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_device *dev = crtc->dev;
  65         unsigned int pipe = drm_crtc_index(crtc);
  66         struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
  67         struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
  68
  69         drm_calc_timestamping_constants(crtc, &crtc->mode);
  70
  71         hrtimer_init(&out->vblank_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
  72         out->vblank_hrtimer.function = &vkms_vblank_simulate;
  73         out->period_ns = ktime_set(0, vblank->framedur_ns);
  74         hrtimer_start(&out->vblank_hrtimer, out->period_ns, HRTIMER_MODE_REL);
  75
  76         return 0;
  77 }
  78
  79 static void vkms_disable_vblank(struct drm_crtc *crtc)
  80 {
  81         struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
  82
  83         hrtimer_cancel(&out->vblank_hrtimer);
  84 }
  85
  86 static bool vkms_get_vblank_timestamp(struct drm_crtc *crtc,
  87                                       int *max_error, ktime_t *vblank_time,
  88                                       bool in_vblank_irq)
  89 {
  90         struct drm_device *dev = crtc->dev;
  91         unsigned int pipe = crtc->index;
  92         struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
  93         struct vkms_output *output = &vkmsdev->output;
  94         struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
  95
  96         if (!READ_ONCE(vblank->enabled)) {
  97                 *vblank_time = ktime_get();
  98                 return true;
  99         }
 100
 101         *vblank_time = READ_ONCE(output->vblank_hrtimer.node.expires);
 102
 103         if (WARN_ON(*vblank_time == vblank->time))
 104                 return true;
 105
 106         /*
 107          * To prevent races we roll the hrtimer forward before we do any
 108          * interrupt processing - this is how real hw works (the interrupt is
 109          * only generated after all the vblank registers are updated) and what
 110          * the vblank core expects. Therefore we need to always correct the
 111          * timestampe by one frame.
 112          */
 113         *vblank_time -= output->period_ns;
 114
 115         return true;
 116 }
 117
 118 static struct drm_crtc_state *
 119 vkms_atomic_crtc_duplicate_state(struct drm_crtc *crtc)
 120 {
 121         struct vkms_crtc_state *vkms_state;
 122
 123         if (WARN_ON(!crtc->state))
 124                 return NULL;
 125
 126         vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
 127         if (!vkms_state)
 128                 return NULL;
 129
 130         __drm_atomic_helper_crtc_duplicate_state(crtc, &vkms_state->base);
 131
 132         INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
 133
 134         return &vkms_state->base;
 135 }
 136
 137 static void vkms_atomic_crtc_destroy_state(struct drm_crtc *crtc,
 138                                            struct drm_crtc_state *state)
 139 {
 140         struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(state);
 141
 142         __drm_atomic_helper_crtc_destroy_state(state);
 143
 144         WARN_ON(work_pending(&vkms_state->composer_work));
 145         kfree(vkms_state->active_planes);
 146         kfree(vkms_state);
 147 }
 148
 149 static void vkms_atomic_crtc_reset(struct drm_crtc *crtc)
 150 {
 151         struct vkms_crtc_state *vkms_state =
 152                 kzalloc(sizeof(*vkms_state), GFP_KERNEL);
 153
 154         if (crtc->state)
 155                 vkms_atomic_crtc_destroy_state(crtc, crtc->state);
 156
 157         __drm_atomic_helper_crtc_reset(crtc, &vkms_state->base);
 158         if (vkms_state)
 159                 INIT_WORK(&vkms_state->composer_work, vkms_composer_worker);
 160 }
 161
 162 static const struct drm_crtc_funcs vkms_crtc_funcs = {
 163         .set_config             = drm_atomic_helper_set_config,
 164         .destroy                = drm_crtc_cleanup,
 165         .page_flip              = drm_atomic_helper_page_flip,
 166         .reset                  = vkms_atomic_crtc_reset,
 167         .atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
 168         .atomic_destroy_state   = vkms_atomic_crtc_destroy_state,
 169         .enable_vblank          = vkms_enable_vblank,
 170         .disable_vblank         = vkms_disable_vblank,
 171         .get_vblank_timestamp   = vkms_get_vblank_timestamp,
 172         .get_crc_sources        = vkms_get_crc_sources,
 173         .set_crc_source         = vkms_set_crc_source,
 174         .verify_crc_source      = vkms_verify_crc_source,
 175 };
 176
 177 static int vkms_crtc_atomic_check(struct drm_crtc *crtc,
 178                                   struct drm_atomic_state *state)
 179 {
 180         struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
 181                                                                           crtc);
 182         struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(crtc_state);
 183         struct drm_plane *plane;
 184         struct drm_plane_state *plane_state;
 185         int i = 0, ret;
 186
 187         if (vkms_state->active_planes)
 188                 return 0;
 189
 190         ret = drm_atomic_add_affected_planes(crtc_state->state, crtc);
 191         if (ret < 0)
 192                 return ret;
 193
 194         drm_for_each_plane_mask(plane, crtc->dev, crtc_state->plane_mask) {
 195                 plane_state = drm_atomic_get_existing_plane_state(crtc_state->state,
 196                                                                   plane);
 197                 WARN_ON(!plane_state);
 198
 199                 if (!plane_state->visible)
 200                         continue;
 201
 202                 i++;
 203         }
 204
 205         vkms_state->active_planes = kcalloc(i, sizeof(plane), GFP_KERNEL);
 206         if (!vkms_state->active_planes)
 207                 return -ENOMEM;
 208         vkms_state->num_active_planes = i;
 209
 210         i = 0;
 211         drm_for_each_plane_mask(plane, crtc->dev, crtc_state->plane_mask) {
 212                 plane_state = drm_atomic_get_existing_plane_state(crtc_state->state,
 213                                                                   plane);
 214
 215                 if (!plane_state->visible)
 216                         continue;
 217
 218                 vkms_state->active_planes[i++] =
 219                         to_vkms_plane_state(plane_state);
 220         }
 221
 222         return 0;
 223 }
 224
 225 static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
 226                                     struct drm_atomic_state *state)
 227 {
 228         drm_crtc_vblank_on(crtc);
 229 }
 230
 231 static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
 232                                      struct drm_atomic_state *state)
 233 {
 234         drm_crtc_vblank_off(crtc);
 235 }
 236
 237 static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
 238                                    struct drm_atomic_state *state)
 239 {
 240         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 241
 242         /* This lock is held across the atomic commit to block vblank timer
 243          * from scheduling vkms_composer_worker until the composer is updated
 244          */
 245         spin_lock_irq(&vkms_output->lock);
 246 }
 247
 248 static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
 249                                    struct drm_atomic_state *state)
 250 {
 251         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 252
 253         if (crtc->state->event) {
 254                 spin_lock(&crtc->dev->event_lock);
 255
 256                 if (drm_crtc_vblank_get(crtc) != 0)
 257                         drm_crtc_send_vblank_event(crtc, crtc->state->event);
 258                 else
 259                         drm_crtc_arm_vblank_event(crtc, crtc->state->event);
 260
 261                 spin_unlock(&crtc->dev->event_lock);
 262
 263                 crtc->state->event = NULL;
 264         }
 265
 266         vkms_output->composer_state = to_vkms_crtc_state(crtc->state);
 267
 268         spin_unlock_irq(&vkms_output->lock);
 269 }
 270
 271 static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
 272         .atomic_check   = vkms_crtc_atomic_check,
 273         .atomic_begin   = vkms_crtc_atomic_begin,
 274         .atomic_flush   = vkms_crtc_atomic_flush,
 275         .atomic_enable  = vkms_crtc_atomic_enable,
 276         .atomic_disable = vkms_crtc_atomic_disable,
 277 };
 278
 279 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 280                    struct drm_plane *primary, struct drm_plane *cursor)
 281 {
 282         struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
 283         int ret;
 284
 285         ret = drm_crtc_init_with_planes(dev, crtc, primary, cursor,
 286                                         &vkms_crtc_funcs, NULL);
 287         if (ret) {
 288                 DRM_ERROR("Failed to init CRTC\n");
 289                 return ret;
 290         }
 291
 292         drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
 293
 294         spin_lock_init(&vkms_out->lock);
 295         spin_lock_init(&vkms_out->composer_lock);
 296
 297         vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0);
 298         if (!vkms_out->composer_workq)
 299                 return -ENOMEM;
 300
 301         return ret;
 302 }