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x86: prepare merger of <asm/alternative_{32,64}.h>
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Prepare for merging <asm/alternative_{32,64}.h> by making the 32- and
64-bit versions textually identical.  This involves:

- removing arbitrary header inclusion differences
- reorganizing the 32-bit version slightly to match the 64-bit version
- using <asm/asm.h> to unify the assembly code
- renaming struct paravirt_patch to struct paravirt_patch_site in the
  64-bit version to match the 32-bit version; there are no references
  to struct paravirt_patch elsewhere in the tree.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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H. Peter Anvin authored and Ingo Molnar committed Jan 30, 2008
1 parent 2b8e05b commit 1d8a1f6
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Showing 2 changed files with 112 additions and 103 deletions.
131 changes: 69 additions & 62 deletions include/asm-x86/alternative_32.h
View file
Original file line number Diff line number Diff line change
@@ -1,23 +1,63 @@
#ifndef _I386_ALTERNATIVE_H
#define _I386_ALTERNATIVE_H

#include <asm/types.h>
#include <linux/stddef.h>
#include <linux/types.h>
#include <linux/stddef.h>
#include <asm/asm.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" \
_ASM_ALIGN "\n" \
_ASM_PTR "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 *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;
u8 replacementlen; /* length of new instruction, <= instrlen */
u8 pad1;
#ifdef CONFIG_X86_64
u32 pad2;
#endif
};

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,
Expand Down Expand Up @@ -45,17 +85,17 @@ static inline void alternatives_smp_switch(int smp) {}
* without volatile and memory clobber.
*/
#define alternative(oldinstr, newinstr, feature) \
asm volatile ("661:\n\t" oldinstr "\n662:\n" \
asm volatile ("661:\n\t" oldinstr "\n662:\n" \
".section .altinstructions,\"a\"\n" \
" .align 4\n" \
" .long 661b\n" /* label */ \
" .long 663f\n" /* new instruction */ \
" .byte %c0\n" /* feature bit */ \
" .byte 662b-661b\n" /* sourcelen */ \
" .byte 664f-663f\n" /* replacementlen */ \
_ASM_ALIGN "\n" \
_ASM_PTR "661b\n" /* label */ \
_ASM_PTR "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 */\
"663:\n\t" newinstr "\n664:\n" /* replacement */ \
".previous" :: "i" (feature) : "memory")

/*
Expand All @@ -66,35 +106,35 @@ static inline void alternatives_smp_switch(int smp) {}
* 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 maake sure to pad to the worst case length.
* 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 4\n" \
" .long 661b\n" /* label */ \
" .long 663f\n" /* new instruction */ \
" .byte %c0\n" /* feature bit */ \
" .byte 662b-661b\n" /* sourcelen */ \
" .byte 664f-663f\n" /* replacementlen */ \
_ASM_ALIGN "\n" \
_ASM_PTR "661b\n" /* label */ \
_ASM_PTR "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 */\
"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...) \
#define alternative_io(oldinstr, newinstr, feature, output, input...) \
asm volatile ("661:\n\t" oldinstr "\n662:\n" \
".section .altinstructions,\"a\"\n" \
" .align 4\n" \
" .long 661b\n" /* label */ \
" .long 663f\n" /* new instruction */ \
" .byte %c[feat]\n" /* feature bit */ \
" .byte 662b-661b\n" /* sourcelen */ \
" .byte 664f-663f\n" /* replacementlen */ \
_ASM_ALIGN "\n" \
_ASM_PTR "661b\n" /* label */ \
_ASM_PTR "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 */ \
"663:\n\t" newinstr "\n664:\n" /* replacement */ \
".previous" : output : [feat] "i" (feature), ##input)

/*
Expand All @@ -103,39 +143,6 @@ static inline void alternatives_smp_switch(int smp) {}
*/
#define ASM_OUTPUT2(a, b) a, b

/*
* 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 4\n" \
" .long 661f\n" /* address */ \
".previous\n" \
"661:\n\tlock; "

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

struct paravirt_patch_site;
#ifdef CONFIG_PARAVIRT
void apply_paravirt(struct paravirt_patch_site *start,
Expand Down
84 changes: 43 additions & 41 deletions include/asm-x86/alternative_64.h
View file
Original file line number Diff line number Diff line change
@@ -1,10 +1,9 @@
#ifndef _X86_64_ALTERNATIVE_H
#define _X86_64_ALTERNATIVE_H

#ifdef __KERNEL__

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

/*
* Alternative inline assembly for SMP.
Expand All @@ -30,10 +29,10 @@
#ifdef CONFIG_SMP
#define LOCK_PREFIX \
".section .smp_locks,\"a\"\n" \
" .align 8\n" \
" .quad 661f\n" /* address */ \
_ASM_ALIGN "\n" \
_ASM_PTR "661f\n" /* address */ \
".previous\n" \
"661:\n\tlock; "
"661:\n\tlock; "

#else /* ! CONFIG_SMP */
#define LOCK_PREFIX ""
Expand All @@ -43,12 +42,15 @@
#include <asm/cpufeature.h>

struct alt_instr {
u8 *instr; /* original instruction */
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];
u8 replacementlen; /* length of new instruction, <= instrlen */
u8 pad1;
#ifdef CONFIG_X86_64
u32 pad2;
#endif
};

extern void alternative_instructions(void);
Expand All @@ -68,9 +70,7 @@ static inline void alternatives_smp_module_add(struct module *mod, char *name,
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
#endif /* CONFIG_SMP */

/*
* Alternative instructions for different CPU types or capabilities.
Expand All @@ -84,18 +84,18 @@ static inline void alternatives_smp_switch(int smp) {}
* 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 */ \
#define alternative(oldinstr, newinstr, feature) \
asm volatile ("661:\n\t" oldinstr "\n662:\n" \
".section .altinstructions,\"a\"\n" \
_ASM_ALIGN "\n" \
_ASM_PTR "661b\n" /* label */ \
_ASM_PTR "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 */ \
"663:\n\t" newinstr "\n664:\n" /* replacement */ \
".previous" :: "i" (feature) : "memory")

/*
Expand All @@ -111,30 +111,30 @@ static inline void alternatives_smp_switch(int smp) {}
#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 */ \
_ASM_ALIGN "\n" \
_ASM_PTR "661b\n" /* label */ \
_ASM_PTR "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 */ \
"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...) \
#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 */ \
_ASM_ALIGN "\n" \
_ASM_PTR "661b\n" /* label */ \
_ASM_PTR "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 */ \
"663:\n\t" newinstr "\n664:\n" /* replacement */ \
".previous" : output : [feat] "i" (feature), ##input)

/*
Expand All @@ -143,15 +143,17 @@ static inline void alternatives_smp_switch(int smp) {}
*/
#define ASM_OUTPUT2(a, b) a, b

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

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

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