diff options
Diffstat (limited to 'src/cpu/intel/common/hyperthreading.c')
| -rw-r--r-- | src/cpu/intel/common/hyperthreading.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/src/cpu/intel/common/hyperthreading.c b/src/cpu/intel/common/hyperthreading.c index 3297b381b3..f9170b383a 100644 --- a/src/cpu/intel/common/hyperthreading.c +++ b/src/cpu/intel/common/hyperthreading.c @@ -1,6 +1,5 @@ /* SPDX-License-Identifier: GPL-2.0-only */ -#include <cpu/x86/lapic.h> #include <cpu/intel/common/common.h> #include <arch/cpu.h> #include <types.h> @@ -18,22 +17,27 @@ bool intel_ht_supported(void) bool intel_ht_sibling(void) { struct cpuid_result result; - unsigned int core_ids, apic_ids, threads; + unsigned int core_ids, apic_ids; unsigned int max_leaf; + uint32_t initial_lapicid, threads; if (!intel_ht_supported()) return false; max_leaf = cpuid_get_max_func(); + + /* Detect from 32-bit X2APIC ID. */ if (max_leaf >= 0xb) { result = cpuid_ext(0xb, 0); - const uint32_t div = 1 << (result.eax & 0x1f); - return result.edx % div > 0; + threads = 1 << (result.eax & 0x1f); + initial_lapicid = result.edx; + return initial_lapicid % threads > 0; } - apic_ids = 1; - if (max_leaf >= 1) - apic_ids = (cpuid_ebx(1) >> 16) & 0xff; + /* Detect from 8-bit XAPIC ID. */ + result = cpuid_ext(0x1, 0); + initial_lapicid = result.ebx >> 24; + apic_ids = (result.ebx >> 16) & 0xff; if (apic_ids == 0) apic_ids = 1; @@ -44,5 +48,5 @@ bool intel_ht_sibling(void) } threads = (apic_ids / core_ids); - return !!(lapicid() & (threads - 1)); + return initial_lapicid % threads > 0; } |