Add a check in get_cpu_info() for the ability to read frequencies
from hardware and set the CPUPOWER_CAP_AMD_HW_PSTATE cpuid flag.
The cpuid flag is set when CPUID_80000007_EDX[7] is set,
which is all families >= 10h. The check excludes family 14h
because HW pstate reporting was not implemented on family 14h.
This is intended to reduce family checks in the main code paths.
Signed-off-by: Nathan Fontenot <nathan.fonte...@amd.com>
---
Updates for v2: Update and add back previously removed comment.
---
tools/power/cpupower/utils/helpers/amd.c | 9 ++++-----
tools/power/cpupower/utils/helpers/cpuid.c | 12 +++++++++---
tools/power/cpupower/utils/helpers/helpers.h | 1 +
3 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/tools/power/cpupower/utils/helpers/amd.c
b/tools/power/cpupower/utils/helpers/amd.c
index 34368436bbd6..8b69c7ff639a 100644
--- a/tools/power/cpupower/utils/helpers/amd.c
+++ b/tools/power/cpupower/utils/helpers/amd.c
@@ -94,11 +94,10 @@ int decode_pstates(unsigned int cpu, unsigned int
cpu_family,
union core_pstate pstate;
unsigned long long val;
- /* Only read out frequencies from HW when CPU might be boostable
- to keep the code as short and clean as possible.
- Otherwise frequencies are exported via ACPI tables.
- */
- if (cpu_family < 0x10 || cpu_family == 0x14)
+ /* Only read out frequencies from HW if HW Pstate is supported,
+ * otherwise frequencies are exported via ACPI tables.
+ */
+ if (!(cpupower_cpu_info.caps & CPUPOWER_CAP_AMD_HW_PSTATE))
return -1;
if (read_msr(cpu, MSR_AMD_PSTATE_LIMIT, &val))
diff --git a/tools/power/cpupower/utils/helpers/cpuid.c
b/tools/power/cpupower/utils/helpers/cpuid.c
index f9a66a430b72..d577220a193b 100644
--- a/tools/power/cpupower/utils/helpers/cpuid.c
+++ b/tools/power/cpupower/utils/helpers/cpuid.c
@@ -128,9 +128,15 @@ int get_cpu_info(struct cpupower_cpu_info *cpu_info)
/* AMD or Hygon Boost state enable/disable register */
if (cpu_info->vendor == X86_VENDOR_AMD ||
cpu_info->vendor == X86_VENDOR_HYGON) {
- if (ext_cpuid_level >= 0x80000007 &&
- (cpuid_edx(0x80000007) & (1 << 9)))
- cpu_info->caps |= CPUPOWER_CAP_AMD_CPB;
+ if (ext_cpuid_level >= 0x80000007) {
+ if (cpuid_edx(0x80000007) & (1 << 9))
+ cpu_info->caps |= CPUPOWER_CAP_AMD_CPB;
+
+ if ((cpuid_edx(0x80000007) & (1 << 7)) &&
+ cpu_info->family != 0x14)
+ /* HW pstate was not implemented in family 0x14
*/
+ cpu_info->caps |= CPUPOWER_CAP_AMD_HW_PSTATE;
+ }
if (ext_cpuid_level >= 0x80000008 &&
cpuid_ebx(0x80000008) & (1 << 4))
diff --git a/tools/power/cpupower/utils/helpers/helpers.h
b/tools/power/cpupower/utils/helpers/helpers.h
index a84f85a9dbd2..5f61eefff5b2 100644
--- a/tools/power/cpupower/utils/helpers/helpers.h
+++ b/tools/power/cpupower/utils/helpers/helpers.h
@@ -70,6 +70,7 @@ enum cpupower_cpu_vendor {X86_VENDOR_UNKNOWN = 0,
X86_VENDOR_INTEL,
#define CPUPOWER_CAP_IS_SNB 0x00000020
#define CPUPOWER_CAP_INTEL_IDA 0x00000040
#define CPUPOWER_CAP_AMD_RDPRU 0x00000080
+#define CPUPOWER_CAP_AMD_HW_PSTATE 0x00000100
#define CPUPOWER_AMD_CPBDIS 0x02000000
