Messages in this thread Patch in this message | | | From | Aravind Gopalakrishnan <> | Subject | [PATCH V2 7/9] x86, amd: Factor out number of nodes calculation | Date | Tue, 2 Jun 2015 15:36:00 -0500 |
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Factoring out number of nodes calculation out of amd_get_topology() and saving the value in a static variable.
A later patch will introduce a accessor for this value so we can use the information elsewhere in EDAC. The usage will be included in a future patch too.
While at it, remove X86_HT #ifdefs around the code block for amd_get_topology() and it's caller amd_detect_cmp(). Since CONFIG_X86_HT defaults to Y, this code is always built-in. Besides, amd_get_topology() extracts necessary info from cpuid_[eax|ebx](0x8000001e) for platforms that are not 'HT'
Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: Jacob Shin <jacob.w.shin@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> --- arch/x86/kernel/cpu/amd.c | 36 +++++++++++++++++++++++++++--------- 1 file changed, 27 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 94e7051..c595669 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -19,6 +19,13 @@ #include "cpu.h" +/* + * nodes_per_processor: Specifies number of nodes per socket + * Refer Fam15h Models 00-0fh BKDG- + * CPUID Fn8000_001E_ECX Node Identifiers[10:8] + */ +static u32 nodes_per_processor = 1; + static inline int rdmsrl_amd_safe(unsigned msr, unsigned long long *p) { u32 gprs[8] = { 0 }; @@ -282,25 +289,40 @@ static int nearby_node(int apicid) } #endif +static void amd_set_num_nodes(void) +{ + if (cpu_has_topoext) { + u32 ecx; + + ecx = cpuid_ecx(0x8000001e); + nodes_per_processor = ((ecx >> 8) & 7) + 1; + } else if (static_cpu_has(X86_FEATURE_NODEID_MSR)) { + u64 value; + + rdmsrl(MSR_FAM10H_NODE_ID, value); + nodes_per_processor = ((value >> 3) & 7) + 1; + } +} + /* * Fixup core topology information for * (1) AMD multi-node processors * Assumption: Number of cores in each internal node is the same. * (2) AMD processors supporting compute units */ -#ifdef CONFIG_X86_HT static void amd_get_topology(struct cpuinfo_x86 *c) { - u32 nodes, cores_per_cu = 1; + u32 cores_per_cu = 1; u8 node_id; int cpu = smp_processor_id(); + amd_set_num_nodes(); + /* get information required for multi-node processors */ if (cpu_has_topoext) { u32 eax, ebx, ecx, edx; cpuid(0x8000001e, &eax, &ebx, &ecx, &edx); - nodes = ((ecx >> 8) & 7) + 1; node_id = ecx & 7; /* get compute unit information */ @@ -311,18 +333,17 @@ static void amd_get_topology(struct cpuinfo_x86 *c) u64 value; rdmsrl(MSR_FAM10H_NODE_ID, value); - nodes = ((value >> 3) & 7) + 1; node_id = value & 7; } else return; /* fixup multi-node processor information */ - if (nodes > 1) { + if (nodes_per_processor > 1) { u32 cores_per_node; u32 cus_per_node; set_cpu_cap(c, X86_FEATURE_AMD_DCM); - cores_per_node = c->x86_max_cores / nodes; + cores_per_node = c->x86_max_cores / nodes_per_processor; cus_per_node = cores_per_node / cores_per_cu; /* store NodeID, use llc_shared_map to store sibling info */ @@ -333,7 +354,6 @@ static void amd_get_topology(struct cpuinfo_x86 *c) c->compute_unit_id %= cus_per_node; } } -#endif /* * On a AMD dual core setup the lower bits of the APIC id distinguish the cores. @@ -341,7 +361,6 @@ static void amd_get_topology(struct cpuinfo_x86 *c) */ static void amd_detect_cmp(struct cpuinfo_x86 *c) { -#ifdef CONFIG_X86_HT unsigned bits; int cpu = smp_processor_id(); @@ -353,7 +372,6 @@ static void amd_detect_cmp(struct cpuinfo_x86 *c) /* use socket ID also for last level cache */ per_cpu(cpu_llc_id, cpu) = c->phys_proc_id; amd_get_topology(c); -#endif } u16 amd_get_nb_id(int cpu) -- 2.4.0
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