soc/intel/alderlake: Implement get_soc_cpu_type helper function

The patch implements get_soc_cpu_type() helper function which
determines whether the executing CPU is a small or a big core. This is
the SoC-specific callback that must be implemented for SoCs that select
SOC_INTEL_COMMON_BLOCK_ACPI_CPU_HYBRID. It will be called from
set_cpu_type().

TEST=verified on Brya

Signed-off-by: Sridhar Siricilla <sridhar.siricilla@intel.com>
Change-Id: Icd0d7e8a42c4b20d3e1d34998bca6321509df2d8
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61075
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/soc/intel/alderlake/cpu.c

@@ -19,12 +19,18 @@
 #include <intelblocks/cpulib.h>
 #include <intelblocks/mp_init.h>
 #include <intelblocks/msr.h>
+#include <intelblocks/acpi.h>
 #include <soc/cpu.h>
 #include <soc/msr.h>
 #include <soc/pci_devs.h>
 #include <soc/soc_chip.h>
 #include <types.h>
 
+enum alderlake_model {
+	ADL_MODEL_P_M = 0x9A,
+	ADL_MODEL_N = 0xBE,
+};
+
 bool cpu_soc_is_in_untrusted_mode(void)
 {
 	msr_t msr;
@@ -69,6 +75,21 @@ static void configure_misc(void)
 	wrmsr(MSR_POWER_CTL, msr);
 }
 
+enum core_type get_soc_cpu_type(void)
+{
+	struct cpuinfo_x86 cpuinfo;
+
+	if (cpu_is_hybrid_supported())
+		return cpu_get_cpu_type();
+
+	get_fms(&cpuinfo, cpuid_eax(1));
+
+	if (cpuinfo.x86 == 0x6 && cpuinfo.x86_model == ADL_MODEL_N)
+		return CPUID_CORE_TYPE_INTEL_ATOM;
+	else
+		return CPUID_CORE_TYPE_INTEL_CORE;
+}
+
 /* All CPUs including BSP will run the following function. */
 void soc_core_init(struct device *cpu)
 {