soc/intel/common: Add CPU related APIs

The patch defines below APIs :
cpu_is_hybrid_supported() : Check whether CPU is hybrid CPU or not.
cpu_get_bus_frequency() : Get CPU's bus frequency in MHz
cpu_get_max_non_turbo_ratio() : Get CPU's max non-turbo ratio
cpu_get_cpu_type() : Get CPU type. The function must be called if
executing CPU is hybrid.

TEST=Verified the APIs on the Brya board

Signed-off-by: Sridhar Siricilla <sridhar.siricilla@intel.com>
Change-Id: I680f43952ab4abce6e342206688ad32814970a91
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59124
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

2 files changed, 68 insertions, 0 deletions

diff --git a/src/soc/intel/common/block/cpu/cpulib.c b/src/soc/intel/common/block/cpu/cpulib.c
index 93725132b2..617968a1bc 100644
--- a/src/soc/intel/common/block/cpu/cpulib.c
+++ b/src/soc/intel/common/block/cpu/cpulib.c
@@ -31,6 +31,13 @@
 #define CPUID_CPU_TOPOLOGY_CORE_BITS(res, threadbits) \
 	((CPUID_CPU_TOPOLOGY(LEVEL_BITS, (res).eax)) - threadbits)
 
+#define CPUID_PROCESSOR_FREQUENCY		0X16
+#define CPUID_HYBRID_INFORMATION		0x1a
+
+/* Structured Extended Feature Flags */
+#define CPUID_STRUCT_EXTENDED_FEATURE_FLAGS	0x7
+#define HYBRID_FEATURE				BIT(15)
+
 /*
  * Set PERF_CTL MSR (0x199) P_Req with
  * Turbo Ratio which is the Maximum Ratio.
@@ -185,6 +192,40 @@ int cpu_get_burst_mode_state(void)
 	return burst_state;
 }
 
+bool cpu_is_hybrid_supported(void)
+{
+	struct cpuid_result cpuid_regs;
+
+	/* CPUID.(EAX=07H, ECX=00H):EDX[15] indicates CPU is hybrid CPU or not*/
+	cpuid_regs = cpuid_ext(CPUID_STRUCT_EXTENDED_FEATURE_FLAGS, 0);
+	return !!(cpuid_regs.edx & HYBRID_FEATURE);
+}
+
+/*
+ * The function must be called if CPU is hybrid. If CPU is hybrid, the CPU type
+ * information is available in the Hybrid Information Enumeration Leaf(EAX=0x1A, ECX=0).
+ */
+uint8_t cpu_get_cpu_type(void)
+{
+	union cpuid_nat_model_id_and_core_type {
+		struct {
+			u32 native_mode_id:24;
+			u32 core_type:8;
+		} bits;
+		u32 hybrid_info;
+	};
+	union cpuid_nat_model_id_and_core_type eax;
+
+	eax.hybrid_info = cpuid_eax(CPUID_HYBRID_INFORMATION);
+	return (u8)eax.bits.core_type;
+}
+
+/* It gets CPU bus frequency in MHz */
+uint32_t cpu_get_bus_frequency(void)
+{
+	return cpuid_ecx(CPUID_PROCESSOR_FREQUENCY);
+}
+
 /*
  * Program CPU Burst mode
  * true = Enable Burst mode.
@@ -275,6 +316,18 @@ uint32_t cpu_get_max_ratio(void)
 	return ratio_max;
 }
 
+uint8_t cpu_get_max_non_turbo_ratio(void)
+{
+	msr_t msr;
+
+	/*
+	 * PLATFORM_INFO(0xCE) MSR Bits[15:8] tells
+	 * MAX_NON_TURBO_LIM_RATIO
+	 */
+	msr = rdmsr(MSR_PLATFORM_INFO);
+	return ((msr.lo >> 8) & 0xff);
+}
+
 void configure_tcc_thermal_target(void)
 {
 	const config_t *conf = config_of_soc();
diff --git a/src/soc/intel/common/block/include/intelblocks/cpulib.h b/src/soc/intel/common/block/include/intelblocks/cpulib.h
index 7e3deb0fd4..094acebd54 100644
--- a/src/soc/intel/common/block/include/intelblocks/cpulib.h
+++ b/src/soc/intel/common/block/include/intelblocks/cpulib.h
@@ -11,6 +11,21 @@
  */
 void cpu_set_max_ratio(void);
 
+/* Get CPU bus frequency in MHz */
+u32 cpu_get_bus_frequency(void);
+
+/* Get CPU's max non-turbo ratio */
+u8 cpu_get_max_non_turbo_ratio(void);
+
+/* Check if CPU is hybrid CPU or not */
+bool cpu_is_hybrid_supported(void);
+
+/*
+ * Returns type of CPU that executing the function. It returns 0x20
+ * if CPU is atom, otherwise 0x40 if CPU is CORE. The API must be called
+ * if CPU is hybrid.
+ */
+uint8_t cpu_get_cpu_type(void);
 /*
  * Get the TDP Nominal Ratio from MSR 0x648 Bits 7:0.
  */