[PATCH v2 6/7] platform/x86/intel/pmc: Retrieve PMC info only for available PMCs

Xi Pardee
2026-04-08T22:21:52Z

Update the Intel PMC Core driver to fetch PMC information only for
available PMCs. Previously, the driver attempted to retrieve PMC info
even when the corresponding PMC was not present.

This change aligns with recent updates to the Intel SSRAM Telemetry
driver. Starting with NVL, the SSRAM Telemetry driver is probed for
each individual SSRAM device. The prior implementation could not
differentiate between an unavailable PMC and one that had not yet
completed information retrieval. To resolve this, the PMC Core driver
now skips obtaining PMC info for unavailable PMCs.

Signed-off-by: Xi Pardee <xi.pardee@linux.intel.com>
---
drivers/platform/x86/intel/pmc/arl.c | 7 +++++++
drivers/platform/x86/intel/pmc/core.c | 19 +++++++++++--------
drivers/platform/x86/intel/pmc/core.h | 4 ++++
drivers/platform/x86/intel/pmc/lnl.c | 4 ++++
drivers/platform/x86/intel/pmc/mtl.c | 4 ++++
drivers/platform/x86/intel/pmc/ptl.c | 4 ++++
drivers/platform/x86/intel/pmc/wcl.c | 4 ++++
7 files changed, 38 insertions(+), 8 deletions(-)

diff --git a/drivers/platform/x86/intel/pmc/arl.c b/drivers/platform/x86/intel/pmc/arl.c
index 4d91ee010f6d0..cd15559864317 100644
--- a/drivers/platform/x86/intel/pmc/arl.c
+++ b/drivers/platform/x86/intel/pmc/arl.c
@@ -672,6 +672,9 @@ static struct pmc_info arl_pmc_info_list[] = {
{}
};

+static u8 arl_pmc_list[] = {PMC_IDX_MAIN, PMC_IDX_IOE, PMC_IDX_PCH};
+static u8 arl_h_pmc_list[] = {PMC_IDX_MAIN, PMC_IDX_IOE};
+
#define ARL_NPU_PCI_DEV 0xad1d
#define ARL_GNA_PCI_DEV 0xae4c
#define ARL_H_NPU_PCI_DEV 0x7d1d
@@ -721,6 +724,8 @@ static int arl_h_core_init(struct pmc_dev *pmcdev, struct pmc_dev_info *pmc_dev_
static u32 ARL_PMT_DMU_GUIDS[] = {ARL_PMT_DMU_GUID, 0x0};
struct pmc_dev_info arl_pmc_dev = {
.dmu_guids = ARL_PMT_DMU_GUIDS,
+ .num_pmcs = ARRAY_SIZE(arl_pmc_list),
+ .pmc_list = arl_pmc_list,
.regmap_list = arl_pmc_info_list,
.map = &arl_socs_reg_map,
.sub_req_show = &pmc_core_substate_req_regs_fops,
@@ -735,6 +740,8 @@ struct pmc_dev_info arl_pmc_dev = {
static u32 ARL_H_PMT_DMU_GUIDS[] = {ARL_PMT_DMU_GUID, ARL_H_PMT_DMU_GUID, 0x0};
struct pmc_dev_info arl_h_pmc_dev = {
.dmu_guids = ARL_H_PMT_DMU_GUIDS,
+ .num_pmcs = ARRAY_SIZE(arl_h_pmc_list),
+ .pmc_list = arl_h_pmc_list,
.regmap_list = arl_pmc_info_list,
.map = &mtl_socm_reg_map,
.sub_req_show = &pmc_core_substate_req_regs_fops,
diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 5d2e2681b0eba..c84e75b19aac3 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -1734,16 +1734,17 @@ static int pmc_core_pmc_add(struct pmc_dev *pmcdev, unsigned int pmc_idx)
return 0;
}

-static int pmc_core_ssram_get_reg_base(struct pmc_dev *pmcdev)
+static int pmc_core_ssram_get_reg_base(struct pmc_dev *pmcdev, u8 num_pmcs, u8 *pmc_list)
{
+ unsigned int i;
int ret;

- ret = pmc_core_pmc_add(pmcdev, PMC_IDX_MAIN);
- if (ret)
- return ret;
-
- pmc_core_pmc_add(pmcdev, PMC_IDX_IOE);
- pmc_core_pmc_add(pmcdev, PMC_IDX_PCH);
+ for (i = 0; i < num_pmcs; ++i) {
+ /* Non-MAIN PMCs are allowed to fail */
+ ret = pmc_core_pmc_add(pmcdev, pmc_list[i]);
+ if (ret && (pmc_list[i] == PMC_IDX_MAIN))
+ return ret;
+ }

return 0;
}
@@ -1765,7 +1766,9 @@ int generic_core_init(struct pmc_dev *pmcdev, struct pmc_dev_info *pmc_dev_info)
ssram = pmc_dev_info->regmap_list != NULL;
if (ssram) {
pmcdev->regmap_list = pmc_dev_info->regmap_list;
- ret = pmc_core_ssram_get_reg_base(pmcdev);
+ ret = pmc_core_ssram_get_reg_base(pmcdev,
+ pmc_dev_info->num_pmcs,
+ pmc_dev_info->pmc_list);
/*
* EAGAIN error code indicates Intel PMC SSRAM Telemetry driver
* has not finished probe and PMC info is not available yet. Try
diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
index ef69de160ffbc..a741e4698f195 100644
--- a/drivers/platform/x86/intel/pmc/core.h
+++ b/drivers/platform/x86/intel/pmc/core.h
@@ -501,6 +501,8 @@ enum pmc_index {
* @pc_guid: GUID for telemetry region to read PKGC blocker info
* @pkgc_ltr_blocker_offset: Offset to PKGC LTR blockers in telemetry region
* @pkgc_blocker_offset:Offset to PKGC blocker in telemetry region
+ * @num_pmcs: Number of entries in @pmc_list
+ * @pmc_list: Index list of available PMC
* @regmap_list: Pointer to a list of pmc_info structure that could be
* available for the platform. When set, this field implies
* SSRAM support.
@@ -521,6 +523,8 @@ struct pmc_dev_info {
u32 pc_guid;
u32 pkgc_ltr_blocker_offset;
u32 pkgc_blocker_offset;
+ u8 num_pmcs;
+ u8 *pmc_list;
struct pmc_info *regmap_list;
const struct pmc_reg_map *map;
const struct file_operations *sub_req_show;
diff --git a/drivers/platform/x86/intel/pmc/lnl.c b/drivers/platform/x86/intel/pmc/lnl.c
index 18f303af328e3..02cbcfbb8e2a6 100644
--- a/drivers/platform/x86/intel/pmc/lnl.c
+++ b/drivers/platform/x86/intel/pmc/lnl.c
@@ -544,6 +544,8 @@ static struct pmc_info lnl_pmc_info_list[] = {
{}
};

+static u8 lnl_pmc_list[] = {PMC_IDX_MAIN};
+
#define LNL_NPU_PCI_DEV 0x643e
#define LNL_IPU_PCI_DEV 0x645d

@@ -571,6 +573,8 @@ static int lnl_core_init(struct pmc_dev *pmcdev, struct pmc_dev_info *pmc_dev_in
}

struct pmc_dev_info lnl_pmc_dev = {
+ .num_pmcs = ARRAY_SIZE(lnl_pmc_list),
+ .pmc_list = lnl_pmc_list,
.regmap_list = lnl_pmc_info_list,
.map = &lnl_socm_reg_map,
.sub_req_show = &pmc_core_substate_req_regs_fops,
diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
index b724dd8c34dba..e4ac09ce07a71 100644
--- a/drivers/platform/x86/intel/pmc/mtl.c
+++ b/drivers/platform/x86/intel/pmc/mtl.c
@@ -965,6 +965,8 @@ static struct pmc_info mtl_pmc_info_list[] = {
{}
};

+static u8 mtl_pmc_list[] = {PMC_IDX_MAIN, PMC_IDX_IOE};
+
#define MTL_GNA_PCI_DEV 0x7e4c
#define MTL_IPU_PCI_DEV 0x7d19
#define MTL_VPU_PCI_DEV 0x7d1d
@@ -995,6 +997,8 @@ static int mtl_core_init(struct pmc_dev *pmcdev, struct pmc_dev_info *pmc_dev_in
static u32 MTL_PMT_DMU_GUIDS[] = {MTL_PMT_DMU_GUID, 0x0};
struct pmc_dev_info mtl_pmc_dev = {
.dmu_guids = MTL_PMT_DMU_GUIDS,
+ .num_pmcs = ARRAY_SIZE(mtl_pmc_list),
+ .pmc_list = mtl_pmc_list,
.regmap_list = mtl_pmc_info_list,
.map = &mtl_socm_reg_map,
.sub_req_show = &pmc_core_substate_req_regs_fops,
diff --git a/drivers/platform/x86/intel/pmc/ptl.c b/drivers/platform/x86/intel/pmc/ptl.c
index 6c68772e738c8..7aa39db256770 100644
--- a/drivers/platform/x86/intel/pmc/ptl.c
+++ b/drivers/platform/x86/intel/pmc/ptl.c
@@ -543,6 +543,8 @@ static struct pmc_info ptl_pmc_info_list[] = {
{}
};

+static u8 ptl_pmc_list[] = {PMC_IDX_MAIN};
+
#define PTL_NPU_PCI_DEV 0xb03e
#define PTL_IPU_PCI_DEV 0xb05d

@@ -569,6 +571,8 @@ static int ptl_core_init(struct pmc_dev *pmcdev, struct pmc_dev_info *pmc_dev_in
}

struct pmc_dev_info ptl_pmc_dev = {
+ .num_pmcs = ARRAY_SIZE(ptl_pmc_list),
+ .pmc_list = ptl_pmc_list,
.regmap_list = ptl_pmc_info_list,
.map = &ptl_pcdp_reg_map,
.sub_req_show = &pmc_core_substate_blk_req_fops,
diff --git a/drivers/platform/x86/intel/pmc/wcl.c b/drivers/platform/x86/intel/pmc/wcl.c
index b55069945e9e7..4cae8501872aa 100644
--- a/drivers/platform/x86/intel/pmc/wcl.c
+++ b/drivers/platform/x86/intel/pmc/wcl.c
@@ -469,6 +469,8 @@ static struct pmc_info wcl_pmc_info_list[] = {
{}
};

+static u8 wcl_pmc_list[] = {PMC_IDX_MAIN};
+
#define WCL_NPU_PCI_DEV 0xfd3e

/*
@@ -494,6 +496,8 @@ static int wcl_core_init(struct pmc_dev *pmcdev, struct pmc_dev_info *pmc_dev_in

struct pmc_dev_info wcl_pmc_dev = {
.regmap_list = wcl_pmc_info_list,
+ .num_pmcs = ARRAY_SIZE(wcl_pmc_list),
+ .pmc_list = wcl_pmc_list,
.map = &wcl_pcdn_reg_map,
.sub_req_show = &pmc_core_substate_blk_req_fops,
.suspend = cnl_suspend,
--
2.43.0