[PATCH] tools/power/cpupower: Fix Pstate frequency reporting on AMD Family 1Ah CPUs

From: Dhananjay Ugwekar
Date: Tue Apr 30 2024 - 04:37:32 EST


Update cpupower's P-State frequency calculation and reporting with AMD
Family 1Ah+ processors, when using the acpi-cpufreq driver. This is due
to a change in the PStateDef MSR layout in AMD Family 1Ah+.

[ dhananjay: commit log, tested on 4th and 5th Gen AMD EPYC system ]

Signed-off-by: Ananth Narayan <Ananth.Narayan@xxxxxxx>
Signed-off-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@xxxxxxx>
---
tools/power/cpupower/utils/helpers/amd.c | 26 +++++++++++++++++++++---
1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/tools/power/cpupower/utils/helpers/amd.c b/tools/power/cpupower/utils/helpers/amd.c
index c519cc89c97f..0a56e22240fc 100644
--- a/tools/power/cpupower/utils/helpers/amd.c
+++ b/tools/power/cpupower/utils/helpers/amd.c
@@ -41,6 +41,16 @@ union core_pstate {
unsigned res1:31;
unsigned en:1;
} pstatedef;
+ /* since fam 1Ah: */
+ struct {
+ unsigned fid:12;
+ unsigned res1:2;
+ unsigned vid:8;
+ unsigned iddval:8;
+ unsigned idddiv:2;
+ unsigned res2:31;
+ unsigned en:1;
+ } pstatedef2;
unsigned long long val;
};

@@ -48,6 +58,10 @@ static int get_did(union core_pstate pstate)
{
int t;

+ /* Fam 1Ah onward do not use did */
+ if (cpupower_cpu_info.family >= 0x1A)
+ return 0;
+
if (cpupower_cpu_info.caps & CPUPOWER_CAP_AMD_PSTATEDEF)
t = pstate.pstatedef.did;
else if (cpupower_cpu_info.family == 0x12)
@@ -61,12 +75,18 @@ static int get_did(union core_pstate pstate)
static int get_cof(union core_pstate pstate)
{
int t;
- int fid, did, cof;
+ int fid, did, cof = 0;

did = get_did(pstate);
if (cpupower_cpu_info.caps & CPUPOWER_CAP_AMD_PSTATEDEF) {
- fid = pstate.pstatedef.fid;
- cof = 200 * fid / did;
+ if (cpupower_cpu_info.family >= 0x1A) {
+ fid = pstate.pstatedef2.fid;
+ if (fid > 0x0f)
+ cof = (fid * 5);
+ } else {
+ fid = pstate.pstatedef.fid;
+ cof = 200 * fid / did;
+ }
} else {
t = 0x10;
fid = pstate.pstate.fid;
--
2.34.1