diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/arch/x86/smbios.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/src/arch/x86/smbios.c b/src/arch/x86/smbios.c index 7e05408242..a599addb61 100644 --- a/src/arch/x86/smbios.c +++ b/src/arch/x86/smbios.c @@ -647,7 +647,26 @@ static int smbios_write_type4(unsigned long *current, int handle) t->processor_version = smbios_processor_name(t->eos); t->processor_family = (res.eax > 0) ? 0x0c : 0x6; t->processor_type = 3; /* System Processor */ - t->core_count = (res.ebx >> 16) & 0xff; + /* + * If CPUID leaf 11 is available, calculate "core count" by dividing + * SMT_ID (logical processors in a core) by Core_ID (number of cores). + * This seems to be the way to arrive to a number of cores mentioned on + * ark.intel.com. + */ + if (cpu_have_cpuid() && cpuid_get_max_func() >= 0xb) { + uint32_t leaf_b_cores = 0, leaf_b_threads = 0; + res = cpuid_ext(0xb, 1); + leaf_b_cores = res.ebx; + res = cpuid_ext(0xb, 0); + leaf_b_threads = res.ebx; + /* if hyperthreading is not available, pretend this is 1 */ + if (leaf_b_threads == 0) { + leaf_b_threads = 1; + } + t->core_count = leaf_b_cores / leaf_b_threads; + } else { + t->core_count = (res.ebx >> 16) & 0xff; + } /* Assume we enable all the cores always, capped only by MAX_CPUS */ t->core_enabled = MIN(t->core_count, CONFIG_MAX_CPUS); t->l1_cache_handle = 0xffff; |