linux-stable.git/arch/mips/include/asm, branch v5.4.166

MIPS: Fix assembly error from MIPSr2 code used within MIPS_ISA_ARCH_LEVEL

2021-11-21T12:38:50+00:00

commit a923a2676e60683aee46aa4b93c30aff240ac20d 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 aac8aa7717a2 ("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
cfd54de3b0e4 ("MIPS: Avoid move psuedo-instruction whilst using
MIPS_ISA_LEVEL") and commit 378ed6f0e3c5 ("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 
Signed-off-by: Maciej W. Rozycki 
Fixes: c7e2d71dda7a ("MIPS: Fix set_pte() for Netlogic XLR using cmpxchg64()")
Cc: stable@vger.kernel.org # v5.1+
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Greg Kroah-Hartman

mips: cm: Convert to bitfield API to fix out-of-bounds access

2021-11-17T08:48:44+00:00

[ Upstream commit 18b8f5b6fc53d097cadb94a93d8d6566ba88e389 ]

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: 3885c2b463f6a236 ("MIPS: CM: Add support for reporting CM cache errors")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Jiaxun Yang 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

Revert "MIPS: add PMD table accounting into MIPS'pmd_alloc_one"

2021-07-28T11:30:58+00:00

This reverts commit 002d8b395fa1c0679fc3c3e68873de6c1cc300a2 which is
commit ed914d48b6a1040d1039d371b56273d422c0081e upstream.

Commit b2b29d6d011944 (mm: account PMD tables like PTE tables) is
introduced between v5.9 and v5.10, so this fix (commit 002d8b395fa1)
should NOT apply to any pre-5.10 branch.

Signed-off-by: Huang Pei 
Signed-off-by: Greg Kroah-Hartman

MIPS: vdso: Invalid GIC access through VDSO

2021-07-20T14:10:53+00:00

[ Upstream commit 47ce8527fbba145a7723685bc9a27d9855e06491 ]

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: a7f4df4e21dd ("MIPS: VDSO: Add implementations of gettimeofday() and clock_gettime()")
Signed-off-by: Martin Fäcknitz 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

MIPS: set mips32r5 for virt extensions

2021-07-19T06:53:13+00:00

[ Upstream commit c994a3ec7ecc8bd2a837b2061e8a76eb8efc082b ]

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 
Signed-off-by: Nick Desaulniers 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

MIPS: add PMD table accounting into MIPS'pmd_alloc_one

2021-07-19T06:53:12+00:00

[ Upstream commit ed914d48b6a1040d1039d371b56273d422c0081e ]

This fixes Page Table accounting bug.

MIPS is the ONLY arch just defining __HAVE_ARCH_PMD_ALLOC_ONE alone.
Since commit b2b29d6d011944 (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 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

hugetlb: clear huge pte during flush function on mips platform

2021-07-19T06:53:08+00:00

[ Upstream commit 33ae8f801ad8bec48e886d368739feb2816478f2 ]

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 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

MIPS: Fix PKMAP with 32-bit MIPS huge page support

2021-07-14T14:53:36+00:00

[ Upstream commit cf02ce742f09188272bcc8b0e62d789eb671fc4c ]

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: 35476311e529 ("MIPS: Add partial 32-bit huge page support")
Signed-off-by: Wei Li 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

MIPS: Avoid handcoded DIVU in `__div64_32' altogether

2021-05-19T08:08:32+00:00

commit 25ab14cbe9d1b66fda44c71a2db7582a31b6f5cd 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 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Greg Kroah-Hartman

MIPS: Avoid DIVU in `__div64_32' is result would be zero

2021-05-19T08:08:32+00:00

commit c1d337d45ec0a802299688e17d568c4e3a585895 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 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Greg Kroah-Hartman