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>

1 files changed, 18 insertions, 0 deletions

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 */