drivers/gpu/drm/vkms/vkms_crtc.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2
   3 #include <linux/dma-fence.h>
   4
   5 #include <drm/drm_atomic.h>
   6 #include <drm/drm_atomic_helper.h>
   7 #include <drm/drm_probe_helper.h>
   8 #include <drm/drm_vblank.h>
   9
  10 #include "vkms_drv.h"
  11
  12 static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer)
  13 {
  14         struct vkms_output *output = container_of(timer, struct vkms_output,
  15                                                   vblank_hrtimer);
  16         struct drm_crtc *crtc = &output->crtc;
  17         struct vkms_crtc_state *state;
  18         u64 ret_overrun;
  19         bool ret, fence_cookie;
  20
  21         fence_cookie = dma_fence_begin_signalling();
  22
  23         ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer,
  24                                           output->period_ns);
  25         if (ret_overrun != 1)
  26                 pr_warn("%s: vblank timer overrun\n", __func__);
  27
  28         spin_lock(&output->lock);
  29         ret = drm_crtc_handle_vblank(crtc);
  30         if (!ret)
  31                 DRM_ERROR("vkms failure on handling vblank");
  32
  33         state = output->composer_state;
  34         spin_unlock(&output->lock);
  35
  36         if (state && output->composer_enabled) {
  37                 u64 frame = drm_crtc_accurate_vblank_count(crtc);
  38
  39                 /* update frame_start only if a queued vkms_composer_worker()
  40                  * has read the data
  41                  */
  42                 spin_lock(&output->composer_lock);
  43                 if (!state->crc_pending)
  44                         state->frame_start = frame;
  45                 else
  46                         DRM_DEBUG_DRIVER("crc worker falling behind, frame_start: %llu, frame_end: %llu\n",
  47                                          state->frame_start, frame);
  48                 state->frame_end = frame;
  49                 state->crc_pending = true;
  50                 spin_unlock(&output->composer_lock);
  51
  52                 ret = queue_work(output->composer_workq, &state->composer_work);
  53                 if (!ret)
  54                         DRM_DEBUG_DRIVER("Composer worker already queued\n");
  55         }
  56
  57         dma_fence_end_signalling(fence_cookie);
  58
  59         return HRTIMER_RESTART;
  60 }
  61
  62 static int vkms_enable_vblank(struct drm_crtc *crtc)
  63 {
  64         struct drm_vblank_crtc *vblank = drm_crtc_vblank_crtc(crtc);
  65         struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
  66
  67         hrtimer_init(&out->vblank_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
  68         out->vblank_hrtimer.function = &vkms_vblank_simulate;
  69         out->period_ns = ktime_set(0, vblank->framedur_ns);
  70         hrtimer_start(&out->vblank_hrtimer, out->period_ns, HRTIMER_MODE_REL);
  71
  72         return 0;
  73 }
  74
  75 static void vkms_disable_vblank(struct drm_crtc *crtc)
  76 {
  77         struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
  78
  79         hrtimer_cancel(&out->vblank_hrtimer);
  80 }
  81
  82 static bool vkms_get_vblank_timestamp(struct drm_crtc *crtc,
  83                                       int *max_error, ktime_t *vblank_time,
  84                                       bool in_vblank_irq)
  85 {
  86         struct drm_device *dev = crtc->dev;
  87         struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
  88         struct vkms_output *output = &vkmsdev->output;
  89         struct drm_vblank_crtc *vblank = drm_crtc_vblank_crtc(crtc);
  90
  91         if (!READ_ONCE(vblank->enabled)) {
  92                 *vblank_time = ktime_get();
  93                 return true;
  94         }
  95
  96         *vblank_time = READ_ONCE(output->vblank_hrtimer.node.expires);
  97
  98         if (WARN_ON(*vblank_time == vblank->time))
  99                 return true;
 100
 101         /*
 102          * To prevent races we roll the hrtimer forward before we do any
 103          * interrupt processing - this is how real hw works (the interrupt is
 104          * only generated after all the vblank registers are updated) and what
 105          * the vblank core expects. Therefore we need to always correct the
 106          * timestampe by one frame.
 107          */
 108         *vblank_time -= output->period_ns;
 109
 110         return true;
 111 }
 112
 113 static struct drm_crtc_state *
 114 vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
 115 {
 116         struct vkms_crtc_state *vkms_state;
 117
 118         if (WARN_ON(!crtc->state))
 119                 return NULL;
 120
 121         vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
 122         if (!vkms_state)
 123                 return NULL;
 124
 125         __drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
 126
 127         INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
 128
 129         return &vkms_state->base;
 130 }
 131
 132 static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
 133                                            struct drm_crtc_state *state)
 134 {
 135         struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
 136
 137         __drm_atomic_helper_crtc_destroy_state(state);
 138
 139         WARN_ON(work_pending(&vkms_state->composer_work));
 140         kfree(vkms_state->active_planes);
 141         kfree(vkms_state);
 142 }
 143
 144 static void vkms_atomic_crtc_reset(struct drm_crtc *crtc)
 145 {
 146         struct vkms_crtc_state *vkms_state =
 147                 kzalloc(sizeof(*vkms_state), GFP_KERNEL);
 148
 149         if (crtc->state)
 150                 vkms_atomic_crtc_destroy_state(crtc, crtc->state);
 151
 152         __drm_atomic_helper_crtc_reset(crtc, &vkms_state->base);
 153         if (vkms_state)
 154                 INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
 155 }
 156
 157 static const struct drm_crtc_funcs vkms_crtc_funcs = {
 158         .set_config             = drm_atomic_helper_set_config,
 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_atomic_state *state)
 173 {
 174         struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
 175                                                                           crtc);
 176         struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(crtc_state);
 177         struct drm_plane *plane;
 178         struct drm_plane_state *plane_state;
 179         int i = 0, ret;
 180
 181         if (vkms_state->active_planes)
 182                 return 0;
 183
 184         ret = drm_atomic_add_affected_planes(crtc_state->state, crtc);
 185         if (ret < 0)
 186                 return ret;
 187
 188         drm_for_each_plane_mask(plane, crtc->dev, crtc_state->plane_mask) {
 189                 plane_state = drm_atomic_get_existing_plane_state(crtc_state->state, plane);
 190                 WARN_ON(!plane_state);
 191
 192                 if (!plane_state->visible)
 193                         continue;
 194
 195                 i++;
 196         }
 197
 198         vkms_state->active_planes = kcalloc(i, sizeof(plane), GFP_KERNEL);
 199         if (!vkms_state->active_planes)
 200                 return -ENOMEM;
 201         vkms_state->num_active_planes = i;
 202
 203         i = 0;
 204         drm_for_each_plane_mask(plane, crtc->dev, crtc_state->plane_mask) {
 205                 plane_state = drm_atomic_get_existing_plane_state(crtc_state->state, 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_atomic_state *state)
 219 {
 220         drm_crtc_vblank_on(crtc);
 221 }
 222
 223 static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
 224                                      struct drm_atomic_state *state)
 225 {
 226         drm_crtc_vblank_off(crtc);
 227 }
 228
 229 static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
 230                                    struct drm_atomic_state *state)
 231         __acquires(&vkms_output->lock)
 232 {
 233         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 234
 235         /* This lock is held across the atomic commit to block vblank timer
 236          * from scheduling vkms_composer_worker until the composer is updated
 237          */
 238         spin_lock_irq(&vkms_output->lock);
 239 }
 240
 241 static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
 242                                    struct drm_atomic_state *state)
 243         __releases(&vkms_output->lock)
 244 {
 245         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 246
 247         if (crtc->state->event) {
 248                 spin_lock(&crtc->dev->event_lock);
 249
 250                 if (drm_crtc_vblank_get(crtc) != 0)
 251                         drm_crtc_send_vblank_event(crtc, crtc->state->event);
 252                 else
 253                         drm_crtc_arm_vblank_event(crtc, crtc->state->event);
 254
 255                 spin_unlock(&crtc->dev->event_lock);
 256
 257                 crtc->state->event = NULL;
 258         }
 259
 260         vkms_output->composer_state = to_vkms_crtc_state(crtc->state);
 261
 262         spin_unlock_irq(&vkms_output->lock);
 263 }
 264
 265 static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
 266         .atomic_check   = vkms_crtc_atomic_check,
 267         .atomic_begin   = vkms_crtc_atomic_begin,
 268         .atomic_flush   = vkms_crtc_atomic_flush,
 269         .atomic_enable  = vkms_crtc_atomic_enable,
 270         .atomic_disable = vkms_crtc_atomic_disable,
 271 };
 272
 273 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 274                    struct drm_plane *primary, struct drm_plane *cursor)
 275 {
 276         struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
 277         int ret;
 278
 279         ret = drmm_crtc_init_with_planes(dev, crtc, primary, cursor,
 280                                          &vkms_crtc_funcs, NULL);
 281         if (ret) {
 282                 DRM_ERROR("Failed to init CRTC\n");
 283                 return ret;
 284         }
 285
 286         drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
 287
 288         ret = drm_mode_crtc_set_gamma_size(crtc, VKMS_LUT_SIZE);
 289         if (ret) {
 290                 DRM_ERROR("Failed to set gamma size\n");
 291                 return ret;
 292         }
 293
 294         drm_crtc_enable_color_mgmt(crtc, 0, false, VKMS_LUT_SIZE);
 295
 296         spin_lock_init(&vkms_out->lock);
 297         spin_lock_init(&vkms_out->composer_lock);
 298
 299         vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0);
 300         if (!vkms_out->composer_workq)
 301                 return -ENOMEM;
 302
 303         return ret;
 304 }