drivers/gpu/drm/vkms/vkms_crtc.c

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