projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 76f30759 PA |
1 | #ifndef _ASM_X86_ALTERNATIVE_ASM_H |
| 2 | #define _ASM_X86_ALTERNATIVE_ASM_H | |
| 3 | ||
| 7e02cb94 AB |
4 | #ifdef __ASSEMBLY__ |
| 5 | ||
| 99063c0b | 6 | #include <asm/asm.h> |
| 7e02cb94 AB |
7 | |
| 8 | #ifdef CONFIG_SMP | |
| 9 | .macro LOCK_PREFIX | |
| ceb7b40b | 10 | 672: lock |
| 9cebed42 | 11 | .pushsection .smp_locks,"a" |
| 5967ed87 | 12 | .balign 4 |
| ceb7b40b | 13 | .long 672b - . |
| 9cebed42 | 14 | .popsection |
| 7e02cb94 AB |
15 | .endm |
| 16 | #else | |
| 17 | .macro LOCK_PREFIX | |
| 18 | .endm | |
| 19 | #endif | |
| 20 | ||
| 5b673a48 BP |
21 | /* |
| 22 | * Issue one struct alt_instr descriptor entry (need to put it into | |
| 23 | * the section .altinstructions, see below). This entry contains | |
| 24 | * enough information for the alternatives patching code to patch an | |
| 25 | * instruction. See apply_alternatives(). | |
| 26 | */ | |
| 4332195c | 27 | .macro altinstruction_entry orig alt feature orig_len alt_len pad_len |
| 59e97e4d AL |
28 | .long \orig - . |
| 29 | .long \alt - . | |
| 9072d11d FY |
30 | .word \feature |
| 31 | .byte \orig_len | |
| 32 | .byte \alt_len | |
| 4332195c BP |
33 | .byte \pad_len |
| 34 | .endm | |
| 35 | ||
| 5b673a48 BP |
36 | /* |
| 37 | * Define an alternative between two instructions. If @feature is | |
| 38 | * present, early code in apply_alternatives() replaces @oldinstr with | |
| 39 | * @newinstr. ".skip" directive takes care of proper instruction padding | |
| 40 | * in case @newinstr is longer than @oldinstr. | |
| 41 | */ | |
| 4332195c BP |
42 | .macro ALTERNATIVE oldinstr, newinstr, feature |
| 43 | 140: | |
| 44 | \oldinstr | |
| 45 | 141: | |
| 46 | .skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90 | |
| 47 | 142: | |
| 48 | ||
| 49 | .pushsection .altinstructions,"a" | |
| 50 | altinstruction_entry 140b,143f,\feature,142b-140b,144f-143f,142b-141b | |
| 51 | .popsection | |
| 52 | ||
| 53 | .pushsection .altinstr_replacement,"ax" | |
| 54 | 143: | |
| 55 | \newinstr | |
| 56 | 144: | |
| 57 | .popsection | |
| 58 | .endm | |
| 59 | ||
| dbe4058a BP |
60 | #define old_len 141b-140b |
| 61 | #define new_len1 144f-143f | |
| 62 | #define new_len2 145f-144f | |
| 63 | ||
| 64 | /* | |
| 65 | * max without conditionals. Idea adapted from: | |
| 66 | * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax | |
| 67 | */ | |
| 68 | #define alt_max_short(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b))))) | |
| 69 | ||
| 5b673a48 BP |
70 | |
| 71 | /* | |
| 72 | * Same as ALTERNATIVE macro above but for two alternatives. If CPU | |
| 73 | * has @feature1, it replaces @oldinstr with @newinstr1. If CPU has | |
| 74 | * @feature2, it replaces @oldinstr with @feature2. | |
| 75 | */ | |
| 4332195c BP |
76 | .macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2 |
| 77 | 140: | |
| 78 | \oldinstr | |
| 79 | 141: | |
| dbe4058a BP |
80 | .skip -((alt_max_short(new_len1, new_len2) - (old_len)) > 0) * \ |
| 81 | (alt_max_short(new_len1, new_len2) - (old_len)),0x90 | |
| 4332195c BP |
82 | 142: |
| 83 | ||
| 84 | .pushsection .altinstructions,"a" | |
| 85 | altinstruction_entry 140b,143f,\feature1,142b-140b,144f-143f,142b-141b | |
| 86 | altinstruction_entry 140b,144f,\feature2,142b-140b,145f-144f,142b-141b | |
| 87 | .popsection | |
| 88 | ||
| 89 | .pushsection .altinstr_replacement,"ax" | |
| 90 | 143: | |
| 91 | \newinstr1 | |
| 92 | 144: | |
| 93 | \newinstr2 | |
| 94 | 145: | |
| 95 | .popsection | |
| 9072d11d FY |
96 | .endm |
| 97 | ||
| 7e02cb94 | 98 | #endif /* __ASSEMBLY__ */ |
| 76f30759 PA |
99 | |
| 100 | #endif /* _ASM_X86_ALTERNATIVE_ASM_H */ |