drm/vram-helpers: Add helpers for prepare_fb() and cleanup_fb()

The new helpers pin and unpin a framebuffer's GEM VRAM objects during
plane updates. This should be sufficient for most drivers' implementation
of prepare_fb() and cleanup_fb().

v2:
	* provide helpers for struct drm_simple_display_pipe_funcs
	* rename plane-helper funcs

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191024081404.6978-2-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c
index b86fe0fa9d0501ef08db478851c4746598580a60..7fe93cd38eea2291a8d5b79456ea5534353f7d78 100644 (file)
--- a/drivers/gpu/drm/drm_gem_vram_helper.c
+++ b/drivers/gpu/drm/drm_gem_vram_helper.c
@@ -3,10 +3,13 @@
 #include <drm/drm_debugfs.h>
 #include <drm/drm_device.h>
 #include <drm/drm_file.h>
+#include <drm/drm_framebuffer.h>
 #include <drm/drm_gem_ttm_helper.h>
 #include <drm/drm_gem_vram_helper.h>
 #include <drm/drm_mode.h>
+#include <drm/drm_plane.h>
 #include <drm/drm_prime.h>
+#include <drm/drm_simple_kms_helper.h>
 #include <drm/ttm/ttm_page_alloc.h>
 
 static const struct drm_gem_object_funcs drm_gem_vram_object_funcs;
@@ -646,6 +649,129 @@ int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
 }
 EXPORT_SYMBOL(drm_gem_vram_driver_dumb_mmap_offset);
 
+/*
+ * Helpers for struct drm_plane_helper_funcs
+ */
+
+/**
+ * drm_gem_vram_plane_helper_prepare_fb() - \
+ *     Implements &struct drm_plane_helper_funcs.prepare_fb
+ * @plane:     a DRM plane
+ * @new_state: the plane's new state
+ *
+ * During plane updates, this function pins the GEM VRAM
+ * objects of the plane's new framebuffer to VRAM. Call
+ * drm_gem_vram_plane_helper_cleanup_fb() to unpin them.
+ *
+ * Returns:
+ *     0 on success, or
+ *     a negative errno code otherwise.
+ */
+int
+drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
+                                    struct drm_plane_state *new_state)
+{
+       size_t i;
+       struct drm_gem_vram_object *gbo;
+       int ret;
+
+       if (!new_state->fb)
+               return 0;
+
+       for (i = 0; i < ARRAY_SIZE(new_state->fb->obj); ++i) {
+               if (!new_state->fb->obj[i])
+                       continue;
+               gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
+               ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM);
+               if (ret)
+                       goto err_drm_gem_vram_unpin;
+       }
+
+       return 0;
+
+err_drm_gem_vram_unpin:
+       while (i) {
+               --i;
+               gbo = drm_gem_vram_of_gem(new_state->fb->obj[i]);
+               drm_gem_vram_unpin(gbo);
+       }
+       return ret;
+}
+EXPORT_SYMBOL(drm_gem_vram_plane_helper_prepare_fb);
+
+/**
+ * drm_gem_vram_plane_helper_cleanup_fb() - \
+ *     Implements &struct drm_plane_helper_funcs.cleanup_fb
+ * @plane:     a DRM plane
+ * @old_state: the plane's old state
+ *
+ * During plane updates, this function unpins the GEM VRAM
+ * objects of the plane's old framebuffer from VRAM. Complements
+ * drm_gem_vram_plane_helper_prepare_fb().
+ */
+void
+drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
+                                    struct drm_plane_state *old_state)
+{
+       size_t i;
+       struct drm_gem_vram_object *gbo;
+
+       if (!old_state->fb)
+               return;
+
+       for (i = 0; i < ARRAY_SIZE(old_state->fb->obj); ++i) {
+               if (!old_state->fb->obj[i])
+                       continue;
+               gbo = drm_gem_vram_of_gem(old_state->fb->obj[i]);
+               drm_gem_vram_unpin(gbo);
+       }
+}
+EXPORT_SYMBOL(drm_gem_vram_plane_helper_cleanup_fb);
+
+/*
+ * Helpers for struct drm_simple_display_pipe_funcs
+ */
+
+/**
+ * drm_gem_vram_simple_display_pipe_prepare_fb() - \
+ *     Implements &struct drm_simple_display_pipe_funcs.prepare_fb
+ * @pipe:      a simple display pipe
+ * @new_state: the plane's new state
+ *
+ * During plane updates, this function pins the GEM VRAM
+ * objects of the plane's new framebuffer to VRAM. Call
+ * drm_gem_vram_simple_display_pipe_cleanup_fb() to unpin them.
+ *
+ * Returns:
+ *     0 on success, or
+ *     a negative errno code otherwise.
+ */
+int drm_gem_vram_simple_display_pipe_prepare_fb(
+       struct drm_simple_display_pipe *pipe,
+       struct drm_plane_state *new_state)
+{
+       return drm_gem_vram_plane_helper_prepare_fb(&pipe->plane, new_state);
+}
+EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_prepare_fb);
+
+/**
+ * drm_gem_vram_simple_display_pipe_cleanup_fb() - \
+ *     Implements &struct drm_simple_display_pipe_funcs.cleanup_fb
+ * @pipe:      a simple display pipe
+ * @old_state: the plane's old state
+ *
+ * During plane updates, this function unpins the GEM VRAM
+ * objects of the plane's old framebuffer from VRAM. Complements
+ * drm_gem_vram_simple_display_pipe_prepare_fb().
+ */
+void drm_gem_vram_simple_display_pipe_cleanup_fb(
+       struct drm_simple_display_pipe *pipe,
+       struct drm_plane_state *old_state)
+{
+       drm_gem_vram_plane_helper_cleanup_fb(&pipe->plane, old_state);
+}
+EXPORT_SYMBOL(drm_gem_vram_simple_display_pipe_cleanup_fb);
+
 /*
  * PRIME helpers
  */

diff --git a/include/drm/drm_gem_vram_helper.h b/include/drm/drm_gem_vram_helper.h
index b8ad4531ebb41f3176cfad3d8e1ec371570caa1a..e040541a105f7c702dbcbfe9b0da078524fb9ad4 100644 (file)
--- a/include/drm/drm_gem_vram_helper.h
+++ b/include/drm/drm_gem_vram_helper.h
@@ -13,6 +13,9 @@
 #include <linux/kernel.h> /* for container_of() */
 
 struct drm_mode_create_dumb;
+struct drm_plane;
+struct drm_plane_state;
+struct drm_simple_display_pipe;
 struct drm_vram_mm_funcs;
 struct filp;
 struct vm_area_struct;
@@ -124,6 +127,28 @@ int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
                                         struct drm_device *dev,
                                         uint32_t handle, uint64_t *offset);
 
+/*
+ * Helpers for struct drm_plane_helper_funcs
+ */
+int
+drm_gem_vram_plane_helper_prepare_fb(struct drm_plane *plane,
+                                    struct drm_plane_state *new_state);
+void
+drm_gem_vram_plane_helper_cleanup_fb(struct drm_plane *plane,
+                                    struct drm_plane_state *old_state);
+
+/*
+ * Helpers for struct drm_simple_display_pipe_funcs
+ */
+
+int drm_gem_vram_simple_display_pipe_prepare_fb(
+       struct drm_simple_display_pipe *pipe,
+       struct drm_plane_state *new_state);
+
+void drm_gem_vram_simple_display_pipe_cleanup_fb(
+       struct drm_simple_display_pipe *pipe,
+       struct drm_plane_state *old_state);
+
 /**
  * define DRM_GEM_VRAM_DRIVER - default callback functions for \
        &struct drm_driver