linux-kernel - [PATCH v2 1/2] x86/amd: Refactor topology extension related code

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Date:   Fri, 21 Jul 2017 21:00:38 -0500
From:   Suravee Suthikulpanit <suravee.suthikulpanit@....com>
To:     linux-kernel@...r.kernel.org, x86@...nel.org
Cc:     tglx@...utronix.de, mingo@...hat.com, hpa@...or.com, bp@...e.de,
        peterz@...radead.org, Yazen.Ghannam@....com,
        Suravee Suthikulpanit <suravee.suthikulpanit@....com>
Subject: [PATCH v2 1/2] x86/amd: Refactor topology extension related code

Refactoring in preparation for subsequent changes.
There is no functional change.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@....com>
---
 arch/x86/kernel/cpu/amd.c | 79 ++++++++++++++++++++++++++---------------------
 1 file changed, 44 insertions(+), 35 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index bb5abe8..74d8d7c 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -297,54 +297,63 @@ static int nearby_node(int apicid)
 #endif
 
 /*
- * 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
+ * Get topology information via X86_FEATURE_TOPOEXT
  */
-#ifdef CONFIG_SMP
-static void amd_get_topology(struct cpuinfo_x86 *c)
+static void __get_topoext(struct cpuinfo_x86 *c)
 {
-	u8 node_id;
+	u32 eax, ebx, ecx, edx;
 	int cpu = smp_processor_id();
 
-	/* get information required for multi-node processors */
-	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
-		u32 eax, ebx, ecx, edx;
+	cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
 
-		cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
+	smp_num_siblings = ((ebx >> 8) & 0xff) + 1;
 
-		node_id  = ecx & 0xff;
-		smp_num_siblings = ((ebx >> 8) & 0xff) + 1;
+	if (c->x86 == 0x15)
+		c->cu_id = ebx & 0xff;
 
-		if (c->x86 == 0x15)
-			c->cu_id = ebx & 0xff;
+	if (c->x86 >= 0x17) {
+		c->cpu_core_id = ebx & 0xff;
 
-		if (c->x86 >= 0x17) {
-			c->cpu_core_id = ebx & 0xff;
+		if (smp_num_siblings > 1)
+			c->x86_max_cores /= smp_num_siblings;
+	}
 
-			if (smp_num_siblings > 1)
-				c->x86_max_cores /= smp_num_siblings;
-		}
+	/*
+	 * We may have multiple LLCs if L3 caches exist, so check if we
+	 * have an L3 cache by looking at the L3 cache CPUID leaf.
+	 */
+	if (cpuid_edx(0x80000006)) {
+		if (c->x86 == 0x17) {
+			/*
+			 * LLC is at the core complex level.
+			 * Core complex id is ApicId[3].
+			 */
+			per_cpu(cpu_llc_id, cpu) = c->apicid >> 3;
+		} else {
+			/* LLC is at the node level. */
+			u8 node_id = ecx & 0xff;
 
-		/*
-		 * We may have multiple LLCs if L3 caches exist, so check if we
-		 * have an L3 cache by looking at the L3 cache CPUID leaf.
-		 */
-		if (cpuid_edx(0x80000006)) {
-			if (c->x86 == 0x17) {
-				/*
-				 * LLC is at the core complex level.
-				 * Core complex id is ApicId[3].
-				 */
-				per_cpu(cpu_llc_id, cpu) = c->apicid >> 3;
-			} else {
-				/* LLC is at the node level. */
-				per_cpu(cpu_llc_id, cpu) = node_id;
-			}
+			per_cpu(cpu_llc_id, cpu) = node_id;
 		}
+	}
+}
+
+/*
+ * 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_SMP
+static void amd_get_topology(struct cpuinfo_x86 *c)
+{
+	/* get information required for multi-node processors */
+	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
+		__get_topoext(c);
 	} else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
+		u8 node_id;
 		u64 value;
+		int cpu = smp_processor_id();
 
 		rdmsrl(MSR_FAM10H_NODE_ID, value);
 		node_id = value & 7;
-- 
2.7.4