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 static void msm_atomic_wait_for_commit_done(struct drm_device *dev, 88 struct drm_atomic_state *old_state) 89 { 90 struct drm_crtc *crtc; 91 struct msm_drm_private *priv = old_state->dev->dev_private; 92 struct msm_kms *kms = priv->kms; 93 int ncrtcs = old_state->dev->mode_config.num_crtc; 94 int i; 95 96 for (i = 0; i < ncrtcs; i++) { 97 crtc = old_state->crtcs[i]; 98 99 if (!crtc) 100 continue; 101 102 if (!crtc->state->enable) 103 continue; 104 105 /* Legacy cursor ioctls are completely unsynced, and userspace 106 * relies on that (by doing tons of cursor updates). */ 107 if (old_state->legacy_cursor_update) 108 continue; 109 110 kms->funcs->wait_for_crtc_commit_done(kms, crtc); 111 } 112 } 113 114 /* The (potentially) asynchronous part of the commit. At this point 115 * nothing can fail short of armageddon. 116 */ 117 static void complete_commit(struct msm_commit *c) 118 { 119 struct drm_atomic_state *state = c->state; 120 struct drm_device *dev = state->dev; 121 struct msm_drm_private *priv = dev->dev_private; 122 struct msm_kms *kms = priv->kms; 123 124 kms->funcs->prepare_commit(kms, state); 125 126 drm_atomic_helper_commit_modeset_disables(dev, state); 127 128 drm_atomic_helper_commit_planes(dev, state); 129 130 drm_atomic_helper_commit_modeset_enables(dev, state); 131 132 /* NOTE: _wait_for_vblanks() only waits for vblank on 133 * enabled CRTCs. So we end up faulting when disabling 134 * due to (potentially) unref'ing the outgoing fb's 135 * before the vblank when the disable has latched. 136 * 137 * But if it did wait on disabled (or newly disabled) 138 * CRTCs, that would be racy (ie. we could have missed 139 * the irq. We need some way to poll for pipe shut 140 * down. Or just live with occasionally hitting the 141 * timeout in the CRTC disable path (which really should 142 * not be critical path) 143 */ 144 145 msm_atomic_wait_for_commit_done(dev, state); 146 147 drm_atomic_helper_cleanup_planes(dev, state); 148 149 kms->funcs->complete_commit(kms, state); 150 151 drm_atomic_state_free(state); 152 153 commit_destroy(c); 154 } 155 156 static void fence_cb(struct msm_fence_cb *cb) 157 { 158 struct msm_commit *c = 159 container_of(cb, struct msm_commit, fence_cb); 160 complete_commit(c); 161 } 162 163 static void add_fb(struct msm_commit *c, struct drm_framebuffer *fb) 164 { 165 struct drm_gem_object *obj = msm_framebuffer_bo(fb, 0); 166 c->fence = max(c->fence, msm_gem_fence(to_msm_bo(obj), MSM_PREP_READ)); 167 } 168 169 int msm_atomic_check(struct drm_device *dev, 170 struct drm_atomic_state *state) 171 { 172 int ret; 173 174 /* 175 * msm ->atomic_check can update ->mode_changed for pixel format 176 * changes, hence must be run before we check the modeset changes. 177 */ 178 ret = drm_atomic_helper_check_planes(dev, state); 179 if (ret) 180 return ret; 181 182 ret = drm_atomic_helper_check_modeset(dev, state); 183 if (ret) 184 return ret; 185 186 return ret; 187 } 188 189 /** 190 * drm_atomic_helper_commit - commit validated state object 191 * @dev: DRM device 192 * @state: the driver state object 193 * @async: asynchronous commit 194 * 195 * This function commits a with drm_atomic_helper_check() pre-validated state 196 * object. This can still fail when e.g. the framebuffer reservation fails. For 197 * now this doesn't implement asynchronous commits. 198 * 199 * RETURNS 200 * Zero for success or -errno. 201 */ 202 int msm_atomic_commit(struct drm_device *dev, 203 struct drm_atomic_state *state, bool async) 204 { 205 int nplanes = dev->mode_config.num_total_plane; 206 int ncrtcs = dev->mode_config.num_crtc; 207 ktime_t timeout; 208 struct msm_commit *c; 209 int i, ret; 210 211 ret = drm_atomic_helper_prepare_planes(dev, state); 212 if (ret) 213 return ret; 214 215 c = commit_init(state); 216 if (!c) { 217 ret = -ENOMEM; 218 goto error; 219 } 220 221 /* 222 * Figure out what crtcs we have: 223 */ 224 for (i = 0; i < ncrtcs; i++) { 225 struct drm_crtc *crtc = state->crtcs[i]; 226 if (!crtc) 227 continue; 228 c->crtc_mask |= (1 << drm_crtc_index(crtc)); 229 } 230 231 /* 232 * Figure out what fence to wait for: 233 */ 234 for (i = 0; i < nplanes; i++) { 235 struct drm_plane *plane = state->planes[i]; 236 struct drm_plane_state *new_state = state->plane_states[i]; 237 238 if (!plane) 239 continue; 240 241 if ((plane->state->fb != new_state->fb) && new_state->fb) 242 add_fb(c, new_state->fb); 243 } 244 245 /* 246 * Wait for pending updates on any of the same crtc's and then 247 * mark our set of crtc's as busy: 248 */ 249 ret = start_atomic(dev->dev_private, c->crtc_mask); 250 if (ret) { 251 kfree(c); 252 goto error; 253 } 254 255 /* 256 * This is the point of no return - everything below never fails except 257 * when the hw goes bonghits. Which means we can commit the new state on 258 * the software side now. 259 */ 260 261 drm_atomic_helper_swap_state(dev, state); 262 263 /* 264 * Everything below can be run asynchronously without the need to grab 265 * any modeset locks at all under one conditions: It must be guaranteed 266 * that the asynchronous work has either been cancelled (if the driver 267 * supports it, which at least requires that the framebuffers get 268 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed 269 * before the new state gets committed on the software side with 270 * drm_atomic_helper_swap_state(). 271 * 272 * This scheme allows new atomic state updates to be prepared and 273 * checked in parallel to the asynchronous completion of the previous 274 * update. Which is important since compositors need to figure out the 275 * composition of the next frame right after having submitted the 276 * current layout. 277 */ 278 279 if (async) { 280 msm_queue_fence_cb(dev, &c->fence_cb, c->fence); 281 return 0; 282 } 283 284 timeout = ktime_add_ms(ktime_get(), 1000); 285 286 /* uninterruptible wait */ 287 msm_wait_fence(dev, c->fence, &timeout, false); 288 289 complete_commit(c); 290 291 return 0; 292 293 error: 294 drm_atomic_helper_cleanup_planes(dev, state); 295 return ret; 296 } 297