[deliverable/linux.git] / include / asm-x86 / alternative_64.h

#ifndef _X86_64_ALTERNATIVE_H
#define _X86_64_ALTERNATIVE_H

#ifdef __KERNEL__

#include <linux/types.h>
#include <linux/stddef.h>

/*
 * Alternative inline assembly for SMP.
 *
 * The LOCK_PREFIX macro defined here replaces the LOCK and
 * LOCK_PREFIX macros used everywhere in the source tree.
 *
 * SMP alternatives use the same data structures as the other
 * alternatives and the X86_FEATURE_UP flag to indicate the case of a
 * UP system running a SMP kernel.  The existing apply_alternatives()
 * works fine for patching a SMP kernel for UP.
 *
 * The SMP alternative tables can be kept after boot and contain both
 * UP and SMP versions of the instructions to allow switching back to
 * SMP at runtime, when hotplugging in a new CPU, which is especially
 * useful in virtualized environments.
 *
 * The very common lock prefix is handled as special case in a
 * separate table which is a pure address list without replacement ptr
 * and size information.  That keeps the table sizes small.
 */

#ifdef CONFIG_SMP
#define LOCK_PREFIX \
		".section .smp_locks,\"a\"\n"	\
		"  .align 8\n"			\
		"  .quad 661f\n" /* address */	\
		".previous\n"			\
	       	"661:\n\tlock; "

#else /* ! CONFIG_SMP */
#define LOCK_PREFIX ""
#endif

/* This must be included *after* the definition of LOCK_PREFIX */
#include <asm/cpufeature.h>

struct alt_instr {
	u8 *instr; 		/* original instruction */
	u8 *replacement;
	u8  cpuid;		/* cpuid bit set for replacement */
	u8  instrlen;		/* length of original instruction */
	u8  replacementlen; 	/* length of new instruction, <= instrlen */
	u8  pad[5];
};

extern void alternative_instructions(void);
extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);

struct module;

#ifdef CONFIG_SMP
extern void alternatives_smp_module_add(struct module *mod, char *name,
					void *locks, void *locks_end,
					void *text, void *text_end);
extern void alternatives_smp_module_del(struct module *mod);
extern void alternatives_smp_switch(int smp);
#else
static inline void alternatives_smp_module_add(struct module *mod, char *name,
					void *locks, void *locks_end,
					void *text, void *text_end) {}
static inline void alternatives_smp_module_del(struct module *mod) {}
static inline void alternatives_smp_switch(int smp) {}
#endif

#endif

/*
 * Alternative instructions for different CPU types or capabilities.
 *
 * This allows to use optimized instructions even on generic binary
 * kernels.
 *
 * length of oldinstr must be longer or equal the length of newinstr
 * It can be padded with nops as needed.
 *
 * For non barrier like inlines please define new variants
 * without volatile and memory clobber.
 */
#define alternative(oldinstr, newinstr, feature) 	\
	asm volatile ("661:\n\t" oldinstr "\n662:\n" 		     \
		      ".section .altinstructions,\"a\"\n"     	     \
		      "  .align 8\n"				       \
		      "  .quad 661b\n"            /* label */          \
		      "  .quad 663f\n"		  /* new instruction */ \
		      "  .byte %c0\n"             /* feature bit */    \
		      "  .byte 662b-661b\n"       /* sourcelen */      \
		      "  .byte 664f-663f\n"       /* replacementlen */ \
		      ".previous\n"					\
		      ".section .altinstr_replacement,\"ax\"\n"		\
		      "663:\n\t" newinstr "\n664:\n"   /* replacement */ \
		      ".previous" :: "i" (feature) : "memory")

/*
 * Alternative inline assembly with input.
 *
 * Pecularities:
 * No memory clobber here.
 * Argument numbers start with 1.
 * Best is to use constraints that are fixed size (like (%1) ... "r")
 * If you use variable sized constraints like "m" or "g" in the
 * replacement make sure to pad to the worst case length.
 */
#define alternative_input(oldinstr, newinstr, feature, input...)	\
	asm volatile ("661:\n\t" oldinstr "\n662:\n"			\
		      ".section .altinstructions,\"a\"\n"		\
		      "  .align 8\n"					\
		      "  .quad 661b\n"            /* label */		\
		      "  .quad 663f\n"		  /* new instruction */	\
		      "  .byte %c0\n"             /* feature bit */	\
		      "  .byte 662b-661b\n"       /* sourcelen */	\
		      "  .byte 664f-663f\n"       /* replacementlen */	\
		      ".previous\n"					\
		      ".section .altinstr_replacement,\"ax\"\n"		\
		      "663:\n\t" newinstr "\n664:\n"   /* replacement */ \
		      ".previous" :: "i" (feature), ##input)

/* Like alternative_input, but with a single output argument */
#define alternative_io(oldinstr, newinstr, feature, output, input...) \
	asm volatile ("661:\n\t" oldinstr "\n662:\n"			\
		      ".section .altinstructions,\"a\"\n"		\
		      "  .align 8\n"					\
		      "  .quad 661b\n"            /* label */		\
		      "  .quad 663f\n"		  /* new instruction */	\
		      "  .byte %c[feat]\n"        /* feature bit */	\
		      "  .byte 662b-661b\n"       /* sourcelen */	\
		      "  .byte 664f-663f\n"       /* replacementlen */	\
		      ".previous\n"					\
		      ".section .altinstr_replacement,\"ax\"\n"		\
		      "663:\n\t" newinstr "\n664:\n"   /* replacement */ \
		      ".previous" : output : [feat] "i" (feature), ##input)

/*
 * use this macro(s) if you need more than one output parameter
 * in alternative_io
 */
#define ASM_OUTPUT2(a, b) a, b

struct paravirt_patch;
#ifdef CONFIG_PARAVIRT
void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end);
#else
static inline void
apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end)
{}
#define __parainstructions NULL
#define __parainstructions_end NULL
#endif

extern void text_poke(void *addr, unsigned char *opcode, int len);

#endif /* _X86_64_ALTERNATIVE_H */
Commit	Line	Data
d167a518 GH	1	#ifndef _X86_64_ALTERNATIVE_H
	2	#define _X86_64_ALTERNATIVE_H
	3
	4	#ifdef __KERNEL__
	5
	6	#include <linux/types.h>
139ec7c4	7	#include <linux/stddef.h>
ec481536 PA	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 */
61171b8d	43	#include <asm/cpufeature.h>
d167a518 GH	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
c169859d	54	extern void alternative_instructions(void);
d167a518 GH	55	extern void apply_alternatives(struct alt_instr start, struct alt_instr end);
	56
	57	struct module;
8ec4d41f GH	58
8ec4d41f GH	59	#ifdef CONFIG_SMP
d167a518 GH	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);
8ec4d41f GH	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
d167a518 GH	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
6041b57c JR	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
139ec7c4 RR	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	{}
441d40dc JF	153	#define __parainstructions NULL
441d40dc JF	154	#define __parainstructions_end NULL
139ec7c4 RR	155	#endif
139ec7c4 RR	156
19d36ccd AK	157	extern void text_poke(void addr, unsigned char opcode, int len);
19d36ccd AK	158
d167a518	159	#endif /* _X86_64_ALTERNATIVE_H */