From d518573de63fb119e5e9a3137386544671387681 Mon Sep 17 00:00:00 2001 From: Andreas Herrmann Date: Mon, 24 Jan 2011 16:05:40 +0100 Subject: x86, amd: Normalize compute unit IDs on multi-node processors On multi-node CPUs we don't need the socket wide compute unit ID but the node-wide compute unit ID. Thus we need to normalize the value. This is similar to what we do with cpu_core_id. A compute unit is then identified by physical_package_id, node_id, and compute_unit_id. Signed-off-by: Andreas Herrmann LKML-Reference: <1295881543-572552-2-git-send-email-hans.rosenfeld@amd.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/amd.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'arch/x86/kernel/cpu/amd.c') diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 7c7bedb83c5..990cc486158 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -261,7 +261,7 @@ static int __cpuinit nearby_node(int apicid) #ifdef CONFIG_X86_HT static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c) { - u32 nodes; + u32 nodes, cores_per_cu; u8 node_id; int cpu = smp_processor_id(); @@ -276,6 +276,7 @@ static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c) /* get compute unit information */ smp_num_siblings = ((ebx >> 8) & 3) + 1; c->compute_unit_id = ebx & 0xff; + cores_per_cu = ((ebx >> 8) & 3) + 1; } else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) { u64 value; @@ -288,15 +289,18 @@ static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c) /* fixup multi-node processor information */ if (nodes > 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; + cus_per_node = cores_per_node / cores_per_cu; /* store NodeID, use llc_shared_map to store sibling info */ per_cpu(cpu_llc_id, cpu) = node_id; /* core id to be in range from 0 to (cores_per_node - 1) */ - c->cpu_core_id = c->cpu_core_id % cores_per_node; + c->cpu_core_id %= cores_per_node; + c->compute_unit_id %= cus_per_node; } } #endif -- cgit v1.2.3-70-g09d2 From 9e81509efc4fefcdd75cc6a4121672fa71ae8745 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Mon, 14 Feb 2011 18:14:51 +0100 Subject: x86, amd: Initialize variable properly Commit d518573de63f ("x86, amd: Normalize compute unit IDs on multi-node processors") introduced compute unit normalization but causes a compiler warning: arch/x86/kernel/cpu/amd.c: In function 'amd_detect_cmp': arch/x86/kernel/cpu/amd.c:268: warning: 'cores_per_cu' may be used uninitialized in this function arch/x86/kernel/cpu/amd.c:268: note: 'cores_per_cu' was declared here The compiler is right - initialize it with a proper value. Also, fix up a comment while at it. Reported-by: Andrew Morton Signed-off-by: Borislav Petkov Cc: Andreas Herrmann LKML-Reference: <20110214171451.GB10076@kryptos.osrc.amd.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/amd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/cpu/amd.c') diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 990cc486158..589bdd7a4cf 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -261,7 +261,7 @@ static int __cpuinit nearby_node(int apicid) #ifdef CONFIG_X86_HT static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c) { - u32 nodes, cores_per_cu; + u32 nodes, cores_per_cu = 1; u8 node_id; int cpu = smp_processor_id(); @@ -276,7 +276,7 @@ static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c) /* get compute unit information */ smp_num_siblings = ((ebx >> 8) & 3) + 1; c->compute_unit_id = ebx & 0xff; - cores_per_cu = ((ebx >> 8) & 3) + 1; + cores_per_cu += ((ebx >> 8) & 3); } else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) { u64 value; @@ -298,7 +298,7 @@ static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c) /* store NodeID, use llc_shared_map to store sibling info */ per_cpu(cpu_llc_id, cpu) = node_id; - /* core id to be in range from 0 to (cores_per_node - 1) */ + /* core id has to be in the [0 .. cores_per_node - 1] range */ c->cpu_core_id %= cores_per_node; c->compute_unit_id %= cus_per_node; } -- cgit v1.2.3-70-g09d2