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/*
* Copyright (C) 2014 Red Hat
* Author: Rob Clark <robdclark@gmail.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "msm_drv.h"
#include "msm_kms.h"
#include "msm_gem.h"
struct msm_commit {
struct drm_atomic_state *state;
uint32_t fence;
struct msm_fence_cb fence_cb;
uint32_t crtc_mask;
};
static void fence_cb(struct msm_fence_cb *cb);
/* block until specified crtcs are no longer pending update, and
* atomically mark them as pending update
*/
static int start_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
{
int ret;
spin_lock(&priv->pending_crtcs_event.lock);
ret = wait_event_interruptible_locked(priv->pending_crtcs_event,
!(priv->pending_crtcs & crtc_mask));
if (ret == 0) {
DBG("start: %08x", crtc_mask);
priv->pending_crtcs |= crtc_mask;
}
spin_unlock(&priv->pending_crtcs_event.lock);
return ret;
}
/* clear specified crtcs (no longer pending update)
*/
static void end_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
{
spin_lock(&priv->pending_crtcs_event.lock);
DBG("end: %08x", crtc_mask);
priv->pending_crtcs &= ~crtc_mask;
wake_up_all_locked(&priv->pending_crtcs_event);
spin_unlock(&priv->pending_crtcs_event.lock);
}
static struct msm_commit *new_commit(struct drm_atomic_state *state)
{
struct msm_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);
if (!c)
return NULL;
c->state = state;
/* TODO we might need a way to indicate to run the cb on a
* different wq so wait_for_vblanks() doesn't block retiring
* bo's..
*/
INIT_FENCE_CB(&c->fence_cb, fence_cb);
return c;
}
/* The (potentially) asynchronous part of the commit. At this point
* nothing can fail short of armageddon.
*/
static void complete_commit(struct msm_commit *c)
{
struct drm_atomic_state *state = c->state;
struct drm_device *dev = state->dev;
drm_atomic_helper_commit_pre_planes(dev, state);
drm_atomic_helper_commit_planes(dev, state);
drm_atomic_helper_commit_post_planes(dev, state);
/* NOTE: _wait_for_vblanks() only waits for vblank on
* enabled CRTCs. So we end up faulting when disabling
* due to (potentially) unref'ing the outgoing fb's
* before the vblank when the disable has latched.
*
* But if it did wait on disabled (or newly disabled)
* CRTCs, that would be racy (ie. we could have missed
* the irq. We need some way to poll for pipe shut
* down. Or just live with occasionally hitting the
* timeout in the CRTC disable path (which really should
* not be critical path)
*/
drm_atomic_helper_wait_for_vblanks(dev, state);
drm_atomic_helper_cleanup_planes(dev, state);
drm_atomic_state_free(state);
end_atomic(dev->dev_private, c->crtc_mask);
kfree(c);
}
static void fence_cb(struct msm_fence_cb *cb)
{
struct msm_commit *c =
container_of(cb, struct msm_commit, fence_cb);
complete_commit(c);
}
static void add_fb(struct msm_commit *c, struct drm_framebuffer *fb)
{
struct drm_gem_object *obj = msm_framebuffer_bo(fb, 0);
c->fence = max(c->fence, msm_gem_fence(to_msm_bo(obj), MSM_PREP_READ));
}
/**
* drm_atomic_helper_commit - commit validated state object
* @dev: DRM device
* @state: the driver state object
* @async: asynchronous commit
*
* This function commits a with drm_atomic_helper_check() pre-validated state
* object. This can still fail when e.g. the framebuffer reservation fails. For
* now this doesn't implement asynchronous commits.
*
* RETURNS
* Zero for success or -errno.
*/
int msm_atomic_commit(struct drm_device *dev,
struct drm_atomic_state *state, bool async)
{
int nplanes = dev->mode_config.num_total_plane;
int ncrtcs = dev->mode_config.num_crtc;
struct msm_commit *c;
int i, ret;
ret = drm_atomic_helper_prepare_planes(dev, state);
if (ret)
return ret;
c = new_commit(state);
if (!c)
return -ENOMEM;
/*
* Figure out what crtcs we have:
*/
for (i = 0; i < ncrtcs; i++) {
struct drm_crtc *crtc = state->crtcs[i];
if (!crtc)
continue;
c->crtc_mask |= (1 << drm_crtc_index(crtc));
}
/*
* Figure out what fence to wait for:
*/
for (i = 0; i < nplanes; i++) {
struct drm_plane *plane = state->planes[i];
struct drm_plane_state *new_state = state->plane_states[i];
if (!plane)
continue;
if ((plane->state->fb != new_state->fb) && new_state->fb)
add_fb(c, new_state->fb);
}
/*
* Wait for pending updates on any of the same crtc's and then
* mark our set of crtc's as busy:
*/
ret = start_atomic(dev->dev_private, c->crtc_mask);
if (ret)
return ret;
/*
* This is the point of no return - everything below never fails except
* when the hw goes bonghits. Which means we can commit the new state on
* the software side now.
*/
drm_atomic_helper_swap_state(dev, state);
/*
* Everything below can be run asynchronously without the need to grab
* any modeset locks at all under one conditions: It must be guaranteed
* that the asynchronous work has either been cancelled (if the driver
* supports it, which at least requires that the framebuffers get
* cleaned up with drm_atomic_helper_cleanup_planes()) or completed
* before the new state gets committed on the software side with
* drm_atomic_helper_swap_state().
*
* This scheme allows new atomic state updates to be prepared and
* checked in parallel to the asynchronous completion of the previous
* update. Which is important since compositors need to figure out the
* composition of the next frame right after having submitted the
* current layout.
*/
if (async) {
msm_queue_fence_cb(dev, &c->fence_cb, c->fence);
return 0;
}
ret = msm_wait_fence_interruptable(dev, c->fence, NULL);
if (ret) {
WARN_ON(ret); // TODO unswap state back? or??
kfree(c);
return ret;
}
complete_commit(c);
return 0;
}
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