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authorThomas Zimmermann <tzimmermann@suse.de>2021-07-16 16:07:55 +0200
committerThomas Zimmermann <tzimmermann@suse.de>2021-07-23 20:17:13 +0200
commit37408cd825a47b89c2302b88ad3c071f796a2ec0 (patch)
tree923fda1cb2afdbb0a3a1b118a0db24dd56aa307d /drivers/gpu
parenta791cde6d2720944a50122b2039aac26b4c196c2 (diff)
downloadlinux-37408cd825a47b89c2302b88ad3c071f796a2ec0.tar.bz2
drm/gem: Provide drm_gem_fb_{begin,end}_cpu_access() helpers
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 <tzimmermann@suse.de> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Noralf Trønnes <noralf@tronnes.org> Link: https://patchwork.freedesktop.org/patch/msgid/20210716140801.1215-2-tzimmermann@suse.de
Diffstat (limited to 'drivers/gpu')
-rw-r--r--drivers/gpu/drm/drm_gem_framebuffer_helper.c89
1 files changed, 89 insertions, 0 deletions
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)
{