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cpu/intel/hyperthreading: Use CPUID leaf 0xb without X2APIC 

It is not a requirement to have X2APIC mode enabled to use
CPUID leaf 0xb EDX to detect logical CPU is a hyperthreading
sibling.

Change-Id: I288f2df5a392c396f92bb6d18908df35de55915d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58383
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
This commit is contained in:
Kyösti Mälkki 2021-10-16 13:35:04 +03:00 committed by Felix Held
parent b31b033ccc
commit 5f4ae427ed
1 changed files with 4 additions and 6 deletions
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10
src/cpu/intel/common/hyperthreading.c
View File

@ -23,12 +23,10 @@ bool intel_ht_sibling(void)
if (!intel_ht_supported())
return false;
if (is_x2apic_mode()) {
if (cpuid_eax(0) >= 0xb) {
result = cpuid_ext(0xb, 0);
const uint32_t div = 1 << (result.eax & 0x1f);
return result.edx % div > 0;
}
if (cpuid_eax(0) >= 0xb) {
result = cpuid_ext(0xb, 0);
const uint32_t div = 1 << (result.eax & 0x1f);
return result.edx % div > 0;
}
apic_ids = 1;