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_modeset_disables(dev, state); 100 101 drm_atomic_helper_commit_planes(dev, state); 102 103 drm_atomic_helper_commit_modeset_enables(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 } 269