson-3's COP2 is Multi-Media coprocessor, it is disabled in kernel
mode by default. However, gslq/gssq (16-bytes load/store instructions)
overrides the instruction format of lwc2/swc2. If we wan't to use gslq/
gssq for optimization in kernel, we should enable COP2 usage in kernel.

Please pay attention that in this patch we only enable COP2 in kernel,
which means it will lose ST0_CU2 when a process go to user space (try
to use COP2 in user space will trigger an exception and then grab COP2,
which is similar to FPU). And as a result, we need to modify the context
switching code because the new scheduled process doesn't contain ST0_CU2
in its THERAD_STATUS probably.

For zboot, we disable gslq/gssq be generated by toolchain.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: head.S: Init fw_passed_dtb to builtin DTB

Init the 'fw_passed_dtb' pointer to the buit-in Device Tree blob when it
has been compiled in with CONFIG_BUILTIN_DTB.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: Clear XContext at boot time

XContext might be dirty at boot time. We need to clear it
to ensure early stackframe is safe.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS/head: Store ELF appended dtb in a global variable too

Since commit 15f37e158892 ("MIPS: store the appended
dtb address in a variable"),
in kernels with MIPS_RAW_APPENDED_DTB=y, the early boot code detects
the dtb and stores it in the 'fw_passed_dtb' variable.

However, the dtb is not stored in 'fw_passed_dtb' in kernels with
MIPS_ELF_APPENDED_DTB=y.

Under MIPS_ELF_APPENDED_DTB=y, the dtb is also located in the
__appended_dtb section, so we just need to update the #ifdef.

This will allow to access the dtb in a more uniform way.

Fixes: 15f37e158892 ("MIPS: store the appended dtb address in a variable")
Signed-off-by: Yasha Cherikovsky <yasha.che3@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20803/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org

MIPS/head: Add comments after #endif and #else

It makes the code more readable, especially in the nested ifdefs.

Signed-off-by: Yasha Cherikovsky <yasha.che3@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20802/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org

MIPS: head: Reorder instructions missing a delay slot

In this sequence the 'move' is assumed in the delay slot of the 'beq',
but head.S is in reorder mode and the former gets pushed one 'nop'
farther by the assembler.

The corrected behavior made booting with an UHI supplied dtb erratic.

Fixes: 15f37e158892 ("MIPS: store the appended dtb address in a variable")
Signed-off-by: Karl Beldan <karl.beldan+oss@gmail.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16614/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: store the appended dtb address in a variable

Instead of rewriting the arguments to match the UHI spec, store the
address of a appended or UHI supplied dtb in fw_supplied_dtb.

That way the original bootloader arugments are kept intact while still
making the use of an appended dtb invisible for mach code.

Mach code can still find out if it is an appended dtb by comparing
fw_arg1 with fw_supplied_dtb.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: John Crispin <john@phrozen.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Alban Bedel <albeu@free.fr>
Cc: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13699/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Remove redundant asm/pgtable-bits.h inclusions

asm/pgtable-bits.h is included in 2 assembly files and thus has to
ifdef around C code, however nothing defined by the header is used
in either of the assembly files that include it.

Remove the redundant inclusions such that asm/pgtable-bits.h doesn't
need to #ifdef around C code, for cleanliness and in preparation for
later patches which will add more C.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13114/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Call relocate_kernel if CONFIG_RELOCATABLE=y

If CONFIG_RELOCATABLE is enabled, call relocate_kernel.

This function will return the entry point of the relocated kernel if
copy/relocate is sucessful or the original entry point if not. The stack
pointer must then be pointed into the new image.

Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: kernel-hardening@lists.openwall.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12984/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Add support for vmlinux.bin appended dtb

Add support for detecting a vmlinux.bin appended dtb and overriding
the boot arguments to match the UHI interface.

Due to the PERCPU section being empty for !SMP, but still modifying
the current address by aligning it to the page size, do not define
it for !SMP builds to allow __appended_dtb to still point to
the actual end of the data.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: John Crispin <blogic@openwrt.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hartley <James.Hartley@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/9739/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: MT: Remove SMTC support

Nobody is maintaining SMTC anymore and there also seems to be no userbase.
Which is a pity - the SMTC technology primarily developed by Kevin D.
Kissell <kevink@paralogos.com> is an ingenious demonstration for the MT
ASE's power and elegance.

Based on Markos Chandras <Markos.Chandras@imgtec.com> patch
https://patchwork.linux-mips.org/patch/6719/ which while very similar did
no longer apply cleanly when I tried to merge it plus some additional
post-SMTC cleanup - SMTC was a feature as tricky to remove as it was to
merge once upon a time.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: malta: Add support for SMP EVA

Allow secondary cores to program their segment control registers
during smp bootstrap code. This enables EVA on Malta SMP
configurations

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

MIPS: Delete __cpuinit/__CPUINIT usage from MIPS code

commit 3747069b25e419f6b51395f48127e9812abc3596 upstream.

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
and are flagged as __cpuinit -- so if we remove the __cpuinit from
the arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
related content into no-ops as early as possible, since that will get
rid of these warnings. In any case, they are temporary and harmless.

Here, we remove all the MIPS __cpuinit from C code and __CPUINIT
from asm files. MIPS is interesting in this respect, because there
are also uasm users hiding behind their own renamed versions of the
__cpuinit macros.

[1] https://lkml.org/lkml/2013/5/20/589

[ralf@linux-mips.org: Folded in Paul's followup fix.]

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5494/
Patchwork: https://patchwork.linux-mips.org/patch/5495/
Patchwork: https://patchwork.linux-mips.org/patch/5509/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Move gas macro MAPPED_KERNEL_SETUP_TLB to IP27-specific code.

It's IP27-specific and can only cause trouble in head.S.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Whitespace cleanup.

Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Don't include <asm/page.h> unnecessarily.

So far we're jumping through hoops to keep the file usable from assembler
source but it's getting just too painful. Turns out that many uses of
<asm/page.h> are unnecessary anyway, so just remove those.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Avoid potential hazard on Context register

set_saved_sp reads Context register. Avoid reading stale value from
earlier incomplete write.

Issue found and fixed for head.S by Chris Dearman <chris@mips.com>.

Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Avoid clobbering struct pt_regs in kthreads

The resume() implementation octeon_switch.S examines the saved cp0_status
register. We were clobbering the entire pt_regs structure in kernel
threads leading to random crashes.

When switching away from a kernel thread, the saved cp0_status is examined
and if bit 30 is set it is cleared and the CP2 state saved into the pt_regs
structure. Since the kernel thread stack overlaid the pt_regs structure
this resulted in a corrupt stack. When the kthread with the corrupt stack
was resumed, it could crash if it used any of the data in the stack that was
clobbered.

We fix it by moving the kernel thread stack down so it doesn't overlay
pt_regs.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] IP27: Fix build errors if CONFIG_MAPPED_KERNEL=y

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] Fix loads of section missmatches

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] Fix build after b0rked changes to <linux/init.h>.

Commit 312b1485fb509c9bc32eda28ad29537896658cb8 made __INIT_REFOK expand
into .section .section ".ref.text", "ax". Since the assembler doesn't
tolerate stuttering in the source that broke all MIPS builds.

Since with this change Sam downgraded __INIT_REFOK the best fix is to
get replace it by the modern days operator. With MIPS the only user
of __INIT_REFOK and __INITDATA_REFOK (which was equally broken) being
unused anyway these can be deleted but that's subject of a separate
commit.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] Fix CONFIG_BOOT_RAW.

This was broken by 017e3a492683b32d17dcd1b13b279745cc656073 (lmo) /
396a2ae08e5080b140330645743ab2567f6bc426 (kernel.org).

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] Always do the ARC64_TWIDDLE_PC thing.

Always jump to the place where the kernel is linked to. This helps where
the bootloaders/proms ignores the start address inside the ELF header.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] Fix modpost warning in raw binary builds.

MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0x478): Section mismatch: reference to .init.text:start_kernel (between '_stext' and 'run_init_process')

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] Replace use of stext with _stext.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] Fix marge error due to conflict in arch/mips/kernel/head.S

__INIT directive just before kernel_entry was ignored for most platforms.
This patch fixes it and get rid of this warning:

WARNING: vmlinux.o(.text+0x478): Section mismatch: reference to .init.text:start_kernel (between '_stext' and 'run_init_process')

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] PMC MSP71xx mips common

Patch to add mips common support for the PMC-Sierra MSP71xx devices.

Signed-off-by: Marc St-Jean <Marc_St-Jean@pmc-sierra.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] MIPSsim: Move code away from the other MIPS Inc. BSP code.

It shares no code at all. While at it also fix up the beginning bitrot.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] Move some kernel globals from asm file to C file.

This get rid of some undesirable hole in BSS section due to random
order of placement.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] Qemu now has an ELF loader.

So nuke kludge for flat binaries.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] Load modules to CKSEG0 if CONFIG_BUILD_ELF64=n

This is a patch to load 64-bit modules to CKSEG0 so that can be
compiled with -msym32 option. This makes each module ~10% smaller.

* introduce MODULE_START and MODULE_END
* custom module_alloc()
* PGD for modules
* change XTLB refill handler synthesizer
* enable -msym32 for modules again
(revert ca78b1a5c6a6e70e052d3ea253828e49b5d07c8a)

New XTLB refill handler looks like this:

80000080 dmfc0 k0,C0_BADVADDR
80000084 bltz k0,800000e4 # goto l_module_alloc
80000088 lui k1,0x8046 # %high(pgd_current)
8000008c ld k1,24600(k1) # %low(pgd_current)
80000090 dsrl k0,k0,0x1b # l_vmalloc_done:
80000094 andi k0,k0,0x1ff8
80000098 daddu k1,k1,k0
8000009c dmfc0 k0,C0_BADVADDR
800000a0 ld k1,0(k1)
800000a4 dsrl k0,k0,0x12
800000a8 andi k0,k0,0xff8
800000ac daddu k1,k1,k0
800000b0 dmfc0 k0,C0_XCONTEXT
800000b4 ld k1,0(k1)
800000b8 andi k0,k0,0xff0
800000bc daddu k1,k1,k0
800000c0 ld k0,0(k1)
800000c4 ld k1,8(k1)
800000c8 dsrl k0,k0,0x6
800000cc mtc0 k0,C0_ENTRYLO0
800000d0 dsrl k1,k1,0x6
800000d4 mtc0 k1,C0_ENTRYL01
800000d8 nop
800000dc tlbwr
800000e0 eret
800000e4 dsll k1,k0,0x2 # l_module_alloc:
800000e8 bgez k1,80000008 # goto l_vmalloc
800000ec lui k1,0xc000
800000f0 dsubu k0,k0,k1
800000f4 lui k1,0x8046 # %high(module_pg_dir)
800000f8 beq zero,zero,80000000
800000fc nop
80000000 beq zero,zero,80000090 # goto l_vmalloc_done
80000004 daddiu k1,k1,0x4000
80000008 dsll32 k1,k1,0x0 # l_vmalloc:
8000000c dsubu k0,k0,k1
80000010 beq zero,zero,80000090 # goto l_vmalloc_done
80000014 lui k1,0x8046 # %high(swapper_pg_dir)

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] 16K & 64K page size fixes

Derived from Peter Watkins <treestem@gmail.com>'s work.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] TRACE_IRQFLAGS_SUPPORT support.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

[MIPS] Fix use of ehb instruction for non-R2 configurations.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[MIPS] MT: Improved multithreading support.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Support for MIPSsim, the cycle accurate MIPS simulator.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Move Origin crapola into a machine-specific header file.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Temporary hack for Qemu and MIPSsim until they get a proper ELF loader.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Fix 64bit SMP TLB handler and stack frame handling, optimize 32bit SMP
TLB handlers a bit, match definitions in pgtable-{32,64}.h better.

Signed-off-by: Thiemo Seufer <ths@networkno.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Move the invalid pmd and pte tables from .data to .bss. Fix alignment.

Signed-off-by: Thiemo Seufer <ths@networkno.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[PATCH] mips: clean up 32/64-bit configuration

Start cleaning 32-bit vs. 64-bit configuration.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!