[PATCH] x86_64: x86_64 version of the smp alternative patch.
Changes are largely identical to the i386 version:
* alternative #define are moved to the new alternative.h file.
* one new elf section with pointers to the lock prefixes which can be
nop'ed out for non-smp.
* two new elf sections simliar to the "classic" alternatives to
replace SMP code with simpler UP code.
* fixup headers to use alternative.h instead of defining their own
LOCK / LOCK_PREFIX macros.
The patch reuses the i386 version of the alternatives code to avoid code
duplication. The code in alternatives.c was shuffled around a bit to
reduce the number of #ifdefs needed. It also got some tweaks needed for
x86_64 (vsyscall page handling) and new features (noreplacement option
which was x86_64 only up to now). Debug printk's are changed from
compile-time to runtime.
Loosely based on a early version from Bastian Blank <waldi@debian.org>
Signed-off-by: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-x86_64/system.h b/include/asm-x86_64/system.h
index f48e0da..68e559f 100644
--- a/include/asm-x86_64/system.h
+++ b/include/asm-x86_64/system.h
@@ -3,15 +3,10 @@
#include <linux/kernel.h>
#include <asm/segment.h>
+#include <asm/alternative.h>
#ifdef __KERNEL__
-#ifdef CONFIG_SMP
-#define LOCK_PREFIX "lock ; "
-#else
-#define LOCK_PREFIX ""
-#endif
-
#define __STR(x) #x
#define STR(x) __STR(x)
@@ -34,7 +29,7 @@
"thread_return:\n\t" \
"movq %%gs:%P[pda_pcurrent],%%rsi\n\t" \
"movq %P[thread_info](%%rsi),%%r8\n\t" \
- LOCK "btr %[tif_fork],%P[ti_flags](%%r8)\n\t" \
+ LOCK_PREFIX "btr %[tif_fork],%P[ti_flags](%%r8)\n\t" \
"movq %%rax,%%rdi\n\t" \
"jc ret_from_fork\n\t" \
RESTORE_CONTEXT \
@@ -69,82 +64,6 @@
".previous" \
: :"r" (value), "r" (0))
-#ifdef __KERNEL__
-struct alt_instr {
- __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];
-};
-#endif
-
-/*
- * 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 ("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 */ \
- ".previous\n" \
- ".section .altinstr_replacement,\"ax\"\n" \
- "663:\n\t" newinstr "\n664:\n" /* replacement */ \
- ".previous" :: "i" (feature) : "memory")
-
-/*
- * Alternative inline assembly with input.
- *
- * Peculiarities:
- * 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.
- */
-#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 */ \
- ".previous\n" \
- ".section .altinstr_replacement,\"ax\"\n" \
- "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...) \
- 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 */ \
- ".previous\n" \
- ".section .altinstr_replacement,\"ax\"\n" \
- "663:\n\t" newinstr "\n664:\n" /* replacement */ \
- ".previous" : output : [feat] "i" (feature), ##input)
-
/*
* Clear and set 'TS' bit respectively
*/
@@ -366,5 +285,6 @@
void cpu_idle_wait(void);
extern unsigned long arch_align_stack(unsigned long sp);
+extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
#endif