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authorJan Beulich <jbeulich@novell.com>2007-10-17 18:04:41 +0200
committerThomas Gleixner <tglx@inhelltoy.tec.linutronix.de>2007-10-17 20:17:04 +0200
commit32c464f5d9701db45bc1673288594e664065388e (patch)
tree342e6e8be44bcdc5bdc3ddd0cbf1ba15a0340602 /arch/x86/kernel/alternative.c
parentc861eff88c92d98ee661cf0d2fa978611edeaceb (diff)
x86: multi-byte single instruction NOPs
Add support for and use the multi-byte NOPs recently documented to be available on all PentiumPro and later processors. This patch only applies cleanly on top of the "x86: misc. constifications" patch sent earlier. [ tglx: arch/x86 adaptation ] Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> arch/x86/kernel/alternative.c | 23 ++++++++++++++++++++++- include/asm-x86/processor_32.h | 22 ++++++++++++++++++++++ include/asm-x86/processor_64.h | 22 ++++++++++++++++++++++ 3 files changed, 66 insertions(+), 1 deletion(-)
Diffstat (limited to 'arch/x86/kernel/alternative.c')
-rw-r--r--arch/x86/kernel/alternative.c23
1 files changed, 22 insertions, 1 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 8cb5dbbd9c2..a3ae8e6c8b3 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -116,12 +116,31 @@ static const unsigned char *const k7_nops[ASM_NOP_MAX+1] = {
};
#endif
+#ifdef P6_NOP1
+asm("\t.section .rodata, \"a\"\np6nops: "
+ P6_NOP1 P6_NOP2 P6_NOP3 P6_NOP4 P6_NOP5 P6_NOP6
+ P6_NOP7 P6_NOP8);
+extern const unsigned char p6nops[];
+static const unsigned char *const p6_nops[ASM_NOP_MAX+1] = {
+ NULL,
+ p6nops,
+ p6nops + 1,
+ p6nops + 1 + 2,
+ p6nops + 1 + 2 + 3,
+ p6nops + 1 + 2 + 3 + 4,
+ p6nops + 1 + 2 + 3 + 4 + 5,
+ p6nops + 1 + 2 + 3 + 4 + 5 + 6,
+ p6nops + 1 + 2 + 3 + 4 + 5 + 6 + 7,
+};
+#endif
+
#ifdef CONFIG_X86_64
extern char __vsyscall_0;
static inline const unsigned char*const * find_nop_table(void)
{
- return k8_nops;
+ return boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||
+ boot_cpu_data.x86 < 6 ? k8_nops : p6_nops;
}
#else /* CONFIG_X86_64 */
@@ -132,6 +151,8 @@ static const struct nop {
} noptypes[] = {
{ X86_FEATURE_K8, k8_nops },
{ X86_FEATURE_K7, k7_nops },
+ { X86_FEATURE_P4, p6_nops },
+ { X86_FEATURE_P3, p6_nops },
{ -1, NULL }
};