drm/msm: Remove msm_commit/worker, use atomic helper commit

Moving further towards switching fully to the the atomic helpers, this
patch removes the hand-rolled worker nonblock commit code and uses the
atomic helpers commit_work model.

Changes in v2:
- Remove commit_destroy()
- Shuffle order of commit_tail calls to further serialize commits
- Use stall in swap_state to avoid abandoned events on disable
Changes in v3:
- Rebased on Archit's private_obj set
Changes in v4:
- None

Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

3 files changed, 42 insertions, 116 deletions

diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
index 94f9c3e0e7bf..95c7868445dd 100644
--- a/drivers/gpu/drm/msm/msm_atomic.c
+++ b/drivers/gpu/drm/msm/msm_atomic.c
@@ -21,66 +21,6 @@
 #include "msm_gem.h"
 #include "msm_fence.h"
 
-struct msm_commit {
-        struct drm_device *dev;
-        struct drm_atomic_state *state;
-        struct work_struct work;
-        uint32_t crtc_mask;
-};
-
-static void commit_worker(struct work_struct *work);
-
-/* 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 *commit_init(struct drm_atomic_state *state)
-{
-        struct msm_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);
-
-        if (!c)
-                return NULL;
-
-        c->dev = state->dev;
-        c->state = state;
-
-        INIT_WORK(&c->work, commit_worker);
-
-        return c;
-}
-
-static void commit_destroy(struct msm_commit *c)
-{
-        end_atomic(c->dev->dev_private, c->crtc_mask);
-        kfree(c);
-}
-
 static void msm_atomic_wait_for_commit_done(struct drm_device *dev,
                 struct drm_atomic_state *old_state)
 {
@@ -148,31 +88,37 @@ static void msm_atomic_commit_tail(struct drm_atomic_state *state)
 
         msm_atomic_wait_for_commit_done(dev, state);
 
-        drm_atomic_helper_cleanup_planes(dev, state);
-
         kms->funcs->complete_commit(kms, state);
+
+        drm_atomic_helper_wait_for_vblanks(dev, state);
+
+        drm_atomic_helper_commit_hw_done(state);
+
+        drm_atomic_helper_cleanup_planes(dev, state);
 }
 
 /* The (potentially) asynchronous part of the commit.  At this point
  * nothing can fail short of armageddon.
  */
-static void complete_commit(struct msm_commit *c)
+static void commit_tail(struct drm_atomic_state *state)
 {
-        struct drm_atomic_state *state = c->state;
-        struct drm_device *dev = state->dev;
+        drm_atomic_helper_wait_for_fences(state->dev, state, false);
 
-        drm_atomic_helper_wait_for_fences(dev, state, false);
+        drm_atomic_helper_wait_for_dependencies(state);
 
         msm_atomic_commit_tail(state);
 
-        drm_atomic_state_put(state);
+        drm_atomic_helper_commit_cleanup_done(state);
 
-        commit_destroy(c);
+        drm_atomic_state_put(state);
 }
 
-static void commit_worker(struct work_struct *work)
+static void commit_work(struct work_struct *work)
 {
-        complete_commit(container_of(work, struct msm_commit, work));
+        struct drm_atomic_state *state = container_of(work,
+                                                      struct drm_atomic_state,
+                                                      commit_work);
+        commit_tail(state);
 }
 
 /**
@@ -191,17 +137,12 @@ int msm_atomic_commit(struct drm_device *dev,
                 struct drm_atomic_state *state, bool nonblock)
 {
         struct msm_drm_private *priv = dev->dev_private;
-        struct msm_commit *c;
         struct drm_crtc *crtc;
         struct drm_crtc_state *crtc_state;
         struct drm_plane *plane;
         struct drm_plane_state *old_plane_state, *new_plane_state;
         int i, ret;
 
-        ret = drm_atomic_helper_prepare_planes(dev, state);
-        if (ret)
-                return ret;
-
         /*
          * Note that plane->atomic_async_check() should fail if we need
          * to re-assign hwpipe or anything that touches global atomic
@@ -209,45 +150,39 @@ int msm_atomic_commit(struct drm_device *dev,
          * cases.
          */
         if (state->async_update) {
+                ret = drm_atomic_helper_prepare_planes(dev, state);
+                if (ret)
+                        return ret;
+
                 drm_atomic_helper_async_commit(dev, state);
                 drm_atomic_helper_cleanup_planes(dev, state);
                 return 0;
         }
 
-        c = commit_init(state);
-        if (!c) {
-                ret = -ENOMEM;
-                goto error;
-        }
+        ret = drm_atomic_helper_setup_commit(state, nonblock);
+        if (ret)
+                return ret;
 
-        /*
-         * Figure out what crtcs we have:
-         */
-        for_each_new_crtc_in_state(state, crtc, crtc_state, i)
-                c->crtc_mask |= drm_crtc_mask(crtc);
+        INIT_WORK(&state->commit_work, commit_work);
 
-        /*
-         * Figure out what fence to wait for:
-         */
-        for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
-                if ((new_plane_state->fb != old_plane_state->fb) && new_plane_state->fb) {
-                        struct drm_gem_object *obj = msm_framebuffer_bo(new_plane_state->fb, 0);
-                        struct msm_gem_object *msm_obj = to_msm_bo(obj);
-                        struct dma_fence *fence = reservation_object_get_excl_rcu(msm_obj->resv);
-
-                        drm_atomic_set_fence_for_plane(new_plane_state, fence);
-                }
+        ret = drm_atomic_helper_prepare_planes(dev, state);
+        if (ret)
+                return ret;
+
+        if (!nonblock) {
+                ret = drm_atomic_helper_wait_for_fences(dev, state, true);
+                if (ret)
+                        goto error;
         }
 
         /*
-         * Wait for pending updates on any of the same crtc's and then
-         * mark our set of crtc's as busy:
+         * 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.
+         *
+         * swap driver private state while still holding state_lock
          */
-        ret = start_atomic(dev->dev_private, c->crtc_mask);
-        if (ret)
-                goto err_free;
-
-        BUG_ON(drm_atomic_helper_swap_state(state, false) < 0);
+        BUG_ON(drm_atomic_helper_swap_state(state, true) < 0);
 
         /*
          * This is the point of no return - everything below never fails except
@@ -272,17 +207,13 @@ int msm_atomic_commit(struct drm_device *dev,
          */
 
         drm_atomic_state_get(state);
-        if (nonblock) {
-                queue_work(priv->atomic_wq, &c->work);
-                return 0;
-        }
-
-        complete_commit(c);
+        if (nonblock)
+                queue_work(system_unbound_wq, &state->commit_work);
+        else
+                commit_tail(state);
 
         return 0;
 
-err_free:
-        kfree(c);
 error:
         drm_atomic_helper_cleanup_planes(dev, state);
         return ret;
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 1c89195da4ff..9cec74c79aa2 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -381,7 +381,6 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
 
         priv->wq = alloc_ordered_workqueue("msm", 0);
         priv->atomic_wq = alloc_ordered_workqueue("msm:atomic", 0);
-        init_waitqueue_head(&priv->pending_crtcs_event);
 
         INIT_LIST_HEAD(&priv->inactive_list);
         INIT_LIST_HEAD(&priv->vblank_ctrl.event_list);
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 98e82230b904..2b2688896295 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -117,10 +117,6 @@ struct msm_drm_private {
         struct workqueue_struct *wq;
         struct workqueue_struct *atomic_wq;
 
-        /* crtcs pending async atomic updates: */
-        uint32_t pending_crtcs;
-        wait_queue_head_t pending_crtcs_event;
-
         unsigned int num_planes;
         struct drm_plane *planes[16];