[tip:x86/amd-nb] x86, amd: Extract compute unit information for AMD CPUs

tip-bot for Andreas Herrmann
2010-10-04T20:26:53Z

Commit-ID: 6057b4d331f19a3ea51aec463ea7839c128b3227
Gitweb: http://git.kernel.org/tip/6057b4d331f19a3ea51aec463ea7839c128b3227
Author: Andreas Herrmann <andreas.herrmann3@amd.com>
AuthorDate: Thu, 30 Sep 2010 14:38:57 +0200
Committer: H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Fri, 1 Oct 2010 16:18:32 -0700

x86, amd: Extract compute unit information for AMD CPUs

Get compute unit information from CPUID Fn8000_001E_EBX.
(See AMD CPUID Specification - publication # 25481, revision 2.34,
September 2010.)

Note that each core on a compute unit still has a core_id of its own.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20100930123857.GE20545@loge.amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/include/asm/processor.h | 2 ++
arch/x86/kernel/cpu/amd.c | 20 +++++++++++++++-----
2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 325b7bd..69e80c2 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -110,6 +110,8 @@ struct cpuinfo_x86 {
u16 phys_proc_id;
/* Core id: */
u16 cpu_core_id;
+ /* Compute unit id */
+ u8 compute_unit_id;
/* Index into per_cpu list: */
u16 cpu_index;
#endif
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 7e6a37d..70168ab 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -256,21 +256,29 @@ static int __cpuinit nearby_node(int apicid)
* 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 __cpuinit amd_get_topology(struct cpuinfo_x86 *c)
{
- u32 nodes, cores_per_node;
+ u32 nodes;
u8 node_id;
- unsigned long long value;
int cpu = smp_processor_id();

/* 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;
+ u32 eax, ebx, ecx, edx;
+
+ cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
+ nodes = ((ecx >> 8) & 7) + 1;
+ node_id = ecx & 7;
+
+ /* get compute unit information */
+ smp_num_siblings = ((ebx >> 8) & 3) + 1;
+ c->compute_unit_id = ebx & 0xff;
} else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
+ u64 value;
+
rdmsrl(MSR_FAM10H_NODE_ID, value);
nodes = ((value >> 3) & 7) + 1;
node_id = value & 7;
@@ -279,6 +287,8 @@ static void __cpuinit amd_get_topology(struct cpuinfo_x86 *c)

/* fixup multi-node processor information */
if (nodes > 1) {
+ u32 cores_per_node;
+
set_cpu_cap(c, X86_FEATURE_AMD_DCM);
cores_per_node = c->x86_max_cores / nodes;