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Diffstat (limited to 'arch/x86/include/asm/alternative.h')
-rw-r--r--arch/x86/include/asm/alternative.h241
1 files changed, 76 insertions, 165 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index ba99ef75f56c..ca9ae606aab9 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -156,102 +156,50 @@ 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 alt_total_slen alt_end_marker"b-661b"
-#define alt_rlen(num) e_replacement(num)"f-"b_replacement(num)"f"
-
-#define OLDINSTR(oldinstr, num) \
- "# ALT: oldnstr\n" \
- "661:\n\t" oldinstr "\n662:\n" \
+#define OLDINSTR(oldinstr) \
+ "# ALT: oldinstr\n" \
+ "771:\n\t" oldinstr "\n772:\n" \
"# ALT: padding\n" \
- ".skip -(((" alt_rlen(num) ")-(" alt_slen ")) > 0) * " \
- "((" alt_rlen(num) ")-(" alt_slen ")),0x90\n" \
- alt_end_marker ":\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 */ \
+ ".skip -(((" alt_rlen ")-(" alt_slen ")) > 0) * " \
+ "((" alt_rlen ")-(" alt_slen ")),0x90\n" \
+ "773:\n"
+
+#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 " alt_total_slen "\n" /* source len */ \
- " .byte " alt_rlen(num) "\n" /* replacement 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 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"
+ 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"
+ 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) \
- ALTERNATIVE_2(oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \
- newinstr_yes, ft_flags)
-
-#define ALTERNATIVE_3(oldinsn, newinsn1, ft_flags1, newinsn2, ft_flags2, \
- newinsn3, ft_flags3) \
- OLDINSTR_3(oldinsn, 1, 2, 3) \
- ".pushsection .altinstructions,\"a\"\n" \
- ALTINSTR_ENTRY(ft_flags1, 1) \
- ALTINSTR_ENTRY(ft_flags2, 2) \
- ALTINSTR_ENTRY(ft_flags3, 3) \
- ".popsection\n" \
- ".pushsection .altinstr_replacement, \"ax\"\n" \
- ALTINSTR_REPLACEMENT(newinsn1, 1) \
- ALTINSTR_REPLACEMENT(newinsn2, 2) \
- ALTINSTR_REPLACEMENT(newinsn3, 3) \
- ".popsection\n"
+ 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) \
+ ALTERNATIVE(ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2), \
+ newinstr3, ft_flags3)
/*
* Alternative instructions for different CPU types or capabilities.
@@ -266,14 +214,11 @@ static inline int alternatives_text_reserved(void *start, void *end)
* without volatile and memory clobber.
*/
#define alternative(oldinstr, newinstr, ft_flags) \
- asm_inline volatile (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(ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) ::: "memory")
-#define alternative_ternary(oldinstr, ft_flags, newinstr_yes, newinstr_no) \
- asm_inline volatile(ALTERNATIVE_TERNARY(oldinstr, ft_flags, newinstr_yes, newinstr_no) ::: "memory")
-
/*
* Alternative inline assembly with input.
*
@@ -283,18 +228,28 @@ 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 (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 (ALTERNATIVE(oldinstr, newinstr, ft_flags) \
+ asm_inline volatile(ALTERNATIVE(oldinstr, newinstr, ft_flags) \
: output : "i" (0), ## input)
-/* Like alternative_io, but for replacing a direct call with another one. */
-#define alternative_call(oldfunc, newfunc, ft_flags, output, input...) \
- asm_inline volatile (ALTERNATIVE("call %c[old]", "call %c[new]", ft_flags) \
- : output : [old] "i" (oldfunc), [new] "i" (newfunc), ## input)
+/*
+ * Like alternative_io, but for replacing a direct call with another one.
+ *
+ * Use the %c operand modifier which is the generic way to print a bare
+ * constant expression with all syntax-specific punctuation omitted. %P
+ * is the x86-specific variant which can handle constants too, for
+ * historical reasons, but it should be used primarily for PIC
+ * references: i.e., if used for a function, it would add the PLT
+ * suffix.
+ */
+#define alternative_call(oldfunc, newfunc, ft_flags, output, input...) \
+ asm_inline volatile(ALTERNATIVE("call %c[old]", "call %c[new]", ft_flags) \
+ : ALT_OUTPUT_SP(output) \
+ : [old] "i" (oldfunc), [new] "i" (newfunc), ## input)
/*
* Like alternative_call, but there are two features and respective functions.
@@ -302,12 +257,12 @@ static inline int alternatives_text_reserved(void *start, void *end)
* Otherwise, if CPU has feature1, function1 is used.
* Otherwise, old function is used.
*/
-#define alternative_call_2(oldfunc, newfunc1, ft_flags1, newfunc2, ft_flags2, \
- output, input...) \
- 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), \
+#define alternative_call_2(oldfunc, newfunc1, ft_flags1, newfunc2, ft_flags2, \
+ output, input...) \
+ asm_inline volatile(ALTERNATIVE_2("call %c[old]", "call %c[new1]", ft_flags1, \
+ "call %c[new2]", ft_flags2) \
+ : ALT_OUTPUT_SP(output) \
+ : [old] "i" (oldfunc), [new1] "i" (newfunc1), \
[new2] "i" (newfunc2), ## input)
/*
@@ -322,6 +277,8 @@ static inline int alternatives_text_reserved(void *start, void *end)
*/
#define ASM_NO_INPUT_CLOBBER(clbr...) "i" (0) : clbr
+#define ALT_OUTPUT_SP(...) ASM_CALL_CONSTRAINT, ## __VA_ARGS__
+
/* Macro for creating assembler functions avoiding any C magic. */
#define DEFINE_ASM_FUNC(func, instr, sec) \
asm (".pushsection " #sec ", \"ax\"\n" \
@@ -388,22 +345,23 @@ void nop_func(void);
* @newinstr. ".skip" directive takes care of proper instruction padding
* in case @newinstr is longer than @oldinstr.
*/
-.macro ALTERNATIVE oldinstr, newinstr, ft_flags
-140:
- \oldinstr
-141:
- .skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90
-142:
-
- .pushsection .altinstructions,"a"
- altinstr_entry 140b,143f,\ft_flags,142b-140b,144f-143f
- .popsection
+#define __ALTERNATIVE(oldinst, newinst, flag) \
+740: \
+ oldinst ; \
+741: \
+ .skip -(((744f-743f)-(741b-740b)) > 0) * ((744f-743f)-(741b-740b)),0x90 ;\
+742: \
+ .pushsection .altinstructions,"a" ; \
+ altinstr_entry 740b,743f,flag,742b-740b,744f-743f ; \
+ .popsection ; \
+ .pushsection .altinstr_replacement,"ax" ; \
+743: \
+ newinst ; \
+744: \
+ .popsection ;
- .pushsection .altinstr_replacement,"ax"
-143:
- \newinstr
-144:
- .popsection
+.macro ALTERNATIVE oldinstr, newinstr, ft_flags
+ __ALTERNATIVE(\oldinstr, \newinstr, \ft_flags)
.endm
#define old_len 141b-140b
@@ -412,65 +370,18 @@ void nop_func(void);
#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
-140:
- \oldinstr
-141:
- .skip -((alt_max_2(new_len1, new_len2) - (old_len)) > 0) * \
- (alt_max_2(new_len1, new_len2) - (old_len)),0x90
-142:
-
- .pushsection .altinstructions,"a"
- altinstr_entry 140b,143f,\ft_flags1,142b-140b,144f-143f
- altinstr_entry 140b,144f,\ft_flags2,142b-140b,145f-144f
- .popsection
-
- .pushsection .altinstr_replacement,"ax"
-143:
- \newinstr1
-144:
- \newinstr2
-145:
- .popsection
+ __ALTERNATIVE(__ALTERNATIVE(\oldinstr, \newinstr1, \ft_flags1),
+ \newinstr2, \ft_flags2)
.endm
.macro ALTERNATIVE_3 oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2, newinstr3, ft_flags3
-140:
- \oldinstr
-141:
- .skip -((alt_max_3(new_len1, new_len2, new_len3) - (old_len)) > 0) * \
- (alt_max_3(new_len1, new_len2, new_len3) - (old_len)),0x90
-142:
-
- .pushsection .altinstructions,"a"
- altinstr_entry 140b,143f,\ft_flags1,142b-140b,144f-143f
- altinstr_entry 140b,144f,\ft_flags2,142b-140b,145f-144f
- altinstr_entry 140b,145f,\ft_flags3,142b-140b,146f-145f
- .popsection
-
- .pushsection .altinstr_replacement,"ax"
-143:
- \newinstr1
-144:
- \newinstr2
-145:
- \newinstr3
-146:
- .popsection
+ __ALTERNATIVE(ALTERNATIVE_2(\oldinstr, \newinstr1, \ft_flags1, \newinstr2, \ft_flags2),
+ \newinstr3, \ft_flags3)
.endm
/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */
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