[PATCH 11/11] platform/x86/intel/pmc/mtl: get LPM information using Intel PMT

David E. Box
2023-03-15T18:35:04Z

From: Xi Pardee <xi.pardee@intel.com>

For Meteor Lake, retrieve the PMC Lower Power Mode (LPM) information using
Intel PMT Telemetry API.

Signed-off-by: Xi Pardee <xi.pardee@intel.com>
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
---
drivers/platform/x86/intel/pmc/core.c | 1 +
drivers/platform/x86/intel/pmc/core.h | 1 +
drivers/platform/x86/intel/pmc/mtl.c | 64 +++++++++++++++++++++++++++
3 files changed, 66 insertions(+)

diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index 3833ea4a758e..2e4a9ca1be62 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -1291,4 +1291,5 @@ module_platform_driver(pmc_core_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Intel PMC Core Driver");
+MODULE_IMPORT_NS(INTEL_PMT);
MODULE_IMPORT_NS(INTEL_VSEC);
diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
index f4b69861c17b..e5d33999c865 100644
--- a/drivers/platform/x86/intel/pmc/core.h
+++ b/drivers/platform/x86/intel/pmc/core.h
@@ -306,6 +306,7 @@ struct pmc_reg_map {
const u32 lpm_status_offset;
const u32 lpm_live_status_offset;
const u32 etr3_offset;
+ const u8 *lpm_reg_index;
};

/**
diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
index 74f1f4c44812..d51ec35e085d 100644
--- a/drivers/platform/x86/intel/pmc/mtl.c
+++ b/drivers/platform/x86/intel/pmc/mtl.c
@@ -21,6 +21,13 @@
#define SSRAM_PCH_OFFSET 0x60
#define SSRAM_IOE_OFFSET 0x68

+#define SOCS_LPM_REQ_GUID 0x2625030
+#define LPM_REG_INDEX_OFFSET 2
+#define LPM_REG_NUM 28
+#define LPM_SUBSTATE_NUM 1
+
+static const u8 MTL_LPM_REG_INDEX[] = {0, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 20};
+
const struct pmc_reg_map mtl_reg_map = {
.pfear_sts = ext_tgl_pfear_map,
.slp_s0_offset = CNP_PMC_SLP_S0_RES_COUNTER_OFFSET,
@@ -45,8 +52,60 @@ const struct pmc_reg_map mtl_reg_map = {
.lpm_sts = adl_lpm_maps,
.lpm_status_offset = MTL_LPM_STATUS_OFFSET,
.lpm_live_status_offset = MTL_LPM_LIVE_STATUS_OFFSET,
+ .lpm_reg_index = MTL_LPM_REG_INDEX,
};

+/*
+ * Only return error EPROBE_DEFER when telem handle is not yet available,
+ * otherwise returns 0.
+ */
+static int pmc_core_get_mtl_lpm_reqs(struct pmc_dev *pmcdev)
+{
+ const u8 *reg_index = pmcdev->map->lpm_reg_index;
+ const int num_maps = pmcdev->map->lpm_num_maps;
+ struct pci_dev *pcidev = pmcdev->ssram_pcidev;
+ u32 lpm_size = LPM_MAX_NUM_MODES * num_maps;
+ struct telem_handle *handle;
+ int i, j, map_offset = 0;
+ u32 *lpm_req_regs;
+
+ if (!pcidev)
+ return 0;
+
+ handle = pmt_telem_find_and_register_handle(pcidev, SOCS_LPM_REQ_GUID, 0);
+ if (IS_ERR(handle)) {
+ dev_err(&pmcdev->pdev->dev,
+ "pmc_core: couldn't get telem handle %ld", PTR_ERR(handle));
+ return -EPROBE_DEFER;
+ }
+
+ lpm_req_regs = devm_kzalloc(&pmcdev->pdev->dev, lpm_size * sizeof(u32),
+ GFP_KERNEL);
+
+ for (j = 0; j < pmcdev->num_lpm_modes; j++) {
+ int mode = pmcdev->lpm_en_modes[j];
+ u32 *ptr = lpm_req_regs + mode * num_maps;
+
+ for (i = 0; i < num_maps; ++i) {
+ u8 index = reg_index[i] + LPM_REG_INDEX_OFFSET + map_offset;
+ int err;
+
+ err = pmt_telem_read32(handle, index, ptr, 1);
+ if (err) {
+ dev_err(&pmcdev->pdev->dev, "pmt_telem read failed: %d", err);
+ pmt_telem_unregister_handle(handle);
+ return 0;
+ }
+ ++ptr;
+ }
+ map_offset += LPM_REG_NUM + LPM_SUBSTATE_NUM;
+ }
+ pmcdev->lpm_req_regs = lpm_req_regs;
+ pmt_telem_unregister_handle(handle);
+
+ return 0;
+}
+
static void
mtl_pmc_add_pmt(struct pmc_dev *pmcdev, struct pci_dev *pdev, u64 ssram_base)
{
@@ -152,6 +211,11 @@ int mtl_core_init(struct pmc_dev *pmcdev)
mtl_pmc_ssram_init(pmcdev);

pmc_core_get_low_power_modes(pmcdev->pdev);
+ ret = pmc_core_get_mtl_lpm_reqs(pmcdev);
+ if (ret) {
+ iounmap(pmcdev->regbase);
+ return ret;
+ }

/* Due to a hardware limitation, the GBE LTR blocks PC10
* when a cable is attached. Tell the PMC to ignore it.
--
2.34.1