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