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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 17:37:26 +0200 |
| commit | b4be123b58ad452e04e1542d9d2a0c96d8e9df11 (patch) | |
| tree | b77393f9265cb395528be56c879ff1733bd79252 | |
| parent | 6886c1b815b81817d00c8d8af0a12cfa2b700e13 (diff) | |
| download | linux-b4be123b58ad452e04e1542d9d2a0c96d8e9df11.tar.gz | |
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>
| -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 882607ff88b89..9eda6f730ec4e 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -661,32 +661,36 @@ 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 38216f678fc30..898da0b974e21 100644 --- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -56,6 +56,7 @@ extern void init_amd_cacheinfo(struct cpuinfo_x86 *c); extern void detect_num_cpu_cores(struct cpuinfo_x86 *c); extern int detect_extended_topology(struct cpuinfo_x86 *c); +extern int detect_ht_early(struct cpuinfo_x86 *c); extern void detect_ht(struct cpuinfo_x86 *c); unsigned int aperfmperf_get_khz(int cpu); |