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author | Patrick Rudolph <patrick.rudolph@9elements.com> | 2019-09-26 10:26:49 +0200 |
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committer | Patrick Georgi <pgeorgi@google.com> | 2019-10-01 15:10:16 +0000 |
commit | 6e079dc120a4aa95a25cfe536d4b1acd178918fd (patch) | |
tree | c8b1d76e5dd361964389c0f628b162102e72add1 /src/cpu/intel/common/hyperthreading.c | |
parent | 5adbc767f66224e617b6c8204a868542b8010999 (diff) | |
download | coreboot-6e079dc120a4aa95a25cfe536d4b1acd178918fd.tar.xz |
cpu/intel/common: Move intel_ht_sibling() to common folder
Make intel_ht_sibling() available on all platforms.
Will be used in MP init to only write "Core" MSRs from one thread
on HyperThreading enabled platforms, to prevent race conditions and
resulting #GP if MSRs are written twice or are already locked.
Change-Id: I5d000b34ba4c6536dc866fbaf106b78e905e3e35
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35619
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Diffstat (limited to 'src/cpu/intel/common/hyperthreading.c')
-rw-r--r-- | src/cpu/intel/common/hyperthreading.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/src/cpu/intel/common/hyperthreading.c b/src/cpu/intel/common/hyperthreading.c new file mode 100644 index 0000000000..4caf49e5b6 --- /dev/null +++ b/src/cpu/intel/common/hyperthreading.c @@ -0,0 +1,45 @@ +/* + * This file is part of the coreboot project. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <cpu/x86/lapic.h> +#include <cpu/intel/common/common.h> +#include <arch/cpu.h> + +/* + * Return true if running thread does not have the smallest lapic ID + * within a CPU core. + */ +bool intel_ht_sibling(void) +{ + struct cpuid_result result; + unsigned int core_ids, apic_ids, threads; + + /* Is Hyper-Threading supported */ + if (!(cpuid_edx(1) & CPUID_FEAURE_HTT)) + return false; + + apic_ids = 1; + if (cpuid_eax(0) >= 1) + apic_ids = (cpuid_ebx(1) >> 16) & 0xff; + if (apic_ids == 0) + apic_ids = 1; + + core_ids = 1; + if (cpuid_eax(0) >= 4) { + result = cpuid_ext(4, 0); + core_ids += (result.eax >> 26) & 0x3f; + } + + threads = (apic_ids / core_ids); + return !!(lapicid() & (threads - 1)); +} |