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 bool vkms_get_vblank_timestamp(struct drm_device *dev, unsigned int pipe,
  80                                int *max_error, ktime_t *vblank_time,
  81                                bool in_vblank_irq)
  82 {
  83         struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
  84         struct vkms_output *output = &vkmsdev->output;
  85         struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
  86
  87         *vblank_time = READ_ONCE(output->vblank_hrtimer.node.expires);
  88
  89         if (WARN_ON(*vblank_time == vblank->time))
  90                 return true;
  91
  92         /*
  93          * To prevent races we roll the hrtimer forward before we do any
  94          * interrupt processing - this is how real hw works (the interrupt is
  95          * only generated after all the vblank registers are updated) and what
  96          * the vblank core expects. Therefore we need to always correct the
  97          * timestampe by one frame.
  98          */
  99         *vblank_time -= output->period_ns;
 100
 101         return true;
 102 }
 103
 104 static struct drm_crtc_state *
 105 vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
 106 {
 107         struct vkms_crtc_state *vkms_state;
 108
 109         if (WARN_ON(!crtc->state))
 110                 return NULL;
 111
 112         vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
 113         if (!vkms_state)
 114                 return NULL;
 115
 116         __drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
 117
 118         INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
 119
 120         return &vkms_state->base;
 121 }
 122
 123 static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
 124                                            struct drm_crtc_state *state)
 125 {
 126         struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
 127
 128         __drm_atomic_helper_crtc_destroy_state(state);
 129
 130         WARN_ON(work_pending(&vkms_state->composer_work));
 131         kfree(vkms_state->active_planes);
 132         kfree(vkms_state);
 133 }
 134
 135 static void vkms_atomic_crtc_reset(struct drm_crtc *crtc)
 136 {
 137         struct vkms_crtc_state *vkms_state =
 138                 kzalloc(sizeof(*vkms_state), GFP_KERNEL);
 139
 140         if (crtc->state)
 141                 vkms_atomic_crtc_destroy_state(crtc, crtc->state);
 142
 143         __drm_atomic_helper_crtc_reset(crtc, &vkms_state->base);
 144         if (vkms_state)
 145                 INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
 146 }
 147
 148 static const struct drm_crtc_funcs vkms_crtc_funcs = {
 149         .set_config             = drm_atomic_helper_set_config,
 150         .destroy                = drm_crtc_cleanup,
 151         .page_flip              = drm_atomic_helper_page_flip,
 152         .reset                  = vkms_atomic_crtc_reset,
 153         .atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
 154         .atomic_destroy_state   = vkms_atomic_crtc_destroy_state,
 155         .enable_vblank          = vkms_enable_vblank,
 156         .disable_vblank         = vkms_disable_vblank,
 157         .get_crc_sources        = vkms_get_crc_sources,
 158         .set_crc_source         = vkms_set_crc_source,
 159         .verify_crc_source      = vkms_verify_crc_source,
 160 };
 161
 162 static int vkms_crtc_atomic_check(struct drm_crtc *crtc,
 163                                   struct drm_crtc_state *state)
 164 {
 165         struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
 166         struct drm_plane *plane;
 167         struct drm_plane_state *plane_state;
 168         int i = 0, ret;
 169
 170         if (vkms_state->active_planes)
 171                 return 0;
 172
 173         ret = drm_atomic_add_affected_planes(state->state, crtc);
 174         if (ret < 0)
 175                 return ret;
 176
 177         drm_for_each_plane_mask(plane, crtc->dev, state->plane_mask) {
 178                 plane_state = drm_atomic_get_existing_plane_state(state->state,
 179                                                                   plane);
 180                 WARN_ON(!plane_state);
 181
 182                 if (!plane_state->visible)
 183                         continue;
 184
 185                 i++;
 186         }
 187
 188         vkms_state->active_planes = kcalloc(i, sizeof(plane), GFP_KERNEL);
 189         if (!vkms_state->active_planes)
 190                 return -ENOMEM;
 191         vkms_state->num_active_planes = i;
 192
 193         i = 0;
 194         drm_for_each_plane_mask(plane, crtc->dev, state->plane_mask) {
 195                 plane_state = drm_atomic_get_existing_plane_state(state->state,
 196                                                                   plane);
 197
 198                 if (!plane_state->visible)
 199                         continue;
 200
 201                 vkms_state->active_planes[i++] =
 202                         to_vkms_plane_state(plane_state);
 203         }
 204
 205         return 0;
 206 }
 207
 208 static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
 209                                     struct drm_crtc_state *old_state)
 210 {
 211         drm_crtc_vblank_on(crtc);
 212 }
 213
 214 static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
 215                                      struct drm_crtc_state *old_state)
 216 {
 217         drm_crtc_vblank_off(crtc);
 218 }
 219
 220 static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
 221                                    struct drm_crtc_state *old_crtc_state)
 222 {
 223         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 224
 225         /* This lock is held across the atomic commit to block vblank timer
 226          * from scheduling vkms_composer_worker until the composer is updated
 227          */
 228         spin_lock_irq(&vkms_output->lock);
 229 }
 230
 231 static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
 232                                    struct drm_crtc_state *old_crtc_state)
 233 {
 234         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 235
 236         if (crtc->state->event) {
 237                 spin_lock(&crtc->dev->event_lock);
 238
 239                 if (drm_crtc_vblank_get(crtc) != 0)
 240                         drm_crtc_send_vblank_event(crtc, crtc->state->event);
 241                 else
 242                         drm_crtc_arm_vblank_event(crtc, crtc->state->event);
 243
 244                 spin_unlock(&crtc->dev->event_lock);
 245
 246                 crtc->state->event = NULL;
 247         }
 248
 249         vkms_output->composer_state = to_vkms_crtc_state(crtc->state);
 250
 251         spin_unlock_irq(&vkms_output->lock);
 252 }
 253
 254 static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
 255         .atomic_check   = vkms_crtc_atomic_check,
 256         .atomic_begin   = vkms_crtc_atomic_begin,
 257         .atomic_flush   = vkms_crtc_atomic_flush,
 258         .atomic_enable  = vkms_crtc_atomic_enable,
 259         .atomic_disable = vkms_crtc_atomic_disable,
 260 };
 261
 262 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 263                    struct drm_plane *primary, struct drm_plane *cursor)
 264 {
 265         struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
 266         int ret;
 267
 268         ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
 269                                         &vkms_crtc_funcs, NULL);
 270         if (ret) {
 271                 DRM_ERROR("Failed to init CRTC\n");
 272                 return ret;
 273         }
 274
 275         drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
 276
 277         spin_lock_init(&vkms_out->lock);
 278         spin_lock_init(&vkms_out->composer_lock);
 279
 280         vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0);
 281         if (!vkms_out->composer_workq)
 282                 return -ENOMEM;
 283
 284         return ret;
 285 }