drm/xe: Add sysfs entry for tile

We have recently introduced tile for each gpu,
so lets add sysfs entry per tile for userspace
to provide required information specific to tile.

V5:
  - define ktype as const
V4:
  - Reorder headers - Aravind
V3:
  - Make API to return void and add drm_warn - Aravind
V2:
  - Add logs in failure path

Reviewed-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com>
Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/xe_tile_sysfs.c

@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <drm/drm_managed.h>
+
+#include "xe_tile.h"
+#include "xe_tile_sysfs.h"
+
+static void xe_tile_sysfs_kobj_release(struct kobject *kobj)
+{
+	kfree(kobj);
+}
+
+static const struct kobj_type xe_tile_sysfs_kobj_type = {
+	.release = xe_tile_sysfs_kobj_release,
+	.sysfs_ops = &kobj_sysfs_ops,
+};
+
+static void tile_sysfs_fini(struct drm_device *drm, void *arg)
+{
+	struct xe_tile *tile = arg;
+
+	kobject_put(tile->sysfs);
+}
+
+void xe_tile_sysfs_init(struct xe_tile *tile)
+{
+	struct xe_device *xe = tile_to_xe(tile);
+	struct device *dev = xe->drm.dev;
+	struct kobj_tile *kt;
+	int err;
+
+	kt = kzalloc(sizeof(*kt), GFP_KERNEL);
+	if (!kt)
+		return;
+
+	kobject_init(&kt->base, &xe_tile_sysfs_kobj_type);
+	kt->tile = tile;
+
+	err = kobject_add(&kt->base, &dev->kobj, "tile%d", tile->id);
+	if (err) {
+		kobject_put(&kt->base);
+		drm_warn(&xe->drm, "failed to register TILE sysfs directory, err: %d\n", err);
+		return;
+	}
+
+	tile->sysfs = &kt->base;
+
+	err = drmm_add_action_or_reset(&xe->drm, tile_sysfs_fini, tile);
+	if (err) {
+		drm_warn(&xe->drm, "%s: drmm_add_action_or_reset failed, err: %d\n",
+			 __func__, err);
+		return;
+	}
+}