x86/CPU/AMD: Derive CPU topology from CPUID function 0xB when available

Derive topology information from Extended Topology Enumeration (CPUID
function 0xB) when the information is available.

Signed-off-by: Suravee Suthikulpanit <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]

Author: ssuthiku-amd

arch/x86/kernel/cpu/amd.c

@@ -327,6 +327,7 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
 
 	/* get information required for multi-node processors */
 	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
+		int err;
 		u32 eax, ebx, ecx, edx;
 
 		cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
@@ -344,6 +345,14 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
 				c->x86_max_cores /= smp_num_siblings;
 		}
 
+		/*
+		 * In case leaf B is available, use it to derive
+		 * topology information.
+		 */
+		err = detect_extended_topology(c);
+		if (!err)
+			c->x86_coreid_bits = get_count_order(c->x86_max_cores);
+
 		cacheinfo_amd_init_llc_id(c, cpu, node_id);
 
 	} else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
@@ -378,7 +387,6 @@ static void 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;
-	amd_get_topology(c);
 }
 
 u16 amd_get_nb_id(int cpu)
@@ -821,6 +829,7 @@ static void init_amd(struct cpuinfo_x86 *c)
 	/* Multi core CPU? */
 	if (c->extended_cpuid_level >= 0x80000008) {
 		amd_detect_cmp(c);
+		amd_get_topology(c);
 		srat_detect_node(c);
 	}