[PATCH 1/4] x86, amd: Normalize compute unit IDs on multi-node processors

From: Hans Rosenfeld
Date: Mon Jan 24 2011 - 10:06:00 EST


From: Andreas Herrmann <andreas.herrmann3@xxxxxxx>

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 <andreas.herrmann3@xxxxxxx>
---
arch/x86/kernel/cpu/amd.c | 8 ++++++--
arch/x86/kernel/smpboot.c | 1 +
2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 7c7bedb..990cc48 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
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 0cbe8c0..fbaa222 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -414,6 +414,7 @@ void __cpuinit set_cpu_sibling_map(int cpu)

if (cpu_has(c, X86_FEATURE_TOPOEXT)) {
if (c->phys_proc_id == o->phys_proc_id &&
+ per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i) &&
c->compute_unit_id == o->compute_unit_id)
link_thread_siblings(cpu, i);
} else if (c->phys_proc_id == o->phys_proc_id &&
--
1.5.6.5


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