cpuid: Add helper function for cpuid(1) functions

This patch introduces 3 helper function for cpuid(1) :

1. cpu_get_cpuid() -> to get processor id (from cpuid.eax)
2. cpu_get_feature_flags_ecx -> to get processor feature flag (from cpuid.ecx)
3. cpu_get_feature_flags_edx -> to get processor feature flag (from cpuid.edx)

Above 3 helper functions are targeted to replace majority of cpuid(1)
references.

Change-Id: Ib96a7c79dadb1feff0b8d58aa408b355fbb3bc50
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/30123
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

4 files changed, 48 insertions, 5 deletions

diff --git a/src/arch/x86/cpu.c b/src/arch/x86/cpu.c
index 6bbeb59464..018ce9ed7a 100644
--- a/src/arch/x86/cpu.c
+++ b/src/arch/x86/cpu.c
@@ -183,7 +183,7 @@ static void identify_cpu(struct device *cpu)
 
 		/* Intel-defined flags: level 0x00000001 */
 		if (cpuid_level >= 0x00000001)
-			cpu->device = cpuid_eax(0x00000001);
+			cpu->device = cpu_get_cpuid();
 		else
 			/* Have CPUID level 0 only unheard of */
 			cpu->device = 0x00000400;
diff --git a/src/arch/x86/cpu_common.c b/src/arch/x86/cpu_common.c
index d328fe9030..119122786d 100644
--- a/src/arch/x86/cpu_common.c
+++ b/src/arch/x86/cpu_common.c
@@ -66,3 +66,30 @@ int cpu_phys_address_size(void)
 		return 36;
 	return 32;
 }
+
+/*
+ * Get processor id using cpuid eax=1
+ * return value in EAX register
+ */
+uint32_t cpu_get_cpuid(void)
+{
+	return cpuid_eax(1);
+}
+
+/*
+ * Get processor feature flag using cpuid eax=1
+ * return value in ECX register
+ */
+uint32_t cpu_get_feature_flags_ecx(void)
+{
+	return cpuid_ecx(1);
+}
+
+/*
+ * Get processor feature flag using cpuid eax=1
+ * return value in EDX register
+ */
+uint32_t cpu_get_feature_flags_edx(void)
+{
+	return cpuid_edx(1);
+}
diff --git a/src/arch/x86/include/arch/cpu.h b/src/arch/x86/include/arch/cpu.h
index 99d10004db..00696e6bea 100644
--- a/src/arch/x86/include/arch/cpu.h
+++ b/src/arch/x86/include/arch/cpu.h
@@ -311,4 +311,22 @@ void late_car_teardown(void);
 
 #endif
 
+/*
+ * Get processor id using cpuid eax=1
+ * return value in EAX register
+ */
+uint32_t cpu_get_cpuid(void);
+
+/*
+ * Get processor feature flag using cpuid eax=1
+ * return value in ECX register
+ */
+uint32_t cpu_get_feature_flags_ecx(void);
+
+/*
+ * Get processor feature flag using cpuid eax=1
+ * return value in EDX register
+ */
+uint32_t cpu_get_feature_flags_edx(void);
+
 #endif /* ARCH_CPU_H */
diff --git a/src/arch/x86/mpspec.c b/src/arch/x86/mpspec.c
index b44662d38b..28a9080e2e 100644
--- a/src/arch/x86/mpspec.c
+++ b/src/arch/x86/mpspec.c
@@ -161,14 +161,12 @@ void smp_write_processors(struct mp_config_table *mc)
 	unsigned int apic_version;
 	unsigned int cpu_features;
 	unsigned int cpu_feature_flags;
-	struct cpuid_result result;
 	struct device *cpu;
 
 	boot_apic_id = lapicid();
 	apic_version = lapic_read(LAPIC_LVR) & 0xff;
-	result = cpuid(1);
-	cpu_features = result.eax;
-	cpu_feature_flags = result.edx;
+	cpu_features = cpu_get_cpuid();
+	cpu_feature_flags = cpu_get_feature_flags_edx();
 	/* order the output of the cpus to fix a bug in kernel 2.6.11 */
 	for (order_id = 0; order_id < 256; order_id++) {
 		for (cpu = all_devices; cpu; cpu = cpu->next) {