From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linutronix.de (146.0.238.70:993) by crypto-ml.lab.linutronix.de with IMAP4-SSL for ; 20 Jun 2018 20:40:38 -0000 Received: from localhost ([127.0.0.1] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1fVjpM-0003oE-Dj for speck@linutronix.de; Wed, 20 Jun 2018 22:35:40 +0200 Message-ID: <20180620201933.162338822@linutronix.de> Date: Wed, 20 Jun 2018 22:19:15 +0200 From: Thomas Gleixner Subject: [patch V4 08/13] x86/cpu/common: Provide detect_ht_early() References: <20180620201907.304694346@linutronix.de> Mime-Version: 1 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: speck@linutronix.de List-ID: Subject: [patch V4 08/13] x86/cpu/common: Provide detect_ht_early() From: Thomas Gleixner 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 Reviewed-by: Konrad Rzeszutek Wilk --- arch/x86/kernel/cpu/common.c | 24 ++++++++++++++---------- arch/x86/kernel/cpu/cpu.h | 1 + 2 files changed, 15 insertions(+), 10 deletions(-) --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -658,32 +658,36 @@ static void cpu_detect_tlb(struct cpuinf 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); --- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -56,6 +56,7 @@ extern void init_amd_cacheinfo(struct cp 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);