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| author | Paul Burton <paul.burton@mips.com> | 2019-10-02 00:53:37 +0300 |
|---|---|---|
| committer | Paul Burton <paul.burton@mips.com> | 2019-10-07 19:43:00 +0300 |
| commit | 6a57d2d1e7c3ac7f47d8c51bddd9082fe2fb485b (patch) | |
| tree | 789103613e6583abba4109f4e01a6c9ac3724358 /arch/mips/include | |
| parent | 9026737703aeee35702a0f990811e9202469c7b4 (diff) | |
| download | linux-6a57d2d1e7c3ac7f47d8c51bddd9082fe2fb485b.tar.xz | |
MIPS: cmpxchg: Emit Loongson3 sync workarounds within asm
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
Diffstat (limited to 'arch/mips/include')
| -rw-r--r-- | arch/mips/include/asm/cmpxchg.h | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h index 5d3f0e3513b4..fc121d20a980 100644 --- a/arch/mips/include/asm/cmpxchg.h +++ b/arch/mips/include/asm/cmpxchg.h @@ -12,6 +12,7 @@ #include <linux/irqflags.h> #include <asm/compiler.h> #include <asm/llsc.h> +#include <asm/sync.h> #include <asm/war.h> /* @@ -36,12 +37,12 @@ extern unsigned long __xchg_called_with_bad_pointer(void) __typeof(*(m)) __ret; \ \ if (kernel_uses_llsc) { \ - loongson_llsc_mb(); \ __asm__ __volatile__( \ " .set push \n" \ " .set noat \n" \ " .set push \n" \ " .set " MIPS_ISA_ARCH_LEVEL " \n" \ + " " __SYNC(full, loongson3_war) " \n" \ "1: " ld " %0, %2 # __xchg_asm \n" \ " .set pop \n" \ " move $1, %z3 \n" \ @@ -108,12 +109,12 @@ static inline unsigned long __xchg(volatile void *ptr, unsigned long x, __typeof(*(m)) __ret; \ \ if (kernel_uses_llsc) { \ - loongson_llsc_mb(); \ __asm__ __volatile__( \ " .set push \n" \ " .set noat \n" \ " .set push \n" \ " .set "MIPS_ISA_ARCH_LEVEL" \n" \ + " " __SYNC(full, loongson3_war) " \n" \ "1: " ld " %0, %2 # __cmpxchg_asm \n" \ " bne %0, %z3, 2f \n" \ " .set pop \n" \ @@ -122,11 +123,10 @@ static inline unsigned long __xchg(volatile void *ptr, unsigned long x, " " st " $1, %1 \n" \ "\t" __SC_BEQZ "$1, 1b \n" \ " .set pop \n" \ - "2: \n" \ + "2: " __SYNC(full, loongson3_war) " \n" \ : "=&r" (__ret), "=" GCC_OFF_SMALL_ASM() (*m) \ : GCC_OFF_SMALL_ASM() (*m), "Jr" (old), "Jr" (new) \ : __LLSC_CLOBBER); \ - loongson_llsc_mb(); \ } else { \ unsigned long __flags; \ \ @@ -222,11 +222,11 @@ static inline unsigned long __cmpxchg64(volatile void *ptr, */ local_irq_save(flags); - loongson_llsc_mb(); asm volatile( " .set push \n" " .set " MIPS_ISA_ARCH_LEVEL " \n" /* Load 64 bits from ptr */ + " " __SYNC(full, loongson3_war) " \n" "1: lld %L0, %3 # __cmpxchg64 \n" /* * Split the 64 bit value we loaded into the 2 registers that hold the @@ -260,7 +260,7 @@ static inline unsigned long __cmpxchg64(volatile void *ptr, /* If we failed, loop! */ "\t" __SC_BEQZ "%L1, 1b \n" " .set pop \n" - "2: \n" + "2: " __SYNC(full, loongson3_war) " \n" : "=&r"(ret), "=&r"(tmp), "=" GCC_OFF_SMALL_ASM() (*(unsigned long long *)ptr) @@ -268,7 +268,6 @@ static inline unsigned long __cmpxchg64(volatile void *ptr, "r" (old), "r" (new) : "memory"); - loongson_llsc_mb(); local_irq_restore(flags); return ret; |