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Commit a065de0d authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86/asm changes from Ingo Molnar:
 "Assorted single-commit improvements, as usual"

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/mtrr: Slightly simplify print_mtrr_state()
  x86/mm/mtrr: Fix alignment determination in range_to_mtrr()
  x86/copy_user_generic: Optimize copy_user_generic with CPU erms feature
  x86/alternatives: Use atomic_xchg() instead atomic_dec_and_test() for stop_machine_text_poke()
parents 3992c032 a7101d15

arch/x86/include/asm/alternative.h

+59 −15
Original line number Diff line number Diff line
@@ -75,22 +75,53 @@ static inline int alternatives_text_reserved(void *start, void *end) 
}

#endif	/* CONFIG_SMP */



#define OLDINSTR(oldinstr)	"661:\n\t" oldinstr "\n662:\n"



#define b_replacement(number)	"663"#number

#define e_replacement(number)	"664"#number



#define alt_slen "662b-661b"

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



#define ALTINSTR_ENTRY(feature, number)					      \

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

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

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

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

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



#define DISCARD_ENTRY(number)				/* rlen <= slen */    \

	" .byte 0xff + (" alt_rlen(number) ") - (" alt_slen ")\n"



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

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



/* alternative assembly primitive: */

#define ALTERNATIVE(oldinstr, newinstr, feature)			\

									\

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

	OLDINSTR(oldinstr)						\

	".section .altinstructions,\"a\"\n"				\

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

      "	 .long 663f - .\n"			/* new instruction */	\

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

      "	 .byte 662b-661b\n"			/* sourcelen       */	\

      "	 .byte 664f-663f\n"			/* replacementlen  */	\

	ALTINSTR_ENTRY(feature, 1)					\

	".previous\n"							\

	".section .discard,\"aw\",@progbits\n"				\

      "	 .byte 0xff + (664f-663f) - (662b-661b)\n" /* rlen <= slen */	\

	DISCARD_ENTRY(1)						\

	".previous\n"							\

	".section .altinstr_replacement, \"ax\"\n"			\

      "663:\n\t" newinstr "\n664:\n"		/* replacement     */	\

	ALTINSTR_REPLACEMENT(newinstr, feature, 1)			\

	".previous"



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

	OLDINSTR(oldinstr)						\

	".section .altinstructions,\"a\"\n"				\

	ALTINSTR_ENTRY(feature1, 1)					\

	ALTINSTR_ENTRY(feature2, 2)					\

	".previous\n"							\

	".section .discard,\"aw\",@progbits\n"				\

	DISCARD_ENTRY(1)						\

	DISCARD_ENTRY(2)						\

	".previous\n"							\

	".section .altinstr_replacement, \"ax\"\n"			\

	ALTINSTR_REPLACEMENT(newinstr1, feature1, 1)			\

	ALTINSTR_REPLACEMENT(newinstr2, feature2, 2)			\

	".previous"



/*
@@ -139,6 +170,19 @@ static inline int alternatives_text_reserved(void *start, void *end) 
	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

arch/x86/include/asm/uaccess_64.h

+10 −1
Original line number Diff line number Diff line
@@ -17,6 +17,8 @@ 


/* Handles exceptions in both to and from, but doesn't do access_ok */

__must_check unsigned long

copy_user_enhanced_fast_string(void *to, const void *from, unsigned len);

__must_check unsigned long

copy_user_generic_string(void *to, const void *from, unsigned len);

__must_check unsigned long

copy_user_generic_unrolled(void *to, const void *from, unsigned len);
@@ -26,9 +28,16 @@ copy_user_generic(void *to, const void *from, unsigned len) 
{

	unsigned ret;



	alternative_call(copy_user_generic_unrolled,

	/*

	 * If CPU has ERMS feature, use copy_user_enhanced_fast_string.

	 * Otherwise, if CPU has rep_good feature, use copy_user_generic_string.

	 * Otherwise, use copy_user_generic_unrolled.

	 */

	alternative_call_2(copy_user_generic_unrolled,

			 copy_user_generic_string,

			 X86_FEATURE_REP_GOOD,

			 copy_user_enhanced_fast_string,

			 X86_FEATURE_ERMS,

			 ASM_OUTPUT2("=a" (ret), "=D" (to), "=S" (from),

				     "=d" (len)),

			 "1" (to), "2" (from), "3" (len)

arch/x86/kernel/alternative.c

+1 −1
Original line number Diff line number Diff line
@@ -664,7 +664,7 @@ static int __kprobes stop_machine_text_poke(void *data) 
	struct text_poke_param *p;

	int i;



	if (atomic_dec_and_test(&stop_machine_first)) {

	if (atomic_xchg(&stop_machine_first, 0)) {

		for (i = 0; i < tpp->nparams; i++) {

			p = &tpp->params[i];

			text_poke(p->addr, p->opcode, p->len);

arch/x86/kernel/cpu/mtrr/cleanup.c

+3 −3
Original line number Diff line number Diff line
@@ -258,11 +258,11 @@ range_to_mtrr(unsigned int reg, unsigned long range_startk, 


		/* Compute the maximum size with which we can make a range: */

		if (range_startk)

			max_align = ffs(range_startk) - 1;

			max_align = __ffs(range_startk);

		else

			max_align = 32;

			max_align = BITS_PER_LONG - 1;



		align = fls(range_sizek) - 1;

		align = __fls(range_sizek);

		if (align > max_align)

			align = max_align;

arch/x86/kernel/cpu/mtrr/generic.c

+1 −5
Original line number Diff line number Diff line
@@ -361,11 +361,7 @@ static void __init print_mtrr_state(void) 
	}

	pr_debug("MTRR variable ranges %sabled:\n",

		 mtrr_state.enabled & 2 ? "en" : "dis");

	if (size_or_mask & 0xffffffffUL)

		high_width = ffs(size_or_mask & 0xffffffffUL) - 1;

	else

		high_width = ffs(size_or_mask>>32) + 32 - 1;

	high_width = (high_width - (32 - PAGE_SHIFT) + 3) / 4;

	high_width = (__ffs64(size_or_mask) - (32 - PAGE_SHIFT) + 3) / 4;



	for (i = 0; i < num_var_ranges; ++i) {

		if (mtrr_state.var_ranges[i].mask_lo & (1 << 11))