From 37408cd825a47b89c2302b88ad3c071f796a2ec0 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Fri, 16 Jul 2021 16:07:55 +0200 Subject: drm/gem: Provide drm_gem_fb_{begin,end}_cpu_access() helpers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Implement helpers drm_gem_fb_begin_cpu_access() and _end_cpu_access(), which call the rsp dma-buf functions for all GEM BOs of the given framebuffer. Calls to dma_buf_end_cpu_access() can return an error code on failure, while drm_gem_fb_end_cpu_access() does not. The latter runs during DRM's atomic commit or during cleanup. Both cases don't allow for errors, so leave out the return value. v2: * fix typo in docs (Daniel) Signed-off-by: Thomas Zimmermann Reviewed-by: Daniel Vetter Reviewed-by: Noralf Trønnes Link: https://patchwork.freedesktop.org/patch/msgid/20210716140801.1215-2-tzimmermann@suse.de --- drivers/gpu/drm/drm_gem_framebuffer_helper.c | 89 ++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) (limited to 'drivers/gpu/drm/drm_gem_framebuffer_helper.c') diff --git a/drivers/gpu/drm/drm_gem_framebuffer_helper.c b/drivers/gpu/drm/drm_gem_framebuffer_helper.c index e2c68822e05c..67bc9edc1d98 100644 --- a/drivers/gpu/drm/drm_gem_framebuffer_helper.c +++ b/drivers/gpu/drm/drm_gem_framebuffer_helper.c @@ -306,6 +306,95 @@ drm_gem_fb_create_with_dirty(struct drm_device *dev, struct drm_file *file, } EXPORT_SYMBOL_GPL(drm_gem_fb_create_with_dirty); +/** + * drm_gem_fb_begin_cpu_access - prepares GEM buffer objects for CPU access + * @fb: the framebuffer + * @dir: access mode + * + * Prepares a framebuffer's GEM buffer objects for CPU access. This function + * must be called before accessing the BO data within the kernel. For imported + * BOs, the function calls dma_buf_begin_cpu_access(). + * + * See drm_gem_fb_end_cpu_access() for signalling the end of CPU access. + * + * Returns: + * 0 on success, or a negative errno code otherwise. + */ +int drm_gem_fb_begin_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir) +{ + struct dma_buf_attachment *import_attach; + struct drm_gem_object *obj; + size_t i; + int ret, ret2; + + for (i = 0; i < ARRAY_SIZE(fb->obj); ++i) { + obj = drm_gem_fb_get_obj(fb, i); + if (!obj) + continue; + import_attach = obj->import_attach; + if (!import_attach) + continue; + ret = dma_buf_begin_cpu_access(import_attach->dmabuf, dir); + if (ret) + goto err_dma_buf_end_cpu_access; + } + + return 0; + +err_dma_buf_end_cpu_access: + while (i) { + --i; + obj = drm_gem_fb_get_obj(fb, i); + if (!obj) + continue; + import_attach = obj->import_attach; + if (!import_attach) + continue; + ret2 = dma_buf_end_cpu_access(import_attach->dmabuf, dir); + if (ret2) { + drm_err(fb->dev, + "dma_buf_end_cpu_access() failed during error handling: %d\n", + ret2); + } + } + + return ret; +} +EXPORT_SYMBOL(drm_gem_fb_begin_cpu_access); + +/** + * drm_gem_fb_end_cpu_access - signals end of CPU access to GEM buffer objects + * @fb: the framebuffer + * @dir: access mode + * + * Signals the end of CPU access to the given framebuffer's GEM buffer objects. This + * function must be paired with a corresponding call to drm_gem_fb_begin_cpu_access(). + * For imported BOs, the function calls dma_buf_end_cpu_access(). + * + * See also drm_gem_fb_begin_cpu_access(). + */ +void drm_gem_fb_end_cpu_access(struct drm_framebuffer *fb, enum dma_data_direction dir) +{ + size_t i = ARRAY_SIZE(fb->obj); + struct dma_buf_attachment *import_attach; + struct drm_gem_object *obj; + int ret; + + while (i) { + --i; + obj = drm_gem_fb_get_obj(fb, i); + if (!obj) + continue; + import_attach = obj->import_attach; + if (!import_attach) + continue; + ret = dma_buf_end_cpu_access(import_attach->dmabuf, dir); + if (ret) + drm_err(fb->dev, "dma_buf_end_cpu_access() failed: %d\n", ret); + } +} +EXPORT_SYMBOL(drm_gem_fb_end_cpu_access); + static __u32 drm_gem_afbc_get_bpp(struct drm_device *dev, const struct drm_mode_fb_cmd2 *mode_cmd) { -- cgit v1.2.3