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| author | Thomas Gleixner <tglx@linutronix.de> | 2018-06-06 00:55:39 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-08-15 17:37:26 +0200 |
| commit | c3155990e210e1809cb14f87bc4b8d31ae7695a7 (patch) | |
| tree | ce97df92c3bc126adadfb30bb962c0de61ab5190 | |
| parent | b4be123b58ad452e04e1542d9d2a0c96d8e9df11 (diff) | |
| download | linux-stable-c3155990e210e1809cb14f87bc4b8d31ae7695a7.tar.gz linux-stable-c3155990e210e1809cb14f87bc4b8d31ae7695a7.tar.bz2 linux-stable-c3155990e210e1809cb14f87bc4b8d31ae7695a7.zip | |
x86/cpu/topology: Provide detect_extended_topology_early()
commit 95f3d39ccf7aaea79d1ffdac1c887c2e100ec1b6 upstream.
To support force disabling of SMT it's required to know the number of
thread siblings early. detect_extended_topology() 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/cpu.h | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/topology.c | 31 |
2 files changed, 23 insertions, 9 deletions
diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h index 898da0b974e2..e59c0ea82a33 100644 --- a/arch/x86/kernel/cpu/cpu.h +++ b/arch/x86/kernel/cpu/cpu.h @@ -55,6 +55,7 @@ extern void init_intel_cacheinfo(struct cpuinfo_x86 *c); extern void init_amd_cacheinfo(struct cpuinfo_x86 *c); extern void detect_num_cpu_cores(struct cpuinfo_x86 *c); +extern int detect_extended_topology_early(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); diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c index 1072b5eda607..71ca064e3794 100644 --- a/arch/x86/kernel/cpu/topology.c +++ b/arch/x86/kernel/cpu/topology.c @@ -22,17 +22,10 @@ #define BITS_SHIFT_NEXT_LEVEL(eax) ((eax) & 0x1f) #define LEVEL_MAX_SIBLINGS(ebx) ((ebx) & 0xffff) -/* - * Check for extended topology enumeration cpuid leaf 0xb and if it - * exists, use it for populating initial_apicid and cpu topology - * detection. - */ -int detect_extended_topology(struct cpuinfo_x86 *c) +int detect_extended_topology_early(struct cpuinfo_x86 *c) { #ifdef CONFIG_SMP - unsigned int eax, ebx, ecx, edx, sub_index; - unsigned int ht_mask_width, core_plus_mask_width; - unsigned int core_select_mask, core_level_siblings; + unsigned int eax, ebx, ecx, edx; if (c->cpuid_level < 0xb) return -1; @@ -51,10 +44,30 @@ int detect_extended_topology(struct cpuinfo_x86 *c) * initial apic id, which also represents 32-bit extended x2apic id. */ c->initial_apicid = edx; + smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx); +#endif + return 0; +} + +/* + * Check for extended topology enumeration cpuid leaf 0xb and if it + * exists, use it for populating initial_apicid and cpu topology + * detection. + */ +int detect_extended_topology(struct cpuinfo_x86 *c) +{ +#ifdef CONFIG_SMP + unsigned int eax, ebx, ecx, edx, sub_index; + unsigned int ht_mask_width, core_plus_mask_width; + unsigned int core_select_mask, core_level_siblings; + + if (detect_extended_topology_early(c) < 0) + return -1; /* * Populate HT related information from sub-leaf level 0. */ + cpuid_count(0xb, SMT_LEVEL, &eax, &ebx, &ecx, &edx); core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx); core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax); |