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Commit 6057b4d3 authored by Andreas Herrmann's avatar Andreas Herrmann Committed by H. Peter Anvin
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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: default avatarAndreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <20100930123857.GE20545@loge.amd.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 23588c38

arch/x86/include/asm/processor.h

+2 −0
Original line number Diff line number Diff line
@@ -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

arch/x86/kernel/cpu/amd.c

+15 −5
Original line number Diff line number Diff line
@@ -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;