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authorH. Peter Anvin <hpa@zytor.com>2008-08-18 20:50:33 -0400
committerH. Peter Anvin <hpa@zytor.com>2008-08-18 21:22:18 -0400
commitf1c5d30e1d79bbfb60eaf189db862d3cb2bcac92 (patch)
tree457aeabcfff8885fbcc66384758e5c31369ca414 /arch/x86/kernel
parent7e00df5818964298c9821365a6cb7a8304227c5c (diff)
x86: use X86_FEATURE_NOPL in alternatives
Use X86_FEATURE_NOPL to determine if it is safe to use P6 NOPs in alternatives. Also, replace table and loop with simple if statement. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/alternative.c36
1 files changed, 13 insertions, 23 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 2763cb37b553..65a0c1b48696 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -145,35 +145,25 @@ static const unsigned char *const p6_nops[ASM_NOP_MAX+1] = {
145extern char __vsyscall_0; 145extern char __vsyscall_0;
146const unsigned char *const *find_nop_table(void) 146const unsigned char *const *find_nop_table(void)
147{ 147{
148 return boot_cpu_data.x86_vendor != X86_VENDOR_INTEL || 148 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
149 boot_cpu_data.x86 < 6 ? k8_nops : p6_nops; 149 boot_cpu_has(X86_FEATURE_NOPL))
150 return p6_nops;
151 else
152 return k8_nops;
150} 153}
151 154
152#else /* CONFIG_X86_64 */ 155#else /* CONFIG_X86_64 */
153 156
154static const struct nop {
155 int cpuid;
156 const unsigned char *const *noptable;
157} noptypes[] = {
158 { X86_FEATURE_K8, k8_nops },
159 { X86_FEATURE_K7, k7_nops },
160 { X86_FEATURE_P4, p6_nops },
161 { X86_FEATURE_P3, p6_nops },
162 { -1, NULL }
163};
164
165const unsigned char *const *find_nop_table(void) 157const unsigned char *const *find_nop_table(void)
166{ 158{
167 const unsigned char *const *noptable = intel_nops; 159 if (boot_cpu_has(X86_FEATURE_K8))
168 int i; 160 return k8_nops;
169 161 else if (boot_cpu_has(X86_FEATURE_K7))
170 for (i = 0; noptypes[i].cpuid >= 0; i++) { 162 return k7_nops;
171 if (boot_cpu_has(noptypes[i].cpuid)) { 163 else if (boot_cpu_has(X86_FEATURE_NOPL))
172 noptable = noptypes[i].noptable; 164 return p6_nops;
173 break; 165 else
174 } 166 return intel_nops;
175 }
176 return noptable;
177} 167}
178 168
179#endif /* CONFIG_X86_64 */ 169#endif /* CONFIG_X86_64 */