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9a0b5817 GH |
1 | #ifndef _I386_ALTERNATIVE_H |
2 | #define _I386_ALTERNATIVE_H | |
3 | ||
30343d6c | 4 | #include <asm/types.h> |
139ec7c4 | 5 | #include <linux/stddef.h> |
d167a518 GH |
6 | #include <linux/types.h> |
7 | ||
9a0b5817 GH |
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 | ||
1353ebb4 | 17 | extern void alternative_instructions(void); |
9a0b5817 GH |
18 | extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); |
19 | ||
20 | struct module; | |
8ec4d41f | 21 | #ifdef CONFIG_SMP |
9a0b5817 GH |
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); | |
8ec4d41f GH |
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) {} | |
d0175ab6 | 33 | #endif /* CONFIG_SMP */ |
9a0b5817 GH |
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 | ||
e859dc55 AK |
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 | ||
6041b57c JR |
100 | /* |
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 | ||
9a0b5817 GH |
106 | /* |
107 | * Alternative inline assembly for SMP. | |
108 | * | |
9a0b5817 GH |
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 | |
9a0b5817 GH |
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 */ | |
9a0b5817 GH |
136 | #define LOCK_PREFIX "" |
137 | #endif | |
138 | ||
98de032b | 139 | struct paravirt_patch_site; |
139ec7c4 | 140 | #ifdef CONFIG_PARAVIRT |
98de032b JF |
141 | void apply_paravirt(struct paravirt_patch_site *start, |
142 | struct paravirt_patch_site *end); | |
139ec7c4 RR |
143 | #else |
144 | static inline void | |
98de032b JF |
145 | apply_paravirt(struct paravirt_patch_site *start, |
146 | struct paravirt_patch_site *end) | |
139ec7c4 | 147 | {} |
441d40dc JF |
148 | #define __parainstructions NULL |
149 | #define __parainstructions_end NULL | |
139ec7c4 RR |
150 | #endif |
151 | ||
9a0b5817 | 152 | #endif /* _I386_ALTERNATIVE_H */ |