soc/amd/common/cpu: smbios: CPU frequency & voltage
Determine CPU frequency & voltage for use in smbios type 4 table.
Reference:
AMD PPR 57254 v1.59 Section 2.1.15 CPUID Instruction
TEST=Build for glinda SoC & verify output to reflect CPU frequency
& voltage.
Sample Output:
dmidecode -t
...
Voltage: 1.2 V
...
Current Speed: 2600 MHz
...
Change-Id: Ibd7c7f1e299a0a8d294e7e30ae3130faae16ae22
Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/86757
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/amd/common/block/cpu/noncar/cpu.c b/src/soc/amd/common/block/cpu/noncar/cpu.c
index 74b29cd..e67d669 100644
--- a/src/soc/amd/common/block/cpu/noncar/cpu.c
+++ b/src/soc/amd/common/block/cpu/noncar/cpu.c
@@ -9,8 +9,59 @@
#include <cpu/amd/mtrr.h>
#include <smbios.h>
#include <soc/iomap.h>
+#include <soc/msr.h>
#include <types.h>
+#define UNSUPPORTED 0
+
+#define UNINITIALIZED ((uint64_t)-1)
+
+static union pstate_msr get_pstate0_msr(void)
+{
+ static union pstate_msr pstate_reg = { .raw = UNINITIALIZED };
+
+ struct cpuid_result res;
+
+ /* Check if we have already determined P-state support */
+ if (pstate_reg.raw == UNINITIALIZED) {
+ if (cpu_cpuid_extended_level() < CPUID_EXT_PM) {
+ pstate_reg.pstate_en = UNSUPPORTED;
+ return pstate_reg;
+ }
+
+ res = cpuid(CPUID_EXT_PM);
+
+ if (!(res.edx & BIT(7))) { /* Hardware P-state control */
+ pstate_reg.pstate_en = UNSUPPORTED;
+ return pstate_reg;
+ }
+
+ pstate_reg.raw = rdmsr(PSTATE_MSR(get_pstate_0_reg())).raw;
+ }
+
+ return pstate_reg;
+}
+
+unsigned int smbios_cpu_get_current_speed_mhz(void)
+{
+ union pstate_msr pstate_reg = get_pstate0_msr();
+
+ if (!pstate_reg.pstate_en)
+ return 0;
+
+ return get_pstate_core_freq(pstate_reg);
+}
+
+unsigned int smbios_cpu_get_voltage(void)
+{
+ union pstate_msr pstate_reg = get_pstate0_msr();
+
+ if (!pstate_reg.pstate_en)
+ return 0;
+
+ return get_pstate_core_uvolts(pstate_reg) / 100000; /* uV to (10 * V) */
+}
+
uint32_t get_pstate_0_reg(void)
{
return 0;
