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Commit f776e41f authored by Borislav Petkov (AMD)'s avatar Borislav Petkov (AMD)
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x86/alternative: Replace the old macros 

Now that the new macros have been gradually put in place, replace the
old ones. Leave the new label numbers starting at 7xx as a hint that the
new nested alternatives are being used now.
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240607111701.8366-15-bp@kernel.org
parent 1a6ade82
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Showing with 32 additions and 121 deletions
arch/x86/include/asm/alternative.h
View file @ f776e41f
......@@ -156,131 +156,51 @@ static inline int alternatives_text_reserved(void *start, void *end)
#define ALT_CALL_INSTR "call BUG_func"
#define b_replacement(num) "664"#num
#define e_replacement(num) "665"#num
#define alt_slen "772b-771b"
#define alt_total_slen "773b-771b"
#define alt_rlen "775f-774f"
#define alt_end_marker "663"
#define alt_slen "662b-661b"
#define n_alt_slen "772b-771b"
#define alt_total_slen alt_end_marker"b-661b"
#define n_alt_total_slen "773b-771b"
#define alt_rlen(num) e_replacement(num)"f-"b_replacement(num)"f"
#define n_alt_rlen "775f-774f"
#define OLDINSTR(oldinstr, num) \
"# ALT: oldnstr\n" \
"661:\n\t" oldinstr "\n662:\n" \
"# ALT: padding\n" \
".skip -(((" alt_rlen(num) ")-(" alt_slen ")) > 0) * " \
"((" alt_rlen(num) ")-(" alt_slen ")),0x90\n" \
alt_end_marker ":\n"
#define N_OLDINSTR(oldinstr) \
"# N_ALT: oldinstr\n" \
#define OLDINSTR(oldinstr) \
"# ALT: oldinstr\n" \
"771:\n\t" oldinstr "\n772:\n" \
"# N_ALT: padding\n" \
".skip -(((" n_alt_rlen ")-(" n_alt_slen ")) > 0) * " \
"((" n_alt_rlen ")-(" n_alt_slen ")),0x90\n" \
"# ALT: padding\n" \
".skip -(((" alt_rlen ")-(" alt_slen ")) > 0) * " \
"((" alt_rlen ")-(" alt_slen ")),0x90\n" \
"773:\n"
/*
* gas compatible max based on the idea from:
* http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
*
* The additional "-" is needed because gas uses a "true" value of -1.
*/
#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) \
"# ALT: oldinstr2\n" \
"661:\n\t" oldinstr "\n662:\n" \
"# ALT: padding2\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 OLDINSTR_3(oldinsn, n1, n2, n3) \
"# ALT: oldinstr3\n" \
"661:\n\t" oldinsn "\n662:\n" \
"# ALT: padding3\n" \
".skip -((" alt_max_short(alt_max_short(alt_rlen(n1), alt_rlen(n2)), alt_rlen(n3)) \
" - (" alt_slen ")) > 0) * " \
"(" alt_max_short(alt_max_short(alt_rlen(n1), alt_rlen(n2)), alt_rlen(n3)) \
" - (" alt_slen ")), 0x90\n" \
alt_end_marker ":\n"
#define ALTINSTR_ENTRY(ft_flags, num) \
" .long 661b - .\n" /* label */ \
" .long " b_replacement(num)"f - .\n" /* new instruction */ \
" .4byte " __stringify(ft_flags) "\n" /* feature + flags */ \
" .byte " alt_total_slen "\n" /* source len */ \
" .byte " alt_rlen(num) "\n" /* replacement len */
#define N_ALTINSTR_ENTRY(ft_flags) \
#define ALTINSTR_ENTRY(ft_flags) \
".pushsection .altinstructions,\"a\"\n" \
" .long 771b - .\n" /* label */ \
" .long 774f - .\n" /* new instruction */ \
" .4byte " __stringify(ft_flags) "\n" /* feature + flags */ \
" .byte " n_alt_total_slen "\n" /* source len */ \
" .byte " n_alt_rlen "\n" /* replacement len */ \
" .byte " alt_total_slen "\n" /* source len */ \
" .byte " alt_rlen "\n" /* replacement len */ \
".popsection\n"
#define ALTINSTR_REPLACEMENT(newinstr, num) /* replacement */ \
"# ALT: replacement " #num "\n" \
b_replacement(num)":\n\t" newinstr "\n" e_replacement(num) ":\n"
#define N_ALTINSTR_REPLACEMENT(newinstr) /* replacement */ \
".pushsection .altinstr_replacement, \"ax\"\n" \
"# N_ALT: replacement\n" \
"774:\n\t" newinstr "\n775:\n" \
#define ALTINSTR_REPLACEMENT(newinstr) /* replacement */ \
".pushsection .altinstr_replacement, \"ax\"\n" \
"# ALT: replacement\n" \
"774:\n\t" newinstr "\n775:\n" \
".popsection\n"
/* alternative assembly primitive: */
#define ALTERNATIVE(oldinstr, newinstr, ft_flags) \
OLDINSTR(oldinstr, 1) \
".pushsection .altinstructions,\"a\"\n" \
ALTINSTR_ENTRY(ft_flags, 1) \
".popsection\n" \
".pushsection .altinstr_replacement, \"ax\"\n" \
ALTINSTR_REPLACEMENT(newinstr, 1) \
".popsection\n"
/* Nested alternatives macro variant */
#define N_ALTERNATIVE(oldinstr, newinstr, ft_flags) \
N_OLDINSTR(oldinstr) \
N_ALTINSTR_ENTRY(ft_flags) \
N_ALTINSTR_REPLACEMENT(newinstr)
OLDINSTR(oldinstr) \
ALTINSTR_ENTRY(ft_flags) \
ALTINSTR_REPLACEMENT(newinstr)
#define ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) \
OLDINSTR_2(oldinstr, 1, 2) \
".pushsection .altinstructions,\"a\"\n" \
ALTINSTR_ENTRY(ft_flags1, 1) \
ALTINSTR_ENTRY(ft_flags2, 2) \
".popsection\n" \
".pushsection .altinstr_replacement, \"ax\"\n" \
ALTINSTR_REPLACEMENT(newinstr1, 1) \
ALTINSTR_REPLACEMENT(newinstr2, 2) \
".popsection\n"
#define N_ALTERNATIVE_2(oldinst, newinst1, flag1, newinst2, flag2) \
N_ALTERNATIVE(N_ALTERNATIVE(oldinst, newinst1, flag1), \
newinst2, flag2)
ALTERNATIVE(ALTERNATIVE(oldinstr, newinstr1, ft_flags1), newinstr2, ft_flags2)
/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */
#define ALTERNATIVE_TERNARY(oldinstr, ft_flags, newinstr_yes, newinstr_no) \
N_ALTERNATIVE_2(oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \
newinstr_yes, ft_flags)
ALTERNATIVE_2(oldinstr, newinstr_no, X86_FEATURE_ALWAYS, newinstr_yes, ft_flags)
#define ALTERNATIVE_3(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2, \
newinstr3, ft_flags3) \
N_ALTERNATIVE(N_ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2), \
ALTERNATIVE(ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2), \
newinstr3, ft_flags3)
/*
* Alternative instructions for different CPU types or capabilities.
*
......@@ -294,10 +214,10 @@ static inline int alternatives_text_reserved(void *start, void *end)
* without volatile and memory clobber.
*/
#define alternative(oldinstr, newinstr, ft_flags) \
asm_inline volatile(N_ALTERNATIVE(oldinstr, newinstr, ft_flags) : : : "memory")
asm_inline volatile(ALTERNATIVE(oldinstr, newinstr, ft_flags) : : : "memory")
#define alternative_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) \
asm_inline volatile(N_ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) ::: "memory")
asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) ::: "memory")
/*
* Alternative inline assembly with input.
......@@ -308,12 +228,12 @@ static inline int alternatives_text_reserved(void *start, void *end)
* Leaving an unused argument 0 to keep API compatibility.
*/
#define alternative_input(oldinstr, newinstr, ft_flags, input...) \
asm_inline volatile(N_ALTERNATIVE(oldinstr, newinstr, ft_flags) \
asm_inline volatile(ALTERNATIVE(oldinstr, newinstr, ft_flags) \
: : "i" (0), ## input)
/* Like alternative_input, but with a single output argument */
#define alternative_io(oldinstr, newinstr, ft_flags, output, input...) \
asm_inline volatile(N_ALTERNATIVE(oldinstr, newinstr, ft_flags) \
asm_inline volatile(ALTERNATIVE(oldinstr, newinstr, ft_flags) \
: output : "i" (0), ## input)
/*
......@@ -327,7 +247,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
* suffix.
*/
#define alternative_call(oldfunc, newfunc, ft_flags, output, input...) \
asm_inline volatile(N_ALTERNATIVE("call %c[old]", "call %c[new]", ft_flags) \
asm_inline volatile(ALTERNATIVE("call %c[old]", "call %c[new]", ft_flags) \
: output : [old] "i" (oldfunc), [new] "i" (newfunc), ## input)
/*
......@@ -338,7 +258,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
*/
#define alternative_call_2(oldfunc, newfunc1, ft_flags1, newfunc2, ft_flags2, \
output, input...) \
asm_inline volatile(N_ALTERNATIVE_2("call %c[old]", "call %c[new1]", ft_flags1, \
asm_inline volatile(ALTERNATIVE_2("call %c[old]", "call %c[new1]", ft_flags1, \
"call %c[new2]", ft_flags2) \
: output, ASM_CALL_CONSTRAINT \
: [old] "i" (oldfunc), [new1] "i" (newfunc1), \
......@@ -422,7 +342,7 @@ void nop_func(void);
* @newinstr. ".skip" directive takes care of proper instruction padding
* in case @newinstr is longer than @oldinstr.
*/
#define __N_ALTERNATIVE(oldinst, newinst, flag) \
#define __ALTERNATIVE(oldinst, newinst, flag) \
740: \
oldinst ; \
741: \
......@@ -438,7 +358,7 @@ void nop_func(void);
.popsection ;
.macro ALTERNATIVE oldinstr, newinstr, ft_flags
__N_ALTERNATIVE(\oldinstr, \newinstr, \ft_flags)
__ALTERNATIVE(\oldinstr, \newinstr, \ft_flags)
.endm
#define old_len 141b-140b
......@@ -446,27 +366,18 @@ void nop_func(void);
#define new_len2 145f-144f
#define new_len3 146f-145f
/*
* gas compatible max based on the idea from:
* http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
*
* The additional "-" is needed because gas uses a "true" value of -1.
*/
#define alt_max_2(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b)))))
#define alt_max_3(a, b, c) (alt_max_2(alt_max_2(a, b), c))
/*
* Same as ALTERNATIVE macro above but for two alternatives. If CPU
* has @feature1, it replaces @oldinstr with @newinstr1. If CPU has
* @feature2, it replaces @oldinstr with @feature2.
*/
.macro ALTERNATIVE_2 oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2
__N_ALTERNATIVE(__N_ALTERNATIVE(\oldinstr, \newinstr1, \ft_flags1),
__ALTERNATIVE(__ALTERNATIVE(\oldinstr, \newinstr1, \ft_flags1),
\newinstr2, \ft_flags2)
.endm
.macro ALTERNATIVE_3 oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2, newinstr3, ft_flags3
__N_ALTERNATIVE(N_ALTERNATIVE_2(\oldinstr, \newinstr1, \ft_flags1, \newinstr2, \ft_flags2),
__ALTERNATIVE(ALTERNATIVE_2(\oldinstr, \newinstr1, \ft_flags1, \newinstr2, \ft_flags2),
\newinstr3, \ft_flags3)
.endm
......
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