[PATCH v2 3/3] accel/amdpk: add debugfs support

[Nipun Gupta <nipun.gupta@amd.com>]

Add debugfs support for AMD PKI accelerator. The debugfs support prints
the following:

- Hardware info
- Hardware configuration
- Busy and idle cycles count in the PK engines
- pending requests for each queue

Signed-off-by: Nipun Gupta <nipun.gupta@amd.com>
---

Changes RFC->v2:
- this is a new patch which adds debugfs (removed some sysfs which was
  defined in RFC patch) and added more debugfs information

 drivers/accel/amdpk/Makefile        |   3 +-
 drivers/accel/amdpk/amdpk_debugfs.c | 107 ++++++++++++++++++++++++++++
 drivers/accel/amdpk/amdpk_drv.c     |   1 +
 drivers/accel/amdpk/amdpk_drv.h     |   2 +
 4 files changed, 112 insertions(+), 1 deletion(-)
 create mode 100644 drivers/accel/amdpk/amdpk_debugfs.c

diff --git a/drivers/accel/amdpk/Makefile b/drivers/accel/amdpk/Makefile
index 826f43ccebdf..8c0532e45a4f 100644
--- a/drivers/accel/amdpk/Makefile
+++ b/drivers/accel/amdpk/Makefile
@@ -5,4 +5,5 @@

 obj-$(CONFIG_DRM_ACCEL_AMDPK) := amdpk.o

-amdpk-y := amdpk_drv.o
+amdpk-y := amdpk_drv.o \
+	   amdpk_debugfs.o
diff --git a/drivers/accel/amdpk/amdpk_debugfs.c b/drivers/accel/amdpk/amdpk_debugfs.c
new file mode 100644
index 000000000000..341f1817503d
--- /dev/null
+++ b/drivers/accel/amdpk/amdpk_debugfs.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2025 Advanced Micro Devices, Inc.
+ */
+
+#include <linux/seq_file.h>
+#include <drm/drm_debugfs.h>
+#include "amdpk_drv.h"
+
+static int amdpk_hw_info(struct seq_file *s, void *unused)
+{
+	struct drm_debugfs_entry *entry = s->private;
+	u64 maxtotalreqs, rqmaxpending, mults;
+	struct amdpk_dev *pkdev;
+	u64 v, hwv, cnt;
+
+	pkdev = to_amdpk_dev(entry->dev);
+
+	v = pk_rdreg(pkdev->regs, REG_SEMVER);
+	seq_printf(s, "Hardware interface version: %lld.%lld.%lld\n",
+		   AMDPK_SEMVER_MAJOR(v), AMDPK_SEMVER_MINOR(v), AMDPK_SEMVER_PATCH(v));
+
+	hwv = pk_rdreg(pkdev->regs, REG_HW_VERSION);
+	seq_printf(s, "Hardware implementation version: %lld.%lld.%lld\n",
+		   AMDPK_HWVER_MAJOR(hwv), AMDPK_HWVER_MINOR(hwv), AMDPK_HWVER_SVN(hwv));
+
+	cnt = pk_rdreg(pkdev->regs, REG_CFG_REQ_QUEUES_CNT);
+	seq_printf(s, "Count request queues: %lld\n", cnt);
+
+	maxtotalreqs = pk_rdreg(pkdev->regs, REG_CFG_MAX_PENDING_REQ);
+	seq_printf(s, "Total max pending requests: %lld\n", maxtotalreqs);
+
+	rqmaxpending = pk_rdreg(pkdev->regs, REG_CFG_MAX_REQ_QUEUE_ENTRIES);
+	seq_printf(s, "Total max pending requests: %lld\n", rqmaxpending);
+
+	mults = pk_rdreg(pkdev->regs, REG_CFG_PK_INST);
+	seq_printf(s, "Pkcores 64 multipliers: %lld\n", mults >> 16);
+	seq_printf(s, "Pkcores 256 multipliers: %lld\n", mults & 0xFFFF);
+
+	return 0;
+}
+
+static int amdpk_hw_config(struct seq_file *s, void *unused)
+{
+	struct drm_debugfs_entry *entry = s->private;
+	struct amdpk_dev *pkdev;
+	u64 addr, size, depth;
+	int i, j;
+
+	pkdev = to_amdpk_dev(entry->dev);
+	for (i = 0; i < pkdev->max_queues; i++) {
+		seq_printf(s, "Queue-%d:\n", i);
+		for (j = 0; j < MAX_RQMEM_PER_QUEUE; j++) {
+			addr = pk_rdreg(pkdev->regs, REG_RQ_CFG_PAGE(i, j));
+			seq_printf(s, "    page_addr[%d]: %llx\n", j, addr);
+		}
+		size = pk_rdreg(pkdev->regs, REG_RQ_CFG_PAGE_SIZE(i));
+		seq_printf(s, "    page_size: %lld\n", size);
+		depth = pk_rdreg(pkdev->regs, REG_RQ_CFG_DEPTH(i));
+		seq_printf(s, "    page_depth: %lld\n", depth);
+	}
+
+	return 0;
+}
+
+static int amdpk_cycle_count(struct seq_file *s, void *unused)
+{
+	struct drm_debugfs_entry *entry = s->private;
+	u64 busy_cycles, idle_cycles;
+	struct amdpk_dev *pkdev;
+
+	pkdev = to_amdpk_dev(entry->dev);
+	busy_cycles = pk_rdreg(pkdev->regs, REG_PK_BUSY_CYCLES);
+	seq_printf(s, "PK busy cycles: %lld\n", busy_cycles);
+	idle_cycles = pk_rdreg(pkdev->regs, REG_PK_IDLE_CYCLES);
+	seq_printf(s, "PK idle cycles: %lld\n", idle_cycles);
+
+	return 0;
+}
+
+static int amdpk_pending_reqs(struct seq_file *s, void *unused)
+{
+	struct drm_debugfs_entry *entry = s->private;
+	struct amdpk_dev *pkdev;
+	u64 pending_reqs;
+	int i;
+
+	pkdev = to_amdpk_dev(entry->dev);
+	for (i = 0; i < pkdev->max_queues; i++) {
+		pending_reqs = pk_rdreg(pkdev->regs, REG_CTL_BASE(i) + REG_CTL_PENDING_REQS);
+		seq_printf(s, "Queue-%d pending requests: %lld\n", i, pending_reqs);
+	}
+
+	return 0;
+}
+
+static const struct drm_debugfs_info amdpk_debugfs_list[] = {
+	{"hw_info", amdpk_hw_info, 0},
+	{"hw_config", amdpk_hw_config, 0},
+	{"cycle_count", amdpk_cycle_count, 0},
+	{"pending_reqs", amdpk_pending_reqs, 0},
+};
+
+void amdpk_debugfs_init(struct amdpk_dev *pkdev)
+{
+	drm_debugfs_add_files(&pkdev->ddev, amdpk_debugfs_list, ARRAY_SIZE(amdpk_debugfs_list));
+}
diff --git a/drivers/accel/amdpk/amdpk_drv.c b/drivers/accel/amdpk/amdpk_drv.c
index 17c328d03db8..14cb6e7449ce 100644
--- a/drivers/accel/amdpk/amdpk_drv.c
+++ b/drivers/accel/amdpk/amdpk_drv.c
@@ -678,6 +678,7 @@ static int amdpk_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "DRM register failed, ret %d", ret);
 		return ret;
 	}
+	amdpk_debugfs_init(pkdev);

 	return amdpk_create_device(pkdev, dev, irq);
 }
diff --git a/drivers/accel/amdpk/amdpk_drv.h b/drivers/accel/amdpk/amdpk_drv.h
index c14c10db5d97..c260c3fb5626 100644
--- a/drivers/accel/amdpk/amdpk_drv.h
+++ b/drivers/accel/amdpk/amdpk_drv.h
@@ -258,6 +258,8 @@ struct amdpk_user {
 #define to_amdpk_dev(dev) container_of(dev, struct amdpk_dev, ddev)
 #define to_amdpk_work(work) container_of(work, struct amdpk_work, cq_work)

+void amdpk_debugfs_init(struct amdpk_dev *pkdev);
+
 static void __maybe_unused pk_wrreg(char __iomem *regs, int addr, u64 val)
 {
 	iowrite64(val, regs + addr);
--
2.34.1