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 #include "msm_fence.h" 22 23 struct msm_commit { 24 struct drm_device *dev; 25 struct drm_atomic_state *state; 26 struct work_struct work; 27 uint32_t crtc_mask; 28 }; 29 30 static void commit_worker(struct work_struct *work); 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 INIT_WORK(&c->work, commit_worker); 73 74 return c; 75 } 76 77 static void commit_destroy(struct msm_commit *c) 78 { 79 end_atomic(c->dev->dev_private, c->crtc_mask); 80 kfree(c); 81 } 82 83 static void msm_atomic_wait_for_commit_done(struct drm_device *dev, 84 struct drm_atomic_state *old_state) 85 { 86 struct drm_crtc *crtc; 87 struct drm_crtc_state *crtc_state; 88 struct msm_drm_private *priv = old_state->dev->dev_private; 89 struct msm_kms *kms = priv->kms; 90 int i; 91 92 for_each_crtc_in_state(old_state, crtc, crtc_state, i) { 93 if (!crtc->state->enable) 94 continue; 95 96 /* Legacy cursor ioctls are completely unsynced, and userspace 97 * relies on that (by doing tons of cursor updates). */ 98 if (old_state->legacy_cursor_update) 99 continue; 100 101 kms->funcs->wait_for_crtc_commit_done(kms, crtc); 102 } 103 } 104 105 /* The (potentially) asynchronous part of the commit. At this point 106 * nothing can fail short of armageddon. 107 */ 108 static void complete_commit(struct msm_commit *c, bool async) 109 { 110 struct drm_atomic_state *state = c->state; 111 struct drm_device *dev = state->dev; 112 struct msm_drm_private *priv = dev->dev_private; 113 struct msm_kms *kms = priv->kms; 114 115 drm_atomic_helper_wait_for_fences(dev, state, false); 116 117 kms->funcs->prepare_commit(kms, state); 118 119 drm_atomic_helper_commit_modeset_disables(dev, state); 120 121 drm_atomic_helper_commit_planes(dev, state, 0); 122 123 drm_atomic_helper_commit_modeset_enables(dev, state); 124 125 /* NOTE: _wait_for_vblanks() only waits for vblank on 126 * enabled CRTCs. So we end up faulting when disabling 127 * due to (potentially) unref'ing the outgoing fb's 128 * before the vblank when the disable has latched. 129 * 130 * But if it did wait on disabled (or newly disabled) 131 * CRTCs, that would be racy (ie. we could have missed 132 * the irq. We need some way to poll for pipe shut 133 * down. Or just live with occasionally hitting the 134 * timeout in the CRTC disable path (which really should 135 * not be critical path) 136 */ 137 138 msm_atomic_wait_for_commit_done(dev, state); 139 140 drm_atomic_helper_cleanup_planes(dev, state); 141 142 kms->funcs->complete_commit(kms, state); 143 144 drm_atomic_state_put(state); 145 146 commit_destroy(c); 147 } 148 149 static void commit_worker(struct work_struct *work) 150 { 151 complete_commit(container_of(work, struct msm_commit, work), true); 152 } 153 154 int msm_atomic_check(struct drm_device *dev, 155 struct drm_atomic_state *state) 156 { 157 int ret; 158 159 /* 160 * msm ->atomic_check can update ->mode_changed for pixel format 161 * changes, hence must be run before we check the modeset changes. 162 */ 163 ret = drm_atomic_helper_check_planes(dev, state); 164 if (ret) 165 return ret; 166 167 ret = drm_atomic_helper_check_modeset(dev, state); 168 if (ret) 169 return ret; 170 171 return ret; 172 } 173 174 /** 175 * drm_atomic_helper_commit - commit validated state object 176 * @dev: DRM device 177 * @state: the driver state object 178 * @nonblock: nonblocking commit 179 * 180 * This function commits a with drm_atomic_helper_check() pre-validated state 181 * object. This can still fail when e.g. the framebuffer reservation fails. 182 * 183 * RETURNS 184 * Zero for success or -errno. 185 */ 186 int msm_atomic_commit(struct drm_device *dev, 187 struct drm_atomic_state *state, bool nonblock) 188 { 189 struct msm_drm_private *priv = dev->dev_private; 190 struct msm_commit *c; 191 struct drm_crtc *crtc; 192 struct drm_crtc_state *crtc_state; 193 struct drm_plane *plane; 194 struct drm_plane_state *plane_state; 195 int i, ret; 196 197 ret = drm_atomic_helper_prepare_planes(dev, state); 198 if (ret) 199 return ret; 200 201 c = commit_init(state); 202 if (!c) { 203 ret = -ENOMEM; 204 goto error; 205 } 206 207 /* 208 * Figure out what crtcs we have: 209 */ 210 for_each_crtc_in_state(state, crtc, crtc_state, i) 211 c->crtc_mask |= drm_crtc_mask(crtc); 212 213 /* 214 * Figure out what fence to wait for: 215 */ 216 for_each_plane_in_state(state, plane, plane_state, i) { 217 if ((plane->state->fb != plane_state->fb) && plane_state->fb) { 218 struct drm_gem_object *obj = msm_framebuffer_bo(plane_state->fb, 0); 219 struct msm_gem_object *msm_obj = to_msm_bo(obj); 220 struct dma_fence *fence = reservation_object_get_excl_rcu(msm_obj->resv); 221 222 drm_atomic_set_fence_for_plane(plane_state, fence); 223 } 224 } 225 226 /* 227 * Wait for pending updates on any of the same crtc's and then 228 * mark our set of crtc's as busy: 229 */ 230 ret = start_atomic(dev->dev_private, c->crtc_mask); 231 if (ret) { 232 kfree(c); 233 goto error; 234 } 235 236 /* 237 * This is the point of no return - everything below never fails except 238 * when the hw goes bonghits. Which means we can commit the new state on 239 * the software side now. 240 */ 241 242 drm_atomic_helper_swap_state(state, true); 243 244 /* 245 * Everything below can be run asynchronously without the need to grab 246 * any modeset locks at all under one conditions: It must be guaranteed 247 * that the asynchronous work has either been cancelled (if the driver 248 * supports it, which at least requires that the framebuffers get 249 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed 250 * before the new state gets committed on the software side with 251 * drm_atomic_helper_swap_state(). 252 * 253 * This scheme allows new atomic state updates to be prepared and 254 * checked in parallel to the asynchronous completion of the previous 255 * update. Which is important since compositors need to figure out the 256 * composition of the next frame right after having submitted the 257 * current layout. 258 */ 259 260 drm_atomic_state_get(state); 261 if (nonblock) { 262 queue_work(priv->atomic_wq, &c->work); 263 return 0; 264 } 265 266 complete_commit(c, false); 267 268 return 0; 269 270 error: 271 drm_atomic_helper_cleanup_planes(dev, state); 272 return ret; 273 } 274