diff options
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 39e9ec3dea98..b48775445523 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1007,17 +1007,18 @@ void get_cpu_cap(struct cpuinfo_x86 *c) c->x86_capability[CPUID_D_1_EAX] = eax; } - /* AMD-defined flags: level 0x80000001 */ + /* + * Check if extended CPUID leaves are implemented: Max extended + * CPUID leaf must be in the 0x80000001-0x8000ffff range. + */ eax = cpuid_eax(0x80000000); - c->extended_cpuid_level = eax; + c->extended_cpuid_level = ((eax & 0xffff0000) == 0x80000000) ? eax : 0; - if ((eax & 0xffff0000) == 0x80000000) { - if (eax >= 0x80000001) { - cpuid(0x80000001, &eax, &ebx, &ecx, &edx); + if (c->extended_cpuid_level >= 0x80000001) { + cpuid(0x80000001, &eax, &ebx, &ecx, &edx); - c->x86_capability[CPUID_8000_0001_ECX] = ecx; - c->x86_capability[CPUID_8000_0001_EDX] = edx; - } + c->x86_capability[CPUID_8000_0001_ECX] = ecx; + c->x86_capability[CPUID_8000_0001_EDX] = edx; } if (c->extended_cpuid_level >= 0x80000007) { |