diff options
Diffstat (limited to 'arch/x86/include/asm/special_insns.h')
-rw-r--r-- | arch/x86/include/asm/special_insns.h | 57 |
1 files changed, 18 insertions, 39 deletions
diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h index 2e9fc5c400cd..ecda17efa042 100644 --- a/arch/x86/include/asm/special_insns.h +++ b/arch/x86/include/asm/special_insns.h @@ -10,30 +10,19 @@ #include <linux/irqflags.h> #include <linux/jump_label.h> -/* - * The compiler should not reorder volatile asm statements with respect to each - * other: they should execute in program order. However GCC 4.9.x and 5.x have - * a bug (which was fixed in 8.1, 7.3 and 6.5) where they might reorder - * volatile asm. The write functions are not affected since they have memory - * clobbers preventing reordering. To prevent reads from being reordered with - * respect to writes, use a dummy memory operand. - */ - -#define __FORCE_ORDER "m"(*(unsigned int *)0x1000UL) - void native_write_cr0(unsigned long val); static inline unsigned long native_read_cr0(void) { unsigned long val; - asm volatile("mov %%cr0,%0\n\t" : "=r" (val) : __FORCE_ORDER); + asm volatile("mov %%cr0,%0" : "=r" (val)); return val; } static __always_inline unsigned long native_read_cr2(void) { unsigned long val; - asm volatile("mov %%cr2,%0\n\t" : "=r" (val) : __FORCE_ORDER); + asm volatile("mov %%cr2,%0" : "=r" (val)); return val; } @@ -42,14 +31,14 @@ static __always_inline void native_write_cr2(unsigned long val) asm volatile("mov %0,%%cr2": : "r" (val) : "memory"); } -static inline unsigned long __native_read_cr3(void) +static __always_inline unsigned long __native_read_cr3(void) { unsigned long val; - asm volatile("mov %%cr3,%0\n\t" : "=r" (val) : __FORCE_ORDER); + asm volatile("mov %%cr3,%0" : "=r" (val)); return val; } -static inline void native_write_cr3(unsigned long val) +static __always_inline void native_write_cr3(unsigned long val) { asm volatile("mov %0,%%cr3": : "r" (val) : "memory"); } @@ -66,10 +55,10 @@ static inline unsigned long native_read_cr4(void) asm volatile("1: mov %%cr4, %0\n" "2:\n" _ASM_EXTABLE(1b, 2b) - : "=r" (val) : "0" (0), __FORCE_ORDER); + : "=r" (val) : "0" (0)); #else /* CR4 always exists on x86_64. */ - asm volatile("mov %%cr4,%0\n\t" : "=r" (val) : __FORCE_ORDER); + asm volatile("mov %%cr4,%0" : "=r" (val)); #endif return val; } @@ -115,7 +104,7 @@ static inline void wrpkru(u32 pkru) } #endif -static __always_inline void native_wbinvd(void) +static __always_inline void wbinvd(void) { asm volatile("wbinvd": : :"memory"); } @@ -167,12 +156,6 @@ static inline void __write_cr4(unsigned long x) { native_write_cr4(x); } - -static __always_inline void wbinvd(void) -{ - native_wbinvd(); -} - #endif /* CONFIG_PARAVIRT_XXL */ static __always_inline void clflush(volatile void *__p) @@ -182,9 +165,8 @@ static __always_inline void clflush(volatile void *__p) static inline void clflushopt(volatile void *__p) { - alternative_io(".byte 0x3e; clflush %P0", - ".byte 0x66; clflush %P0", - X86_FEATURE_CLFLUSHOPT, + alternative_io("ds clflush %0", + "clflushopt %0", X86_FEATURE_CLFLUSHOPT, "+m" (*(volatile char __force *)__p)); } @@ -192,22 +174,19 @@ static inline void clwb(volatile void *__p) { volatile struct { char x[64]; } *p = __p; - asm volatile(ALTERNATIVE_2( - ".byte 0x3e; clflush (%[pax])", - ".byte 0x66; clflush (%[pax])", /* clflushopt (%%rax) */ - X86_FEATURE_CLFLUSHOPT, - ".byte 0x66, 0x0f, 0xae, 0x30", /* clwb (%%rax) */ - X86_FEATURE_CLWB) - : [p] "+m" (*p) - : [pax] "a" (p)); + asm_inline volatile(ALTERNATIVE_2( + "ds clflush %0", + "clflushopt %0", X86_FEATURE_CLFLUSHOPT, + "clwb %0", X86_FEATURE_CLWB) + : "+m" (*p)); } #ifdef CONFIG_X86_USER_SHADOW_STACK static inline int write_user_shstk_64(u64 __user *addr, u64 val) { - asm goto("1: wrussq %[val], (%[addr])\n" + asm goto("1: wrussq %[val], %[addr]\n" _ASM_EXTABLE(1b, %l[fail]) - :: [addr] "r" (addr), [val] "r" (val) + :: [addr] "m" (*addr), [val] "r" (val) :: fail); return 0; fail: @@ -217,7 +196,7 @@ fail: #define nop() asm volatile ("nop") -static inline void serialize(void) +static __always_inline void serialize(void) { /* Instruction opcode for SERIALIZE; supported in binutils >= 2.35. */ asm volatile(".byte 0xf, 0x1, 0xe8" ::: "memory"); |