Message-ID: <20250815224611.2460255-6-xi.pardee@linux.intel.com>
Date: Fri, 15 Aug 2025 15:46:03 -0700
From: Xi Pardee <xi.pardee@...ux.intel.com>
To: xi.pardee@...ux.intel.com,
	irenic.rajneesh@...il.com,
	david.e.box@...ux.intel.com,
	hdegoede@...hat.com,
	ilpo.jarvinen@...ux.intel.com,
	platform-driver-x86@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org
Subject: [PATCH v3 5/6] platform/x86:intel/pmc: Show device and function number

Add support to show device and function number for S0ix blockers. This
feature depends on S0ix blocker substate requirement table and BDF
association table. This feature is available for platforms starting from
Pather Lake.

Only a subset of S0ix blockers has device and function number associated
to it. Get the availability information from the substate requirement
table. Get the device and function number mapping information for each
S0ix blocker from the BDF association table.

Signed-off-by: Xi Pardee <xi.pardee@...ux.intel.com>
---
 drivers/platform/x86/intel/pmc/core.c | 182 +++++++++++++++++++++++++-
 drivers/platform/x86/intel/pmc/core.h |  23 +++-
 2 files changed, 203 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
index a0b948a875a5a..69ee40cbb8b8a 100644
--- a/drivers/platform/x86/intel/pmc/core.c
+++ b/drivers/platform/x86/intel/pmc/core.c
@@ -1017,6 +1017,38 @@ const struct file_operations pmc_core_substate_req_regs_fops = {
 	.release	= single_release,
 };
 
+static int pmc_core_bdf_show(struct seq_file *s, void *unused)
+{
+	struct pmc_dev *pmcdev = s->private;
+	unsigned int pmcidx;
+
+	seq_printf(s, "%36s | %15s | %15s |\n", "Element", "Device Number", "Function Number");
+	for (pmcidx = 0; pmcidx < ARRAY_SIZE(pmcdev->pmcs); pmcidx++) {
+		const char *name = NULL;
+		struct list_head *cur;
+		struct bdf_entry *bdf;
+		struct pmc *pmc;
+
+		pmc = pmcdev->pmcs[pmcidx];
+		if (!pmc)
+			continue;
+
+		list_for_each(cur, pmc->bdf_list) {
+			bdf = list_entry(cur, struct bdf_entry, node);
+			if (bdf->name != name) {
+				seq_printf(s, "pmc%d: %30s | %15x | %15x |\n", pmcidx,
+					   bdf->name, bdf->dev_num, bdf->fun_num);
+				name = bdf->name;
+			} else {
+				seq_printf(s, "%54x | %15x |\n",
+					   bdf->dev_num, bdf->fun_num);
+			}
+		}
+	}
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(pmc_core_bdf);
+
 static unsigned int pmc_core_get_crystal_freq(void)
 {
 	unsigned int eax_denominator, ebx_numerator, ecx_hz, edx;
@@ -1418,6 +1450,10 @@ static void pmc_core_dbgfs_register(struct pmc_dev *pmcdev, struct pmc_dev_info
 				    pmc_dev_info->sub_req_show);
 	}
 
+	if (primary_pmc->bdf_list) {
+		debugfs_create_file("bdf", 0444, pmcdev->dbgfs_dir, pmcdev, &pmc_core_bdf_fops);
+	}
+
 	if (primary_pmc->map->pson_residency_offset && pmc_core_is_pson_residency_enabled(pmcdev)) {
 		debugfs_create_file("pson_residency_usec", 0444,
 				    pmcdev->dbgfs_dir, primary_pmc, &pmc_core_pson_residency);
@@ -1521,7 +1557,7 @@ int pmc_core_pmt_get_lpm_req(struct pmc_dev *pmcdev, struct pmc *pmc, struct tel
 	return ret;
 }
 
-int pmc_core_pmt_get_blk_sub_req(struct pmc_dev *pmcdev, struct pmc *pmc,
+static int pmc_core_pmt_get_blk_sub_req(struct pmc_dev *pmcdev, struct pmc *pmc,
 				 struct telem_endpoint *ep)
 {
 	u32 num_blocker, sample_id;
@@ -1551,6 +1587,150 @@ int pmc_core_pmt_get_blk_sub_req(struct pmc_dev *pmcdev, struct pmc *pmc,
 	return 0;
 }
 
+static const char *pmc_core_get_next_bdf_ip_name(struct pmc *pmc, unsigned int *r_idx,
+						 unsigned int *i_idx, u32 **lpm_req_regs)
+{
+	const struct pmc_bit_map **maps;
+	unsigned int arr_size;
+	bool reset = FALSE;
+
+	maps = pmc->map->s0ix_blocker_maps;
+	arr_size = pmc_core_lpm_get_arr_size(maps);
+
+	// Iteration reaches the end of the bitmap array
+	if (!maps[*r_idx][*i_idx].name)
+		(*r_idx)++;
+
+	// Iteration reaches the end of the maps
+	if (*r_idx >= arr_size)
+		return NULL;
+
+	for (; *r_idx < arr_size; (*r_idx)++) {
+		const char *ip_name;
+
+		if (reset)
+			*i_idx = 0;
+
+		for (; maps[*r_idx][*i_idx].name; reset = TRUE, (*i_idx)++) {
+			if (!maps[*r_idx][*i_idx].blk)
+				continue;
+
+			bool exist = **lpm_req_regs & BIT(BDF_EXIST_BIT);
+			(*lpm_req_regs)++;
+			if (exist) {
+				ip_name = maps[*r_idx][*i_idx].name;
+				(*i_idx)++;
+				return ip_name;
+			}
+		}
+	}
+	return NULL;
+}
+
+static int pmc_core_process_bdf(struct pmc_dev *pmcdev,  struct pmc *pmc, u32 data,
+				unsigned int *r_idx, unsigned int *i_idx, u32 **lpm_req_regs,
+				const char **name)
+{
+	unsigned int i;
+
+	if (!data)
+		return 0;
+
+	if (!*name)
+		return -EINVAL;
+
+	for (i = BDF_FUN_LOW_BIT; i <= BDF_FUN_HIGH_BIT; i++) {
+		struct bdf_entry *b_entry;
+		u32 function_data;
+
+		function_data = (data & BIT(i));
+		if (function_data) {
+			b_entry = devm_kzalloc(&pmcdev->pdev->dev, sizeof(*b_entry), GFP_KERNEL);
+			if (!b_entry)
+				return -ENOMEM;
+			b_entry->dev_num = data & GENMASK(BDF_DEV_HIGH_BIT, BDF_DEV_LOW_BIT);
+			b_entry->fun_num = i - BDF_FUN_LOW_BIT;
+			b_entry->name = *name;
+			list_add_tail(&b_entry->node, pmc->bdf_list);
+		}
+	}
+
+	if (!(data & BIT(BDF_REQ_BIT)))
+		*name = pmc_core_get_next_bdf_ip_name(pmc, r_idx, i_idx, lpm_req_regs);
+
+	return 0;
+}
+
+static int pmc_core_pmt_get_bdf(struct pmc_dev *pmcdev, struct pmc *pmc, struct telem_endpoint *ep)
+{
+	unsigned int sample_id, max_sample_id, header_id, size, r_idx, i_idx;
+	struct bdf_entry *entry;
+	u32 *lpm_reg_regs;
+	const char *name;
+	int ret;
+
+	header_id = pmc->map->bdf_offset;
+	sample_id = header_id;
+	max_sample_id = sample_id + pmc->map->bdf_table_size;
+	lpm_reg_regs = pmc->lpm_req_regs;
+	r_idx = 0;
+	i_idx = 0;
+
+	name = pmc_core_get_next_bdf_ip_name(pmc, &r_idx, &i_idx, &lpm_reg_regs);
+	if (!name)
+		return -EINVAL;
+
+	pmc->bdf_list = devm_kzalloc(&pmcdev->pdev->dev, sizeof(struct list_head), GFP_KERNEL);
+	if (!pmc->bdf_list)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(pmc->bdf_list);
+
+	for (; sample_id < max_sample_id; sample_id++) {
+		u32 data;
+
+		ret = pmt_telem_read32(ep, sample_id, &data, 1);
+		if (ret) {
+			dev_err(&pmcdev->pdev->dev,
+				"couldn't read bdf: %d\n", ret);
+			return ret;
+		}
+
+		if (sample_id == header_id) {
+			size = (data & GENMASK(BDF_SIZE_HIGH_BIT, BDF_SIZE_LOW_BIT))
+			       >> BDF_SIZE_LOW_BIT;
+			header_id += size + 1;
+			continue;
+		}
+
+		ret = pmc_core_process_bdf(pmcdev, pmc, data, &r_idx, &i_idx, &lpm_reg_regs, &name);
+		if (ret)
+			return ret;
+		data = data >> BDF_SIZE;
+		ret = pmc_core_process_bdf(pmcdev, pmc, data, &r_idx, &i_idx, &lpm_reg_regs, &name);
+		if (ret)
+			return ret;
+	}
+
+	list_for_each_entry(entry, pmc->bdf_list, node) {
+		dev_dbg(&pmcdev->pdev->dev, "bdf info: name %s, dev_num %x, fun_num %x",
+			entry->name, entry->dev_num, entry->fun_num);
+	}
+	return 0;
+}
+
+int pmc_core_pmt_get_sub_req_bdf(struct pmc_dev *pmcdev, struct pmc *pmc,
+				 struct telem_endpoint *ep)
+{
+	int ret;
+
+	ret = pmc_core_pmt_get_blk_sub_req(pmcdev, pmc, ep);
+	if (ret)
+		return ret;
+
+	return pmc_core_pmt_get_bdf(pmcdev, pmc, ep);
+}
+
 static int pmc_core_get_telem_info(struct pmc_dev *pmcdev, struct pmc_dev_info *pmc_dev_info)
 {
 	struct pci_dev *pcidev __free(pci_dev_put) = NULL;
diff --git a/drivers/platform/x86/intel/pmc/core.h b/drivers/platform/x86/intel/pmc/core.h
index bfe8fba808063..6ff2d171dc2ba 100644
--- a/drivers/platform/x86/intel/pmc/core.h
+++ b/drivers/platform/x86/intel/pmc/core.h
@@ -317,6 +317,24 @@ enum ppfear_regs {
 #define PMC_DEVID_MTL_IOEP	0x7ecf
 #define PMC_DEVID_MTL_IOEM	0x7ebf
 
+/* BDF offset */
+#define BDF_EXIST_BIT		3
+#define BDF_SIZE_HIGH_BIT	23
+#define BDF_SIZE_LOW_BIT	16
+#define BDF_DEV_HIGH_BIT	4
+#define BDF_DEV_LOW_BIT		0
+#define BDF_FUN_HIGH_BIT	12
+#define BDF_FUN_LOW_BIT		5
+#define BDF_REQ_BIT		15
+#define BDF_SIZE		16
+
+struct bdf_entry {
+	struct list_head node;
+	const char *name;
+	u32 dev_num;
+	u32 fun_num;
+};
+
 extern const char *pmc_lpm_modes[];
 
 struct pmc_bit_map {
@@ -373,6 +391,8 @@ struct pmc_reg_map {
 	const u32 s0ix_blocker_offset;
 	const u32 num_s0ix_blocker;
 	const u32 blocker_req_offset;
+	const u32 bdf_offset;
+	const u32 bdf_table_size;
 	/* Low Power Mode registers */
 	const int lpm_num_maps;
 	const int lpm_num_modes;
@@ -418,6 +438,7 @@ struct pmc {
 	const struct pmc_reg_map *map;
 	u32 *lpm_req_regs;
 	u32 ltr_ign;
+	struct list_head *bdf_list;
 };
 
 /**
@@ -540,7 +561,7 @@ extern struct pmc_dev_info ptl_pmc_dev;
 void cnl_suspend(struct pmc_dev *pmcdev);
 int cnl_resume(struct pmc_dev *pmcdev);
 int pmc_core_pmt_get_lpm_req(struct pmc_dev *pmcdev, struct pmc *pmc, struct telem_endpoint *ep);
-int pmc_core_pmt_get_blk_sub_req(struct pmc_dev *pmcdev, struct pmc *pmc,
+int pmc_core_pmt_get_sub_req_bdf(struct pmc_dev *pmcdev, struct pmc *pmc,
 				 struct telem_endpoint *ep);
 
 extern const struct file_operations pmc_core_substate_req_regs_fops;
-- 
2.43.0

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