drm: Integrate VRAM MM into struct drm_device

There's now a pointer to struct drm_vram_mm stored in struct drm_device.
DRM drivers that use VRAM MM should use this field to refer to their
instance of the data structure. Appropriate helpers are now provided as
well.

Adding struct drm_vram_mm to struct drm_device further avoids wrappers
and boilerplate code in drivers. This patch implements default functions
for callbacks in struct drm_driver and struct file_operations that use
the struct drm_vram_mm stored in struct drm_device. Drivers that need to
provide their own implementations can still do so.

The patch also adds documentation for the VRAM helper library in general.

v5:
	* set .llseek to no_llseek() from DRM_VRAM_MM_FILE_OPERATIONS
v4:
	* cleanups from checkpatch.pl
	* document VRAM helper library

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20190508082630.15116-9-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c
index c21b1f920e0a..8f142b810eb4 100644
--- a/drivers/gpu/drm/drm_gem_vram_helper.c
+++ b/drivers/gpu/drm/drm_gem_vram_helper.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #include <drm/drm_gem_vram_helper.h>
+#include <drm/drm_device.h>
 #include <drm/drm_mode.h>
 #include <drm/drm_prime.h>
 #include <drm/drm_vram_mm_helper.h>
@@ -556,6 +557,33 @@ void drm_gem_vram_driver_gem_free_object_unlocked(struct drm_gem_object *gem)
 EXPORT_SYMBOL(drm_gem_vram_driver_gem_free_object_unlocked);
 
 /**
+ * drm_gem_vram_driver_create_dumb() - \
+	Implements &struct drm_driver.dumb_create
+ * @file:		the DRM file
+ * @dev:		the DRM device
+ * @args:		the arguments as provided to \
+				&struct drm_driver.dumb_create
+ *
+ * This function requires the driver to use @drm_device.vram_mm for its
+ * instance of VRAM MM.
+ *
+ * Returns:
+ * 0 on success, or
+ * a negative error code otherwise.
+ */
+int drm_gem_vram_driver_dumb_create(struct drm_file *file,
+				    struct drm_device *dev,
+				    struct drm_mode_create_dumb *args)
+{
+	if (WARN_ONCE(!dev->vram_mm, "VRAM MM not initialized"))
+		return -EINVAL;
+
+	return drm_gem_vram_fill_create_dumb(file, dev, &dev->vram_mm->bdev, 0,
+					     false, args);
+}
+EXPORT_SYMBOL(drm_gem_vram_driver_dumb_create);
+
+/**
  * drm_gem_vram_driver_dumb_mmap_offset() - \
 	Implements &struct drm_driver.dumb_mmap_offset
  * @file:	DRM file pointer.