drivers/gpu/drm/vkms/vkms_crtc.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2
   3 #include <drm/drm_atomic.h>
   4 #include <drm/drm_atomic_helper.h>
   5 #include <drm/drm_probe_helper.h>
   6 #include <drm/drm_vblank.h>
   7
   8 #include "vkms_drv.h"
   9
  10 static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer)
  11 {
  12         struct vkms_output *output = container_of(timer, struct vkms_output,
  13                                                   vblank_hrtimer);
  14         struct drm_crtc *crtc = &output->crtc;
  15         struct vkms_crtc_state *state;
  16         u64 ret_overrun;
  17         bool ret;
  18
  19         ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer,
  20                                           output->period_ns);
  21         WARN_ON(ret_overrun != 1);
  22
  23         spin_lock(&output->lock);
  24         ret = drm_crtc_handle_vblank(crtc);
  25         if (!ret)
  26                 DRM_ERROR("vkms failure on handling vblank");
  27
  28         state = output->composer_state;
  29         spin_unlock(&output->lock);
  30
  31         if (state && output->composer_enabled) {
  32                 u64 frame = drm_crtc_accurate_vblank_count(crtc);
  33
  34                 /* update frame_start only if a queued vkms_composer_worker()
  35                  * has read the data
  36                  */
  37                 spin_lock(&output->composer_lock);
  38                 if (!state->crc_pending)
  39                         state->frame_start = frame;
  40                 else
  41                         DRM_DEBUG_DRIVER("crc worker falling behind, frame_start: %llu, frame_end: %llu\n",
  42                                          state->frame_start, frame);
  43                 state->frame_end = frame;
  44                 state->crc_pending = true;
  45                 spin_unlock(&output->composer_lock);
  46
  47                 ret = queue_work(output->composer_workq, &state->composer_work);
  48                 if (!ret)
  49                         DRM_DEBUG_DRIVER("Composer worker already queued\n");
  50         }
  51
  52         return HRTIMER_RESTART;
  53 }
  54
  55 static int vkms_enable_vblank(struct drm_crtc *crtc)
  56 {
  57         struct drm_device *dev = crtc->dev;
  58         unsigned int pipe = drm_crtc_index(crtc);
  59         struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
  60         struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
  61
  62         drm_calc_timestamping_constants(crtc, &crtc->mode);
  63
  64         hrtimer_init(&out->vblank_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
  65         out->vblank_hrtimer.function = &vkms_vblank_simulate;
  66         out->period_ns = ktime_set(0, vblank->framedur_ns);
  67         hrtimer_start(&out->vblank_hrtimer, out->period_ns, HRTIMER_MODE_REL);
  68
  69         return 0;
  70 }
  71
  72 static void vkms_disable_vblank(struct drm_crtc *crtc)
  73 {
  74         struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
  75
  76         hrtimer_cancel(&out->vblank_hrtimer);
  77 }
  78
  79 static bool vkms_get_vblank_timestamp(struct drm_crtc *crtc,
  80                                       int *max_error, ktime_t *vblank_time,
  81                                       bool in_vblank_irq)
  82 {
  83         struct drm_device *dev = crtc->dev;
  84         unsigned int pipe = crtc->index;
  85         struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
  86         struct vkms_output *output = &vkmsdev->output;
  87         struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
  88
  89         if (!READ_ONCE(vblank->enabled)) {
  90                 *vblank_time = ktime_get();
  91                 return true;
  92         }
  93
  94         *vblank_time = READ_ONCE(output->vblank_hrtimer.node.expires);
  95
  96         if (WARN_ON(*vblank_time == vblank->time))
  97                 return true;
  98
  99         /*
 100          * To prevent races we roll the hrtimer forward before we do any
 101          * interrupt processing - this is how real hw works (the interrupt is
 102          * only generated after all the vblank registers are updated) and what
 103          * the vblank core expects. Therefore we need to always correct the
 104          * timestampe by one frame.
 105          */
 106         *vblank_time -= output->period_ns;
 107
 108         return true;
 109 }
 110
 111 static struct drm_crtc_state *
 112 vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
 113 {
 114         struct vkms_crtc_state *vkms_state;
 115
 116         if (WARN_ON(!crtc->state))
 117                 return NULL;
 118
 119         vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
 120         if (!vkms_state)
 121                 return NULL;
 122
 123         __drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
 124
 125         INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
 126
 127         return &vkms_state->base;
 128 }
 129
 130 static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
 131                                            struct drm_crtc_state *state)
 132 {
 133         struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
 134
 135         __drm_atomic_helper_crtc_destroy_state(state);
 136
 137         WARN_ON(work_pending(&vkms_state->composer_work));
 138         kfree(vkms_state->active_planes);
 139         kfree(vkms_state);
 140 }
 141
 142 static void vkms_atomic_crtc_reset(struct drm_crtc *crtc)
 143 {
 144         struct vkms_crtc_state *vkms_state =
 145                 kzalloc(sizeof(*vkms_state), GFP_KERNEL);
 146
 147         if (crtc->state)
 148                 vkms_atomic_crtc_destroy_state(crtc, crtc->state);
 149
 150         __drm_atomic_helper_crtc_reset(crtc, &vkms_state->base);
 151         if (vkms_state)
 152                 INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
 153 }
 154
 155 static const struct drm_crtc_funcs vkms_crtc_funcs = {
 156         .set_config             = drm_atomic_helper_set_config,
 157         .destroy                = drm_crtc_cleanup,
 158         .page_flip              = drm_atomic_helper_page_flip,
 159         .reset                  = vkms_atomic_crtc_reset,
 160         .atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
 161         .atomic_destroy_state   = vkms_atomic_crtc_destroy_state,
 162         .enable_vblank          = vkms_enable_vblank,
 163         .disable_vblank         = vkms_disable_vblank,
 164         .get_vblank_timestamp   = vkms_get_vblank_timestamp,
 165         .get_crc_sources        = vkms_get_crc_sources,
 166         .set_crc_source         = vkms_set_crc_source,
 167         .verify_crc_source      = vkms_verify_crc_source,
 168 };
 169
 170 static int vkms_crtc_atomic_check(struct drm_crtc *crtc,
 171                                   struct drm_crtc_state *state)
 172 {
 173         struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
 174         struct drm_plane *plane;
 175         struct drm_plane_state *plane_state;
 176         int i = 0, ret;
 177
 178         if (vkms_state->active_planes)
 179                 return 0;
 180
 181         ret = drm_atomic_add_affected_planes(state->state, crtc);
 182         if (ret < 0)
 183                 return ret;
 184
 185         drm_for_each_plane_mask(plane, crtc->dev, state->plane_mask) {
 186                 plane_state = drm_atomic_get_existing_plane_state(state->state,
 187                                                                   plane);
 188                 WARN_ON(!plane_state);
 189
 190                 if (!plane_state->visible)
 191                         continue;
 192
 193                 i++;
 194         }
 195
 196         vkms_state->active_planes = kcalloc(i, sizeof(plane), GFP_KERNEL);
 197         if (!vkms_state->active_planes)
 198                 return -ENOMEM;
 199         vkms_state->num_active_planes = i;
 200
 201         i = 0;
 202         drm_for_each_plane_mask(plane, crtc->dev, state->plane_mask) {
 203                 plane_state = drm_atomic_get_existing_plane_state(state->state,
 204                                                                   plane);
 205
 206                 if (!plane_state->visible)
 207                         continue;
 208
 209                 vkms_state->active_planes[i++] =
 210                         to_vkms_plane_state(plane_state);
 211         }
 212
 213         return 0;
 214 }
 215
 216 static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
 217                                     struct drm_crtc_state *old_state)
 218 {
 219         drm_crtc_vblank_on(crtc);
 220 }
 221
 222 static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
 223                                      struct drm_crtc_state *old_state)
 224 {
 225         drm_crtc_vblank_off(crtc);
 226 }
 227
 228 static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
 229                                    struct drm_crtc_state *old_crtc_state)
 230 {
 231         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 232
 233         /* This lock is held across the atomic commit to block vblank timer
 234          * from scheduling vkms_composer_worker until the composer is updated
 235          */
 236         spin_lock_irq(&vkms_output->lock);
 237 }
 238
 239 static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
 240                                    struct drm_crtc_state *old_crtc_state)
 241 {
 242         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 243
 244         if (crtc->state->event) {
 245                 spin_lock(&crtc->dev->event_lock);
 246
 247                 if (drm_crtc_vblank_get(crtc) != 0)
 248                         drm_crtc_send_vblank_event(crtc, crtc->state->event);
 249                 else
 250                         drm_crtc_arm_vblank_event(crtc, crtc->state->event);
 251
 252                 spin_unlock(&crtc->dev->event_lock);
 253
 254                 crtc->state->event = NULL;
 255         }
 256
 257         vkms_output->composer_state = to_vkms_crtc_state(crtc->state);
 258
 259         spin_unlock_irq(&vkms_output->lock);
 260 }
 261
 262 static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
 263         .atomic_check   = vkms_crtc_atomic_check,
 264         .atomic_begin   = vkms_crtc_atomic_begin,
 265         .atomic_flush   = vkms_crtc_atomic_flush,
 266         .atomic_enable  = vkms_crtc_atomic_enable,
 267         .atomic_disable = vkms_crtc_atomic_disable,
 268 };
 269
 270 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 271                    struct drm_plane *primary, struct drm_plane *cursor)
 272 {
 273         struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
 274         int ret;
 275
 276         ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
 277                                         &vkms_crtc_funcs, NULL);
 278         if (ret) {
 279                 DRM_ERROR("Failed to init CRTC\n");
 280                 return ret;
 281         }
 282
 283         drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
 284
 285         spin_lock_init(&vkms_out->lock);
 286         spin_lock_init(&vkms_out->composer_lock);
 287
 288         vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0);
 289         if (!vkms_out->composer_workq)
 290                 return -ENOMEM;
 291
 292         return ret;
 293 }