diff options
Diffstat (limited to 'arch/x86_64/kernel/setup.c')
| -rw-r--r-- | arch/x86_64/kernel/setup.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c index fb850b52b4da..1cb3e21c571a 100644 --- a/arch/x86_64/kernel/setup.c +++ b/arch/x86_64/kernel/setup.c @@ -873,10 +873,18 @@ static void __init amd_detect_cmp(struct cpuinfo_x86 *c) int node = 0; unsigned apicid = hard_smp_processor_id(); #endif + unsigned ecx = cpuid_ecx(0x80000008); - bits = 0; - while ((1 << bits) < c->x86_max_cores) - bits++; + c->x86_max_cores = (ecx & 0xff) + 1; + + /* CPU telling us the core id bits shift? */ + bits = (ecx >> 12) & 0xF; + + /* Otherwise recompute */ + if (bits == 0) { + while ((1 << bits) < c->x86_max_cores) + bits++; + } /* Low order bits define the core id (index of core in socket) */ cpu_core_id[cpu] = phys_proc_id[cpu] & ((1 << bits)-1); @@ -964,11 +972,9 @@ static int __init init_amd(struct cpuinfo_x86 *c) if (c->x86_power & (1<<8)) set_bit(X86_FEATURE_CONSTANT_TSC, &c->x86_capability); - if (c->extended_cpuid_level >= 0x80000008) { - c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1; - + /* Multi core CPU? */ + if (c->extended_cpuid_level >= 0x80000008) amd_detect_cmp(c); - } return r; } |