Commit 43676605 authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

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: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Acked-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: default avatarSam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-6-tzimmermann@suse.de
parent f216fcb8

drivers/gpu/drm/drm_gem_ttm_helper.c

+37 −0
Original line number Diff line number Diff line
@@ -49,6 +49,43 @@ void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent, 
}

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.

drivers/gpu/drm/ttm/ttm_bo_util.c

+72 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 
#include <drm/ttm/ttm_bo_driver.h>

#include <drm/ttm/ttm_placement.h>

#include <drm/drm_vma_manager.h>

#include <linux/dma-buf-map.h>

#include <linux/io.h>

#include <linux/highmem.h>

#include <linux/wait.h>
@@ -471,6 +472,77 @@ void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map) 
}

EXPORT_SYMBOL(ttm_bo_kunmap);



int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)

{

	struct ttm_resource *mem = &bo->mem;

	int ret;



	ret = ttm_mem_io_reserve(bo->bdev, mem);

	if (ret)

		return ret;



	if (mem->bus.is_iomem) {

		void __iomem *vaddr_iomem;

		size_t size = bo->num_pages << PAGE_SHIFT;



		if (mem->bus.addr)

			vaddr_iomem = (void __iomem *)mem->bus.addr;

		else if (mem->bus.caching == ttm_write_combined)

			vaddr_iomem = ioremap_wc(mem->bus.offset, size);

		else

			vaddr_iomem = ioremap(mem->bus.offset, size);



		if (!vaddr_iomem)

			return -ENOMEM;



		dma_buf_map_set_vaddr_iomem(map, vaddr_iomem);



	} else {

		struct ttm_operation_ctx ctx = {

			.interruptible = false,

			.no_wait_gpu = false

		};

		struct ttm_tt *ttm = bo->ttm;

		pgprot_t prot;

		void *vaddr;



		ret = ttm_tt_populate(bo->bdev, ttm, &ctx);

		if (ret)

			return ret;



		/*

		 * We need to use vmap to get the desired page protection

		 * or to make the buffer object look contiguous.

		 */

		prot = ttm_io_prot(bo, mem, PAGE_KERNEL);

		vaddr = vmap(ttm->pages, bo->num_pages, 0, prot);

		if (!vaddr)

			return -ENOMEM;



		dma_buf_map_set_vaddr(map, vaddr);

	}



	return 0;

}

EXPORT_SYMBOL(ttm_bo_vmap);



void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)

{

	struct ttm_resource *mem = &bo->mem;



	if (dma_buf_map_is_null(map))

		return;



	if (!map->is_iomem)

		vunmap(map->vaddr);

	else if (!mem->bus.addr)

		iounmap(map->vaddr_iomem);

	dma_buf_map_clear(map);



	ttm_mem_io_free(bo->bdev, &bo->mem);

}

EXPORT_SYMBOL(ttm_bo_vunmap);



static int ttm_bo_wait_free_node(struct ttm_buffer_object *bo,

				 bool dst_use_tt)

{

include/drm/drm_gem_ttm_helper.h

+6 −0
Original line number Diff line number Diff line
@@ -10,11 +10,17 @@ 
#include <drm/ttm/ttm_bo_api.h>

#include <drm/ttm/ttm_bo_driver.h>



struct dma_buf_map;



#define drm_gem_ttm_of_gem(gem_obj) \

	container_of(gem_obj, struct ttm_buffer_object, base)



void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent,

			    const struct drm_gem_object *gem);

int drm_gem_ttm_vmap(struct drm_gem_object *gem,

		     struct dma_buf_map *map);

void drm_gem_ttm_vunmap(struct drm_gem_object *gem,

			struct dma_buf_map *map);

int drm_gem_ttm_mmap(struct drm_gem_object *gem,

		     struct vm_area_struct *vma);

include/drm/ttm/ttm_bo_api.h

+28 −0
Original line number Diff line number Diff line
@@ -48,6 +48,8 @@ struct ttm_bo_global; 


struct ttm_bo_device;



struct dma_buf_map;



struct drm_mm_node;



struct ttm_placement;
@@ -495,6 +497,32 @@ int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page, 
 */

void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);



/**

 * ttm_bo_vmap

 *

 * @bo: The buffer object.

 * @map: pointer to a struct dma_buf_map representing the map.

 *

 * Sets up a kernel virtual mapping, using ioremap or vmap to the

 * data in the buffer object. The parameter @map returns the virtual

 * address as struct dma_buf_map. Unmap the buffer with ttm_bo_vunmap().

 *

 * Returns

 * -ENOMEM: Out of memory.

 * -EINVAL: Invalid range.

 */

int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);



/**

 * ttm_bo_vunmap

 *

 * @bo: The buffer object.

 * @map: Object describing the map to unmap.

 *

 * Unmaps a kernel map set up by ttm_bo_vmap().

 */

void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);



/**

 * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.

 *

include/linux/dma-buf-map.h

+20 −0
Original line number Diff line number Diff line
@@ -45,6 +45,12 @@ 
 *

 *	dma_buf_map_set_vaddr(&map. 0xdeadbeaf);

 *

 * To set an address in I/O memory, use dma_buf_map_set_vaddr_iomem().

 *

 * .. code-block:: c

 *

 *	dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf);

 *

 * Test if a mapping is valid with either dma_buf_map_is_set() or

 * dma_buf_map_is_null().

 *
@@ -118,6 +124,20 @@ static inline void dma_buf_map_set_vaddr(struct dma_buf_map *map, void *vaddr) 
	map->is_iomem = false;

}



/**

 * dma_buf_map_set_vaddr_iomem - Sets a dma-buf mapping structure to an address in I/O memory

 * @map:		The dma-buf mapping structure

 * @vaddr_iomem:	An I/O-memory address

 *

 * Sets the address and the I/O-memory flag.

 */

static inline void dma_buf_map_set_vaddr_iomem(struct dma_buf_map *map,

					       void __iomem *vaddr_iomem)

{

	map->vaddr_iomem = vaddr_iomem;

	map->is_iomem = true;

}



/**

 * dma_buf_map_is_equal - Compares two dma-buf mapping structures for equality

 * @lhs:	The dma-buf mapping structure

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