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-rw-r--r--drivers/gpu/drm/drm_damage_helper.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_damage_helper.c b/drivers/gpu/drm/drm_damage_helper.c
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index 000000000000..d2a1c7372f36
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+++ b/drivers/gpu/drm/drm_damage_helper.c
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+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/**************************************************************************
+ *
+ * Copyright (c) 2018 VMware, Inc., Palo Alto, CA., USA
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ * Deepak Rawat <drawat@vmware.com>
+ * Rob Clark <robdclark@gmail.com>
+ *
+ **************************************************************************/
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_damage_helper.h>
+
+/**
+ * DOC: overview
+ *
+ * FB_DAMAGE_CLIPS is an optional plane property which provides a means to
+ * specify a list of damage rectangles on a plane in framebuffer coordinates of
+ * the framebuffer attached to the plane. In current context damage is the area
+ * of plane framebuffer that has changed since last plane update (also called
+ * page-flip), irrespective of whether currently attached framebuffer is same as
+ * framebuffer attached during last plane update or not.
+ *
+ * FB_DAMAGE_CLIPS is a hint to kernel which could be helpful for some drivers
+ * to optimize internally especially for virtual devices where each framebuffer
+ * change needs to be transmitted over network, usb, etc.
+ *
+ * Since FB_DAMAGE_CLIPS is a hint so it is an optional property. User-space can
+ * ignore damage clips property and in that case driver will do a full plane
+ * update. In case damage clips are provided then it is guaranteed that the area
+ * inside damage clips will be updated to plane. For efficiency driver can do
+ * full update or can update more than specified in damage clips. Since driver
+ * is free to read more, user-space must always render the entire visible
+ * framebuffer. Otherwise there can be corruptions. Also, if a user-space
+ * provides damage clips which doesn't encompass the actual damage to
+ * framebuffer (since last plane update) can result in incorrect rendering.
+ *
+ * FB_DAMAGE_CLIPS is a blob property with the layout of blob data is simply an
+ * array of &drm_mode_rect. Unlike plane &drm_plane_state.src coordinates,
+ * damage clips are not in 16.16 fixed point. Similar to plane src in
+ * framebuffer, damage clips cannot be negative. In damage clip, x1/y1 are
+ * inclusive and x2/y2 are exclusive. While kernel does not error for overlapped
+ * damage clips, it is strongly discouraged.
+ *
+ * Drivers that are interested in damage interface for plane should enable
+ * FB_DAMAGE_CLIPS property by calling drm_plane_enable_fb_damage_clips().
+ * Drivers implementing damage can use drm_atomic_helper_damage_iter_init() and
+ * drm_atomic_helper_damage_iter_next() helper iterator function to get damage
+ * rectangles clipped to &drm_plane_state.src.
+ */
+
+static void convert_clip_rect_to_rect(const struct drm_clip_rect *src,
+ struct drm_mode_rect *dest,
+ uint32_t num_clips, uint32_t src_inc)
+{
+ while (num_clips > 0) {
+ dest->x1 = src->x1;
+ dest->y1 = src->y1;
+ dest->x2 = src->x2;
+ dest->y2 = src->y2;
+ src += src_inc;
+ dest++;
+ num_clips--;
+ }
+}
+
+/**
+ * drm_plane_enable_fb_damage_clips - Enables plane fb damage clips property.
+ * @plane: Plane on which to enable damage clips property.
+ *
+ * This function lets driver to enable the damage clips property on a plane.
+ */
+void drm_plane_enable_fb_damage_clips(struct drm_plane *plane)
+{
+ struct drm_device *dev = plane->dev;
+ struct drm_mode_config *config = &dev->mode_config;
+
+ drm_object_attach_property(&plane->base, config->prop_fb_damage_clips,
+ 0);
+}
+EXPORT_SYMBOL(drm_plane_enable_fb_damage_clips);
+
+/**
+ * drm_atomic_helper_check_plane_damage - Verify plane damage on atomic_check.
+ * @state: The driver state object.
+ * @plane_state: Plane state for which to verify damage.
+ *
+ * This helper function makes sure that damage from plane state is discarded
+ * for full modeset. If there are more reasons a driver would want to do a full
+ * plane update rather than processing individual damage regions, then those
+ * cases should be taken care of here.
+ *
+ * Note that &drm_plane_state.fb_damage_clips == NULL in plane state means that
+ * full plane update should happen. It also ensure helper iterator will return
+ * &drm_plane_state.src as damage.
+ */
+void drm_atomic_helper_check_plane_damage(struct drm_atomic_state *state,
+ struct drm_plane_state *plane_state)
+{
+ struct drm_crtc_state *crtc_state;
+
+ if (plane_state->crtc) {
+ crtc_state = drm_atomic_get_new_crtc_state(state,
+ plane_state->crtc);
+
+ if (WARN_ON(!crtc_state))
+ return;
+
+ if (drm_atomic_crtc_needs_modeset(crtc_state)) {
+ drm_property_blob_put(plane_state->fb_damage_clips);
+ plane_state->fb_damage_clips = NULL;
+ }
+ }
+}
+EXPORT_SYMBOL(drm_atomic_helper_check_plane_damage);
+
+/**
+ * drm_atomic_helper_dirtyfb - Helper for dirtyfb.
+ * @fb: DRM framebuffer.
+ * @file_priv: Drm file for the ioctl call.
+ * @flags: Dirty fb annotate flags.
+ * @color: Color for annotate fill.
+ * @clips: Dirty region.
+ * @num_clips: Count of clip in clips.
+ *
+ * A helper to implement &drm_framebuffer_funcs.dirty using damage interface
+ * during plane update. If num_clips is 0 then this helper will do a full plane
+ * update. This is the same behaviour expected by DIRTFB IOCTL.
+ *
+ * Note that this helper is blocking implementation. This is what current
+ * drivers and userspace expect in their DIRTYFB IOCTL implementation, as a way
+ * to rate-limit userspace and make sure its rendering doesn't get ahead of
+ * uploading new data too much.
+ *
+ * Return: Zero on success, negative errno on failure.
+ */
+int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb,
+ struct drm_file *file_priv, unsigned int flags,
+ unsigned int color, struct drm_clip_rect *clips,
+ unsigned int num_clips)
+{
+ struct drm_modeset_acquire_ctx ctx;
+ struct drm_property_blob *damage = NULL;
+ struct drm_mode_rect *rects = NULL;
+ struct drm_atomic_state *state;
+ struct drm_plane *plane;
+ int ret = 0;
+
+ /*
+ * When called from ioctl, we are interruptable, but not when called
+ * internally (ie. defio worker)
+ */
+ drm_modeset_acquire_init(&ctx,
+ file_priv ? DRM_MODESET_ACQUIRE_INTERRUPTIBLE : 0);
+
+ state = drm_atomic_state_alloc(fb->dev);
+ if (!state) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ state->acquire_ctx = &ctx;
+
+ if (clips) {
+ uint32_t inc = 1;
+
+ if (flags & DRM_MODE_FB_DIRTY_ANNOTATE_COPY) {
+ inc = 2;
+ num_clips /= 2;
+ }
+
+ rects = kcalloc(num_clips, sizeof(*rects), GFP_KERNEL);
+ if (!rects) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ convert_clip_rect_to_rect(clips, rects, num_clips, inc);
+ damage = drm_property_create_blob(fb->dev,
+ num_clips * sizeof(*rects),
+ rects);
+ if (IS_ERR(damage)) {
+ ret = PTR_ERR(damage);
+ damage = NULL;
+ goto out;
+ }
+ }
+
+retry:
+ drm_for_each_plane(plane, fb->dev) {
+ struct drm_plane_state *plane_state;
+
+ if (plane->state->fb != fb)
+ continue;
+
+ plane_state = drm_atomic_get_plane_state(state, plane);
+ if (IS_ERR(plane_state)) {
+ ret = PTR_ERR(plane_state);
+ goto out;
+ }
+
+ drm_property_replace_blob(&plane_state->fb_damage_clips,
+ damage);
+ }
+
+ ret = drm_atomic_commit(state);
+
+out:
+ if (ret == -EDEADLK) {
+ drm_atomic_state_clear(state);
+ ret = drm_modeset_backoff(&ctx);
+ if (!ret)
+ goto retry;
+ }
+
+ drm_property_blob_put(damage);
+ kfree(rects);
+ drm_atomic_state_put(state);
+
+ drm_modeset_drop_locks(&ctx);
+ drm_modeset_acquire_fini(&ctx);
+
+ return ret;
+
+}
+EXPORT_SYMBOL(drm_atomic_helper_dirtyfb);
+
+/**
+ * drm_atomic_helper_damage_iter_init - Initialize the damage iterator.
+ * @iter: The iterator to initialize.
+ * @old_state: Old plane state for validation.
+ * @state: Plane state from which to iterate the damage clips.
+ *
+ * Initialize an iterator, which clips plane damage
+ * &drm_plane_state.fb_damage_clips to plane &drm_plane_state.src. This iterator
+ * returns full plane src in case damage is not present because either
+ * user-space didn't sent or driver discarded it (it want to do full plane
+ * update). Currently this iterator returns full plane src in case plane src
+ * changed but that can be changed in future to return damage.
+ *
+ * For the case when plane is not visible or plane update should not happen the
+ * first call to iter_next will return false. Note that this helper use clipped
+ * &drm_plane_state.src, so driver calling this helper should have called
+ * drm_atomic_helper_check_plane_state() earlier.
+ */
+void
+drm_atomic_helper_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,
+ const struct drm_plane_state *old_state,
+ const struct drm_plane_state *state)
+{
+ memset(iter, 0, sizeof(*iter));
+
+ if (!state || !state->crtc || !state->fb || !state->visible)
+ return;
+
+ iter->clips = drm_helper_get_plane_damage_clips(state);
+ iter->num_clips = drm_plane_get_damage_clips_count(state);
+
+ /* Round down for x1/y1 and round up for x2/y2 to catch all pixels */
+ iter->plane_src.x1 = state->src.x1 >> 16;
+ iter->plane_src.y1 = state->src.y1 >> 16;
+ iter->plane_src.x2 = (state->src.x2 >> 16) + !!(state->src.x2 & 0xFFFF);
+ iter->plane_src.y2 = (state->src.y2 >> 16) + !!(state->src.y2 & 0xFFFF);
+
+ if (!iter->clips || !drm_rect_equals(&state->src, &old_state->src)) {
+ iter->clips = 0;
+ iter->num_clips = 0;
+ iter->full_update = true;
+ }
+}
+EXPORT_SYMBOL(drm_atomic_helper_damage_iter_init);
+
+/**
+ * drm_atomic_helper_damage_iter_next - Advance the damage iterator.
+ * @iter: The iterator to advance.
+ * @rect: Return a rectangle in fb coordinate clipped to plane src.
+ *
+ * Since plane src is in 16.16 fixed point and damage clips are whole number,
+ * this iterator round off clips that intersect with plane src. Round down for
+ * x1/y1 and round up for x2/y2 for the intersected coordinate. Similar rounding
+ * off for full plane src, in case it's returned as damage. This iterator will
+ * skip damage clips outside of plane src.
+ *
+ * Return: True if the output is valid, false if reached the end.
+ *
+ * If the first call to iterator next returns false then it means no need to
+ * update the plane.
+ */
+bool
+drm_atomic_helper_damage_iter_next(struct drm_atomic_helper_damage_iter *iter,
+ struct drm_rect *rect)
+{
+ bool ret = false;
+
+ if (iter->full_update) {
+ *rect = iter->plane_src;
+ iter->full_update = false;
+ return true;
+ }
+
+ while (iter->curr_clip < iter->num_clips) {
+ *rect = iter->clips[iter->curr_clip];
+ iter->curr_clip++;
+
+ if (drm_rect_intersect(rect, &iter->plane_src)) {
+ ret = true;
+ break;
+ }
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_damage_iter_next);