diff options
| author | Ben Hutchings <ben@decadent.org.uk> | 2017-10-04 03:46:14 +0100 |
|---|---|---|
| committer | James Hogan <jhogan@kernel.org> | 2017-11-13 16:49:01 +0000 |
| commit | a3f143106596d739e7fbc4b84c96b1475247d876 (patch) | |
| tree | 54b5775c98fe42831ad7f50f99d1ac22da5df65c /arch/mips | |
| parent | 4dc4704c0024751fe2b4532cf33c80376f1add70 (diff) | |
MIPS: cmpxchg64() and HAVE_VIRT_CPU_ACCOUNTING_GEN don't work for 32-bit SMP
__cmpxchg64_local_generic() is atomic only w.r.t tasks and interrupts
on the same CPU (that's what the 'local' means). We can't use it to
implement cmpxchg64() in SMP configurations.
So, for 32-bit SMP configurations:
- Don't define cmpxchg64()
- Don't enable HAVE_VIRT_CPU_ACCOUNTING_GEN, which requires it
Fixes: e2093c7b03c1 ("MIPS: Fall back to generic implementation of ...")
Fixes: bb877e96bea1 ("MIPS: Add support for full dynticks CPU time accounting")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Deng-Cheng Zhu <dengcheng.zhu@mips.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.1+
Patchwork: https://patchwork.linux-mips.org/patch/17413/
Signed-off-by: James Hogan <jhogan@kernel.org>
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/Kconfig | 2 | ||||
| -rw-r--r-- | arch/mips/include/asm/cmpxchg.h | 2 |
2 files changed, 3 insertions, 1 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index 43411118dd4f..b09b644cd57c 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -64,7 +64,7 @@ config MIPS select HAVE_PERF_EVENTS select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_SYSCALL_TRACEPOINTS - select HAVE_VIRT_CPU_ACCOUNTING_GEN + select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT || !SMP select IRQ_FORCED_THREADING select MODULES_USE_ELF_RELA if MODULES && 64BIT select MODULES_USE_ELF_REL if MODULES diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h index 903f3bf48419..ae2b4583b486 100644 --- a/arch/mips/include/asm/cmpxchg.h +++ b/arch/mips/include/asm/cmpxchg.h @@ -202,8 +202,10 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, #else #include <asm-generic/cmpxchg-local.h> #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) +#ifndef CONFIG_SMP #define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n)) #endif +#endif #undef __scbeqz |