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 msm_drm_private *priv = old_state->dev->dev_private; 88 struct msm_kms *kms = priv->kms; 89 int ncrtcs = old_state->dev->mode_config.num_crtc; 90 int i; 91 92 for (i = 0; i < ncrtcs; i++) { 93 crtc = old_state->crtcs[i]; 94 95 if (!crtc) 96 continue; 97 98 if (!crtc->state->enable) 99 continue; 100 101 /* Legacy cursor ioctls are completely unsynced, and userspace 102 * relies on that (by doing tons of cursor updates). */ 103 if (old_state->legacy_cursor_update) 104 continue; 105 106 kms->funcs->wait_for_crtc_commit_done(kms, crtc); 107 } 108 } 109 110 /* The (potentially) asynchronous part of the commit. At this point 111 * nothing can fail short of armageddon. 112 */ 113 static void complete_commit(struct msm_commit *c, bool async) 114 { 115 struct drm_atomic_state *state = c->state; 116 struct drm_device *dev = state->dev; 117 struct msm_drm_private *priv = dev->dev_private; 118 struct msm_kms *kms = priv->kms; 119 120 drm_atomic_helper_wait_for_fences(dev, state); 121 122 kms->funcs->prepare_commit(kms, state); 123 124 drm_atomic_helper_commit_modeset_disables(dev, state); 125 126 drm_atomic_helper_commit_planes(dev, state, false); 127 128 drm_atomic_helper_commit_modeset_enables(dev, state); 129 130 /* NOTE: _wait_for_vblanks() only waits for vblank on 131 * enabled CRTCs. So we end up faulting when disabling 132 * due to (potentially) unref'ing the outgoing fb's 133 * before the vblank when the disable has latched. 134 * 135 * But if it did wait on disabled (or newly disabled) 136 * CRTCs, that would be racy (ie. we could have missed 137 * the irq. We need some way to poll for pipe shut 138 * down. Or just live with occasionally hitting the 139 * timeout in the CRTC disable path (which really should 140 * not be critical path) 141 */ 142 143 msm_atomic_wait_for_commit_done(dev, state); 144 145 drm_atomic_helper_cleanup_planes(dev, state); 146 147 kms->funcs->complete_commit(kms, state); 148 149 drm_atomic_state_free(state); 150 151 commit_destroy(c); 152 } 153 154 static void commit_worker(struct work_struct *work) 155 { 156 complete_commit(container_of(work, struct msm_commit, work), true); 157 } 158 159 int msm_atomic_check(struct drm_device *dev, 160 struct drm_atomic_state *state) 161 { 162 int ret; 163 164 /* 165 * msm ->atomic_check can update ->mode_changed for pixel format 166 * changes, hence must be run before we check the modeset changes. 167 */ 168 ret = drm_atomic_helper_check_planes(dev, state); 169 if (ret) 170 return ret; 171 172 ret = drm_atomic_helper_check_modeset(dev, state); 173 if (ret) 174 return ret; 175 176 return ret; 177 } 178 179 /** 180 * drm_atomic_helper_commit - commit validated state object 181 * @dev: DRM device 182 * @state: the driver state object 183 * @nonblock: nonblocking commit 184 * 185 * This function commits a with drm_atomic_helper_check() pre-validated state 186 * object. This can still fail when e.g. the framebuffer reservation fails. 187 * 188 * RETURNS 189 * Zero for success or -errno. 190 */ 191 int msm_atomic_commit(struct drm_device *dev, 192 struct drm_atomic_state *state, bool nonblock) 193 { 194 struct msm_drm_private *priv = dev->dev_private; 195 int nplanes = dev->mode_config.num_total_plane; 196 int ncrtcs = dev->mode_config.num_crtc; 197 struct msm_commit *c; 198 int i, ret; 199 200 ret = drm_atomic_helper_prepare_planes(dev, state); 201 if (ret) 202 return ret; 203 204 c = commit_init(state); 205 if (!c) { 206 ret = -ENOMEM; 207 goto error; 208 } 209 210 /* 211 * Figure out what crtcs we have: 212 */ 213 for (i = 0; i < ncrtcs; i++) { 214 struct drm_crtc *crtc = state->crtcs[i]; 215 if (!crtc) 216 continue; 217 c->crtc_mask |= (1 << drm_crtc_index(crtc)); 218 } 219 220 /* 221 * Figure out what fence to wait for: 222 */ 223 for (i = 0; i < nplanes; i++) { 224 struct drm_plane *plane = state->planes[i]; 225 struct drm_plane_state *new_state = state->plane_states[i]; 226 227 if (!plane) 228 continue; 229 230 if ((plane->state->fb != new_state->fb) && new_state->fb) { 231 struct drm_gem_object *obj = msm_framebuffer_bo(new_state->fb, 0); 232 struct msm_gem_object *msm_obj = to_msm_bo(obj); 233 234 new_state->fence = reservation_object_get_excl_rcu(msm_obj->resv); 235 } 236 } 237 238 /* 239 * Wait for pending updates on any of the same crtc's and then 240 * mark our set of crtc's as busy: 241 */ 242 ret = start_atomic(dev->dev_private, c->crtc_mask); 243 if (ret) { 244 kfree(c); 245 goto error; 246 } 247 248 /* 249 * This is the point of no return - everything below never fails except 250 * when the hw goes bonghits. Which means we can commit the new state on 251 * the software side now. 252 */ 253 254 drm_atomic_helper_swap_state(dev, state); 255 256 /* 257 * Everything below can be run asynchronously without the need to grab 258 * any modeset locks at all under one conditions: It must be guaranteed 259 * that the asynchronous work has either been cancelled (if the driver 260 * supports it, which at least requires that the framebuffers get 261 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed 262 * before the new state gets committed on the software side with 263 * drm_atomic_helper_swap_state(). 264 * 265 * This scheme allows new atomic state updates to be prepared and 266 * checked in parallel to the asynchronous completion of the previous 267 * update. Which is important since compositors need to figure out the 268 * composition of the next frame right after having submitted the 269 * current layout. 270 */ 271 272 if (nonblock) { 273 queue_work(priv->atomic_wq, &c->work); 274 return 0; 275 } 276 277 complete_commit(c, false); 278 279 return 0; 280 281 error: 282 drm_atomic_helper_cleanup_planes(dev, state); 283 return ret; 284 } 285