Commit Graph

3396 Commits

Author SHA1 Message Date
Jiaxun Yang
7e5b7360df MIPS: cpu-features: Use boot_cpu_type for CPU type based features
[ Upstream commit 5487a7b606 ]

Some CPU feature macros were using current_cpu_type to mark feature
availability.

However current_cpu_type will use smp_processor_id, which is prohibited
under preemptable context.

Since those features are all uniform on all CPUs in a SMP system, use
boot_cpu_type instead of current_cpu_type to fix preemptable kernel.

Cc: stable@vger.kernel.org
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-30 16:27:21 +02:00
Jiaxun Yang
302a8fbf8c MIPS: cpu-features: Enable octeon_cache by cpu_type
[ Upstream commit f641519409 ]

cpu_has_octeon_cache was tied to 0 for generic cpu-features,
whith this generic kernel built for octeon CPU won't boot.

Just enable this flag by cpu_type. It won't hurt orther platforms
because compiler will eliminate the code path on other processors.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Stable-dep-of: 5487a7b606 ("MIPS: cpu-features: Use boot_cpu_type for CPU type based features")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-30 16:27:21 +02:00
Gustavo A. R. Silva
2225000d62 MIPS: dec: prom: Address -Warray-bounds warning
[ Upstream commit 7b191b9b55 ]

Zero-length arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace zero-length array with flexible-array
member in struct memmap.

Address the following warning found after building (with GCC-13) mips64
with decstation_64_defconfig:
In function 'rex_setup_memory_region',
    inlined from 'prom_meminit' at arch/mips/dec/prom/memory.c:91:3:
arch/mips/dec/prom/memory.c:72:31: error: array subscript i is outside array bounds of 'unsigned char[0]' [-Werror=array-bounds=]
   72 |                 if (bm->bitmap[i] == 0xff)
      |                     ~~~~~~~~~~^~~
In file included from arch/mips/dec/prom/memory.c:16:
./arch/mips/include/asm/dec/prom.h: In function 'prom_meminit':
./arch/mips/include/asm/dec/prom.h:73:23: note: while referencing 'bitmap'
   73 |         unsigned char bitmap[0];

This helps with the ongoing efforts to globally enable -Warray-bounds.

This results in no differences in binary output.

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/323
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-30 16:27:09 +02:00
Thomas Gleixner
18cd611a3e mips/cpu: Switch to arch_cpu_finalize_init()
commit 7f066a22fe upstream

check_bugs() is about to be phased out. Switch over to the new
arch_cpu_finalize_init() implementation.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230613224545.312438573@linutronix.de
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-08 19:56:34 +02:00
xurui
2fea235ef0 MIPS: Fix a compilation issue
[ Upstream commit 109d587a4b ]

arch/mips/include/asm/mach-rc32434/pci.h:377:
cc1: error: result of ‘-117440512 << 16’ requires 44 bits to represent, but ‘int’ only has 32 bits [-Werror=shift-overflow=]

All bits in KORINA_STAT are already at the correct position, so there is
no addtional shift needed.

Signed-off-by: xurui <xurui@kylinos.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-17 08:32:52 +01:00
Elvira Khabirova
58c0d0b2d4 mips: fix syscall_get_nr
commit 85cc91e2ba upstream.

The implementation of syscall_get_nr on mips used to ignore the task
argument and return the syscall number of the calling thread instead of
the target thread.

The bug was exposed to user space by commit 201766a20e ("ptrace: add
PTRACE_GET_SYSCALL_INFO request") and detected by strace test suite.

Link: https://github.com/strace/strace/issues/235
Fixes: c2d9f17757 ("MIPS: Fix syscall_get_nr for the syscall exit tracing.")
Cc: <stable@vger.kernel.org> # v3.19+
Co-developed-by: Dmitry V. Levin <ldv@strace.io>
Signed-off-by: Dmitry V. Levin <ldv@strace.io>
Signed-off-by: Elvira Khabirova <lineprinter0@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-11 16:44:04 +01:00
Randy Dunlap
3acbec356d MIPS: vpe-mt: drop physical_memsize
[ Upstream commit 91dc288f4e ]

When neither LANTIQ nor MIPS_MALTA is set, 'physical_memsize' is not
declared. This causes the build to fail with:

mips-linux-ld: arch/mips/kernel/vpe-mt.o: in function `vpe_run':
arch/mips/kernel/vpe-mt.c:(.text.vpe_run+0x280): undefined reference to `physical_memsize'

LANTIQ is not using 'physical_memsize' and MIPS_MALTA's use of it is
self-contained in mti-malta/malta-dtshim.c.
Use of physical_memsize in vpe-mt.c appears to be unused, so eliminate
this loader mode completely and require VPE programs to be compiled with
DFLT_STACK_SIZE and DFLT_HEAP_SIZE defined.

Fixes: 9050d50e22 ("MIPS: lantiq: Set physical_memsize")
Fixes: 1a2a6d7e88 ("MIPS: APRP: Split VPE loader into separate files.")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/all/202302030625.2g3E98sY-lkp@intel.com/
Cc: Dengcheng Zhu <dzhu@wavecomp.com>
Cc: John Crispin <john@phrozen.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
Cc: "Steven J. Hill" <Steven.Hill@imgtec.com>
Cc: Qais Yousef <Qais.Yousef@imgtec.com>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:43:52 +01:00
Jason A. Donenfeld
9221a53bfc MIPS: pic32: treat port as signed integer
[ Upstream commit 648060902a ]

get_port_from_cmdline() returns an int, yet is assigned to a char, which
is wrong in its own right, but also, with char becoming unsigned, this
poses problems, because -1 is used as an error value. Further
complicating things, fw_init_early_console() is only ever called with a
-1 argument. Fix this up by removing the unused argument from
fw_init_early_console() and treating port as a proper signed integer.

Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-12-08 11:22:57 +01:00
Jason A. Donenfeld
6fa912f987 mips: use fallback for random_get_entropy() instead of just c0 random
commit 1c99c6a7c3 upstream.

For situations in which we don't have a c0 counter register available,
we've been falling back to reading the c0 "random" register, which is
usually bounded by the amount of TLB entries and changes every other
cycle or so. This means it wraps extremely often. We can do better by
combining this fast-changing counter with a potentially slower-changing
counter from random_get_entropy_fallback() in the more significant bits.
This commit combines the two, taking into account that the changing bits
are in a different bit position depending on the CPU model. In addition,
we previously were falling back to 0 for ancient CPUs that Linux does
not support anyway; remove that dead path entirely.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Tested-by: Maciej W. Rozycki <macro@orcam.me.uk>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-22 14:11:15 +02:00
Maciej W. Rozycki
5407341053 MIPS: IP27: Remove incorrect `cpu_has_fpu' override
commit 424c3781dd upstream.

Remove unsupported forcing of `cpu_has_fpu' to 1, which makes the `nofpu'
kernel parameter non-functional, and also causes a link error:

ld: arch/mips/kernel/traps.o: in function `trap_init':
./arch/mips/include/asm/msa.h:(.init.text+0x348): undefined reference to `handle_fpe'
ld: ./arch/mips/include/asm/msa.h:(.init.text+0x354): undefined reference to `handle_fpe'
ld: ./arch/mips/include/asm/msa.h:(.init.text+0x360): undefined reference to `handle_fpe'

where the CONFIG_MIPS_FP_SUPPORT configuration option has been disabled.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Reported-by: Stephen Zhang <starzhangzsd@gmail.com>
Fixes: 0ebb2f4159 ("MIPS: IP27: Update/restructure CPU overrides")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-14 18:11:50 +02:00
Maciej W. Rozycki
0d5bb59858 MIPS: Fix CP0 counter erratum detection for R4k CPUs
commit f0a6c68f69 upstream.

Fix the discrepancy between the two places we check for the CP0 counter
erratum in along with the incorrect comparison of the R4400 revision
number against 0x30 which matches none and consistently consider all
R4000 and R4400 processors affected, as documented in processor errata
publications[1][2][3], following the mapping between CP0 PRId register
values and processor models:

  PRId   |  Processor Model
---------+--------------------
00000422 | R4000 Revision 2.2
00000430 | R4000 Revision 3.0
00000440 | R4400 Revision 1.0
00000450 | R4400 Revision 2.0
00000460 | R4400 Revision 3.0

No other revision of either processor has ever been spotted.

Contrary to what has been stated in commit ce202cbb9e ("[MIPS] Assume
R4000/R4400 newer than 3.0 don't have the mfc0 count bug") marking the
CP0 counter as buggy does not preclude it from being used as either a
clock event or a clock source device.  It just cannot be used as both at
a time, because in that case clock event interrupts will be occasionally
lost, and the use as a clock event device takes precedence.

Compare against 0x4ff in `can_use_mips_counter' so that a single machine
instruction is produced.

References:

[1] "MIPS R4000PC/SC Errata, Processor Revision 2.2 and 3.0", MIPS
    Technologies Inc., May 10, 1994, Erratum 53, p.13

[2] "MIPS R4400PC/SC Errata, Processor Revision 1.0", MIPS Technologies
    Inc., February 9, 1994, Erratum 21, p.4

[3] "MIPS R4400PC/SC Errata, Processor Revision 2.0 & 3.0", MIPS
    Technologies Inc., January 24, 1995, Erratum 14, p.3

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: ce202cbb9e ("[MIPS] Assume R4000/R4400 newer than 3.0 don't have the mfc0 count bug")
Cc: stable@vger.kernel.org # v2.6.24+
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-05-12 12:23:39 +02:00
Alexander Lobakin
0aeaadc52b MIPS: fix fortify panic when copying asm exception handlers
[ Upstream commit d17b664173 ]

With KCFLAGS="-O3", I was able to trigger a fortify-source
memcpy() overflow panic on set_vi_srs_handler().
Although O3 level is not supported in the mainline, under some
conditions that may've happened with any optimization settings,
it's just a matter of inlining luck. The panic itself is correct,
more precisely, 50/50 false-positive and not at the same time.
From the one side, no real overflow happens. Exception handler
defined in asm just gets copied to some reserved places in the
memory.
But the reason behind is that C code refers to that exception
handler declares it as `char`, i.e. something of 1 byte length.
It's obvious that the asm function itself is way more than 1 byte,
so fortify logics thought we are going to past the symbol declared.
The standard way to refer to asm symbols from C code which is not
supposed to be called from C is to declare them as
`extern const u8[]`. This is fully correct from any point of view,
as any code itself is just a bunch of bytes (including 0 as it is
for syms like _stext/_etext/etc.), and the exact size is not known
at the moment of compilation.
Adjust the type of the except_vec_vi_*() and related variables.
Make set_handler() take `const` as a second argument to avoid
cast-away warnings and give a little more room for optimization.

Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-15 14:18:34 +02:00
Maciej W. Rozycki
28859c3a77 DEC: Limit PMAX memory probing to R3k systems
commit 244eae91a9 upstream.

Recent tightening of the opcode table in binutils so as to consistently
disallow the assembly or disassembly of CP0 instructions not supported
by the processor architecture chosen has caused a regression like below:

arch/mips/dec/prom/locore.S: Assembler messages:
arch/mips/dec/prom/locore.S:29: Error: opcode not supported on this processor: r4600 (mips3) `rfe'

in a piece of code used to probe for memory with PMAX DECstation models,
which have non-REX firmware.  Those computers always have an R2000 CPU
and consequently the exception handler used in memory probing uses the
RFE instruction, which those processors use.

While adding 64-bit support this code was correctly excluded for 64-bit
configurations, however it should have also been excluded for irrelevant
32-bit configurations.  Do this now then, and only enable PMAX memory
probing for R3k systems.

Reported-by: Jan-Benedict Glaw <jbglaw@lug-owl.de>
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org # v2.6.12+
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-04-15 14:18:03 +02:00
Tianjia Zhang
1785538d27 MIPS: Octeon: Fix build errors using clang
[ Upstream commit 95339b7067 ]

A large number of the following errors is reported when compiling
with clang:

  cvmx-bootinfo.h:326:3: error: adding 'int' to a string does not append to the string [-Werror,-Wstring-plus-int]
                  ENUM_BRD_TYPE_CASE(CVMX_BOARD_TYPE_NULL)
                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  cvmx-bootinfo.h:321:20: note: expanded from macro 'ENUM_BRD_TYPE_CASE'
          case x: return(#x + 16);        /* Skip CVMX_BOARD_TYPE_ */
                         ~~~^~~~
  cvmx-bootinfo.h:326:3: note: use array indexing to silence this warning
  cvmx-bootinfo.h:321:20: note: expanded from macro 'ENUM_BRD_TYPE_CASE'
          case x: return(#x + 16);        /* Skip CVMX_BOARD_TYPE_ */
                          ^

Follow the prompts to use the address operator '&' to fix this error.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 09:19:48 +01:00
Maciej W. Rozycki
307c6f7287 MIPS: Fix assembly error from MIPSr2 code used within MIPS_ISA_ARCH_LEVEL
commit a923a2676e upstream.

Fix assembly errors like:

{standard input}: Assembler messages:
{standard input}:287: Error: opcode not supported on this processor: mips3 (mips3) `dins $10,$7,32,32'
{standard input}:680: Error: opcode not supported on this processor: mips3 (mips3) `dins $10,$7,32,32'
{standard input}:1274: Error: opcode not supported on this processor: mips3 (mips3) `dins $12,$9,32,32'
{standard input}:2175: Error: opcode not supported on this processor: mips3 (mips3) `dins $10,$7,32,32'
make[1]: *** [scripts/Makefile.build:277: mm/highmem.o] Error 1

with code produced from `__cmpxchg64' for MIPS64r2 CPU configurations
using CONFIG_32BIT and CONFIG_PHYS_ADDR_T_64BIT.

This is due to MIPS_ISA_ARCH_LEVEL downgrading the assembly architecture
to `r4000' i.e. MIPS III for MIPS64r2 configurations, while there is a
block of code containing a DINS MIPS64r2 instruction conditionalized on
MIPS_ISA_REV >= 2 within the scope of the downgrade.

The assembly architecture override code pattern has been put there for
LL/SC instructions, so that code compiles for configurations that select
a processor to build for that does not support these instructions while
still providing run-time support for processors that do, dynamically
switched by non-constant `cpu_has_llsc'.  It went in with linux-mips.org
commit aac8aa7717 ("Enable a suitable ISA for the assembler around
ll/sc so that code builds even for processors that don't support the
instructions. Plus minor formatting fixes.") back in 2005.

Fix the problem by wrapping these instructions along with the adjacent
SYNC instructions only, following the practice established with commit
cfd54de3b0 ("MIPS: Avoid move psuedo-instruction whilst using
MIPS_ISA_LEVEL") and commit 378ed6f0e3 ("MIPS: Avoid using .set mips0
to restore ISA").  Strictly speaking the SYNC instructions do not have
to be wrapped as they are only used as a Loongson3 erratum workaround,
so they will be enabled in the assembler by default, but do this so as
to keep code consistent with other places.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: c7e2d71dda ("MIPS: Fix set_pte() for Netlogic XLR using cmpxchg64()")
Cc: stable@vger.kernel.org # v5.1+
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-21 13:38:50 +01:00
Geert Uytterhoeven
3f698d97f7 mips: cm: Convert to bitfield API to fix out-of-bounds access
[ Upstream commit 18b8f5b6fc ]

mips_cm_error_report() extracts the cause and other cause from the error
register using shifts.  This works fine for the former, as it is stored
in the top bits, and the shift will thus remove all non-related bits.
However, the latter is stored in the bottom bits, hence thus needs masking
to get rid of non-related bits.  Without such masking, using it as an
index into the cm2_causes[] array will lead to an out-of-bounds access,
probably causing a crash.

Fix this by using FIELD_GET() instead.  Bite the bullet and convert all
MIPS CM handling to the bitfield API, to improve readability and safety.

Fixes: 3885c2b463 ("MIPS: CM: Add support for reporting CM cache errors")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-11-17 09:48:44 +01:00
Huang Pei
268132b070 Revert "MIPS: add PMD table accounting into MIPS'pmd_alloc_one"
This reverts commit 002d8b395f which is
commit ed914d48b6 upstream.

Commit b2b29d6d01 (mm: account PMD tables like PTE tables) is
introduced between v5.9 and v5.10, so this fix (commit 002d8b395f)
should NOT apply to any pre-5.10 branch.

Signed-off-by: Huang Pei <huangpei@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-28 13:30:58 +02:00
Martin Fäcknitz
e9602efecf MIPS: vdso: Invalid GIC access through VDSO
[ Upstream commit 47ce8527fb ]

Accessing raw timers (currently only CLOCK_MONOTONIC_RAW) through VDSO
doesn't return the correct time when using the GIC as clock source.
The address of the GIC mapped page is in this case not calculated
correctly. The GIC mapped page is calculated from the VDSO data by
subtracting PAGE_SIZE:

  void *get_gic(const struct vdso_data *data) {
    return (void __iomem *)data - PAGE_SIZE;
  }

However, the data pointer is not page aligned for raw clock sources.
This is because the VDSO data for raw clock sources (CS_RAW = 1) is
stored after the VDSO data for coarse clock sources (CS_HRES_COARSE = 0).
Therefore, only the VDSO data for CS_HRES_COARSE is page aligned:

  +--------------------+
  |                    |
  | vd[CS_RAW]         | ---+
  | vd[CS_HRES_COARSE] |    |
  +--------------------+    | -PAGE_SIZE
  |                    |    |
  |  GIC mapped page   | <--+
  |                    |
  +--------------------+

When __arch_get_hw_counter() is called with &vd[CS_RAW], get_gic returns
the wrong address (somewhere inside the GIC mapped page). The GIC counter
values are not returned which results in an invalid time.

Fixes: a7f4df4e21 ("MIPS: VDSO: Add implementations of gettimeofday() and clock_gettime()")
Signed-off-by: Martin Fäcknitz <faecknitz@hotsplots.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-20 16:10:53 +02:00
Nick Desaulniers
5d4fa5e1b9 MIPS: set mips32r5 for virt extensions
[ Upstream commit c994a3ec7e ]

Clang's integrated assembler only accepts these instructions when the
cpu is set to mips32r5. With this change, we can assemble
malta_defconfig with Clang via `make LLVM_IAS=1`.

Link: https://github.com/ClangBuiltLinux/linux/issues/763
Reported-by: Dmitry Golovin <dima@golovin.in>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19 08:53:13 +02:00
Huang Pei
002d8b395f MIPS: add PMD table accounting into MIPS'pmd_alloc_one
[ Upstream commit ed914d48b6 ]

This fixes Page Table accounting bug.

MIPS is the ONLY arch just defining __HAVE_ARCH_PMD_ALLOC_ONE alone.
Since commit b2b29d6d01 (mm: account PMD tables like PTE tables),
"pmd_free" in asm-generic with PMD table accounting and "pmd_alloc_one"
in MIPS without PMD table accounting causes PageTable accounting number
negative, which read by global_zone_page_state(), always returns 0.

Signed-off-by: Huang Pei <huangpei@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19 08:53:12 +02:00
Bibo Mao
b52b0d996a hugetlb: clear huge pte during flush function on mips platform
[ Upstream commit 33ae8f801a ]

If multiple threads are accessing the same huge page at the same
time, hugetlb_cow will be called if one thread write the COW huge
page. And function huge_ptep_clear_flush is called to notify other
threads to clear the huge pte tlb entry. The other threads clear
the huge pte tlb entry and reload it from page table, the reload
huge pte entry may be old.

This patch fixes this issue on mips platform, and it clears huge
pte entry before notifying other threads to flush current huge
page entry, it is similar with other architectures.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-19 08:53:08 +02:00
Wei Li
e0aef648f5 MIPS: Fix PKMAP with 32-bit MIPS huge page support
[ Upstream commit cf02ce742f ]

When 32-bit MIPS huge page support is enabled, we halve the number of
pointers a PTE page holds, making its last half go to waste.
Correspondingly, we should halve the number of kmap entries, as we just
initialized only a single pte table for that in pagetable_init().

Fixes: 35476311e5 ("MIPS: Add partial 32-bit huge page support")
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-14 16:53:36 +02:00
Maciej W. Rozycki
2c44110300 MIPS: Avoid handcoded DIVU in `__div64_32' altogether
commit 25ab14cbe9 upstream.

Remove the inline asm with a DIVU instruction from `__div64_32' and use
plain C code for the intended DIVMOD calculation instead.  GCC is smart
enough to know that both the quotient and the remainder are calculated
with single DIVU, so with ISAs up to R5 the same instruction is actually
produced with overall similar code.

For R6 compiled code will work, but separate DIVU and MODU instructions
will be produced, which are also interlocked, so scalar implementations
will likely not perform as well as older ISAs with their asynchronous MD
unit.  Likely still faster then the generic algorithm though.

This removes a compilation error for R6 however where the original DIVU
instruction is not supported anymore and the MDU accumulator registers
have been removed and consequently GCC complains as to a constraint it
cannot find a register for:

In file included from ./include/linux/math.h:5,
                 from ./include/linux/kernel.h:13,
                 from mm/page-writeback.c:15:
./include/linux/math64.h: In function 'div_u64_rem':
./arch/mips/include/asm/div64.h:76:17: error: inconsistent operand constraints in an 'asm'
   76 |                 __asm__("divu   $0, %z1, %z2"                           \
      |                 ^~~~~~~
./include/asm-generic/div64.h:245:25: note: in expansion of macro '__div64_32'
  245 |                 __rem = __div64_32(&(n), __base);       \
      |                         ^~~~~~~~~~
./include/linux/math64.h:91:22: note: in expansion of macro 'do_div'
   91 |         *remainder = do_div(dividend, divisor);
      |                      ^~~~~~

This has passed correctness verification with test_div64 and reduced the
module's average execution time down to 1.0404s from 1.0445s with R3400
@40MHz.  The module's MIPS I machine code has also shrunk by 12 bytes or
3 instructions.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-19 10:08:32 +02:00
Maciej W. Rozycki
2759b770b5 MIPS: Avoid DIVU in `__div64_32' is result would be zero
commit c1d337d45e upstream.

We already check the high part of the divident against zero to avoid the
costly DIVU instruction in that case, needed to reduce the high part of
the divident, so we may well check against the divisor instead and set
the high part of the quotient to zero right away.  We need to treat the
high part the divident in that case though as the remainder that would
be calculated by the DIVU instruction we avoided.

This has passed correctness verification with test_div64 and reduced the
module's average execution time down to 1.0445s and 0.2619s from 1.0668s
and 0.2629s respectively for an R3400 CPU @40MHz and a 5Kc CPU @160MHz.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-19 10:08:32 +02:00
Maciej W. Rozycki
02b120493a MIPS: Reinstate platform `__div64_32' handler
commit c49f71f607 upstream.

Our current MIPS platform `__div64_32' handler is inactive, because it
is incorrectly only enabled for 64-bit configurations, for which generic
`do_div' code does not call it anyway.

The handler is not suitable for being called from there though as it
only calculates 32 bits of the quotient under the assumption the 64-bit
divident has been suitably reduced.  Code for such reduction used to be
there, however it has been incorrectly removed with commit c21004cd5b
("MIPS: Rewrite <asm/div64.h> to work with gcc 4.4.0."), which should
have only updated an obsoleted constraint for an inline asm involving
$hi and $lo register outputs, while possibly wiring the original MIPS
variant of the `do_div' macro as `__div64_32' handler for the generic
`do_div' implementation

Correct the handler as follows then:

- Revert most of the commit referred, however retaining the current
  formatting, except for the final two instructions of the inline asm
  sequence, which the original commit missed.  Omit the original 64-bit
  parts though.

- Rename the original `do_div' macro to `__div64_32'.  Use the combined
  `x' constraint referring to the MD accumulator as a whole, replacing
  the original individual `h' and `l' constraints used for $hi and $lo
  registers respectively, of which `h' has been obsoleted with GCC 4.4.
  Update surrounding code accordingly.

  We have since removed support for GCC versions before 4.9, so no need
  for a special arrangement here; GCC has supported the `x' constraint
  since forever anyway, or at least going back to 1991.

- Rename the `__base' local variable in `__div64_32' to `__radix' to
  avoid a conflict with a local variable in `do_div'.

- Actually enable this code for 32-bit rather than 64-bit configurations
  by qualifying it with BITS_PER_LONG being 32 instead of 64.  Include
  <asm/bitsperlong.h> for this macro rather than <linux/types.h> as we
  don't need anything else.

- Finally include <asm-generic/div64.h> last rather than first.

This has passed correctness verification with test_div64 and reduced the
module's average execution time down to 1.0668s and 0.2629s from 2.1529s
and 0.5647s respectively for an R3400 CPU @40MHz and a 5Kc CPU @160MHz.
For a reference 64-bit `do_div' code where we have the DDIVU instruction
available to do the whole calculation right away averages at 0.0660s for
the latter CPU.

Fixes: c21004cd5b ("MIPS: Rewrite <asm/div64.h> to work with gcc 4.4.0.")
Reported-by: Huacai Chen <chenhuacai@kernel.org>
Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Cc: stable@vger.kernel.org # v2.6.30+
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-19 10:08:32 +02:00
Romain Naour
91b08c5319 mips: Do not include hi and lo in clobber list for R6
commit 1d7ba0165d upstream.

From [1]
"GCC 10 (PR 91233) won't silently allow registers that are not
architecturally available to be present in the clobber list anymore,
resulting in build failure for mips*r6 targets in form of:
...
.../sysdep.h:146:2: error: the register ‘lo’ cannot be clobbered in ‘asm’ for the current target
  146 |  __asm__ volatile (      \
      |  ^~~~~~~

This is because base R6 ISA doesn't define hi and lo registers w/o DSP
extension. This patch provides the alternative clobber list for r6 targets
that won't include those registers."

Since kernel 5.4 and mips support for generic vDSO [2], the kernel fail to
build for mips r6 cpus with gcc 10 for the same reason as glibc.

[1] https://sourceware.org/git/?p=glibc.git;a=commit;h=020b2a97bb15f807c0482f0faee2184ed05bcad8
[2] '24640f233b46 ("mips: Add support for generic vDSO")'

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-07 10:51:36 +02:00
Paul Burton
584149c771 MIPS: Drop 32-bit asm string functions
commit 3c0be58492 upstream.

We have assembly implementations of strcpy(), strncpy(), strcmp() &
strncmp() which:

 - Are simple byte-at-a-time loops with no particular optimizations. As
   a comment in the code describes, they're "rather naive".

 - Offer no clear performance advantage over the generic C
   implementations - in microbenchmarks performed by Alexander Lobakin
   the asm functions sometimes win & sometimes lose, but generally not
   by large margins in either direction.

 - Don't support 64-bit kernels, where we already make use of the
   generic C implementations.

 - Tend to bloat kernel code size due to inlining.

 - Don't support CONFIG_FORTIFY_SOURCE.

 - Won't support nanoMIPS without rework.

For all of these reasons, delete the asm implementations & make use of
the generic C implementations for 32-bit kernels just like we already do
for 64-bit kernels.

Signed-off-by: Paul Burton <paul.burton@mips.com>
URL: https://lore.kernel.org/linux-mips/a2a35f1cf58d6db19eb4af9b4ae21e35@dlink.ru/
Cc: Alexander Lobakin <alobakin@dlink.ru>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Cc: linux-mips@vger.kernel.org
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-07 12:20:43 +01:00
Alexander Lobakin
de9b26b513 MIPS: properly stop .eh_frame generation
[ Upstream commit 894ef53001 ]

Commit 866b6a89c6 ("MIPS: Add DWARF unwinding to assembly") added
-fno-asynchronous-unwind-tables to KBUILD_CFLAGS to prevent compiler
from emitting .eh_frame symbols.
However, as MIPS heavily uses CFI, that's not enough. Use the
approach taken for x86 (as it also uses CFI) and explicitly put CFI
symbols into the .debug_frame section (except for VDSO).
This allows us to drop .eh_frame from DISCARDS as it's no longer
being generated.

Fixes: 866b6a89c6 ("MIPS: Add DWARF unwinding to assembly")
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-04 10:26:21 +01:00
Arnd Bergmann
1bef5f25a6 arch: pgtable: define MAX_POSSIBLE_PHYSMEM_BITS where needed
[ Upstream commit cef3970381 ]

Stefan Agner reported a bug when using zsram on 32-bit Arm machines
with RAM above the 4GB address boundary:

  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  pgd = a27bd01c
  [00000000] *pgd=236a0003, *pmd=1ffa64003
  Internal error: Oops: 207 [#1] SMP ARM
  Modules linked in: mdio_bcm_unimac(+) brcmfmac cfg80211 brcmutil raspberrypi_hwmon hci_uart crc32_arm_ce bcm2711_thermal phy_generic genet
  CPU: 0 PID: 123 Comm: mkfs.ext4 Not tainted 5.9.6 #1
  Hardware name: BCM2711
  PC is at zs_map_object+0x94/0x338
  LR is at zram_bvec_rw.constprop.0+0x330/0xa64
  pc : [<c0602b38>]    lr : [<c0bda6a0>]    psr: 60000013
  sp : e376bbe0  ip : 00000000  fp : c1e2921c
  r10: 00000002  r9 : c1dda730  r8 : 00000000
  r7 : e8ff7a00  r6 : 00000000  r5 : 02f9ffa0  r4 : e3710000
  r3 : 000fdffe  r2 : c1e0ce80  r1 : ebf979a0  r0 : 00000000
  Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
  Control: 30c5383d  Table: 235c2a80  DAC: fffffffd
  Process mkfs.ext4 (pid: 123, stack limit = 0x495a22e6)
  Stack: (0xe376bbe0 to 0xe376c000)

As it turns out, zsram needs to know the maximum memory size, which
is defined in MAX_PHYSMEM_BITS when CONFIG_SPARSEMEM is set, or in
MAX_POSSIBLE_PHYSMEM_BITS on the x86 architecture.

The same problem will be hit on all 32-bit architectures that have a
physical address space larger than 4GB and happen to not enable sparsemem
and include asm/sparsemem.h from asm/pgtable.h.

After the initial discussion, I suggested just always defining
MAX_POSSIBLE_PHYSMEM_BITS whenever CONFIG_PHYS_ADDR_T_64BIT is
set, or provoking a build error otherwise. This addresses all
configurations that can currently have this runtime bug, but
leaves all other configurations unchanged.

I looked up the possible number of bits in source code and
datasheets, here is what I found:

 - on ARC, CONFIG_ARC_HAS_PAE40 controls whether 32 or 40 bits are used
 - on ARM, CONFIG_LPAE enables 40 bit addressing, without it we never
   support more than 32 bits, even though supersections in theory allow
   up to 40 bits as well.
 - on MIPS, some MIPS32r1 or later chips support 36 bits, and MIPS32r5
   XPA supports up to 60 bits in theory, but 40 bits are more than
   anyone will ever ship
 - On PowerPC, there are three different implementations of 36 bit
   addressing, but 32-bit is used without CONFIG_PTE_64BIT
 - On RISC-V, the normal page table format can support 34 bit
   addressing. There is no highmem support on RISC-V, so anything
   above 2GB is unused, but it might be useful to eventually support
   CONFIG_ZRAM for high pages.

Fixes: 61989a80fb ("staging: zsmalloc: zsmalloc memory allocation library")
Fixes: 02390b87a9 ("mm/zsmalloc: Prepare to variable MAX_PHYSMEM_BITS")
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Tested-by: Stefan Agner <stefan@agner.ch>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/linux-mm/bdfa44bf1c570b05d6c70898e2bbb0acf234ecdf.1604762181.git.stefan@agner.ch/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-02 08:49:50 +01:00
Wei Li
5c58104841 MIPS: Add the missing 'CPU_1074K' into __get_cpu_type()
[ Upstream commit e393fbe6fa ]

Commit 442e14a2c5 ("MIPS: Add 1074K CPU support explicitly.") split
1074K from the 74K as an unique CPU type, while it missed to add the
'CPU_1074K' in __get_cpu_type(). So let's add it back.

Fixes: 442e14a2c5 ("MIPS: Add 1074K CPU support explicitly.")
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:18:20 +02:00
Will Deacon
e1818ffcca KVM: Pass MMU notifier range flags to kvm_unmap_hva_range()
commit fdfe7cbd58 upstream.

The 'flags' field of 'struct mmu_notifier_range' is used to indicate
whether invalidate_range_{start,end}() are permitted to block. In the
case of kvm_mmu_notifier_invalidate_range_start(), this field is not
forwarded on to the architecture-specific implementation of
kvm_unmap_hva_range() and therefore the backend cannot sensibly decide
whether or not to block.

Add an extra 'flags' parameter to kvm_unmap_hva_range() so that
architectures are aware as to whether or not they are permitted to block.

Cc: <stable@vger.kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20200811102725.7121-2-will@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26 10:41:08 +02:00
Serge Semin
34a45e84ed mips: MAAR: Use more precise address mask
[ Upstream commit bbb5946eb5 ]

Indeed according to the MIPS32 Privileged Resource Architecgture the MAAR
pair register address field either takes [12:31] bits for non-XPA systems
and [12:55] otherwise. In any case the current address mask is just
wrong for 64-bit and 32-bits XPA chips. So lets extend it to 59-bits
of physical address value. This shall cover the 64-bits architecture and
systems with XPA enabled, and won't cause any problem for non-XPA 32-bit
systems, since address values exceeding the architecture specific MAAR
mask will be just truncated with setting zeros in the unsupported upper
bits.

Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-22 09:31:07 +02:00
Serge Semin
a268376588 mips: Fix cpu_has_mips64r1/2 activation for MIPS32 CPUs
[ Upstream commit a2ac81c6ef ]

Commit 1aeba347b3 ("MIPS: Hardcode cpu_has_mips* where target ISA
allows") updated the cpu_has_mips* macro to be replaced with a constant
expression where it's possible. By mistake it wasn't done correctly
for cpu_has_mips64r1/cpu_has_mips64r2 macro. They are defined to
be replaced with conditional expression __isa_range_or_flag(), which
means either ISA revision being within the range or the corresponding
CPU options flag was set at the probe stage or both being true at the
same time. But the ISA level value doesn't indicate whether the ISA is
MIPS32 or MIPS64. Due to this if we select MIPS32r1 - MIPS32r5
architectures the __isa_range() macro will activate the
cpu_has_mips64rX flags, which is incorrect. In order to fix the
problem we make sure the 64bits CPU support is enabled by means of
checking the flag cpu_has_64bits aside with proper ISA range and specific
Revision flag being set.

Fixes: 1aeba347b3 ("MIPS: Hardcode cpu_has_mips* where target ISA allows")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-22 09:30:55 +02:00
Xing Li
8c8238343f KVM: MIPS: Fix VPN2_MASK definition for variable cpu_vmbits
commit 5816c76dea upstream.

If a CPU support more than 32bit vmbits (which is true for 64bit CPUs),
VPN2_MASK set to fixed 0xffffe000 will lead to a wrong EntryHi in some
functions such as _kvm_mips_host_tlb_inv().

The cpu_vmbits definition of 32bit CPU in cpu-features.h is 31, so we
still use the old definition.

Cc: Stable <stable@vger.kernel.org>
Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Signed-off-by: Xing Li <lixing@loongson.cn>
[Huacai: Improve commit messages]
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Message-Id: <1590220602-3547-3-git-send-email-chenhc@lemote.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-17 16:40:34 +02:00
Xing Li
94f4af1b73 KVM: MIPS: Define KVM_ENTRYHI_ASID to cpu_asid_mask(&boot_cpu_data)
commit fe2b73dba4 upstream.

The code in decode_config4() of arch/mips/kernel/cpu-probe.c

        asid_mask = MIPS_ENTRYHI_ASID;
        if (config4 & MIPS_CONF4_AE)
                asid_mask |= MIPS_ENTRYHI_ASIDX;
        set_cpu_asid_mask(c, asid_mask);

set asid_mask to cpuinfo->asid_mask.

So in order to support variable ASID_MASK, KVM_ENTRYHI_ASID should also
be changed to cpu_asid_mask(&boot_cpu_data).

Cc: Stable <stable@vger.kernel.org>  #4.9+
Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Signed-off-by: Xing Li <lixing@loongson.cn>
[Huacai: Change current_cpu_data to boot_cpu_data for optimization]
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Message-Id: <1590220602-3547-2-git-send-email-chenhc@lemote.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-17 16:40:34 +02:00
Vincenzo Frascino
520e3bd3de mips: Fix gettimeofday() in the vdso library
[ Upstream commit 7d2aa4bb90 ]

The libc provides a discovery mechanism for vDSO library and its
symbols. When a symbol is not exposed by the vDSOs the libc falls back
on the system calls.

With the introduction of the unified vDSO library on mips this behavior
is not honored anymore by the kernel in the case of gettimeofday().

The issue has been noticed and reported due to a dhclient failure on the
CI20 board:

root@letux:~# dhclient
../../../../lib/isc/unix/time.c:200: Operation not permitted
root@letux:~#

Restore the original behavior fixing gettimeofday() in the vDSO library.

Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Tested-by: H. Nikolaus Schaller <hns@goldelico.com> # CI20 with JZ4780
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: mips-creator-ci20-dev@googlegroups.com
Cc: letux-kernel@openphoenux.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-17 19:49:04 +01:00
Paul Burton
5b004a2384 MIPS: Avoid VDSO ABI breakage due to global register variable
commit bbcc5672b0 upstream.

Declaring __current_thread_info as a global register variable has the
effect of preventing GCC from saving & restoring its value in cases
where the ABI would typically do so.

To quote GCC documentation:

> If the register is a call-saved register, call ABI is affected: the
> register will not be restored in function epilogue sequences after the
> variable has been assigned. Therefore, functions cannot safely return
> to callers that assume standard ABI.

When our position independent VDSO is built for the n32 or n64 ABIs all
functions it exposes should be preserving the value of $gp/$28 for their
caller, but in the presence of the __current_thread_info global register
variable GCC stops doing so & simply clobbers $gp/$28 when calculating
the address of the GOT.

In cases where the VDSO returns success this problem will typically be
masked by the caller in libc returning & restoring $gp/$28 itself, but
that is by no means guaranteed. In cases where the VDSO returns an error
libc will typically contain a fallback path which will now fail
(typically with a bad memory access) if it attempts anything which
relies upon the value of $gp/$28 - eg. accessing anything via the GOT.

One fix for this would be to move the declaration of
__current_thread_info inside the current_thread_info() function,
demoting it from global register variable to local register variable &
avoiding inadvertently creating a non-standard calling ABI for the VDSO.
Unfortunately this causes issues for clang, which doesn't support local
register variables as pointed out by commit fe92da0f35 ("MIPS: Changed
current_thread_info() to an equivalent supported by both clang and GCC")
which introduced the global register variable before we had a VDSO to
worry about.

Instead, fix this by continuing to use the global register variable for
the kernel proper but declare __current_thread_info as a simple extern
variable when building the VDSO. It should never be referenced, and will
cause a link error if it is. This resolves the calling convention issue
for the VDSO without having any impact upon the build of the kernel
itself for either clang or gcc.

Signed-off-by: Paul Burton <paulburton@kernel.org>
Fixes: ebb5e78cc6 ("MIPS: Initial implementation of a VDSO")
Reported-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Brauner <christian.brauner@canonical.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: <stable@vger.kernel.org> # v4.4+
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-09 10:19:56 +01:00
Greg Kroah-Hartman
ffe485232d Revert "MIPS: futex: Emit Loongson3 sync workarounds within asm"
This reverts commit d754a529a8 which was
commit 3c1d3f0979 upstream.

This breaks the build and should be reverted.

Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: linux-kernel@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-04 19:16:21 +01:00
Greg Kroah-Hartman
03ad5d55be Revert "MIPS: futex: Restore \n after sync instructions"
This reverts commit dc9d0a75ce which is
commit fd7710cb49 upstream.

This, and the follow-on patch, breaks the mips build so it needs to be
reverted.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-04 19:16:20 +01:00
Paul Burton
dc9d0a75ce MIPS: futex: Restore \n after sync instructions
[ Upstream commit fd7710cb49 ]

Commit 3c1d3f0979 ("MIPS: futex: Emit Loongson3 sync workarounds
within asm") inadvertently removed the newlines following
__WEAK_LLSC_MB, which causes build failures for configurations in which
__WEAK_LLSC_MB expands to a sync instruction:

  {standard input}: Assembler messages:
  {standard input}:9346: Error: symbol `sync3' is already defined
  {standard input}:9380: Error: symbol `sync3' is already defined
  ...

Fix this by restoring the newlines to separate the sync instruction from
anything following it (such as the 3: label), preventing inadvertent
concatenation.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: 3c1d3f0979 ("MIPS: futex: Emit Loongson3 sync workarounds within asm")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:45:49 +01:00
Mike Rapoport
6d98463304 mips: fix build when "48 bits virtual memory" is enabled
[ Upstream commit 3ed6751bb8 ]

With CONFIG_MIPS_VA_BITS_48=y the build fails miserably:

  CC      arch/mips/kernel/asm-offsets.s
In file included from arch/mips/include/asm/pgtable.h:644,
                 from include/linux/mm.h:99,
                 from arch/mips/kernel/asm-offsets.c:15:
include/asm-generic/pgtable.h:16:2: error: #error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDED
 #error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDED
  ^~~~~
include/asm-generic/pgtable.h:390:28: error: unknown type name 'p4d_t'; did you mean 'pmd_t'?
 static inline int p4d_same(p4d_t p4d_a, p4d_t p4d_b)
                            ^~~~~
                            pmd_t

[ ... more such errors ... ]

scripts/Makefile.build:99: recipe for target 'arch/mips/kernel/asm-offsets.s' failed
make[2]: *** [arch/mips/kernel/asm-offsets.s] Error 1

This happens because when CONFIG_MIPS_VA_BITS_48 enables 4th level of the
page tables, but neither pgtable-nop4d.h nor 5level-fixup.h are included to
cope with the 5th level.

Replace #ifdef conditions around includes of the pgtable-nop{m,u}d.h with
explicit CONFIG_PGTABLE_LEVELS and add include of 5level-fixup.h for the
case when CONFIG_PGTABLE_LEVELS==4

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:45:45 +01:00
Paul Burton
d754a529a8 MIPS: futex: Emit Loongson3 sync workarounds within asm
[ Upstream commit 3c1d3f0979 ]

Generate the sync instructions required to workaround Loongson3 LL/SC
errata within inline asm blocks, which feels a little safer than doing
it from C where strictly speaking the compiler would be well within its
rights to insert a memory access between the separate asm statements we
previously had, containing sync & ll instructions respectively.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31 16:43:48 +01:00
Huacai Chen
52338415cf timekeeping/vsyscall: Update VDSO data unconditionally
The update of the VDSO data is depending on __arch_use_vsyscall() returning
True. This is a leftover from the attempt to map the features of various
architectures 1:1 into generic code.

The usage of __arch_use_vsyscall() in the actual vsyscall implementations
got dropped and replaced by the requirement for the architecture code to
return U64_MAX if the global clocksource is not usable in the VDSO.

But the __arch_use_vsyscall() check in the update code stayed which causes
the VDSO data to be stale or invalid when an architecture actually
implements that function and returns False when the current clocksource is
not usable in the VDSO.

As a consequence the VDSO implementations of clock_getres(), time(),
clock_gettime(CLOCK_.*_COARSE) operate on invalid data and return bogus
information.

Remove the __arch_use_vsyscall() check from the VDSO update function and
update the VDSO data unconditionally.

[ tglx: Massaged changelog and removed the now useless implementations in
  	asm-generic/ARM64/MIPS ]

Fixes: 44f57d788e ("timekeeping: Provide a generic update_vsyscall() implementation")
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1571887709-11447-1-git-send-email-chenhc@lemote.com
2019-11-04 23:02:53 +01:00
Jonas Gorski
e4f5cb1a9b MIPS: bmips: mark exception vectors as char arrays
The vectors span more than one byte, so mark them as arrays.

Fixes the following build error when building when using GCC 8.3:

In file included from ./include/linux/string.h:19,
                 from ./include/linux/bitmap.h:9,
                 from ./include/linux/cpumask.h:12,
                 from ./arch/mips/include/asm/processor.h:15,
                 from ./arch/mips/include/asm/thread_info.h:16,
                 from ./include/linux/thread_info.h:38,
                 from ./include/asm-generic/preempt.h:5,
                 from ./arch/mips/include/generated/asm/preempt.h:1,
                 from ./include/linux/preempt.h:81,
                 from ./include/linux/spinlock.h:51,
                 from ./include/linux/mmzone.h:8,
                 from ./include/linux/bootmem.h:8,
                 from arch/mips/bcm63xx/prom.c:10:
arch/mips/bcm63xx/prom.c: In function 'prom_init':
./arch/mips/include/asm/string.h:162:11: error: '__builtin_memcpy' forming offset [2, 32] is out of the bounds [0, 1] of object 'bmips_smp_movevec' with type 'char' [-Werror=array-bounds]
   __ret = __builtin_memcpy((dst), (src), __len); \
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/mips/bcm63xx/prom.c:97:3: note: in expansion of macro 'memcpy'
   memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20);
   ^~~~~~
In file included from arch/mips/bcm63xx/prom.c:14:
./arch/mips/include/asm/bmips.h:80:13: note: 'bmips_smp_movevec' declared here
 extern char bmips_smp_movevec;

Fixes: 18a1eef92d ("MIPS: BMIPS: Introduce bmips.h")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
2019-10-23 21:07:28 -07:00
Vincenzo Frascino
8a1bef4193 mips: vdso: Fix __arch_get_hw_counter()
On some MIPS variants (e.g. MIPS r1), vDSO clock_mode is set to
VDSO_CLOCK_NONE.

When VDSO_CLOCK_NONE is set the expected kernel behavior is to fallback
on syscalls. To do that the generic vDSO library expects UULONG_MAX as
return value of __arch_get_hw_counter().

Fix __arch_get_hw_counter() on MIPS defining a __VDSO_USE_SYSCALL case
that addressed the described scenario.

Reported-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Maxime Bizon <mbizon@freebox.fr>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: linux-mips@vger.kernel.org
2019-10-18 14:29:16 -07:00
Jiaxun Yang
38dffe1e4d MIPS: elf_hwcap: Export userspace ASEs
A Golang developer reported MIPS hwcap isn't reflecting instructions
that the processor actually supported so programs can't apply optimized
code at runtime.

Thus we export the ASEs that can be used in userspace programs.

Reported-by: Meng Zhuo <mengzhuo1203@gmail.com>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: linux-mips@vger.kernel.org
Cc: Paul Burton <paul.burton@mips.com>
Cc: <stable@vger.kernel.org> # 4.14+
Signed-off-by: Paul Burton <paul.burton@mips.com>
2019-10-10 11:57:36 -07:00
Thomas Bogendoerfer
46f1619500 MIPS: include: Mark __xchg as __always_inline
Commit ac7c3e4ff4 ("compiler: enable CONFIG_OPTIMIZE_INLINING
forcibly") allows compiler to uninline functions marked as 'inline'.
In cace of __xchg this would cause to reference function
__xchg_called_with_bad_pointer, which is an error case
for catching bugs and will not happen for correct code, if
__xchg is inlined.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
2019-10-09 12:45:31 -07:00
Thomas Bogendoerfer
88356d0990 MIPS: include: Mark __cmpxchg as __always_inline
Commit ac7c3e4ff4 ("compiler: enable CONFIG_OPTIMIZE_INLINING
forcibly") allows compiler to uninline functions marked as 'inline'.
In cace of cmpxchg this would cause to reference function
__cmpxchg_called_with_bad_pointer, which is a error case
for catching bugs and will not happen for correct code, if
__cmpxchg is inlined.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
[paul.burton@mips.com: s/__cmpxchd/__cmpxchg in subject]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
2019-10-07 09:37:01 -07:00
Paul Burton
0671c5b84e MIPS: Wire up clone3 syscall
Wire up the new clone3 syscall for MIPS, using save_static_function() to
generate a wrapper that saves registers $s0-$s7 prior to invoking the
generic sys_clone3 function just like we do for plain old clone.

Tested atop 64r6el_defconfig using o32, n32 & n64 builds of the simple
test program from:

  https://lore.kernel.org/lkml/20190716130631.tohj4ub54md25dys@brauner.io/

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Christian Brauner <christian@brauner.io>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: linux-mips@vger.kernel.org
2019-10-02 14:06:41 -07:00
Paul Burton
0228ecf612 MIPS: octeon: Include required header; fix octeon ethernet build
Commit 171a9bae68 ("staging/octeon: Allow test build on !MIPS") moved
the inclusion of a bunch of headers by various files in the Octeon
ethernet driver into a common header, but in doing so it changed the
order in which those headers are included.

Prior to the referenced commit drivers/staging/octeon/ethernet.c
included asm/octeon/cvmx-pip.h before asm/octeon/cvmx-ipd.h, which makes
use of the CVMX_PIP_SFT_RST definition pulled in by the former. After
commit 171a9bae68 ("staging/octeon: Allow test build on !MIPS") we
pull in asm/octeon/cvmx-ipd.h first & builds fail with:

  In file included from drivers/staging/octeon/octeon-ethernet.h:27,
                   from drivers/staging/octeon/ethernet.c:22:
  arch/mips/include/asm/octeon/cvmx-ipd.h: In function 'cvmx_ipd_free_ptr':
  arch/mips/include/asm/octeon/cvmx-ipd.h:330:27: error: storage size of
    'pip_sft_rst' isn't known
      union cvmx_pip_sft_rst pip_sft_rst;
                             ^~~~~~~~~~~
  arch/mips/include/asm/octeon/cvmx-ipd.h:331:36: error: 'CVMX_PIP_SFT_RST'
    undeclared (first use in this function); did you mean 'CVMX_CIU_SOFT_RST'?
      pip_sft_rst.u64 = cvmx_read_csr(CVMX_PIP_SFT_RST);
                                      ^~~~~~~~~~~~~~~~
                                      CVMX_CIU_SOFT_RST
  arch/mips/include/asm/octeon/cvmx-ipd.h:331:36: note: each undeclared
    identifier is reported only once for each function it appears in
  arch/mips/include/asm/octeon/cvmx-ipd.h:330:27: warning: unused variable
    'pip_sft_rst' [-Wunused-variable]
      union cvmx_pip_sft_rst pip_sft_rst;
                             ^~~~~~~~~~~
  make[4]: *** [scripts/Makefile.build:266: drivers/staging/octeon/ethernet.o]
    Error 1
  make[3]: *** [scripts/Makefile.build:509: drivers/staging/octeon] Error 2

Fix this by having asm/octeon/cvmx-ipd.h include the
asm/octeon/cvmx-pip-defs.h header that it is reliant upon, rather than
requiring its users to pull in that header before it.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: 171a9bae68 ("staging/octeon: Allow test build on !MIPS")
Cc: David S. Miller <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: linux-mips@vger.kernel.org
Cc: David S . Miller <davem@davemloft.net>
Cc: Matthew Wilcox <willy@infradead.org>
2019-10-02 10:08:20 -07:00