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         if (ret_overrun != 1)
  22                 pr_warn("%s: vblank timer overrun\n", __func__);
  23
  24         spin_lock(&output->lock);
  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         spin_unlock(&output->lock);
  31
  32         if (state && output->composer_enabled) {
  33                 u64 frame = drm_crtc_accurate_vblank_count(crtc);
  34
  35                 /* update frame_start only if a queued vkms_composer_worker()
  36                  * has read the data
  37                  */
  38                 spin_lock(&output->composer_lock);
  39                 if (!state->crc_pending)
  40                         state->frame_start = frame;
  41                 else
  42                         DRM_DEBUG_DRIVER("crc worker falling behind, frame_start: %llu, frame_end: %llu\n",
  43                                          state->frame_start, frame);
  44                 state->frame_end = frame;
  45                 state->crc_pending = true;
  46                 spin_unlock(&output->composer_lock);
  47
  48                 ret = queue_work(output->composer_workq, &state->composer_work);
  49                 if (!ret)
  50                         DRM_DEBUG_DRIVER("Composer worker already queued\n");
  51         }
  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 static bool vkms_get_vblank_timestamp(struct drm_crtc *crtc,
  81                                       int *max_error, ktime_t *vblank_time,
  82                                       bool in_vblank_irq)
  83 {
  84         struct drm_device *dev = crtc->dev;
  85         unsigned int pipe = crtc->index;
  86         struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
  87         struct vkms_output *output = &vkmsdev->output;
  88         struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
  89
  90         if (!READ_ONCE(vblank->enabled)) {
  91                 *vblank_time = ktime_get();
  92                 return true;
  93         }
  94
  95         *vblank_time = READ_ONCE(output->vblank_hrtimer.node.expires);
  96
  97         if (WARN_ON(*vblank_time == vblank->time))
  98                 return true;
  99
 100         /*
 101          * To prevent races we roll the hrtimer forward before we do any
 102          * interrupt processing - this is how real hw works (the interrupt is
 103          * only generated after all the vblank registers are updated) and what
 104          * the vblank core expects. Therefore we need to always correct the
 105          * timestampe by one frame.
 106          */
 107         *vblank_time -= output->period_ns;
 108
 109         return true;
 110 }
 111
 112 static struct drm_crtc_state *
 113 vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
 114 {
 115         struct vkms_crtc_state *vkms_state;
 116
 117         if (WARN_ON(!crtc->state))
 118                 return NULL;
 119
 120         vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
 121         if (!vkms_state)
 122                 return NULL;
 123
 124         __drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
 125
 126         INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
 127
 128         return &vkms_state->base;
 129 }
 130
 131 static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
 132                                            struct drm_crtc_state *state)
 133 {
 134         struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
 135
 136         __drm_atomic_helper_crtc_destroy_state(state);
 137
 138         WARN_ON(work_pending(&vkms_state->composer_work));
 139         kfree(vkms_state->active_planes);
 140         kfree(vkms_state);
 141 }
 142
 143 static void vkms_atomic_crtc_reset(struct drm_crtc *crtc)
 144 {
 145         struct vkms_crtc_state *vkms_state =
 146                 kzalloc(sizeof(*vkms_state), GFP_KERNEL);
 147
 148         if (crtc->state)
 149                 vkms_atomic_crtc_destroy_state(crtc, crtc->state);
 150
 151         __drm_atomic_helper_crtc_reset(crtc, &vkms_state->base);
 152         if (vkms_state)
 153                 INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
 154 }
 155
 156 static const struct drm_crtc_funcs vkms_crtc_funcs = {
 157         .set_config             = drm_atomic_helper_set_config,
 158         .destroy                = drm_crtc_cleanup,
 159         .page_flip              = drm_atomic_helper_page_flip,
 160         .reset                  = vkms_atomic_crtc_reset,
 161         .atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
 162         .atomic_destroy_state   = vkms_atomic_crtc_destroy_state,
 163         .enable_vblank          = vkms_enable_vblank,
 164         .disable_vblank         = vkms_disable_vblank,
 165         .get_vblank_timestamp   = vkms_get_vblank_timestamp,
 166         .get_crc_sources        = vkms_get_crc_sources,
 167         .set_crc_source         = vkms_set_crc_source,
 168         .verify_crc_source      = vkms_verify_crc_source,
 169 };
 170
 171 static int vkms_crtc_atomic_check(struct drm_crtc *crtc,
 172                                   struct drm_crtc_state *state)
 173 {
 174         struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
 175         struct drm_plane *plane;
 176         struct drm_plane_state *plane_state;
 177         int i = 0, ret;
 178
 179         if (vkms_state->active_planes)
 180                 return 0;
 181
 182         ret = drm_atomic_add_affected_planes(state->state, crtc);
 183         if (ret < 0)
 184                 return ret;
 185
 186         drm_for_each_plane_mask(plane, crtc->dev, state->plane_mask) {
 187                 plane_state = drm_atomic_get_existing_plane_state(state->state,
 188                                                                   plane);
 189                 WARN_ON(!plane_state);
 190
 191                 if (!plane_state->visible)
 192                         continue;
 193
 194                 i++;
 195         }
 196
 197         vkms_state->active_planes = kcalloc(i, sizeof(plane), GFP_KERNEL);
 198         if (!vkms_state->active_planes)
 199                 return -ENOMEM;
 200         vkms_state->num_active_planes = i;
 201
 202         i = 0;
 203         drm_for_each_plane_mask(plane, crtc->dev, state->plane_mask) {
 204                 plane_state = drm_atomic_get_existing_plane_state(state->state,
 205                                                                   plane);
 206
 207                 if (!plane_state->visible)
 208                         continue;
 209
 210                 vkms_state->active_planes[i++] =
 211                         to_vkms_plane_state(plane_state);
 212         }
 213
 214         return 0;
 215 }
 216
 217 static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
 218                                     struct drm_crtc_state *old_state)
 219 {
 220         drm_crtc_vblank_on(crtc);
 221 }
 222
 223 static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
 224                                      struct drm_crtc_state *old_state)
 225 {
 226         drm_crtc_vblank_off(crtc);
 227 }
 228
 229 static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
 230                                    struct drm_crtc_state *old_crtc_state)
 231 {
 232         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 233
 234         /* This lock is held across the atomic commit to block vblank timer
 235          * from scheduling vkms_composer_worker until the composer is updated
 236          */
 237         spin_lock_irq(&vkms_output->lock);
 238 }
 239
 240 static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
 241                                    struct drm_crtc_state *old_crtc_state)
 242 {
 243         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 244
 245         if (crtc->state->event) {
 246                 spin_lock(&crtc->dev->event_lock);
 247
 248                 if (drm_crtc_vblank_get(crtc) != 0)
 249                         drm_crtc_send_vblank_event(crtc, crtc->state->event);
 250                 else
 251                         drm_crtc_arm_vblank_event(crtc, crtc->state->event);
 252
 253                 spin_unlock(&crtc->dev->event_lock);
 254
 255                 crtc->state->event = NULL;
 256         }
 257
 258         vkms_output->composer_state = to_vkms_crtc_state(crtc->state);
 259
 260         spin_unlock_irq(&vkms_output->lock);
 261 }
 262
 263 static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
 264         .atomic_check   = vkms_crtc_atomic_check,
 265         .atomic_begin   = vkms_crtc_atomic_begin,
 266         .atomic_flush   = vkms_crtc_atomic_flush,
 267         .atomic_enable  = vkms_crtc_atomic_enable,
 268         .atomic_disable = vkms_crtc_atomic_disable,
 269 };
 270
 271 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 272                    struct drm_plane *primary, struct drm_plane *cursor)
 273 {
 274         struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
 275         int ret;
 276
 277         ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
 278                                         &vkms_crtc_funcs, NULL);
 279         if (ret) {
 280                 DRM_ERROR("Failed to init CRTC\n");
 281                 return ret;
 282         }
 283
 284         drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
 285
 286         spin_lock_init(&vkms_out->lock);
 287         spin_lock_init(&vkms_out->composer_lock);
 288
 289         vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0);
 290         if (!vkms_out->composer_workq)
 291                 return -ENOMEM;
 292
 293         return ret;
 294 }