drm/xe/pf: Populate SR-IOV debugfs tree with tiles

Populate new per SR-IOV function debugfs directories with next
level directories that represent tiles. There are no files yet,
but we will continue updating that tree in upcoming patches.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250928140029.198847-4-michal.wajdeczko@intel.com

drivers/gpu/drm/xe/Makefile

@@ -175,7 +175,8 @@ xe-$(CONFIG_PCI_IOV) += \
 	xe_pci_sriov.o \
 	xe_sriov_pf.o \
 	xe_sriov_pf_debugfs.o \
-	xe_sriov_pf_service.o
+	xe_sriov_pf_service.o \
+	xe_tile_sriov_pf_debugfs.o
 
 # include helpers for tests even when XE is built-in
 ifdef CONFIG_DRM_XE_KUNIT_TEST

drivers/gpu/drm/xe/xe_sriov_pf_debugfs.c

@@ -6,12 +6,14 @@
 #include <linux/debugfs.h>
 #include <drm/drm_debugfs.h>
 
+#include "xe_device.h"
 #include "xe_device_types.h"
 #include "xe_sriov_pf.h"
 #include "xe_sriov_pf_debugfs.h"
 #include "xe_sriov_pf_helpers.h"
 #include "xe_sriov_pf_service.h"
 #include "xe_sriov_printk.h"
+#include "xe_tile_sriov_pf_debugfs.h"
 
 static int simple_show(struct seq_file *m, void *data)
 {
@@ -37,6 +39,15 @@ static void pf_populate_pf(struct xe_device *xe, struct dentry *pfdent)
 	drm_debugfs_create_files(debugfs_list, ARRAY_SIZE(debugfs_list), pfdent, minor);
 }
 
+static void pf_populate_with_tiles(struct xe_device *xe, struct dentry *dent, unsigned int vfid)
+{
+	struct xe_tile *tile;
+	unsigned int id;
+
+	for_each_tile(tile, xe, id)
+		xe_tile_sriov_pf_debugfs_populate(tile, dent, vfid);
+}
+
 /**
  * xe_sriov_pf_debugfs_register - Register PF debugfs attributes.
  * @xe: the &xe_device
@@ -76,6 +87,7 @@ void xe_sriov_pf_debugfs_register(struct xe_device *xe, struct dentry *root)
 	pfdent->d_inode->i_private = xe;
 
 	pf_populate_pf(xe, pfdent);
+	pf_populate_with_tiles(xe, pfdent, PFID);
 
 	/*
 	 *      /sys/kernel/debug/dri/BDF/
@@ -90,5 +102,7 @@ void xe_sriov_pf_debugfs_register(struct xe_device *xe, struct dentry *root)
 		if (IS_ERR(vfdent))
 			return;
 		vfdent->d_inode->i_private = (void *)(uintptr_t)VFID(n);
+
+		pf_populate_with_tiles(xe, vfdent, VFID(n));
 	}
 }

drivers/gpu/drm/xe/xe_tile_sriov_pf_debugfs.c

@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#include <linux/debugfs.h>
+#include <drm/drm_debugfs.h>
+
+#include "xe_device_types.h"
+#include "xe_tile_sriov_pf_debugfs.h"
+#include "xe_sriov.h"
+
+/*
+ *      /sys/kernel/debug/dri/BDF/
+ *      ├── sriov		# d_inode->i_private = (xe_device*)
+ *      │   ├── pf		# d_inode->i_private = (xe_device*)
+ *      │   │   ├── tile0	# d_inode->i_private = (xe_tile*)
+ *      │   │   ├── tile1
+ *      │   │   :   :
+ *      │   ├── vf1		# d_inode->i_private = VFID(1)
+ *      │   │   ├── tile0	# d_inode->i_private = (xe_tile*)
+ *      │   │   ├── tile1
+ *      │   │   :   :
+ *      │   ├── vfN		# d_inode->i_private = VFID(N)
+ *      │   │   ├── tile0	# d_inode->i_private = (xe_tile*)
+ *      │   │   ├── tile1
+ *      :   :   :   :
+ */
+
+static void *extract_priv(struct dentry *d)
+{
+	return d->d_inode->i_private;
+}
+
+__maybe_unused
+static struct xe_tile *extract_tile(struct dentry *d)
+{
+	return extract_priv(d);
+}
+
+static struct xe_device *extract_xe(struct dentry *d)
+{
+	return extract_priv(d->d_parent->d_parent);
+}
+
+__maybe_unused
+static unsigned int extract_vfid(struct dentry *d)
+{
+	void *pp = extract_priv(d->d_parent);
+
+	return pp == extract_xe(d) ? PFID : (uintptr_t)pp;
+}
+
+/**
+ * xe_tile_sriov_pf_debugfs_populate() - Populate SR-IOV debugfs tree with tile files.
+ * @tile: the &xe_tile to register
+ * @parent: the parent &dentry that represents the SR-IOV @vfid function
+ * @vfid: the VF identifier
+ *
+ * Add to the @parent directory new debugfs directory that will represent a @tile and
+ * populate it with files that are related to the SR-IOV @vfid function.
+ *
+ * This function can only be called on PF.
+ */
+void xe_tile_sriov_pf_debugfs_populate(struct xe_tile *tile, struct dentry *parent,
+				       unsigned int vfid)
+{
+	struct xe_device *xe = tile->xe;
+	struct dentry *dent;
+	char name[10]; /* should be enough up to "tile%u\0" for 2^16 - 1 */
+
+	xe_tile_assert(tile, IS_SRIOV_PF(xe));
+	xe_tile_assert(tile, extract_priv(parent->d_parent) == xe);
+	xe_tile_assert(tile, extract_priv(parent) == tile->xe ||
+		       (uintptr_t)extract_priv(parent) == vfid);
+
+	/*
+	 *      /sys/kernel/debug/dri/BDF/
+	 *      ├── sriov
+	 *      │   ├── pf		# parent, d_inode->i_private = (xe_device*)
+	 *      │   │   ├── tile0	# d_inode->i_private = (xe_tile*)
+	 *      │   │   ├── tile1
+	 *      │   │   :   :
+	 *      │   ├── vf1		# parent, d_inode->i_private = VFID(1)
+	 *      │   │   ├── tile0	# d_inode->i_private = (xe_tile*)
+	 *      │   │   ├── tile1
+	 *      :   :   :   :
+	 */
+	snprintf(name, sizeof(name), "tile%u", tile->id);
+	dent = debugfs_create_dir(name, parent);
+	if (IS_ERR(dent))
+		return;
+	dent->d_inode->i_private = tile;
+
+	xe_tile_assert(tile, extract_tile(dent) == tile);
+	xe_tile_assert(tile, extract_vfid(dent) == vfid);
+	xe_tile_assert(tile, extract_xe(dent) == xe);
+}

drivers/gpu/drm/xe/xe_tile_sriov_pf_debugfs.h

@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#ifndef _XE_TILE_SRIOV_PF_DEBUGFS_H_
+#define _XE_TILE_SRIOV_PF_DEBUGFS_H_
+
+struct dentry;
+struct xe_tile;
+
+void xe_tile_sriov_pf_debugfs_populate(struct xe_tile *tile, struct dentry *parent,
+				       unsigned int vfid);
+
+#endif