linux/include/drm/drm_writeback.h
Brian Starkey b13cc8dd58 drm: writeback: Add out-fences for writeback connectors
Add the WRITEBACK_OUT_FENCE_PTR property to writeback connectors, to
enable userspace to get a fence which will signal once the writeback is
complete. It is not allowed to request an out-fence without a
framebuffer attached to the connector.

A timeline is added to drm_writeback_connector for use by the writeback
out-fences.

In the case of a commit failure or DRM_MODE_ATOMIC_TEST_ONLY, the fence
is set to -1.

Changes from v2:
 - Rebase onto Gustavo Padovan's v9 explicit sync series
 - Change out_fence_ptr type to s32 __user *
 - Set *out_fence_ptr to -1 in drm_atomic_connector_set_property
 - Store fence in drm_writeback_job
 Gustavo Padovan:
 - Move out_fence_ptr out of connector_state
 - Signal fence from drm_writeback_signal_completion instead of
   in driver directly

Changes from v3:
 - Rebase onto commit 7e9081c5aa ("drm/fence: fix memory overwrite
   when setting out_fence fd") (change out_fence_ptr to s32 __user *,
   for real this time.)
 - Update documentation around WRITEBACK_OUT_FENCE_PTR

Signed-off-by: Brian Starkey <brian.starkey@arm.com>
[rebased and fixed conflicts]
Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/229036/
2018-06-20 15:29:18 +01:00

131 lines
3.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* (C) COPYRIGHT 2016 ARM Limited. All rights reserved.
* Author: Brian Starkey <brian.starkey@arm.com>
*
* This program is free software and is provided to you under the terms of the
* GNU General Public License version 2 as published by the Free Software
* Foundation, and any use by you of this program is subject to the terms
* of such GNU licence.
*/
#ifndef __DRM_WRITEBACK_H__
#define __DRM_WRITEBACK_H__
#include <drm/drm_connector.h>
#include <drm/drm_encoder.h>
#include <linux/workqueue.h>
struct drm_writeback_connector {
struct drm_connector base;
/**
* @encoder: Internal encoder used by the connector to fulfill
* the DRM framework requirements. The users of the
* @drm_writeback_connector control the behaviour of the @encoder
* by passing the @enc_funcs parameter to drm_writeback_connector_init()
* function.
*/
struct drm_encoder encoder;
/**
* @pixel_formats_blob_ptr:
*
* DRM blob property data for the pixel formats list on writeback
* connectors
* See also drm_writeback_connector_init()
*/
struct drm_property_blob *pixel_formats_blob_ptr;
/** @job_lock: Protects job_queue */
spinlock_t job_lock;
/**
* @job_queue:
*
* Holds a list of a connector's writeback jobs; the last item is the
* most recent. The first item may be either waiting for the hardware
* to begin writing, or currently being written.
*
* See also: drm_writeback_queue_job() and
* drm_writeback_signal_completion()
*/
struct list_head job_queue;
/**
* @fence_context:
*
* timeline context used for fence operations.
*/
unsigned int fence_context;
/**
* @fence_lock:
*
* spinlock to protect the fences in the fence_context.
*/
spinlock_t fence_lock;
/**
* @fence_seqno:
*
* Seqno variable used as monotonic counter for the fences
* created on the connector's timeline.
*/
unsigned long fence_seqno;
/**
* @timeline_name:
*
* The name of the connector's fence timeline.
*/
char timeline_name[32];
};
struct drm_writeback_job {
/**
* @cleanup_work:
*
* Used to allow drm_writeback_signal_completion to defer dropping the
* framebuffer reference to a workqueue
*/
struct work_struct cleanup_work;
/**
* @list_entry:
*
* List item for the writeback connector's @job_queue
*/
struct list_head list_entry;
/**
* @fb:
*
* Framebuffer to be written to by the writeback connector. Do not set
* directly, use drm_atomic_set_writeback_fb_for_connector()
*/
struct drm_framebuffer *fb;
/**
* @out_fence:
*
* Fence which will signal once the writeback has completed
*/
struct dma_fence *out_fence;
};
int drm_writeback_connector_init(struct drm_device *dev,
struct drm_writeback_connector *wb_connector,
const struct drm_connector_funcs *con_funcs,
const struct drm_encoder_helper_funcs *enc_helper_funcs,
const u32 *formats, int n_formats);
void drm_writeback_queue_job(struct drm_writeback_connector *wb_connector,
struct drm_writeback_job *job);
void drm_writeback_cleanup_job(struct drm_writeback_job *job);
void
drm_writeback_signal_completion(struct drm_writeback_connector *wb_connector,
int status);
struct dma_fence *
drm_writeback_get_out_fence(struct drm_writeback_connector *wb_connector);
#endif