Re: [PATCH 1/3] drm: add gem ttm helpers

On Tue, Aug 06, 2019 at 03:34:52PM +0200, Gerd Hoffmann wrote:

Now with ttm_buffer_object being a subclass of drm_gem_object we can easily lookup ttm_buffer_object for a given drm_gem_object, which in turm allows to create common helper functions. This patch starts off with dump mmap helpers.

Signed-off-by: Gerd Hoffmann kraxel@redhat.com

include/drm/drm_gem_ttm_helper.h | 27 +++++++++++++++ drivers/gpu/drm/drm_gem_ttm_helper.c | 52 ++++++++++++++++++++++++++++ drivers/gpu/drm/Kconfig | 7 ++++ drivers/gpu/drm/Makefile | 3 ++ 4 files changed, 89 insertions(+) create mode 100644 include/drm/drm_gem_ttm_helper.h create mode 100644 drivers/gpu/drm/drm_gem_ttm_helper.c

diff --git a/include/drm/drm_gem_ttm_helper.h b/include/drm/drm_gem_ttm_helper.h new file mode 100644 index 000000000000..2c6874190b17 --- /dev/null +++ b/include/drm/drm_gem_ttm_helper.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */

+#ifndef DRM_GEM_TTM_HELPER_H +#define DRM_GEM_TTM_HELPER_H

+#include <drm/drm_gem.h> +#include <drm/ttm/ttm_bo_api.h> +#include <linux/kernel.h> /* for container_of() */

+/**

• • Returns the container of type &struct ttm_buffer_object
• • for field base.
• • @gem: the GEM object
• • Returns: The containing GEM VRAM object
• */

+static inline struct ttm_buffer_object *drm_gem_ttm_of_gem(

• struct drm_gem_object *gem)

+{

• return container_of(gem, struct ttm_buffer_object, base);

+}

+u64 drm_gem_ttm_mmap_offset(struct ttm_buffer_object *bo); +int drm_gem_ttm_driver_dumb_mmap_offset(struct drm_file *file,

• 			struct drm_device *dev,
  

• 			uint32_t handle, uint64_t *offset);
  

+#endif diff --git a/drivers/gpu/drm/drm_gem_ttm_helper.c b/drivers/gpu/drm/drm_gem_ttm_helper.c new file mode 100644 index 000000000000..b069bd0c4c94 --- /dev/null +++ b/drivers/gpu/drm/drm_gem_ttm_helper.c @@ -0,0 +1,52 @@ +// SPDX-License-Identifier: GPL-2.0-or-later

+#include <drm/drm_gem_ttm_helper.h>

+/**

• • drm_gem_ttm_mmap_offset() - Returns a GEM ttm object's mmap offset
• • @gbo: the GEM ttm object
• • See drm_vma_node_offset_addr() for more information.
• • Returns:
• • The buffer object's offset for userspace mappings on success, or
• • 0 if no offset is allocated.
• */

+u64 drm_gem_ttm_mmap_offset(struct ttm_buffer_object *bo) +{

• return drm_vma_node_offset_addr(&bo->base.vma_node);

Why do we need a new one here, can't we use the existing gem implementation for this (there really should only be one I hope, but I didn't check).

+} +EXPORT_SYMBOL(drm_gem_ttm_mmap_offset);

+/**

• • drm_gem_ttm_driver_dumb_mmap_offset() - \
• Implements &struct drm_driver.dumb_mmap_offset
• • @file: DRM file pointer.
• • @dev: DRM device.
• • @handle: GEM handle
• • @offset: Returns the mapping's memory offset on success
• • Returns:
• • 0 on success, or
• • a negative errno code otherwise.
• */

+int drm_gem_ttm_driver_dumb_mmap_offset(struct drm_file *file,

• 			 struct drm_device *dev,
  

• 			 uint32_t handle, uint64_t *offset)
  

+{

• struct drm_gem_object *gem;
• struct ttm_buffer_object *bo;
• gem = drm_gem_object_lookup(file, handle);
• if (!gem)

• return -ENOENT;
  

• bo = drm_gem_ttm_of_gem(gem);
• *offset = drm_gem_ttm_mmap_offset(bo);
• drm_gem_object_put_unlocked(gem);
• return 0;

+} +EXPORT_SYMBOL(drm_gem_ttm_driver_dumb_mmap_offset);

Same for this, you're just upcasting to ttm_bo and then downcasting to gem_bo again ... I think just a series to roll out the existing gem helpers everywhere should work? -Daniel

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index e6f40fb54c9a..f7b25519f95c 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -172,6 +172,13 @@ config DRM_VRAM_HELPER help Helpers for VRAM memory management

+config DRM_TTM_HELPER

• tristate
• depends on DRM
• select DRM_TTM
• help

•  Helpers for ttm-based gem objects
  

config DRM_GEM_CMA_HELPER bool depends on DRM diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 10f8329a8b71..545c61d6528b 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -37,6 +37,9 @@ drm_vram_helper-y := drm_gem_vram_helper.o \ drm_vram_mm_helper.o obj-$(CONFIG_DRM_VRAM_HELPER) += drm_vram_helper.o

+drm_ttm_helper-y := drm_gem_ttm_helper.o +obj-$(CONFIG_DRM_TTM_HELPER) += drm_ttm_helper.o

drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper.o \ drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \ drm_kms_helper_common.o drm_dp_dual_mode_helper.o \ -- 2.18.1