Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[linux-2.6-microblaze.git] / drivers / gpu / drm / msm / msm_atomic.c
1 /*
2  * Copyright (C) 2014 Red Hat
3  * Author: Rob Clark <robdclark@gmail.com>
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 as published by
7  * the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * You should have received a copy of the GNU General Public License along with
15  * this program.  If not, see <http://www.gnu.org/licenses/>.
16  */
17
18 #include "msm_drv.h"
19 #include "msm_kms.h"
20 #include "msm_gem.h"
21
22 struct msm_commit {
23         struct drm_device *dev;
24         struct drm_atomic_state *state;
25         uint32_t fence;
26         struct msm_fence_cb fence_cb;
27         uint32_t crtc_mask;
28 };
29
30 static void fence_cb(struct msm_fence_cb *cb);
31
32 /* block until specified crtcs are no longer pending update, and
33  * atomically mark them as pending update
34  */
35 static int start_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
36 {
37         int ret;
38
39         spin_lock(&priv->pending_crtcs_event.lock);
40         ret = wait_event_interruptible_locked(priv->pending_crtcs_event,
41                         !(priv->pending_crtcs & crtc_mask));
42         if (ret == 0) {
43                 DBG("start: %08x", crtc_mask);
44                 priv->pending_crtcs |= crtc_mask;
45         }
46         spin_unlock(&priv->pending_crtcs_event.lock);
47
48         return ret;
49 }
50
51 /* clear specified crtcs (no longer pending update)
52  */
53 static void end_atomic(struct msm_drm_private *priv, uint32_t crtc_mask)
54 {
55         spin_lock(&priv->pending_crtcs_event.lock);
56         DBG("end: %08x", crtc_mask);
57         priv->pending_crtcs &= ~crtc_mask;
58         wake_up_all_locked(&priv->pending_crtcs_event);
59         spin_unlock(&priv->pending_crtcs_event.lock);
60 }
61
62 static struct msm_commit *commit_init(struct drm_atomic_state *state)
63 {
64         struct msm_commit *c = kzalloc(sizeof(*c), GFP_KERNEL);
65
66         if (!c)
67                 return NULL;
68
69         c->dev = state->dev;
70         c->state = state;
71
72         /* TODO we might need a way to indicate to run the cb on a
73          * different wq so wait_for_vblanks() doesn't block retiring
74          * bo's..
75          */
76         INIT_FENCE_CB(&c->fence_cb, fence_cb);
77
78         return c;
79 }
80
81 static void commit_destroy(struct msm_commit *c)
82 {
83         end_atomic(c->dev->dev_private, c->crtc_mask);
84         kfree(c);
85 }
86
87 /* The (potentially) asynchronous part of the commit.  At this point
88  * nothing can fail short of armageddon.
89  */
90 static void complete_commit(struct msm_commit *c)
91 {
92         struct drm_atomic_state *state = c->state;
93         struct drm_device *dev = state->dev;
94         struct msm_drm_private *priv = dev->dev_private;
95         struct msm_kms *kms = priv->kms;
96
97         kms->funcs->prepare_commit(kms, state);
98
99         drm_atomic_helper_commit_pre_planes(dev, state);
100
101         drm_atomic_helper_commit_planes(dev, state);
102
103         drm_atomic_helper_commit_post_planes(dev, state);
104
105         /* NOTE: _wait_for_vblanks() only waits for vblank on
106          * enabled CRTCs.  So we end up faulting when disabling
107          * due to (potentially) unref'ing the outgoing fb's
108          * before the vblank when the disable has latched.
109          *
110          * But if it did wait on disabled (or newly disabled)
111          * CRTCs, that would be racy (ie. we could have missed
112          * the irq.  We need some way to poll for pipe shut
113          * down.  Or just live with occasionally hitting the
114          * timeout in the CRTC disable path (which really should
115          * not be critical path)
116          */
117
118         drm_atomic_helper_wait_for_vblanks(dev, state);
119
120         drm_atomic_helper_cleanup_planes(dev, state);
121
122         kms->funcs->complete_commit(kms, state);
123
124         drm_atomic_state_free(state);
125
126         commit_destroy(c);
127 }
128
129 static void fence_cb(struct msm_fence_cb *cb)
130 {
131         struct msm_commit *c =
132                         container_of(cb, struct msm_commit, fence_cb);
133         complete_commit(c);
134 }
135
136 static void add_fb(struct msm_commit *c, struct drm_framebuffer *fb)
137 {
138         struct drm_gem_object *obj = msm_framebuffer_bo(fb, 0);
139         c->fence = max(c->fence, msm_gem_fence(to_msm_bo(obj), MSM_PREP_READ));
140 }
141
142
143 int msm_atomic_check(struct drm_device *dev,
144                      struct drm_atomic_state *state)
145 {
146         int ret;
147
148         /*
149          * msm ->atomic_check can update ->mode_changed for pixel format
150          * changes, hence must be run before we check the modeset changes.
151          */
152         ret = drm_atomic_helper_check_planes(dev, state);
153         if (ret)
154                 return ret;
155
156         ret = drm_atomic_helper_check_modeset(dev, state);
157         if (ret)
158                 return ret;
159
160         return ret;
161 }
162
163 /**
164  * drm_atomic_helper_commit - commit validated state object
165  * @dev: DRM device
166  * @state: the driver state object
167  * @async: asynchronous commit
168  *
169  * This function commits a with drm_atomic_helper_check() pre-validated state
170  * object. This can still fail when e.g. the framebuffer reservation fails. For
171  * now this doesn't implement asynchronous commits.
172  *
173  * RETURNS
174  * Zero for success or -errno.
175  */
176 int msm_atomic_commit(struct drm_device *dev,
177                 struct drm_atomic_state *state, bool async)
178 {
179         int nplanes = dev->mode_config.num_total_plane;
180         int ncrtcs = dev->mode_config.num_crtc;
181         struct timespec timeout;
182         struct msm_commit *c;
183         int i, ret;
184
185         ret = drm_atomic_helper_prepare_planes(dev, state);
186         if (ret)
187                 return ret;
188
189         c = commit_init(state);
190         if (!c)
191                 return -ENOMEM;
192
193         /*
194          * Figure out what crtcs we have:
195          */
196         for (i = 0; i < ncrtcs; i++) {
197                 struct drm_crtc *crtc = state->crtcs[i];
198                 if (!crtc)
199                         continue;
200                 c->crtc_mask |= (1 << drm_crtc_index(crtc));
201         }
202
203         /*
204          * Figure out what fence to wait for:
205          */
206         for (i = 0; i < nplanes; i++) {
207                 struct drm_plane *plane = state->planes[i];
208                 struct drm_plane_state *new_state = state->plane_states[i];
209
210                 if (!plane)
211                         continue;
212
213                 if ((plane->state->fb != new_state->fb) && new_state->fb)
214                         add_fb(c, new_state->fb);
215         }
216
217         /*
218          * Wait for pending updates on any of the same crtc's and then
219          * mark our set of crtc's as busy:
220          */
221         ret = start_atomic(dev->dev_private, c->crtc_mask);
222         if (ret) {
223                 kfree(c);
224                 return ret;
225         }
226
227         /*
228          * This is the point of no return - everything below never fails except
229          * when the hw goes bonghits. Which means we can commit the new state on
230          * the software side now.
231          */
232
233         drm_atomic_helper_swap_state(dev, state);
234
235         /*
236          * Everything below can be run asynchronously without the need to grab
237          * any modeset locks at all under one conditions: It must be guaranteed
238          * that the asynchronous work has either been cancelled (if the driver
239          * supports it, which at least requires that the framebuffers get
240          * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
241          * before the new state gets committed on the software side with
242          * drm_atomic_helper_swap_state().
243          *
244          * This scheme allows new atomic state updates to be prepared and
245          * checked in parallel to the asynchronous completion of the previous
246          * update. Which is important since compositors need to figure out the
247          * composition of the next frame right after having submitted the
248          * current layout.
249          */
250
251         if (async) {
252                 msm_queue_fence_cb(dev, &c->fence_cb, c->fence);
253                 return 0;
254         }
255
256         jiffies_to_timespec(jiffies + msecs_to_jiffies(1000), &timeout);
257
258         ret = msm_wait_fence_interruptable(dev, c->fence, &timeout);
259         if (ret) {
260                 WARN_ON(ret);  // TODO unswap state back?  or??
261                 commit_destroy(c);
262                 return ret;
263         }
264
265         complete_commit(c);
266
267         return 0;
268 }