linux-stable.git/arch/powerpc/include/asm, branch v4.14.331

word-at-a-time: use the same return type for has_zero regardless of endianness

2023-08-11T09:33:54+00:00

[ Upstream commit 79e8328e5acbe691bbde029a52c89d70dcbc22f3 ]

Compiling big-endian targets with Clang produces the diagnostic:

  fs/namei.c:2173:13: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical]
	} while (!(has_zero(a, &adata, &constants) | has_zero(b, &bdata, &constants)));
	          ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                               ||
  fs/namei.c:2173:13: note: cast one or both operands to int to silence this warning

It appears that when has_zero was introduced, two definitions were
produced with different signatures (in particular different return
types).

Looking at the usage in hash_name() in fs/namei.c, I suspect that
has_zero() is meant to be invoked twice per while loop iteration; using
logical-or would not update `bdata` when `a` did not have zeros.  So I
think it's preferred to always return an unsigned long rather than a
bool than update the while loop in hash_name() to use a logical-or
rather than bitwise-or.

[ Also changed powerpc version to do the same  - Linus ]

Link: https://github.com/ClangBuiltLinux/linux/issues/1832
Link: https://lore.kernel.org/lkml/20230801-bitwise-v1-1-799bec468dc4@google.com/
Fixes: 36126f8f2ed8 ("word-at-a-time: make the interfaces truly generic")
Debugged-by: Nathan Chancellor 
Signed-off-by: Nick Desaulniers 
Acked-by: Heiko Carstens 
Cc: Arnd Bergmann 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin

init: Remove check_bugs() leftovers

2023-08-08T17:48:24+00:00

commit 61235b24b9cb37c13fcad5b9596d59a1afdcec30 upstream

Everything is converted over to arch_cpu_finalize_init(). Remove the
check_bugs() leftovers including the empty stubs in asm-generic, alpha,
parisc, powerpc and xtensa.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Richard Henderson 
Link: https://lore.kernel.org/r/20230613224545.553215951@linutronix.de
Signed-off-by: Daniel Sneddon 
Signed-off-by: Greg Kroah-Hartman

powerpc: define get_cycles macro for arch-override

2022-06-25T09:46:38+00:00

commit 408835832158df0357e18e96da7f2d1ed6b80e7f upstream.

PowerPC defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().

Cc: Thomas Gleixner 
Cc: Arnd Bergmann 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Acked-by: Michael Ellerman 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

powerpc: Use bool in archrandom.h

2022-06-25T09:46:29+00:00

commit 98dcfce69729f9ce0fb14f96a39bbdba21429597 upstream.

The generic interface uses bool not int; match that.

Reviewed-by: Ard Biesheuvel 
Signed-off-by: Richard Henderson 
Signed-off-by: Mark Brown 
Link: https://lore.kernel.org/r/20200110145422.49141-9-broonie@kernel.org
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

powerpc: Remove arch_has_random, arch_has_random_seed

2022-06-25T09:46:28+00:00

commit cbac004995a0ce8453bdc555fab579e2bdb842a6 upstream.

These symbols are currently part of the generic archrandom.h
interface, but are currently unused and can be removed.

Signed-off-by: Richard Henderson 
Signed-off-by: Mark Brown 
Link: https://lore.kernel.org/r/20200110145422.49141-3-broonie@kernel.org
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

powerpc/lib: Add helper to check if offset is within conditional branch range

2021-11-26T10:40:36+00:00

upstream commit 4549c3ea3160fa8b3f37dfe2f957657bb265eda9

Add a helper to check if a given offset is within the branch range for a
powerpc conditional branch instruction, and update some sites to use the
new helper.

Signed-off-by: Naveen N. Rao 
Reviewed-by: Christophe Leroy 
Acked-by: Song Liu 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/442b69a34ced32ca346a0d9a855f3f6cfdbbbd41.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Naveen N. Rao 
Signed-off-by: Greg Kroah-Hartman

arch: pgtable: define MAX_POSSIBLE_PHYSMEM_BITS where needed

2021-11-12T13:28:22+00:00

[ Upstream commit cef397038167ac15d085914493d6c86385773709 ]

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 : []    lr : []    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: 61989a80fb3a ("staging: zsmalloc: zsmalloc memory allocation library")
Fixes: 02390b87a945 ("mm/zsmalloc: Prepare to variable MAX_PHYSMEM_BITS")
Acked-by: Thomas Bogendoerfer 
Reviewed-by: Stefan Agner 
Tested-by: Stefan Agner 
Acked-by: Mike Rapoport 
Link: https://lore.kernel.org/linux-mm/bdfa44bf1c570b05d6c70898e2bbb0acf234ecdf.1604762181.git.stefan@agner.ch/
Signed-off-by: Arnd Bergmann 
Signed-off-by: Sasha Levin 
[florian: patch arch/powerpc/include/asm/pte-common.h for 4.14.y
removed arch/riscv/include/asm/pgtable.h which does not exist]
Signed-off-by: Florian Fainelli 
Signed-off-by: Greg Kroah-Hartman

powerpc/ps3: Add dma_mask to ps3_dma_region

2021-07-20T14:17:50+00:00

[ Upstream commit 9733862e50fdba55e7f1554e4286fcc5302ff28e ]

Commit f959dcd6ddfd29235030e8026471ac1b022ad2b0 (dma-direct: Fix
potential NULL pointer dereference) added a null check on the
dma_mask pointer of the kernel's device structure.

Add a dma_mask variable to the ps3_dma_region structure and set
the device structure's dma_mask pointer to point to this new variable.

Fixes runtime errors like these:
# WARNING: Fixes tag on line 10 doesn't match correct format
# WARNING: Fixes tag on line 10 doesn't match correct format

  ps3_system_bus_match:349: dev=8.0(sb_01), drv=8.0(ps3flash): match
  WARNING: CPU: 0 PID: 1 at kernel/dma/mapping.c:151 .dma_map_page_attrs+0x34/0x1e0
  ps3flash sb_01: ps3stor_setup:193: map DMA region failed

Signed-off-by: Geoff Levand 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/562d0c9ea0100a30c3b186bcc7adb34b0bbd2cd7.1622746428.git.geoff@infradead.org
Signed-off-by: Sasha Levin

powerpc/barrier: Avoid collision with clang's __lwsync macro

2021-07-20T14:17:46+00:00

commit 015d98149b326e0f1f02e44413112ca8b4330543 upstream.

A change in clang 13 results in the __lwsync macro being defined as
__builtin_ppc_lwsync, which emits 'lwsync' or 'msync' depending on what
the target supports. This breaks the build because of -Werror in
arch/powerpc, along with thousands of warnings:

 In file included from arch/powerpc/kernel/pmc.c:12:
 In file included from include/linux/bug.h:5:
 In file included from arch/powerpc/include/asm/bug.h:109:
 In file included from include/asm-generic/bug.h:20:
 In file included from include/linux/kernel.h:12:
 In file included from include/linux/bitops.h:32:
 In file included from arch/powerpc/include/asm/bitops.h:62:
 arch/powerpc/include/asm/barrier.h:49:9: error: '__lwsync' macro redefined [-Werror,-Wmacro-redefined]
 #define __lwsync()      __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory")
        ^
 :308:9: note: previous definition is here
 #define __lwsync __builtin_ppc_lwsync
        ^
 1 error generated.

Undefine this macro so that the runtime patching introduced by
commit 2d1b2027626d ("powerpc: Fixup lwsync at runtime") continues to
work properly with clang and the build no longer breaks.

Cc: stable@vger.kernel.org
Signed-off-by: Nathan Chancellor 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Michael Ellerman 
Link: https://github.com/ClangBuiltLinux/linux/issues/1386
Link: https://github.com/llvm/llvm-project/commit/62b5df7fe2b3fda1772befeda15598fbef96a614
Link: https://lore.kernel.org/r/20210528182752.1852002-1-nathan@kernel.org
Signed-off-by: Greg Kroah-Hartman

powerpc: Force inlining of cpu_has_feature() to avoid build failure

2021-04-07T10:47:01+00:00

[ Upstream commit eed5fae00593ab9d261a0c1ffc1bdb786a87a55a ]

The code relies on constant folding of cpu_has_feature() based
on possible and always true values as defined per
CPU_FTRS_ALWAYS and CPU_FTRS_POSSIBLE.

Build failure is encountered with for instance
book3e_all_defconfig on kisskb in the AMDGPU driver which uses
cpu_has_feature(CPU_FTR_VSX_COMP) to decide whether calling
kernel_enable_vsx() or not.

The failure is due to cpu_has_feature() not being inlined with
that configuration with gcc 4.9.

In the same way as commit acdad8fb4a15 ("powerpc: Force inlining of
mmu_has_feature to fix build failure"), for inlining of
cpu_has_feature().

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/b231dfa040ce4cc37f702f5c3a595fdeabfe0462.1615378209.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin