drm/xe: Add ref counting for xe_file

Add ref counting for xe_file.

v2:
- Add kernel doc for exported functions (Matt)
- Instead of xe_file_destroy, export the get/put helpers (Lucas)

v3: Fixup the kernel-doc format and description (Matt, Lucas)

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240718210548.3580382-3-umesh.nerlige.ramappa@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
(cherry picked from commit ce8c161cbad43f4056451e541f7ae3471d0cca12)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
index 452dbc1..4178bd0 100644 (file)
--- a/drivers/gpu/drm/xe/xe_device.c
+++ b/drivers/gpu/drm/xe/xe_device.c
@@ -87,11 +87,14 @@ static int xe_file_open(struct drm_device *dev, struct drm_file *file)
        spin_unlock(&xe->clients.lock);
 
        file->driver_priv = xef;
+       kref_init(&xef->refcount);
+
        return 0;
 }
 
-static void xe_file_destroy(struct xe_file *xef)
+static void xe_file_destroy(struct kref *ref)
 {
+       struct xe_file *xef = container_of(ref, struct xe_file, refcount);
        struct xe_device *xe = xef->xe;
 
        xa_destroy(&xef->exec_queue.xa);
@@ -107,6 +110,32 @@ static void xe_file_destroy(struct xe_file *xef)
        kfree(xef);
 }
 
+/**
+ * xe_file_get() - Take a reference to the xe file object
+ * @xef: Pointer to the xe file
+ *
+ * Anyone with a pointer to xef must take a reference to the xe file
+ * object using this call.
+ *
+ * Return: xe file pointer
+ */
+struct xe_file *xe_file_get(struct xe_file *xef)
+{
+       kref_get(&xef->refcount);
+       return xef;
+}
+
+/**
+ * xe_file_put() - Drop a reference to the xe file object
+ * @xef: Pointer to the xe file
+ *
+ * Used to drop reference to the xef object
+ */
+void xe_file_put(struct xe_file *xef)
+{
+       kref_put(&xef->refcount, xe_file_destroy);
+}
+
 static void xe_file_close(struct drm_device *dev, struct drm_file *file)
 {
        struct xe_file *xef = file->driver_priv;
@@ -129,7 +158,7 @@ static void xe_file_close(struct drm_device *dev, struct drm_file *file)
                xe_vm_close_and_put(vm);
        mutex_unlock(&xef->vm.lock);
 
-       xe_file_destroy(xef);
+       xe_file_put(xef);
 }
 
 static const struct drm_ioctl_desc xe_ioctls[] = {

diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
index bb07f56..b395271 100644 (file)
--- a/drivers/gpu/drm/xe/xe_device.h
+++ b/drivers/gpu/drm/xe/xe_device.h
@@ -170,4 +170,7 @@ static inline bool xe_device_wedged(struct xe_device *xe)
 
 void xe_device_declare_wedged(struct xe_device *xe);
 
+struct xe_file *xe_file_get(struct xe_file *xef);
+void xe_file_put(struct xe_file *xef);
+
 #endif

diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index 3bca6d3..cbc582b 100644 (file)
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -566,6 +566,9 @@ struct xe_file {
 
        /** @client: drm client */
        struct xe_drm_client *client;
+
+       /** @refcount: ref count of this xe file */
+       struct kref refcount;
 };
 
 #endif