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#ifndef _ASM_X86_ALTERNATIVE_H

#define _ASM_X86_ALTERNATIVE_H

#include 

#include 

#include 

#include 

#include 

/*

 * 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_HERE \

		".pushsection .smp_locks,\"a\"\n"	\

		".balign 4\n"				\

		".long 671f - .\n" /* offset */		\

		".popsection\n"				\

		"671:"

#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; "

#else /* ! CONFIG_SMP */

#define LOCK_PREFIX_HERE ""

#define LOCK_PREFIX ""

#endif

struct alt_instr {

	s32 instr_offset;	/* original instruction */

	s32 repl_offset;	/* offset to replacement instruction */

	u16 cpuid;		/* cpuid bit set for replacement */

	u8  instrlen;		/* length of original instruction */

	u8  replacementlen;	/* length of new instruction */

	u8  padlen;		/* length of build-time padding */

} __packed;

/*

 * Debug flag that can be tested to see whether alternative

 * instructions were patched in already:

 */

extern int alternatives_patched;

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_enable_smp(void);

extern int alternatives_text_reserved(void *start, void *end);

extern bool skip_smp_alternatives;

#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_enable_smp(void) {}

static inline int alternatives_text_reserved(void *start, void *end)

{

	return 0;

}

#endif	/* CONFIG_SMP */

#define b_replacement(num)	"664"#num

#define e_replacement(num)	"665"#num

#define alt_end_marker		"663"

#define alt_slen		"662b-661b"

#define alt_pad_len		alt_end_marker"b-662b"

#define alt_total_slen		alt_end_marker"b-661b"

#define alt_rlen(num)		e_replacement(num)"f-"b_replacement(num)"f"

#define __OLDINSTR(oldinstr, num)					\

	"661:\n\t" oldinstr "\n662:\n"					\

	".skip -(((" alt_rlen(num) ")-(" alt_slen ")) > 0) * "		\

		"((" alt_rlen(num) ")-(" alt_slen ")),0x90\n"

#define OLDINSTR(oldinstr, num)						\

	__OLDINSTR(oldinstr, num)					\

	alt_end_marker ":\n"

/*

 * max without conditionals. Idea adapted from:

 * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax

 *

 * The additional "-" is needed because gas works with s32s.

 */

#define alt_max_short(a, b)	"((" a ") ^ (((" a ") ^ (" b ")) & -(-((" a ") - (" b ")))))"

/*

 * Pad the second replacement alternative with additional NOPs if it is

 * additionally longer than the first replacement alternative.

 */

#define OLDINSTR_2(oldinstr, num1, num2) \

	"661:\n\t" oldinstr "\n662:\n"								\

	".skip -((" alt_max_short(alt_rlen(num1), alt_rlen(num2)) " - (" alt_slen ")) > 0) * "	\

		"(" alt_max_short(alt_rlen(num1), alt_rlen(num2)) " - (" alt_slen ")), 0x90\n"	\

	alt_end_marker ":\n"

#define ALTINSTR_ENTRY(feature, num)					      \

	" .long 661b - .\n"				/* label           */ \

	" .long " b_replacement(num)"f - .\n"		/* new instruction */ \

	" .word " __stringify(feature) "\n"		/* feature bit     */ \

	" .byte " alt_total_slen "\n"			/* source len      */ \

	" .byte " alt_rlen(num) "\n"			/* replacement len */ \

	" .byte " alt_pad_len "\n"			/* pad len */

#define ALTINSTR_REPLACEMENT(newinstr, feature, num)	/* replacement */     \

	b_replacement(num)":\n\t" newinstr "\n" e_replacement(num) ":\n\t"

/* alternative assembly primitive: */

#define ALTERNATIVE(oldinstr, newinstr, feature)			\

	OLDINSTR(oldinstr, 1)						\

	".pushsection .altinstructions,\"a\"\n"				\

	ALTINSTR_ENTRY(feature, 1)					\

	".popsection\n"							\

	".pushsection .altinstr_replacement, \"ax\"\n"			\

	ALTINSTR_REPLACEMENT(newinstr, feature, 1)			\

	".popsection"

#define ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2)\

	OLDINSTR_2(oldinstr, 1, 2)					\

	".pushsection .altinstructions,\"a\"\n"				\

	ALTINSTR_ENTRY(feature1, 1)					\

	ALTINSTR_ENTRY(feature2, 2)					\

	".popsection\n"							\

	".pushsection .altinstr_replacement, \"ax\"\n"			\

	ALTINSTR_REPLACEMENT(newinstr1, feature1, 1)			\

	ALTINSTR_REPLACEMENT(newinstr2, feature2, 2)			\

	".popsection"

/*

 * 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 (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory")

#define alternative_2(oldinstr, newinstr1, feature1, newinstr2, feature2) \

	asm volatile(ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2) ::: "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.

 * Leaving an unused argument 0 to keep API compatibility.

 */

#define alternative_input(oldinstr, newinstr, feature, input...)	\

	asm volatile (ALTERNATIVE(oldinstr, newinstr, feature)		\

		: : "i" (0), ## input)

/*

 * This is similar to alternative_input. But it has two features and

 * respective instructions.

 *

 * If CPU has feature2, newinstr2 is used.

 * Otherwise, if CPU has feature1, newinstr1 is used.

 * Otherwise, oldinstr is used.

 */

#define alternative_input_2(oldinstr, newinstr1, feature1, newinstr2,	     \

			   feature2, input...)				     \

	asm volatile(ALTERNATIVE_2(oldinstr, newinstr1, feature1,	     \

		newinstr2, feature2)					     \

		: : "i" (0), ## input)

/* Like alternative_input, but with a single output argument */

#define alternative_io(oldinstr, newinstr, feature, output, input...)	\

	asm volatile (ALTERNATIVE(oldinstr, newinstr, feature)		\

		: output : "i" (0), ## input)

/* Like alternative_io, but for replacing a direct call with another one. */

#define alternative_call(oldfunc, newfunc, feature, output, input...)	\

	asm volatile (ALTERNATIVE("call %P[old]", "call %P[new]", feature) \

		: output : [old] "i" (oldfunc), [new] "i" (newfunc), ## input)

/*

 * Like alternative_call, but there are two features and respective functions.

 * If CPU has feature2, function2 is used.

 * Otherwise, if CPU has feature1, function1 is used.

 * Otherwise, old function is used.

 */

#define alternative_call_2(oldfunc, newfunc1, feature1, newfunc2, feature2,   \

			   output, input...)				      \

	asm volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", feature1,\

		"call %P[new2]", feature2)				      \

		: output : [old] "i" (oldfunc), [new1] "i" (newfunc1),	      \

		[new2] "i" (newfunc2), ## input)

/*

 * use this macro(s) if you need more than one output parameter

 * in alternative_io

 */

#define ASM_OUTPUT2(a...) a

/*

 * use this macro if you need clobbers but no inputs in

 * alternative_{input,io,call}()

 */

#define ASM_NO_INPUT_CLOBBER(clbr...) "i" (0) : clbr

struct paravirt_patch_site;

#ifdef CONFIG_PARAVIRT

void apply_paravirt(struct paravirt_patch_site *start,

		    struct paravirt_patch_site *end);

#else

static inline void apply_paravirt(struct paravirt_patch_site *start,

				  struct paravirt_patch_site *end)

{}

#define __parainstructions	NULL

#define __parainstructions_end	NULL

#endif

extern void *text_poke_early(void *addr, const void *opcode, size_t len);

/*

 * Clear and restore the kernel write-protection flag on the local CPU.

 * Allows the kernel to edit read-only pages.

 * Side-effect: any interrupt handler running between save and restore will have

 * the ability to write to read-only pages.

 *

 * Warning:

 * Code patching in the UP case is safe if NMIs and MCE handlers are stopped and

 * no thread can be preempted in the instructions being modified (no iret to an

 * invalid instruction possible) or if the instructions are changed from a

 * consistent state to another consistent state atomically.

 * On the local CPU you need to be protected again NMI or MCE handlers seeing an

 * inconsistent instruction while you patch.

 */

extern void *text_poke(void *addr, const void *opcode, size_t len);

extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler);

#endif /* _ASM_X86_ALTERNATIVE_H */