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
This commit is contained in:
Thomas Zimmermann 2020-11-03 10:30:10 +01:00
parent f216fcb8e4
commit 43676605f8
5 changed files with 163 additions and 0 deletions

View File

@ -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.

View File

@ -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)
{

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@ -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);

View File

@ -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.
*

View File

@ -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