drm/xe/pf: Move SR-IOV GT debugfs files to new tree

Instead of expanding GT debugfs directories with large number of
SR-IOV files, as those are replicated per each SR-IOV function,
move them to our new debugfs tree, organized by the function.

But to avoid breaking IGT tests that use current layout, provide
symlinks which could be removed once transition period is over,
or we can we can leave them for convenience.

Signed-off-by: Michal Wajdeczko <[e-mail]>
Cc: Lucas De Marchi <[e-mail]>
Cc: Rodrigo Vivi <[e-mail]>
Reviewed-by: Lucas De Marchi <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.c

···
 #include "xe_sriov_pf.h"
 
 /*
- *      /sys/kernel/debug/dri/0/
- *      ├── gt0		# d_inode->i_private = gt
- *      │   ├── pf	# d_inode->i_private = gt
- *      │   ├── vf1	# d_inode->i_private = VFID(1)
- *      :   :
- *      │   ├── vfN	# d_inode->i_private = VFID(N)
+ *      /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*)
+ *      │   │   │   ├── gt0	# d_inode->i_private = (xe_gt*)
+ *      │   │   │   ├── gt1	# d_inode->i_private = (xe_gt*)
+ *      │   │   ├── tile1
+ *      │   │   │   :
+ *      │   ├── vf1		# d_inode->i_private = VFID(1)
+ *      │   │   ├── tile0	# d_inode->i_private = (xe_tile*)
+ *      │   │   │   ├── gt0	# d_inode->i_private = (xe_gt*)
+ *      │   │   │   ├── gt1	# d_inode->i_private = (xe_gt*)
+ *      │   │   ├── tile1
+ *      │   │   │   :
+ *      :   :
+ *      │   ├── vfN		# d_inode->i_private = VFID(N)
  */
 
 static void *extract_priv(struct dentry *d)
···
 
 static struct xe_gt *extract_gt(struct dentry *d)
 {
-	return extract_priv(d->d_parent);
+	return extract_priv(d);
+}
+
+static struct xe_device *extract_xe(struct dentry *d)
+{
+	return extract_priv(d->d_parent->d_parent->d_parent);
 }
 
 static unsigned int extract_vfid(struct dentry *d)
 {
-	return extract_priv(d) == extract_gt(d) ? PFID : (uintptr_t)extract_priv(d);
+	void *priv = extract_priv(d->d_parent->d_parent);
+
+	return priv == extract_xe(d) ? PFID : (uintptr_t)priv;
 }
 
 /*
- *      /sys/kernel/debug/dri/0/
- *      ├── gt0
- *      │   ├── pf
- *      │   │   ├── contexts_provisioned
- *      │   │   ├── doorbells_provisioned
- *      │   │   ├── runtime_registers
- *      │   │   ├── negotiated_versions
- *      │   │   ├── adverse_events
- *      ├── gt1
- *      │   ├── pf
- *      │   │   ├── ...
+ *      /sys/kernel/debug/dri/BDF/
+ *      ├── sriov
+ *      :   ├── pf
+ *          :   ├── tile0
+ *              :   ├── gt0
+ *                  :   ├── contexts_provisioned
+ *                      ├── doorbells_provisioned
+ *                      ├── runtime_registers
+ *                      ├── adverse_events
  */
 
 static const struct drm_info_list pf_info[] = {
···
 };
 
 /*
- *      /sys/kernel/debug/dri/0/
- *      ├── gt0
- *      │   ├── pf
- *      │   │   ├── ggtt_available
- *      │   │   ├── ggtt_provisioned
+ *      /sys/kernel/debug/dri/BDF/
+ *      ├── sriov
+ *      :   ├── pf
+ *          :   ├── tile0
+ *              :   ├── gt0
+ *                  :   ├── ggtt_available
+ *                      ├── ggtt_provisioned
  */
 
 static const struct drm_info_list pf_ggtt_info[] = {
···
 };
 
 /*
- *      /sys/kernel/debug/dri/0/
- *      ├── gt0
- *      │   ├── pf
- *      │   │   ├── lmem_provisioned
+ *      /sys/kernel/debug/dri/BDF/
+ *      ├── sriov
+ *      :   ├── pf
+ *          :   ├── tile0
+ *              :   ├── gt0
+ *                  :   ├── lmem_provisioned
  */
 
 static const struct drm_info_list pf_lmem_info[] = {
···
 };
 
 /*
- *      /sys/kernel/debug/dri/0/
- *      ├── gt0
- *      │   ├── pf
- *      │   │   ├── reset_engine
- *      │   │   ├── sample_period
- *      │   │   ├── sched_if_idle
+ *      /sys/kernel/debug/dri/BDF/
+ *      ├── sriov
+ *      :   ├── pf
+ *          :   ├── tile0
+ *              :   ├── gt0
+ *                  :   ├── reset_engine
+ *                      ├── sample_period
+ *                      ├── sched_if_idle
  */
 
 #define DEFINE_SRIOV_GT_POLICY_DEBUGFS_ATTRIBUTE(POLICY, TYPE, FORMAT)		\
···
 }
 
 /*
- *      /sys/kernel/debug/dri/0/
- *      ├── gt0
- *      │   ├── pf
- *      │   │   ├── ggtt_spare
- *      │   │   ├── lmem_spare
- *      │   │   ├── doorbells_spare
- *      │   │   ├── contexts_spare
- *      │   │   ├── exec_quantum_ms
- *      │   │   ├── preempt_timeout_us
- *      │   │   ├── sched_priority
- *      │   ├── vf1
- *      │   │   ├── ggtt_quota
- *      │   │   ├── lmem_quota
- *      │   │   ├── doorbells_quota
- *      │   │   ├── contexts_quota
- *      │   │   ├── exec_quantum_ms
- *      │   │   ├── preempt_timeout_us
- *      │   │   ├── sched_priority
+ *      /sys/kernel/debug/dri/BDF/
+ *      ├── sriov
+ *      :   ├── pf
+ *          │   ├── tile0
+ *          │   :   ├── gt0
+ *          │       :   ├── ggtt_spare
+ *          │           ├── lmem_spare
+ *          │           ├── doorbells_spare
+ *          │           ├── contexts_spare
+ *          │           ├── exec_quantum_ms
+ *          │           ├── preempt_timeout_us
+ *          │           ├── sched_priority
+ *          ├── vf1
+ *          :   ├── tile0
+ *              :   ├── gt0
+ *                  :   ├── ggtt_quota
+ *                      ├── lmem_quota
+ *                      ├── doorbells_quota
+ *                      ├── contexts_quota
+ *                      ├── exec_quantum_ms
+ *                      ├── preempt_timeout_us
+ *                      ├── sched_priority
  */
 
 #define DEFINE_SRIOV_GT_CONFIG_DEBUGFS_ATTRIBUTE(CONFIG, TYPE, FORMAT)		\
···
 DEFINE_SRIOV_GT_CONFIG_DEBUGFS_ATTRIBUTE(sched_priority, u32, "%llu\n");
 
 /*
- *      /sys/kernel/debug/dri/0/
- *      ├── gt0
- *      │   ├── pf
- *      │   │   ├── threshold_cat_error_count
- *      │   │   ├── threshold_doorbell_time_us
- *      │   │   ├── threshold_engine_reset_count
- *      │   │   ├── threshold_guc_time_us
- *      │   │   ├── threshold_irq_time_us
- *      │   │   ├── threshold_page_fault_count
- *      │   ├── vf1
- *      │   │   ├── threshold_cat_error_count
- *      │   │   ├── threshold_doorbell_time_us
- *      │   │   ├── threshold_engine_reset_count
- *      │   │   ├── threshold_guc_time_us
- *      │   │   ├── threshold_irq_time_us
- *      │   │   ├── threshold_page_fault_count
+ *      /sys/kernel/debug/dri/BDF/
+ *      ├── sriov
+ *      :   ├── pf
+ *          │   ├── tile0
+ *          │   :   ├── gt0
+ *          │       :   ├── threshold_cat_error_count
+ *          │           ├── threshold_doorbell_time_us
+ *          │           ├── threshold_engine_reset_count
+ *          │           ├── threshold_guc_time_us
+ *          │           ├── threshold_irq_time_us
+ *          │           ├── threshold_page_fault_count
+ *          ├── vf1
+ *          :   ├── tile0
+ *              :   ├── gt0
+ *                  :   ├── threshold_cat_error_count
+ *                      ├── threshold_doorbell_time_us
+ *                      ├── threshold_engine_reset_count
+ *                      ├── threshold_guc_time_us
+ *                      ├── threshold_irq_time_us
+ *                      ├── threshold_page_fault_count
  */
 
 static int set_threshold(void *data, u64 val, enum xe_guc_klv_threshold_index index)
···
 }
 
 /*
- *      /sys/kernel/debug/dri/0/
- *      ├── gt0
- *      │   ├── vf1
- *      │   │   ├── control { stop, pause, resume }
+ *      /sys/kernel/debug/dri/BDF/
+ *      ├── sriov
+ *      :   ├── vf1
+ *          :   ├── tile0
+ *              :   ├── gt0
+ *                  :   ├── control { stop, pause, resume }
  */
 
 static const struct {
···
 };
 
 /*
- *      /sys/kernel/debug/dri/0/
- *      ├── gt0
- *      │   ├── vf1
- *      │   │   ├── guc_state
+ *      /sys/kernel/debug/dri/BDF/
+ *      ├── sriov
+ *      :   ├── vf1
+ *          :   ├── tile0
+ *              :   ├── gt0
+ *                  :   ├── guc_state
  */
+
 static ssize_t guc_state_read(struct file *file, char __user *buf,
 			      size_t count, loff_t *pos)
 {
···
 };
 
 /*
- *      /sys/kernel/debug/dri/0/
- *      ├── gt0
- *      │   ├── vf1
- *      │   │   ├── config_blob
+ *      /sys/kernel/debug/dri/BDF/
+ *      ├── sriov
+ *      :   ├── vf1
+ *          :   ├── tile0
+ *              :   ├── gt0
+ *                  :   ├── config_blob
  */
+
 static ssize_t config_blob_read(struct file *file, char __user *buf,
 				size_t count, loff_t *pos)
 {
···
 	.llseek		= default_llseek,
 };
 
-/**
- * xe_gt_sriov_pf_debugfs_register - Register SR-IOV PF specific entries in GT debugfs.
- * @gt: the &xe_gt to register
- * @root: the &dentry that represents the GT directory
- *
- * Register SR-IOV PF entries that are GT related and must be shown under GT debugfs.
- */
-void xe_gt_sriov_pf_debugfs_register(struct xe_gt *gt, struct dentry *root)
+static void pf_populate_gt(struct xe_gt *gt, struct dentry *dent, unsigned int vfid)
 {
 	struct xe_device *xe = gt_to_xe(gt);
 	struct drm_minor *minor = xe->drm.primary;
-	int n, totalvfs = xe_sriov_pf_get_totalvfs(xe);
-	struct dentry *pfdentry;
-	struct dentry *vfdentry;
-	char buf[14]; /* should be enough up to "vf%u\0" for 2^32 - 1 */
 
-	xe_gt_assert(gt, IS_SRIOV_PF(xe));
-	xe_gt_assert(gt, root->d_inode->i_private == gt);
+	if (vfid) {
+		pf_add_config_attrs(gt, dent, vfid);
 
-	/*
-	 *      /sys/kernel/debug/dri/0/
-	 *      ├── gt0
-	 *      │   ├── pf
-	 */
-	pfdentry = debugfs_create_dir("pf", root);
-	if (IS_ERR(pfdentry))
-		return;
-	pfdentry->d_inode->i_private = gt;
-
-	drm_debugfs_create_files(pf_info, ARRAY_SIZE(pf_info), pfdentry, minor);
-	if (xe_gt_is_main_type(gt)) {
-		drm_debugfs_create_files(pf_ggtt_info,
-					 ARRAY_SIZE(pf_ggtt_info),
-					 pfdentry, minor);
-		if (xe_device_has_lmtt(gt_to_xe(gt)))
-			drm_debugfs_create_files(pf_lmem_info,
-						 ARRAY_SIZE(pf_lmem_info),
-						 pfdentry, minor);
-	}
-
-	pf_add_policy_attrs(gt, pfdentry);
-	pf_add_config_attrs(gt, pfdentry, PFID);
-
-	for (n = 1; n <= totalvfs; n++) {
-		/*
-		 *      /sys/kernel/debug/dri/0/
-		 *      ├── gt0
-		 *      │   ├── vf1
-		 *      │   ├── vf2
-		 */
-		snprintf(buf, sizeof(buf), "vf%u", n);
-		vfdentry = debugfs_create_dir(buf, root);
-		if (IS_ERR(vfdentry))
-			break;
-		vfdentry->d_inode->i_private = (void *)(uintptr_t)n;
-
-		pf_add_config_attrs(gt, vfdentry, VFID(n));
-		debugfs_create_file("control", 0600, vfdentry, NULL, &control_ops);
+		debugfs_create_file("control", 0600, dent, NULL, &control_ops);
 
 		/* for testing/debugging purposes only! */
 		if (IS_ENABLED(CONFIG_DRM_XE_DEBUG)) {
 			debugfs_create_file("guc_state",
 					    IS_ENABLED(CONFIG_DRM_XE_DEBUG_SRIOV) ? 0600 : 0400,
-					    vfdentry, NULL, &guc_state_ops);
+					    dent, NULL, &guc_state_ops);
 			debugfs_create_file("config_blob",
 					    IS_ENABLED(CONFIG_DRM_XE_DEBUG_SRIOV) ? 0600 : 0400,
-					    vfdentry, NULL, &config_blob_ops);
+					    dent, NULL, &config_blob_ops);
+		}
+
+	} else {
+		pf_add_config_attrs(gt, dent, PFID);
+		pf_add_policy_attrs(gt, dent);
+
+		drm_debugfs_create_files(pf_info, ARRAY_SIZE(pf_info), dent, minor);
+
+		if (xe_gt_is_main_type(gt)) {
+			drm_debugfs_create_files(pf_ggtt_info,
+						 ARRAY_SIZE(pf_ggtt_info),
+						 dent, minor);
+			if (xe_device_has_lmtt(xe))
+				drm_debugfs_create_files(pf_lmem_info,
+							 ARRAY_SIZE(pf_lmem_info),
+							 dent, minor);
 		}
 	}
+}
+
+/**
+ * xe_gt_sriov_pf_debugfs_populate() - Create SR-IOV GT-level debugfs directories and files.
+ * @gt: the &xe_gt to register
+ * @parent: the parent &dentry that represents a &xe_tile
+ * @vfid: the VF identifier
+ *
+ * Add to the @parent directory new debugfs directory that will represent a @gt and
+ * populate it with GT files that are related to the SR-IOV @vfid function.
+ *
+ * This function can only be called on PF.
+ */
+void xe_gt_sriov_pf_debugfs_populate(struct xe_gt *gt, struct dentry *parent, unsigned int vfid)
+{
+	struct dentry *dent;
+	char name[8]; /* should be enough up to "gt%u\0" for 2^8 - 1 */
+
+	xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
+	xe_gt_assert(gt, extract_priv(parent) == gt->tile);
+	xe_gt_assert(gt, extract_priv(parent->d_parent) == gt_to_xe(gt) ||
+		     (uintptr_t)extract_priv(parent->d_parent) == vfid);
+
+	/*
+	 *      /sys/kernel/debug/dri/BDF/
+	 *      ├── sriov
+	 *      │   ├── pf
+	 *      │   │   ├── tile0		# parent
+	 *      │   │   │   ├── gt0		# d_inode->i_private = (xe_gt*)
+	 *      │   │   │   ├── gt1
+	 *      │   │   :   :
+	 *      │   ├── vf1
+	 *      │   │   ├── tile0		# parent
+	 *      │   │   │   ├── gt0		# d_inode->i_private = (xe_gt*)
+	 *      │   │   │   ├── gt1
+	 *      │   :   :   :
+	 */
+	snprintf(name, sizeof(name), "gt%u", gt->info.id);
+	dent = debugfs_create_dir(name, parent);
+	if (IS_ERR(dent))
+		return;
+	dent->d_inode->i_private = gt;
+
+	xe_gt_assert(gt, extract_gt(dent) == gt);
+	xe_gt_assert(gt, extract_vfid(dent) == vfid);
+
+	pf_populate_gt(gt, dent, vfid);
+}
+
+static void pf_add_links(struct xe_gt *gt, struct dentry *dent)
+{
+	unsigned int totalvfs = xe_gt_sriov_pf_get_totalvfs(gt);
+	unsigned int vfid;
+	char name[16];		/* should be more than enough for "vf%u\0" and VFID(UINT_MAX) */
+	char symlink[64];	/* should be more enough for "../../sriov/vf%u/tile%u/gt%u\0" */
+
+	for (vfid = 0; vfid <= totalvfs; vfid++) {
+		if (vfid)
+			snprintf(name, sizeof(name), "vf%u", vfid);
+		else
+			snprintf(name, sizeof(name), "pf");
+		snprintf(symlink, sizeof(symlink), "../../sriov/%s/tile%u/gt%u",
+			 name, gt->tile->id, gt->info.id);
+		debugfs_create_symlink(name, dent, symlink);
+	}
+}
+
+/**
+ * xe_gt_sriov_pf_debugfs_register - Register SR-IOV PF specific entries in GT debugfs.
+ * @gt: the &xe_gt to register
+ * @dent: the &dentry that represents the GT directory
+ *
+ * Instead of actual files, create symlinks for PF and each VF to their GT specific
+ * attributes that should be already exposed in the dedicated debugfs SR-IOV tree.
+ */
+void xe_gt_sriov_pf_debugfs_register(struct xe_gt *gt, struct dentry *dent)
+{
+	xe_gt_assert(gt, IS_SRIOV_PF(gt_to_xe(gt)));
+	xe_gt_assert(gt, dent->d_inode->i_private == gt);
+
+	pf_add_links(gt, dent);
 }

drivers/gpu/drm/xe/xe_gt_sriov_pf_debugfs.h

···
 
 #ifdef CONFIG_PCI_IOV
 void xe_gt_sriov_pf_debugfs_register(struct xe_gt *gt, struct dentry *root);
+void xe_gt_sriov_pf_debugfs_populate(struct xe_gt *gt, struct dentry *parent, unsigned int vfid);
 #else
 static inline void xe_gt_sriov_pf_debugfs_register(struct xe_gt *gt, struct dentry *root) { }
 #endif

drivers/gpu/drm/xe/xe_tile_sriov_pf_debugfs.c

···
 #include <linux/debugfs.h>
 #include <drm/drm_debugfs.h>
 
+#include "xe_device.h"
 #include "xe_device_types.h"
+#include "xe_gt_sriov_pf_debugfs.h"
 #include "xe_tile_sriov_pf_debugfs.h"
 #include "xe_sriov.h"
 
···
 	void *pp = extract_priv(d->d_parent);
 
 	return pp == extract_xe(d) ? PFID : (uintptr_t)pp;
+}
+
+static void pf_populate_tile(struct xe_tile *tile, struct dentry *dent, unsigned int vfid)
+{
+	struct xe_gt *gt;
+	unsigned int id;
+
+	for_each_gt_on_tile(gt, tile, id)
+		xe_gt_sriov_pf_debugfs_populate(gt, dent, vfid);
 }
 
 /**
···
 	xe_tile_assert(tile, extract_tile(dent) == tile);
 	xe_tile_assert(tile, extract_vfid(dent) == vfid);
 	xe_tile_assert(tile, extract_xe(dent) == xe);
+
+	pf_populate_tile(tile, dent, vfid);
 }