Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 1 | #ifndef _I386_ALTERNATIVE_H |
| 2 | #define _I386_ALTERNATIVE_H |
| 3 | |
Kirill Smelkov | 30343d6 | 2006-06-23 02:04:33 -0700 | [diff] [blame] | 4 | #include <asm/types.h> |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 5 | #include <linux/stddef.h> |
Gerd Hoffmann | d167a51 | 2006-06-26 13:56:16 +0200 | [diff] [blame] | 6 | #include <linux/types.h> |
| 7 | |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 8 | struct alt_instr { |
| 9 | u8 *instr; /* original instruction */ |
| 10 | u8 *replacement; |
| 11 | u8 cpuid; /* cpuid bit set for replacement */ |
| 12 | u8 instrlen; /* length of original instruction */ |
| 13 | u8 replacementlen; /* length of new instruction, <= instrlen */ |
| 14 | u8 pad; |
| 15 | }; |
| 16 | |
Jeremy Fitzhardinge | 1353ebb | 2007-05-02 19:27:12 +0200 | [diff] [blame] | 17 | extern void alternative_instructions(void); |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 18 | extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); |
| 19 | |
| 20 | struct module; |
Gerd Hoffmann | 8ec4d41 | 2006-07-01 04:36:18 -0700 | [diff] [blame] | 21 | #ifdef CONFIG_SMP |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 22 | extern void alternatives_smp_module_add(struct module *mod, char *name, |
| 23 | void *locks, void *locks_end, |
| 24 | void *text, void *text_end); |
| 25 | extern void alternatives_smp_module_del(struct module *mod); |
| 26 | extern void alternatives_smp_switch(int smp); |
Gerd Hoffmann | 8ec4d41 | 2006-07-01 04:36:18 -0700 | [diff] [blame] | 27 | #else |
| 28 | static inline void alternatives_smp_module_add(struct module *mod, char *name, |
| 29 | void *locks, void *locks_end, |
| 30 | void *text, void *text_end) {} |
| 31 | static inline void alternatives_smp_module_del(struct module *mod) {} |
| 32 | static inline void alternatives_smp_switch(int smp) {} |
Jeremy Fitzhardinge | d0175ab | 2007-05-02 19:27:13 +0200 | [diff] [blame] | 33 | #endif /* CONFIG_SMP */ |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 34 | |
| 35 | /* |
| 36 | * Alternative instructions for different CPU types or capabilities. |
| 37 | * |
| 38 | * This allows to use optimized instructions even on generic binary |
| 39 | * kernels. |
| 40 | * |
| 41 | * length of oldinstr must be longer or equal the length of newinstr |
| 42 | * It can be padded with nops as needed. |
| 43 | * |
| 44 | * For non barrier like inlines please define new variants |
| 45 | * without volatile and memory clobber. |
| 46 | */ |
| 47 | #define alternative(oldinstr, newinstr, feature) \ |
| 48 | asm volatile ("661:\n\t" oldinstr "\n662:\n" \ |
| 49 | ".section .altinstructions,\"a\"\n" \ |
| 50 | " .align 4\n" \ |
| 51 | " .long 661b\n" /* label */ \ |
| 52 | " .long 663f\n" /* new instruction */ \ |
| 53 | " .byte %c0\n" /* feature bit */ \ |
| 54 | " .byte 662b-661b\n" /* sourcelen */ \ |
| 55 | " .byte 664f-663f\n" /* replacementlen */ \ |
| 56 | ".previous\n" \ |
| 57 | ".section .altinstr_replacement,\"ax\"\n" \ |
| 58 | "663:\n\t" newinstr "\n664:\n" /* replacement */\ |
| 59 | ".previous" :: "i" (feature) : "memory") |
| 60 | |
| 61 | /* |
| 62 | * Alternative inline assembly with input. |
| 63 | * |
| 64 | * Pecularities: |
| 65 | * No memory clobber here. |
| 66 | * Argument numbers start with 1. |
| 67 | * Best is to use constraints that are fixed size (like (%1) ... "r") |
| 68 | * If you use variable sized constraints like "m" or "g" in the |
| 69 | * replacement maake sure to pad to the worst case length. |
| 70 | */ |
| 71 | #define alternative_input(oldinstr, newinstr, feature, input...) \ |
| 72 | asm volatile ("661:\n\t" oldinstr "\n662:\n" \ |
| 73 | ".section .altinstructions,\"a\"\n" \ |
| 74 | " .align 4\n" \ |
| 75 | " .long 661b\n" /* label */ \ |
| 76 | " .long 663f\n" /* new instruction */ \ |
| 77 | " .byte %c0\n" /* feature bit */ \ |
| 78 | " .byte 662b-661b\n" /* sourcelen */ \ |
| 79 | " .byte 664f-663f\n" /* replacementlen */ \ |
| 80 | ".previous\n" \ |
| 81 | ".section .altinstr_replacement,\"ax\"\n" \ |
| 82 | "663:\n\t" newinstr "\n664:\n" /* replacement */\ |
| 83 | ".previous" :: "i" (feature), ##input) |
| 84 | |
Andi Kleen | e859dc55 | 2007-05-02 19:27:20 +0200 | [diff] [blame] | 85 | /* Like alternative_input, but with a single output argument */ |
| 86 | #define alternative_io(oldinstr, newinstr, feature, output, input...) \ |
| 87 | asm volatile ("661:\n\t" oldinstr "\n662:\n" \ |
| 88 | ".section .altinstructions,\"a\"\n" \ |
| 89 | " .align 4\n" \ |
| 90 | " .long 661b\n" /* label */ \ |
| 91 | " .long 663f\n" /* new instruction */ \ |
| 92 | " .byte %c[feat]\n" /* feature bit */ \ |
| 93 | " .byte 662b-661b\n" /* sourcelen */ \ |
| 94 | " .byte 664f-663f\n" /* replacementlen */ \ |
| 95 | ".previous\n" \ |
| 96 | ".section .altinstr_replacement,\"ax\"\n" \ |
| 97 | "663:\n\t" newinstr "\n664:\n" /* replacement */ \ |
| 98 | ".previous" : output : [feat] "i" (feature), ##input) |
| 99 | |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 100 | /* |
Joerg Roedel | 6041b57 | 2007-05-10 22:22:14 -0700 | [diff] [blame] | 101 | * use this macro(s) if you need more than one output parameter |
| 102 | * in alternative_io |
| 103 | */ |
| 104 | #define ASM_OUTPUT2(a, b) a, b |
| 105 | |
| 106 | /* |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 107 | * Alternative inline assembly for SMP. |
| 108 | * |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 109 | * The LOCK_PREFIX macro defined here replaces the LOCK and |
| 110 | * LOCK_PREFIX macros used everywhere in the source tree. |
| 111 | * |
| 112 | * SMP alternatives use the same data structures as the other |
| 113 | * alternatives and the X86_FEATURE_UP flag to indicate the case of a |
| 114 | * UP system running a SMP kernel. The existing apply_alternatives() |
| 115 | * works fine for patching a SMP kernel for UP. |
| 116 | * |
| 117 | * The SMP alternative tables can be kept after boot and contain both |
| 118 | * UP and SMP versions of the instructions to allow switching back to |
| 119 | * SMP at runtime, when hotplugging in a new CPU, which is especially |
| 120 | * useful in virtualized environments. |
| 121 | * |
| 122 | * The very common lock prefix is handled as special case in a |
| 123 | * separate table which is a pure address list without replacement ptr |
| 124 | * and size information. That keeps the table sizes small. |
| 125 | */ |
| 126 | |
| 127 | #ifdef CONFIG_SMP |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 128 | #define LOCK_PREFIX \ |
| 129 | ".section .smp_locks,\"a\"\n" \ |
| 130 | " .align 4\n" \ |
| 131 | " .long 661f\n" /* address */ \ |
| 132 | ".previous\n" \ |
| 133 | "661:\n\tlock; " |
| 134 | |
| 135 | #else /* ! CONFIG_SMP */ |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 136 | #define LOCK_PREFIX "" |
| 137 | #endif |
| 138 | |
Jeremy Fitzhardinge | 98de032 | 2007-05-02 19:27:14 +0200 | [diff] [blame] | 139 | struct paravirt_patch_site; |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 140 | #ifdef CONFIG_PARAVIRT |
Jeremy Fitzhardinge | 98de032 | 2007-05-02 19:27:14 +0200 | [diff] [blame] | 141 | void apply_paravirt(struct paravirt_patch_site *start, |
| 142 | struct paravirt_patch_site *end); |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 143 | #else |
| 144 | static inline void |
Jeremy Fitzhardinge | 98de032 | 2007-05-02 19:27:14 +0200 | [diff] [blame] | 145 | apply_paravirt(struct paravirt_patch_site *start, |
| 146 | struct paravirt_patch_site *end) |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 147 | {} |
Jeremy Fitzhardinge | 441d40d | 2007-05-02 19:27:16 +0200 | [diff] [blame] | 148 | #define __parainstructions NULL |
| 149 | #define __parainstructions_end NULL |
Rusty Russell | 139ec7c | 2006-12-07 02:14:08 +0100 | [diff] [blame] | 150 | #endif |
| 151 | |
Gerd Hoffmann | 9a0b581 | 2006-03-23 02:59:32 -0800 | [diff] [blame] | 152 | #endif /* _I386_ALTERNATIVE_H */ |