Implementations of the vmap/vunmap GEM callbacks may perform pinning of the BO and may acquire the associated reservation object's lock. It's somewhat inconvenient to callers that simply require a mapping of the contained memory; and also ipmplies a certain overhead.
Therefore provide drm_gem_vram_vmap_local() drm_gem_vram_vunmap_local(), which only perform the vmap/vunmap operations. Callers have to hold the reservation lock while the mapping persists; or have to pin the BO by themselves.
This patch connects GEM VRAM helpers to GEM object functions with equivalent functionality.
v4: * move driver changes into separate patches (Daniel) * update documentation (Daniel)
Signed-off-by: Thomas Zimmermann tzimmermann@suse.de Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_gem_vram_helper.c | 141 +++++++++++++++++--------- include/drm/drm_gem_vram_helper.h | 2 + 2 files changed, 95 insertions(+), 48 deletions(-)
diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c index 02ca22e90290..c7fba3a0758e 100644 --- a/drivers/gpu/drm/drm_gem_vram_helper.c +++ b/drivers/gpu/drm/drm_gem_vram_helper.c @@ -379,47 +379,6 @@ int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo) } EXPORT_SYMBOL(drm_gem_vram_unpin);
-static int drm_gem_vram_kmap_locked(struct drm_gem_vram_object *gbo, - struct dma_buf_map *map) -{ - int ret; - - if (gbo->vmap_use_count > 0) - goto out; - - ret = ttm_bo_vmap(&gbo->bo, &gbo->map); - if (ret) - return ret; - -out: - ++gbo->vmap_use_count; - *map = gbo->map; - - return 0; -} - -static void drm_gem_vram_kunmap_locked(struct drm_gem_vram_object *gbo, - struct dma_buf_map *map) -{ - struct drm_device *dev = gbo->bo.base.dev; - - if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count)) - return; - - if (drm_WARN_ON_ONCE(dev, !dma_buf_map_is_equal(&gbo->map, map))) - return; /* BUG: map not mapped from this BO */ - - if (--gbo->vmap_use_count > 0) - return; - - /* - * Permanently mapping and unmapping buffers adds overhead from - * updating the page tables and creates debugging output. Therefore, - * we delay the actual unmap operation until the BO gets evicted - * from memory. See drm_gem_vram_bo_driver_move_notify(). - */ -} - /** * drm_gem_vram_vmap() - Pins and maps a GEM VRAM object into kernel address * space @@ -447,7 +406,7 @@ int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map) ret = drm_gem_vram_pin_locked(gbo, 0); if (ret) goto err_ttm_bo_unreserve; - ret = drm_gem_vram_kmap_locked(gbo, map); + ret = drm_gem_vram_vmap_local(gbo, map); if (ret) goto err_drm_gem_vram_unpin_locked;
@@ -479,13 +438,83 @@ void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *ma if (WARN_ONCE(ret, "ttm_bo_reserve_failed(): ret=%d\n", ret)) return;
- drm_gem_vram_kunmap_locked(gbo, map); + drm_gem_vram_vunmap_local(gbo, map); drm_gem_vram_unpin_locked(gbo);
ttm_bo_unreserve(&gbo->bo); } EXPORT_SYMBOL(drm_gem_vram_vunmap);
+/** + * drm_gem_vram_vmap_local() - Maps a GEM VRAM object into kernel address space + * @gbo: The GEM VRAM object to map + * @map: Returns the kernel virtual address of the VRAM GEM object's backing + * store. + * + * The vmap_local function maps the buffer of a GEM VRAM object into kernel address + * space. Call drm_gem_vram_vunmap_local() with the returned address to unmap and + * unpin the GEM VRAM object. + * + * The function is called with the BO's reservation object locked. For short-term + * mappings, callers must hold the BO's reservation lock until after unmapping the + * buffer. + * + * Returns: + * 0 on success, or a negative error code otherwise. + */ +int drm_gem_vram_vmap_local(struct drm_gem_vram_object *gbo, struct dma_buf_map *map) +{ + int ret; + + dma_resv_assert_held(gbo->bo.base.resv); + + if (gbo->vmap_use_count > 0) + goto out; + + ret = ttm_bo_vmap(&gbo->bo, &gbo->map); + if (ret) + return ret; + +out: + ++gbo->vmap_use_count; + *map = gbo->map; + + return 0; +} +EXPORT_SYMBOL(drm_gem_vram_vmap_local); + +/** + * drm_gem_vram_vunmap_local() - Unmaps a GEM VRAM object + * @gbo: The GEM VRAM object to unmap + * @map: Kernel virtual address where the VRAM GEM object was mapped + * + * A call to drm_gem_vram_vunmap_local() unmaps a GEM VRAM object's buffer. See + * the documentation for drm_gem_vram_vmap_local() for more information. + */ +void drm_gem_vram_vunmap_local(struct drm_gem_vram_object *gbo, struct dma_buf_map *map) +{ + struct drm_device *dev = gbo->bo.base.dev; + + dma_resv_assert_held(gbo->bo.base.resv); + + if (drm_WARN_ON_ONCE(dev, !gbo->vmap_use_count)) + return; + + if (drm_WARN_ON_ONCE(dev, !dma_buf_map_is_equal(&gbo->map, map))) + return; /* BUG: map not mapped from this BO */ + + if (--gbo->vmap_use_count > 0) + return; + + /* + * Permanently mapping and unmapping buffers adds overhead from + * updating the page tables and creates debugging output. Therefore, + * we delay the actual unmap operation until the BO gets evicted + * from memory. See drm_gem_vram_bo_driver_move_notify(). + */ +} +EXPORT_SYMBOL(drm_gem_vram_vunmap_local); + /** * drm_gem_vram_fill_create_dumb() - \ Helper for implementing &struct drm_driver.dumb_create @@ -871,17 +900,33 @@ static void drm_gem_vram_object_vunmap(struct drm_gem_object *gem, struct dma_bu drm_gem_vram_vunmap(gbo, map); }
+static int drm_gem_vram_object_vmap_local(struct drm_gem_object *gem, struct dma_buf_map *map) +{ + struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); + + return drm_gem_vram_vmap_local(gbo, map); +} + +static void drm_gem_vram_object_vunmap_local(struct drm_gem_object *gem, struct dma_buf_map *map) +{ + struct drm_gem_vram_object *gbo = drm_gem_vram_of_gem(gem); + + drm_gem_vram_vunmap_local(gbo, map); +} + /* * GEM object funcs */
static const struct drm_gem_object_funcs drm_gem_vram_object_funcs = { - .free = drm_gem_vram_object_free, - .pin = drm_gem_vram_object_pin, - .unpin = drm_gem_vram_object_unpin, - .vmap = drm_gem_vram_object_vmap, + .free = drm_gem_vram_object_free, + .pin = drm_gem_vram_object_pin, + .unpin = drm_gem_vram_object_unpin, + .vmap = drm_gem_vram_object_vmap, .vunmap = drm_gem_vram_object_vunmap, - .mmap = drm_gem_ttm_mmap, + .vmap_local = drm_gem_vram_object_vmap_local, + .vunmap_local = drm_gem_vram_object_vunmap_local, + .mmap = drm_gem_ttm_mmap, .print_info = drm_gem_ttm_print_info, };
diff --git a/include/drm/drm_gem_vram_helper.h b/include/drm/drm_gem_vram_helper.h index a4bac02249c2..bd6a60e7c22b 100644 --- a/include/drm/drm_gem_vram_helper.h +++ b/include/drm/drm_gem_vram_helper.h @@ -99,6 +99,8 @@ int drm_gem_vram_pin(struct drm_gem_vram_object *gbo, unsigned long pl_flag); int drm_gem_vram_unpin(struct drm_gem_vram_object *gbo); int drm_gem_vram_vmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map); void drm_gem_vram_vunmap(struct drm_gem_vram_object *gbo, struct dma_buf_map *map); +int drm_gem_vram_vmap_local(struct drm_gem_vram_object *gbo, struct dma_buf_map *map); +void drm_gem_vram_vunmap_local(struct drm_gem_vram_object *gbo, struct dma_buf_map *map);
int drm_gem_vram_fill_create_dumb(struct drm_file *file, struct drm_device *dev,