drm: extract drm_gem_object_init

This function can be used by drivers who allocate the drm gem object
on their own. No functional change in here, just preparation.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 31 insertions, 10 deletions

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index aa89d4b0b4c4..3b64d0ef1998 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -124,6 +124,31 @@ drm_gem_destroy(struct drm_device *dev)
 }
 
 /**
+ * Initialize an already allocate GEM object of the specified size with
+ * shmfs backing store.
+ */
+int drm_gem_object_init(struct drm_device *dev,
+                        struct drm_gem_object *obj, size_t size)
+{
+        BUG_ON((size & (PAGE_SIZE - 1)) != 0);
+
+        obj->dev = dev;
+        obj->filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
+        if (IS_ERR(obj->filp))
+                return -ENOMEM;
+
+        kref_init(&obj->refcount);
+        kref_init(&obj->handlecount);
+        obj->size = size;
+
+        atomic_inc(&dev->object_count);
+        atomic_add(obj->size, &dev->object_memory);
+
+        return 0;
+}
+EXPORT_SYMBOL(drm_gem_object_init);
+
+/**
  * Allocate a GEM object of the specified size with shmfs backing store
  */
 struct drm_gem_object *
@@ -131,28 +156,22 @@ drm_gem_object_alloc(struct drm_device *dev, size_t size)
 {
         struct drm_gem_object *obj;
 
-        BUG_ON((size & (PAGE_SIZE - 1)) != 0);
-
         obj = kzalloc(sizeof(*obj), GFP_KERNEL);
         if (!obj)
                 goto free;
 
-        obj->dev = dev;
-        obj->filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
-        if (IS_ERR(obj->filp))
+        if (drm_gem_object_init(dev, obj, size) != 0)
                 goto free;
 
-        kref_init(&obj->refcount);
-        kref_init(&obj->handlecount);
-        obj->size = size;
         if (dev->driver->gem_init_object != NULL &&
             dev->driver->gem_init_object(obj) != 0) {
                 goto fput;
         }
-        atomic_inc(&dev->object_count);
-        atomic_add(obj->size, &dev->object_memory);
         return obj;
 fput:
+        /* Object_init mangles the global counters - readjust them. */
+        atomic_dec(&dev->object_count);
+        atomic_sub(obj->size, &dev->object_memory);
         fput(obj->filp);
 free:
         kfree(obj);
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 2f3b3a00b7a3..b3b57b561b92 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1432,6 +1432,8 @@ void drm_gem_object_free(struct kref *kref);
 void drm_gem_object_free_unlocked(struct kref *kref);
 struct drm_gem_object *drm_gem_object_alloc(struct drm_device *dev,
                                             size_t size);
+int drm_gem_object_init(struct drm_device *dev,
+                        struct drm_gem_object *obj, size_t size);
 void drm_gem_object_handle_free(struct kref *kref);
 void drm_gem_vm_open(struct vm_area_struct *vma);
 void drm_gem_vm_close(struct vm_area_struct *vma);