From 23588c38a84c9175c6668789b64ffba4651e5c6a Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Thu, 30 Sep 2010 14:36:28 +0200 Subject: [PATCH] x86, amd: Add support for CPUID topology extension of AMD CPUs Node information (ID, number of internal nodes) is provided via CPUID Fn8000_001e_ECX. See AMD CPUID Specification (Publication # 25481, Revision 2.34, September 2010). Signed-off-by: Andreas Herrmann LKML-Reference: <20100930123628.GD20545@loge.amd.com> Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/amd.c | 50 ++++++++++++++++++++------------------- 1 file changed, 26 insertions(+), 24 deletions(-) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 0f0ace5d7db5..7e6a37d24253 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -253,37 +253,41 @@ static int __cpuinit nearby_node(int apicid) #endif /* - * Fixup core topology information for AMD multi-node processors. - * Assumption: Number of cores in each internal node is the same. + * Fixup core topology information for + * (1) AMD multi-node processors + * Assumption: Number of cores in each internal node is the same. */ #ifdef CONFIG_X86_HT -static void __cpuinit amd_fixup_dcm(struct cpuinfo_x86 *c) +static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c) { - unsigned long long value; u32 nodes, cores_per_node; + u8 node_id; + unsigned long long value; int cpu = smp_processor_id(); - if (!cpu_has(c, X86_FEATURE_NODEID_MSR)) - return; - - /* fixup topology information only once for a core */ - if (cpu_has(c, X86_FEATURE_AMD_DCM)) + /* get information required for multi-node processors */ + if (cpu_has(c, X86_FEATURE_TOPOEXT)) { + value = cpuid_ecx(0x8000001e); + nodes = ((value >> 8) & 7) + 1; + node_id = value & 7; + } else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) { + rdmsrl(MSR_FAM10H_NODE_ID, value); + nodes = ((value >> 3) & 7) + 1; + node_id = value & 7; + } else return; - rdmsrl(MSR_FAM10H_NODE_ID, value); + /* fixup multi-node processor information */ + if (nodes > 1) { + set_cpu_cap(c, X86_FEATURE_AMD_DCM); + cores_per_node = c->x86_max_cores / nodes; - nodes = ((value >> 3) & 7) + 1; - if (nodes == 1) - return; - - set_cpu_cap(c, X86_FEATURE_AMD_DCM); - cores_per_node = c->x86_max_cores / nodes; + /* store NodeID, use llc_shared_map to store sibling info */ + per_cpu(cpu_llc_id, cpu) = node_id; - /* store NodeID, use llc_shared_map to store sibling info */ - per_cpu(cpu_llc_id, cpu) = value & 7; - - /* fixup core id to be in range from 0 to (cores_per_node - 1) */ - c->cpu_core_id = c->cpu_core_id % cores_per_node; + /* core id to be in range from 0 to (cores_per_node - 1) */ + c->cpu_core_id = c->cpu_core_id % cores_per_node; + } } #endif @@ -304,9 +308,7 @@ static void __cpuinit amd_detect_cmp(struct cpuinfo_x86 *c) c->phys_proc_id = c->initial_apicid >> bits; /* use socket ID also for last level cache */ per_cpu(cpu_llc_id, cpu) = c->phys_proc_id; - /* fixup topology information on multi-node processors */ - if ((c->x86 == 0x10) && (c->x86_model == 9)) - amd_fixup_dcm(c); + amd_get_topology(c); #endif } -- 2.20.1