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.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
arch/i386/kernel/alternative.c | 23 ++++++++++++++++++++++-
include/asm-i386/processor.h | 22 ++++++++++++++++++++++
include/asm-x86_64/processor.h | 22 ++++++++++++++++++++++
3 files changed, 66 insertions(+), 1 deletion(-)
--- linux-2.6.23-rc5/arch/i386/kernel/alternative.c 2007-09-10 13:31:43.000000000 +0200
+++ 2.6.23-rc5-x86-const/arch/i386/kernel/alternative.c 2007-09-10 13:31:57.000000000 +0200
@@ -115,12 +115,31 @@ static const unsigned char *const k7_nop
};
#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 */
@@ -131,6 +150,8 @@ 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 }
};
--- linux-2.6.23-rc5/include/asm-i386/processor.h 2007-09-10 13:31:43.000000000 +0200
+++ 2.6.23-rc5-x86-const/include/asm-i386/processor.h 2007-09-10 13:31:57.000000000 +0200
@@ -674,6 +674,17 @@ static inline unsigned int cpuid_edx(uns
#define K7_NOP7 ".byte 0x8D,0x04,0x05,0,0,...
