diff options
Diffstat (limited to 'arch/x86/include/asm/alternative.h')
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 59 |
1 files changed, 23 insertions, 36 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index f6aa18eadf7..1a37bcdc860 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h | |||
| @@ -3,6 +3,7 @@ | |||
| 3 | 3 | ||
| 4 | #include <linux/types.h> | 4 | #include <linux/types.h> |
| 5 | #include <linux/stddef.h> | 5 | #include <linux/stddef.h> |
| 6 | #include <linux/stringify.h> | ||
| 6 | #include <asm/asm.h> | 7 | #include <asm/asm.h> |
| 7 | 8 | ||
| 8 | /* | 9 | /* |
| @@ -74,6 +75,22 @@ static inline void alternatives_smp_switch(int smp) {} | |||
| 74 | 75 | ||
| 75 | const unsigned char *const *find_nop_table(void); | 76 | const unsigned char *const *find_nop_table(void); |
| 76 | 77 | ||
| 78 | /* alternative assembly primitive: */ | ||
| 79 | #define ALTERNATIVE(oldinstr, newinstr, feature) \ | ||
| 80 | \ | ||
| 81 | "661:\n\t" oldinstr "\n662:\n" \ | ||
| 82 | ".section .altinstructions,\"a\"\n" \ | ||
| 83 | _ASM_ALIGN "\n" \ | ||
| 84 | _ASM_PTR "661b\n" /* label */ \ | ||
| 85 | _ASM_PTR "663f\n" /* new instruction */ \ | ||
| 86 | " .byte " __stringify(feature) "\n" /* feature bit */ \ | ||
| 87 | " .byte 662b-661b\n" /* sourcelen */ \ | ||
| 88 | " .byte 664f-663f\n" /* replacementlen */ \ | ||
| 89 | ".previous\n" \ | ||
| 90 | ".section .altinstr_replacement, \"ax\"\n" \ | ||
| 91 | "663:\n\t" newinstr "\n664:\n" /* replacement */ \ | ||
| 92 | ".previous" | ||
| 93 | |||
| 77 | /* | 94 | /* |
| 78 | * Alternative instructions for different CPU types or capabilities. | 95 | * Alternative instructions for different CPU types or capabilities. |
| 79 | * | 96 | * |
| @@ -87,18 +104,7 @@ const unsigned char *const *find_nop_table(void); | |||
| 87 | * without volatile and memory clobber. | 104 | * without volatile and memory clobber. |
| 88 | */ | 105 | */ |
| 89 | #define alternative(oldinstr, newinstr, feature) \ | 106 | #define alternative(oldinstr, newinstr, feature) \ |
| 90 | asm volatile ("661:\n\t" oldinstr "\n662:\n" \ | 107 | asm volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory") |
| 91 | ".section .altinstructions,\"a\"\n" \ | ||
| 92 | _ASM_ALIGN "\n" \ | ||
| 93 | _ASM_PTR "661b\n" /* label */ \ | ||
| 94 | _ASM_PTR "663f\n" /* new instruction */ \ | ||
| 95 | " .byte %c0\n" /* feature bit */ \ | ||
| 96 | " .byte 662b-661b\n" /* sourcelen */ \ | ||
| 97 | " .byte 664f-663f\n" /* replacementlen */ \ | ||
| 98 | ".previous\n" \ | ||
| 99 | ".section .altinstr_replacement,\"ax\"\n" \ | ||
| 100 | "663:\n\t" newinstr "\n664:\n" /* replacement */ \ | ||
| 101 | ".previous" :: "i" (feature) : "memory") | ||
| 102 | 108 | ||
| 103 | /* | 109 | /* |
| 104 | * Alternative inline assembly with input. | 110 | * Alternative inline assembly with input. |
| @@ -109,35 +115,16 @@ const unsigned char *const *find_nop_table(void); | |||
| 109 | * Best is to use constraints that are fixed size (like (%1) ... "r") | 115 | * Best is to use constraints that are fixed size (like (%1) ... "r") |
| 110 | * If you use variable sized constraints like "m" or "g" in the | 116 | * If you use variable sized constraints like "m" or "g" in the |
| 111 | * replacement make sure to pad to the worst case length. | 117 | * replacement make sure to pad to the worst case length. |
| 118 | * Leaving an unused argument 0 to keep API compatibility. | ||
| 112 | */ | 119 | */ |
| 113 | #define alternative_input(oldinstr, newinstr, feature, input...) \ | 120 | #define alternative_input(oldinstr, newinstr, feature, input...) \ |
| 114 | asm volatile ("661:\n\t" oldinstr "\n662:\n" \ | 121 | asm volatile (ALTERNATIVE(oldinstr, newinstr, feature) \ |
| 115 | ".section .altinstructions,\"a\"\n" \ | 122 | : : "i" (0), ## input) |
| 116 | _ASM_ALIGN "\n" \ | ||
| 117 | _ASM_PTR "661b\n" /* label */ \ | ||
| 118 | _ASM_PTR "663f\n" /* new instruction */ \ | ||
| 119 | " .byte %c0\n" /* feature bit */ \ | ||
| 120 | " .byte 662b-661b\n" /* sourcelen */ \ | ||
| 121 | " .byte 664f-663f\n" /* replacementlen */ \ | ||
| 122 | ".previous\n" \ | ||
| 123 | ".section .altinstr_replacement,\"ax\"\n" \ | ||
| 124 | "663:\n\t" newinstr "\n664:\n" /* replacement */ \ | ||
| 125 | ".previous" :: "i" (feature), ##input) | ||
| 126 | 123 | ||
| 127 | /* Like alternative_input, but with a single output argument */ | 124 | /* Like alternative_input, but with a single output argument */ |
| 128 | #define alternative_io(oldinstr, newinstr, feature, output, input...) \ | 125 | #define alternative_io(oldinstr, newinstr, feature, output, input...) \ |
| 129 | asm volatile ("661:\n\t" oldinstr "\n662:\n" \ | 126 | asm volatile (ALTERNATIVE(oldinstr, newinstr, feature) \ |
| 130 | ".section .altinstructions,\"a\"\n" \ | 127 | : output : "i" (0), ## input) |
| 131 | _ASM_ALIGN "\n" \ | ||
| 132 | _ASM_PTR "661b\n" /* label */ \ | ||
| 133 | _ASM_PTR "663f\n" /* new instruction */ \ | ||
| 134 | " .byte %c[feat]\n" /* feature bit */ \ | ||
| 135 | " .byte 662b-661b\n" /* sourcelen */ \ | ||
| 136 | " .byte 664f-663f\n" /* replacementlen */ \ | ||
| 137 | ".previous\n" \ | ||
| 138 | ".section .altinstr_replacement,\"ax\"\n" \ | ||
| 139 | "663:\n\t" newinstr "\n664:\n" /* replacement */ \ | ||
| 140 | ".previous" : output : [feat] "i" (feature), ##input) | ||
| 141 | 128 | ||
| 142 | /* | 129 | /* |
| 143 | * use this macro(s) if you need more than one output parameter | 130 | * use this macro(s) if you need more than one output parameter |