drm/xe: Add drm-client infrastructure

Add drm-client infrastructure to record stats of consumption
done by individual drm client.

V2:
  - Typo - CI

Reviewed-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/Makefile

@@ -54,6 +54,7 @@ xe-y += xe_bb.o \
 	xe_device.o \
 	xe_device_sysfs.o \
 	xe_dma_buf.o \
+	xe_drm_client.o \
 	xe_exec.o \
 	xe_execlist.o \
 	xe_exec_queue.o \

drivers/gpu/drm/xe/xe_device.c

@@ -17,6 +17,7 @@
 #include "xe_bo.h"
 #include "xe_debugfs.h"
 #include "xe_dma_buf.h"
+#include "xe_drm_client.h"
 #include "xe_drv.h"
 #include "xe_exec_queue.h"
 #include "xe_exec.h"
@@ -42,13 +43,24 @@ struct lockdep_map xe_device_mem_access_lockdep_map = {
 
 static int xe_file_open(struct drm_device *dev, struct drm_file *file)
 {
+	struct xe_device *xe = to_xe_device(dev);
+	struct xe_drm_client *client;
 	struct xe_file *xef;
+	int ret = -ENOMEM;
 
 	xef = kzalloc(sizeof(*xef), GFP_KERNEL);
 	if (!xef)
-		return -ENOMEM;
+		return ret;
+
+	client = xe_drm_client_alloc();
+	if (!client) {
+		kfree(xef);
+		return ret;
+	}
 
 	xef->drm = file;
+	xef->client = client;
+	xef->xe = xe;
 
 	mutex_init(&xef->vm.lock);
 	xa_init_flags(&xef->vm.xa, XA_FLAGS_ALLOC1);
@@ -88,6 +100,7 @@ static void xe_file_close(struct drm_device *dev, struct drm_file *file)
 	xa_destroy(&xef->vm.xa);
 	mutex_destroy(&xef->vm.lock);
 
+	xe_drm_client_put(xef->client);
 	kfree(xef);
 }
 

drivers/gpu/drm/xe/xe_device_types.h

@@ -356,6 +356,9 @@ struct xe_device {
  * struct xe_file - file handle for XE driver
  */
 struct xe_file {
+	/** @xe: xe DEVICE **/
+	struct xe_device *xe;
+
 	/** @drm: base DRM file */
 	struct drm_file *drm;
 
@@ -374,6 +377,9 @@ struct xe_file {
 		/** @lock: protects file engine state */
 		struct mutex lock;
 	} exec_queue;
+
+	/** @client: drm client */
+	struct xe_drm_client *client;
 };
 
 #endif

drivers/gpu/drm/xe/xe_drm_client.c

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include <drm/drm_print.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "xe_device_types.h"
+#include "xe_drm_client.h"
+
+/**
+ * xe_drm_client_alloc() - Allocate drm client
+ * @void: No arg
+ *
+ * Allocate drm client struct to track client memory against
+ * same till client life. Call this API whenever new client
+ * has opened xe device.
+ *
+ * Return: pointer to client struct or NULL if can't allocate
+ */
+struct xe_drm_client *xe_drm_client_alloc(void)
+{
+	struct xe_drm_client *client;
+
+	client = kzalloc(sizeof(*client), GFP_KERNEL);
+	if (!client)
+		return NULL;
+
+	kref_init(&client->kref);
+
+	return client;
+}
+
+/**
+ * __xe_drm_client_free() - Free client struct
+ * @kref: The reference
+ *
+ * This frees client struct. Call this API when xe device is closed
+ * by drm client.
+ *
+ * Return: void
+ */
+void __xe_drm_client_free(struct kref *kref)
+{
+	struct xe_drm_client *client =
+		container_of(kref, typeof(*client), kref);
+
+	kfree(client);
+}

drivers/gpu/drm/xe/xe_drm_client.h

@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#ifndef _XE_DRM_CLIENT_H_
+#define _XE_DRM_CLIENT_H_
+
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/pid.h>
+#include <linux/rcupdate.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+
+struct drm_file;
+struct drm_printer;
+
+struct xe_drm_client {
+	struct kref kref;
+	unsigned int id;
+};
+
+	static inline struct xe_drm_client *
+xe_drm_client_get(struct xe_drm_client *client)
+{
+	kref_get(&client->kref);
+	return client;
+}
+
+void __xe_drm_client_free(struct kref *kref);
+
+static inline void xe_drm_client_put(struct xe_drm_client *client)
+{
+	kref_put(&client->kref, __xe_drm_client_free);
+}
+
+struct xe_drm_client *xe_drm_client_alloc(void);
+static inline struct xe_drm_client *
+xe_drm_client_get(struct xe_drm_client *client);
+static inline void xe_drm_client_put(struct xe_drm_client *client);
+
+#endif