x86/CPU: Make intel_num_cpu_cores() generic

intel_num_cpu_cores() is a static function in intel.c which can't be used
by other files. Define another function called detect_num_cpu_cores() in
common.c to replace this function so it can be reused.
Signed-off-by: David Wang <davidwang@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: lukelin@viacpu.com
Cc: qiyuanwang@zhaoxin.com
Cc: gregkh@linuxfoundation.org
Cc: brucechang@via-alliance.com
Cc: timguo@zhaoxin.com
Cc: cooperyan@zhaoxin.com
Cc: hpa@zytor.com
Cc: benjaminpan@viatech.com
Link: https://lkml.kernel.org/r/1525314766-18910-2-git-send-email-davidwang@zhaoxin.com

arch/x86/kernel/cpu/common.c

@@ -584,6 +584,20 @@ static void get_model_name(struct cpuinfo_x86 *c)
 	*(s + 1) = '\0';
 }
 
+int detect_num_cpu_cores(struct cpuinfo_x86 *c)
+{
+	unsigned int eax, ebx, ecx, edx;
+
+	if (!IS_ENABLED(CONFIG_SMP) || c->cpuid_level < 4)
+		return 1;
+
+	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
+	if (eax & 0x1f)
+		return (eax >> 26) + 1;
+	else
+		return 1;
+}
+
 void cpu_detect_cache_sizes(struct cpuinfo_x86 *c)
 {
 	unsigned int n, dummy, ebx, ecx, edx, l2size;

arch/x86/kernel/cpu/cpu.h

@@ -54,6 +54,7 @@ extern u32 get_scattered_cpuid_leaf(unsigned int level,
 extern unsigned int init_intel_cacheinfo(struct cpuinfo_x86 *c);
 extern void init_amd_cacheinfo(struct cpuinfo_x86 *c);
 
+extern int detect_num_cpu_cores(struct cpuinfo_x86 *c);
 extern int detect_extended_topology(struct cpuinfo_x86 *c);
 extern void detect_ht(struct cpuinfo_x86 *c);
 

arch/x86/kernel/cpu/intel.c

@@ -453,24 +453,6 @@ static void srat_detect_node(struct cpuinfo_x86 *c)
 #endif
 }
 
-/*
- * find out the number of processor cores on the die
- */
-static int intel_num_cpu_cores(struct cpuinfo_x86 *c)
-{
-	unsigned int eax, ebx, ecx, edx;
-
-	if (!IS_ENABLED(CONFIG_SMP) || c->cpuid_level < 4)
-		return 1;
-
-	/* Intel has a non-standard dependency on %ecx for this CPUID level. */
-	cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
-	if (eax & 0x1f)
-		return (eax >> 26) + 1;
-	else
-		return 1;
-}
-
 static void detect_vmx_virtcap(struct cpuinfo_x86 *c)
 {
 	/* Intel VMX MSR indicated features */
@@ -671,7 +653,7 @@ static void init_intel(struct cpuinfo_x86 *c)
 		 * let's use the legacy cpuid vector 0x1 and 0x4 for topology
 		 * detection.
 		 */
-		c->x86_max_cores = intel_num_cpu_cores(c);
+		c->x86_max_cores = detect_num_cpu_cores(c);
 #ifdef CONFIG_X86_32
 		detect_ht(c);
 #endif