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| author | Borislav Petkov <bp@suse.de> | 2015-01-18 17:48:18 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2015-02-23 13:44:17 +0100 |
| commit | a930dc4543a2b213deb9fde12682716edff8a4a6 (patch) | |
| tree | 33211f604e11c55382f6ba6430d442cf931b157e | |
| parent | c70e1b475f37f07ab7181ad28458666d59aae634 (diff) | |
| download | talos-obmc-linux-a930dc4543a2b213deb9fde12682716edff8a4a6.tar.gz talos-obmc-linux-a930dc4543a2b213deb9fde12682716edff8a4a6.zip | |
x86/asm: Cleanup prefetch primitives
This is based on a patch originally by hpa.
With the current improvements to the alternatives, we can simply use %P1
as a mem8 operand constraint and rely on the toolchain to generate the
proper instruction sizes. For example, on 32-bit, where we use an empty
old instruction we get:
apply_alternatives: feat: 6*32+8, old: (c104648b, len: 4), repl: (c195566c, len: 4)
c104648b: alt_insn: 90 90 90 90
c195566c: rpl_insn: 0f 0d 4b 5c
...
apply_alternatives: feat: 6*32+8, old: (c18e09b4, len: 3), repl: (c1955948, len: 3)
c18e09b4: alt_insn: 90 90 90
c1955948: rpl_insn: 0f 0d 08
...
apply_alternatives: feat: 6*32+8, old: (c1190cf9, len: 7), repl: (c1955a79, len: 7)
c1190cf9: alt_insn: 90 90 90 90 90 90 90
c1955a79: rpl_insn: 0f 0d 0d a0 d4 85 c1
all with the proper padding done depending on the size of the
replacement instruction the compiler generates.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@linux.intel.com>
| -rw-r--r-- | arch/x86/include/asm/apic.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/processor.h | 16 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 5 |
3 files changed, 13 insertions, 10 deletions
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index efc3b22d896e..8118e94d50ab 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -91,7 +91,7 @@ static inline void native_apic_mem_write(u32 reg, u32 v) { volatile u32 *addr = (volatile u32 *)(APIC_BASE + reg); - alternative_io("movl %0, %1", "xchgl %0, %1", X86_BUG_11AP, + alternative_io("movl %0, %P1", "xchgl %0, %P1", X86_BUG_11AP, ASM_OUTPUT2("=r" (v), "=m" (*addr)), ASM_OUTPUT2("0" (v), "m" (*addr))); } diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index ec1c93588cef..7be2c9a6caba 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -761,10 +761,10 @@ extern char ignore_fpu_irq; #define ARCH_HAS_SPINLOCK_PREFETCH #ifdef CONFIG_X86_32 -# define BASE_PREFETCH ASM_NOP4 +# define BASE_PREFETCH "" # define ARCH_HAS_PREFETCH #else -# define BASE_PREFETCH "prefetcht0 (%1)" +# define BASE_PREFETCH "prefetcht0 %P1" #endif /* @@ -775,10 +775,9 @@ extern char ignore_fpu_irq; */ static inline void prefetch(const void *x) { - alternative_input(BASE_PREFETCH, - "prefetchnta (%1)", + alternative_input(BASE_PREFETCH, "prefetchnta %P1", X86_FEATURE_XMM, - "r" (x)); + "m" (*(const char *)x)); } /* @@ -788,10 +787,9 @@ static inline void prefetch(const void *x) */ static inline void prefetchw(const void *x) { - alternative_input(BASE_PREFETCH, - "prefetchw (%1)", - X86_FEATURE_3DNOW, - "r" (x)); + alternative_input(BASE_PREFETCH, "prefetchw %P1", + X86_FEATURE_3DNOWPREFETCH, + "m" (*(const char *)x)); } static inline void spin_lock_prefetch(const void *x) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index a220239cea65..dd9e50500297 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -711,6 +711,11 @@ static void init_amd(struct cpuinfo_x86 *c) set_cpu_bug(c, X86_BUG_AMD_APIC_C1E); rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy); + + /* 3DNow or LM implies PREFETCHW */ + if (!cpu_has(c, X86_FEATURE_3DNOWPREFETCH)) + if (cpu_has(c, X86_FEATURE_3DNOW) || cpu_has(c, X86_FEATURE_LM)) + set_cpu_cap(c, X86_FEATURE_3DNOWPREFETCH); } #ifdef CONFIG_X86_32 |
