linux/drivers/gpu/drm/drm_gem_ttm_helper.c
Thomas Zimmermann 43676605f8 drm/ttm: Add vmap/vunmap to TTM and TTM GEM helpers
The new functions ttm_bo_{vmap,vunmap}() map and unmap a TTM BO in kernel
address space. The mapping's address is returned as struct dma_buf_map.
Each function is a simplified version of TTM's existing kmap code. Both
functions respect the memory's location ani/or writecombine flags.

On top TTM's functions, GEM TTM helpers got drm_gem_ttm_{vmap,vunmap}(),
two helpers that convert a GEM object into the TTM BO and forward the call
to TTM's vmap/vunmap. These helpers can be dropped into the rsp GEM object
callbacks.

v5:
	* use size_t for storing mapping size (Christian)
	* ignore premapped memory areas correctly in ttm_bo_vunmap()
	* rebase onto latest TTM interfaces (Christian)
	* remove BUG() from ttm_bo_vmap() (Christian)
v4:
	* drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel,
	  Christian)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-6-tzimmermann@suse.de
2020-11-09 09:17:36 +01:00

119 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/module.h>
#include <drm/drm_gem_ttm_helper.h>
/**
* DOC: overview
*
* This library provides helper functions for gem objects backed by
* ttm.
*/
/**
* drm_gem_ttm_print_info() - Print &ttm_buffer_object info for debugfs
* @p: DRM printer
* @indent: Tab indentation level
* @gem: GEM object
*
* This function can be used as &drm_gem_object_funcs.print_info
* callback.
*/
void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent,
const struct drm_gem_object *gem)
{
static const char * const plname[] = {
[ TTM_PL_SYSTEM ] = "system",
[ TTM_PL_TT ] = "tt",
[ TTM_PL_VRAM ] = "vram",
[ TTM_PL_PRIV ] = "priv",
[ 16 ] = "cached",
[ 17 ] = "uncached",
[ 18 ] = "wc",
[ 19 ] = "contig",
[ 21 ] = "pinned", /* NO_EVICT */
[ 22 ] = "topdown",
};
const struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
drm_printf_indent(p, indent, "placement=");
drm_print_bits(p, bo->mem.placement, plname, ARRAY_SIZE(plname));
drm_printf(p, "\n");
if (bo->mem.bus.is_iomem)
drm_printf_indent(p, indent, "bus.offset=%lx\n",
(unsigned long)bo->mem.bus.offset);
}
EXPORT_SYMBOL(drm_gem_ttm_print_info);
/**
* drm_gem_ttm_vmap() - vmap &ttm_buffer_object
* @gem: GEM object.
* @map: [out] returns the dma-buf mapping.
*
* Maps a GEM object with ttm_bo_vmap(). This function can be used as
* &drm_gem_object_funcs.vmap callback.
*
* Returns:
* 0 on success, or a negative errno code otherwise.
*/
int drm_gem_ttm_vmap(struct drm_gem_object *gem,
struct dma_buf_map *map)
{
struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
return ttm_bo_vmap(bo, map);
}
EXPORT_SYMBOL(drm_gem_ttm_vmap);
/**
* drm_gem_ttm_vunmap() - vunmap &ttm_buffer_object
* @gem: GEM object.
* @map: dma-buf mapping.
*
* Unmaps a GEM object with ttm_bo_vunmap(). This function can be used as
* &drm_gem_object_funcs.vmap callback.
*/
void drm_gem_ttm_vunmap(struct drm_gem_object *gem,
struct dma_buf_map *map)
{
struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
ttm_bo_vunmap(bo, map);
}
EXPORT_SYMBOL(drm_gem_ttm_vunmap);
/**
* drm_gem_ttm_mmap() - mmap &ttm_buffer_object
* @gem: GEM object.
* @vma: vm area.
*
* This function can be used as &drm_gem_object_funcs.mmap
* callback.
*/
int drm_gem_ttm_mmap(struct drm_gem_object *gem,
struct vm_area_struct *vma)
{
struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
int ret;
ret = ttm_bo_mmap_obj(vma, bo);
if (ret < 0)
return ret;
/*
* ttm has its own object refcounting, so drop gem reference
* to avoid double accounting counting.
*/
drm_gem_object_put(gem);
return 0;
}
EXPORT_SYMBOL(drm_gem_ttm_mmap);
MODULE_DESCRIPTION("DRM gem ttm helpers");
MODULE_LICENSE("GPL");