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| author | Thomas Gleixner <tglx@linutronix.de> | 2018-06-06 00:53:57 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-15 18:12:52 +0200 |
| commit | bfa4f8aeb0f38c68b3060b9c27ee533c89404ad1 (patch) | |
| tree | 7c847f44ea1a8f442d66ca855e0fd2264a6053f4 /arch/x86/kernel | |
| parent | 33c8be23981353f141937b37e0659eb5c1857c02 (diff) | |
| download | linux-stable-bfa4f8aeb0f38c68b3060b9c27ee533c89404ad1.tar.gz linux-stable-bfa4f8aeb0f38c68b3060b9c27ee533c89404ad1.tar.bz2 linux-stable-bfa4f8aeb0f38c68b3060b9c27ee533c89404ad1.zip | |
x86/cpu/common: Provide detect_ht_early()
commit 545401f4448a807b963ff17b575e0a393e68b523 upstream
To support force disabling of SMT it's required to know the number of
thread siblings early. detect_ht() cannot be called before the APIC driver
is selected, so split out the part which initializes smp_num_siblings.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 24 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/cpu.h | 1 |
2 files changed, 15 insertions, 10 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 835cd1c3400e..c925498224d0 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -614,32 +614,36 @@ static void cpu_detect_tlb(struct cpuinfo_x86 *c) tlb_lld_4m[ENTRIES], tlb_lld_1g[ENTRIES]); } -void detect_ht(struct cpuinfo_x86 *c) +int detect_ht_early(struct cpuinfo_x86 *c) { #ifdef CONFIG_SMP u32 eax, ebx, ecx, edx; - int index_msb, core_bits; if (!cpu_has(c, X86_FEATURE_HT)) - return; + return -1; if (cpu_has(c, X86_FEATURE_CMP_LEGACY)) - return; + return -1; if (cpu_has(c, X86_FEATURE_XTOPOLOGY)) - return; + return -1; cpuid(1, &eax, &ebx, &ecx, &edx); smp_num_siblings = (ebx & 0xff0000) >> 16; + if (smp_num_siblings == 1) + pr_info_once("CPU0: Hyper-Threading is disabled\n"); +#endif + return 0; +} - if (!smp_num_siblings) - smp_num_siblings = 1; +void detect_ht(struct cpuinfo_x86 *c) +{ +#ifdef CONFIG_SMP + int index_msb, core_bits; - if (smp_num_siblings == 1) { - pr_info_once("CPU0: Hyper-Threading is disabled\n"); + if (detect_ht_early(c) < 0) return; - } index_msb = get_count_order(smp_num_siblings); c->phys_proc_id = apic->phys_pkg_id(c->initial_apicid, index_msb); diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h index 37672d299e35..1f14d9d00228 100644 --- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -47,6 +47,7 @@ extern const struct cpu_dev *const __x86_cpu_dev_start[], extern void get_cpu_cap(struct cpuinfo_x86 *c); extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c); +extern int detect_ht_early(struct cpuinfo_x86 *c); unsigned int aperfmperf_get_khz(int cpu); |