linux-stable.git/arch/mips/include, branch linux-5.17.y

MIPS: IP30: Remove incorrect `cpu_has_fpu' override

2022-06-09T08:26:31+00:00

commit f44b3e74c33fe04defeff24ebcae98c3bcc5b285 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 
Reported-by: Stephen Zhang 
Fixes: 7505576d1c1a ("MIPS: add support for SGI Octane (IP30)")
Cc: stable@vger.kernel.org # v5.5+
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Greg Kroah-Hartman

MIPS: IP27: Remove incorrect `cpu_has_fpu' override

2022-06-09T08:26:31+00:00

commit 424c3781dd1cb401857585331eaaa425a13f2429 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 
Reported-by: Stephen Zhang 
Fixes: 0ebb2f4159af ("MIPS: IP27: Update/restructure CPU overrides")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Greg Kroah-Hartman

MIPS: RALINK: Define pci_remap_iospace under CONFIG_PCI_DRIVERS_GENERIC

2022-06-09T08:26:14+00:00

[ Upstream commit 7e4fd16b38923028b01d3dbadf4ca973d885c53e ]

kernel test robot reports a build error used with clang compiler and
mips-randconfig [1]:

    ld.lld: error: undefined symbol: pci_remap_iospace

we can see the following configs in the mips-randconfig file:

    CONFIG_RALINK=y
    CONFIG_SOC_MT7620=y
    CONFIG_PCI_DRIVERS_LEGACY=y
    CONFIG_PCI=y

CONFIG_RALINK is set, so pci_remap_iospace is defined in the related
arch/mips/include/asm/mach-ralink/spaces.h header file:

    #define pci_remap_iospace pci_remap_iospace

CONFIG_PCI is set, so pci_remap_iospace() in drivers/pci/pci.c is not
built due to pci_remap_iospace is defined under CONFIG_RALINK.

    #ifndef pci_remap_iospace
    int pci_remap_iospace(const struct resource *res, ...)

    $ objdump -d drivers/pci/pci.o | grep pci_remap_iospace
    00004cc8 :
        4d18:	10400008 	beqz	v0,4d3c 
        4d2c:	1040000c 	beqz	v0,4d60 
        4d70:	1000fff3 	b	4d40 

In addition, CONFIG_PCI_DRIVERS_GENERIC is not set, so pci_remap_iospace()
in arch/mips/pci/pci-generic.c is not built too.

    #ifdef pci_remap_iospace
    int pci_remap_iospace(const struct resource *res, ...)

For the above reasons, undefined reference pci_remap_iospace() looks like
reasonable.

Here are simple steps to reproduce used with gcc and defconfig:

    cd mips.git
    make vocore2_defconfig # set RALINK, SOC_MT7620, PCI_DRIVERS_LEGACY
    make menuconfig        # set PCI
    make

there exists the following build error:

      LD      vmlinux.o
      MODPOST vmlinux.symvers
      MODINFO modules.builtin.modinfo
      GEN     modules.builtin
      LD      .tmp_vmlinux.kallsyms1
    drivers/pci/pci.o: In function `devm_pci_remap_iospace':
    pci.c:(.text+0x4d24): undefined reference to `pci_remap_iospace'
    Makefile:1158: recipe for target 'vmlinux' failed
    make: *** [vmlinux] Error 1

Define pci_remap_iospace under CONFIG_PCI_DRIVERS_GENERIC can fix the build
error, with this patch, no build error remains. This patch is similar with
commit e538e8649892 ("MIPS: asm: pci: define arch-specific
'pci_remap_iospace()' dependent on 'CONFIG_PCI_DRIVERS_GENERIC'").

[1] https://lore.kernel.org/lkml/202205251247.nQ5cxSV6-lkp@intel.com/

Fixes: 09d97da660ff ("MIPS: Only define pci_remap_iospace() for Ralink")
Reported-by: kernel test robot 
Signed-off-by: Tiezhu Yang 
Acked-by: Sergio Paracuellos 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

mips: use fallback for random_get_entropy() instead of just c0 random

2022-05-30T07:27:14+00:00

commit 1c99c6a7c3c599a68321b01b9ec243215ede5a68 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 
Cc: Arnd Bergmann 
Tested-by: Maciej W. Rozycki 
Acked-by: Thomas Bogendoerfer 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

MIPS: Fix CP0 counter erratum detection for R4k CPUs

2022-05-12T10:32:15+00:00

commit f0a6c68f69981214cb7858738dd2bc81475111f7 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 ce202cbb9e0b ("[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 
Fixes: ce202cbb9e0b ("[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 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Greg Kroah-Hartman

MIPS: fix fortify panic when copying asm exception handlers

2022-04-13T17:27:20+00:00

[ Upstream commit d17b66417308996e7e64b270a3c7f3c1fbd4cfc8 ]

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

MIPS: pgalloc: fix memory leak caused by pgd_free()

2022-04-08T11:58:17+00:00

[ Upstream commit 2bc5bab9a763d520937e4f3fe8df51c6a1eceb97 ]

pgd page is freed by generic implementation pgd_free() since commit
f9cb654cb550 ("asm-generic: pgalloc: provide generic pgd_free()"),
however, there are scenarios that the system uses more than one page as
the pgd table, in such cases the generic implementation pgd_free() won't
be applicable anymore. For example, when PAGE_SIZE_4KB is enabled and
MIPS_VA_BITS_48 is not enabled in a 64bit system, the macro "PGD_ORDER"
will be set as "1", which will cause allocating two pages as the pgd
table. Well, at the same time, the generic implementation pgd_free()
just free one pgd page, which will result in the memory leak.

The memory leak can be easily detected by executing shell command:
"while true; do ls > /dev/null; grep MemFree /proc/meminfo; done"

Fixes: f9cb654cb550 ("asm-generic: pgalloc: provide generic pgd_free()")
Signed-off-by: Yaliang Wang 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

DEC: Limit PMAX memory probing to R3k systems

2022-04-08T11:57:28+00:00

commit 244eae91a94c6dab82b3232967d10eeb9dfa21c6 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 
Reported-by: Sudip Mukherjee 
Signed-off-by: Maciej W. Rozycki 
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org # v2.6.12+
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Greg Kroah-Hartman

MIPS: Fix build error due to PTR used in more places

2022-01-27T08:04:19+00:00

Use PTR_WD instead of PTR to avoid clashes with other parts.

Signed-off-by: Thomas Bogendoerfer

Merge tag 'bitmap-5.17-rc1' of git://github.com/norov/linux

2022-01-23T04:20:44+00:00

Pull bitmap updates from Yury Norov:

 - introduce for_each_set_bitrange()

 - use find_first_*_bit() instead of find_next_*_bit() where possible

 - unify for_each_bit() macros

* tag 'bitmap-5.17-rc1' of git://github.com/norov/linux:
  vsprintf: rework bitmap_list_string
  lib: bitmap: add performance test for bitmap_print_to_pagebuf
  bitmap: unify find_bit operations
  mm/percpu: micro-optimize pcpu_is_populated()
  Replace for_each_*_bit_from() with for_each_*_bit() where appropriate
  find: micro-optimize for_each_{set,clear}_bit()
  include/linux: move for_each_bit() macros from bitops.h to find.h
  cpumask: replace cpumask_next_* with cpumask_first_* where appropriate
  tools: sync tools/bitmap with mother linux
  all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate
  cpumask: use find_first_and_bit()
  lib: add find_first_and_bit()
  arch: remove GENERIC_FIND_FIRST_BIT entirely
  include: move find.h from asm_generic to linux
  bitops: move find_bit_*_le functions from le.h to find.h
  bitops: protect find_first_{,zero}_bit properly