i386/x86_64: move headers to include/asm-x86
[linux-3.10.git] / include / asm-x86 / alternative_64.h
1 #ifndef _X86_64_ALTERNATIVE_H
2 #define _X86_64_ALTERNATIVE_H
3
4 #ifdef __KERNEL__
5
6 #include <linux/types.h>
7 #include <linux/stddef.h>
8
9 /*
10  * Alternative inline assembly for SMP.
11  *
12  * The LOCK_PREFIX macro defined here replaces the LOCK and
13  * LOCK_PREFIX macros used everywhere in the source tree.
14  *
15  * SMP alternatives use the same data structures as the other
16  * alternatives and the X86_FEATURE_UP flag to indicate the case of a
17  * UP system running a SMP kernel.  The existing apply_alternatives()
18  * works fine for patching a SMP kernel for UP.
19  *
20  * The SMP alternative tables can be kept after boot and contain both
21  * UP and SMP versions of the instructions to allow switching back to
22  * SMP at runtime, when hotplugging in a new CPU, which is especially
23  * useful in virtualized environments.
24  *
25  * The very common lock prefix is handled as special case in a
26  * separate table which is a pure address list without replacement ptr
27  * and size information.  That keeps the table sizes small.
28  */
29
30 #ifdef CONFIG_SMP
31 #define LOCK_PREFIX \
32                 ".section .smp_locks,\"a\"\n"   \
33                 "  .align 8\n"                  \
34                 "  .quad 661f\n" /* address */  \
35                 ".previous\n"                   \
36                 "661:\n\tlock; "
37
38 #else /* ! CONFIG_SMP */
39 #define LOCK_PREFIX ""
40 #endif
41
42 /* This must be included *after* the definition of LOCK_PREFIX */
43 #include <asm/cpufeature.h>
44
45 struct alt_instr {
46         u8 *instr;              /* original instruction */
47         u8 *replacement;
48         u8  cpuid;              /* cpuid bit set for replacement */
49         u8  instrlen;           /* length of original instruction */
50         u8  replacementlen;     /* length of new instruction, <= instrlen */
51         u8  pad[5];
52 };
53
54 extern void alternative_instructions(void);
55 extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
56
57 struct module;
58
59 #ifdef CONFIG_SMP
60 extern void alternatives_smp_module_add(struct module *mod, char *name,
61                                         void *locks, void *locks_end,
62                                         void *text, void *text_end);
63 extern void alternatives_smp_module_del(struct module *mod);
64 extern void alternatives_smp_switch(int smp);
65 #else
66 static inline void alternatives_smp_module_add(struct module *mod, char *name,
67                                         void *locks, void *locks_end,
68                                         void *text, void *text_end) {}
69 static inline void alternatives_smp_module_del(struct module *mod) {}
70 static inline void alternatives_smp_switch(int smp) {}
71 #endif
72
73 #endif
74
75 /*
76  * Alternative instructions for different CPU types or capabilities.
77  *
78  * This allows to use optimized instructions even on generic binary
79  * kernels.
80  *
81  * length of oldinstr must be longer or equal the length of newinstr
82  * It can be padded with nops as needed.
83  *
84  * For non barrier like inlines please define new variants
85  * without volatile and memory clobber.
86  */
87 #define alternative(oldinstr, newinstr, feature)        \
88         asm volatile ("661:\n\t" oldinstr "\n662:\n"                 \
89                       ".section .altinstructions,\"a\"\n"            \
90                       "  .align 8\n"                                   \
91                       "  .quad 661b\n"            /* label */          \
92                       "  .quad 663f\n"            /* new instruction */ \
93                       "  .byte %c0\n"             /* feature bit */    \
94                       "  .byte 662b-661b\n"       /* sourcelen */      \
95                       "  .byte 664f-663f\n"       /* replacementlen */ \
96                       ".previous\n"                                     \
97                       ".section .altinstr_replacement,\"ax\"\n"         \
98                       "663:\n\t" newinstr "\n664:\n"   /* replacement */ \
99                       ".previous" :: "i" (feature) : "memory")
100
101 /*
102  * Alternative inline assembly with input.
103  *
104  * Pecularities:
105  * No memory clobber here.
106  * Argument numbers start with 1.
107  * Best is to use constraints that are fixed size (like (%1) ... "r")
108  * If you use variable sized constraints like "m" or "g" in the
109  * replacement make sure to pad to the worst case length.
110  */
111 #define alternative_input(oldinstr, newinstr, feature, input...)        \
112         asm volatile ("661:\n\t" oldinstr "\n662:\n"                    \
113                       ".section .altinstructions,\"a\"\n"               \
114                       "  .align 8\n"                                    \
115                       "  .quad 661b\n"            /* label */           \
116                       "  .quad 663f\n"            /* new instruction */ \
117                       "  .byte %c0\n"             /* feature bit */     \
118                       "  .byte 662b-661b\n"       /* sourcelen */       \
119                       "  .byte 664f-663f\n"       /* replacementlen */  \
120                       ".previous\n"                                     \
121                       ".section .altinstr_replacement,\"ax\"\n"         \
122                       "663:\n\t" newinstr "\n664:\n"   /* replacement */ \
123                       ".previous" :: "i" (feature), ##input)
124
125 /* Like alternative_input, but with a single output argument */
126 #define alternative_io(oldinstr, newinstr, feature, output, input...) \
127         asm volatile ("661:\n\t" oldinstr "\n662:\n"                    \
128                       ".section .altinstructions,\"a\"\n"               \
129                       "  .align 8\n"                                    \
130                       "  .quad 661b\n"            /* label */           \
131                       "  .quad 663f\n"            /* new instruction */ \
132                       "  .byte %c[feat]\n"        /* feature bit */     \
133                       "  .byte 662b-661b\n"       /* sourcelen */       \
134                       "  .byte 664f-663f\n"       /* replacementlen */  \
135                       ".previous\n"                                     \
136                       ".section .altinstr_replacement,\"ax\"\n"         \
137                       "663:\n\t" newinstr "\n664:\n"   /* replacement */ \
138                       ".previous" : output : [feat] "i" (feature), ##input)
139
140 /*
141  * use this macro(s) if you need more than one output parameter
142  * in alternative_io
143  */
144 #define ASM_OUTPUT2(a, b) a, b
145
146 struct paravirt_patch;
147 #ifdef CONFIG_PARAVIRT
148 void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end);
149 #else
150 static inline void
151 apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end)
152 {}
153 #define __parainstructions NULL
154 #define __parainstructions_end NULL
155 #endif
156
157 extern void text_poke(void *addr, unsigned char *opcode, int len);
158
159 #endif /* _X86_64_ALTERNATIVE_H */