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, composer_enabled;
  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         ret = drm_crtc_handle_vblank(crtc);
  29         if (!ret)
  30                 DRM_ERROR("vkms failure on handling vblank");
  31
  32         state = output->composer_state;
  33         composer_enabled = output->composer_enabled;
  34         mutex_unlock(&output->enabled_lock);
  35
  36         if (state && 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         .page_flip              = drm_atomic_helper_page_flip,
 165         .reset                  = vkms_atomic_crtc_reset,
 166         .atomic_duplicate_state = vkms_atomic_crtc_duplicate_state,
 167         .atomic_destroy_state   = vkms_atomic_crtc_destroy_state,
 168         .enable_vblank          = vkms_enable_vblank,
 169         .disable_vblank         = vkms_disable_vblank,
 170         .get_vblank_timestamp   = vkms_get_vblank_timestamp,
 171         .get_crc_sources        = vkms_get_crc_sources,
 172         .set_crc_source         = vkms_set_crc_source,
 173         .verify_crc_source      = vkms_verify_crc_source,
 174 };
 175
 176 static int vkms_crtc_atomic_check(struct drm_crtc *crtc,
 177                                   struct drm_atomic_state *state)
 178 {
 179         struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
 180                                                                           crtc);
 181         struct vkms_crtc_state *vkms_state = to_vkms_crtc_state(crtc_state);
 182         struct drm_plane *plane;
 183         struct drm_plane_state *plane_state;
 184         int i = 0, ret;
 185
 186         if (vkms_state->active_planes)
 187                 return 0;
 188
 189         ret = drm_atomic_add_affected_planes(crtc_state->state, crtc);
 190         if (ret < 0)
 191                 return ret;
 192
 193         drm_for_each_plane_mask(plane, crtc->dev, crtc_state->plane_mask) {
 194                 plane_state = drm_atomic_get_existing_plane_state(crtc_state->state,
 195                                                                   plane);
 196                 WARN_ON(!plane_state);
 197
 198                 if (!plane_state->visible)
 199                         continue;
 200
 201                 i++;
 202         }
 203
 204         vkms_state->active_planes = kcalloc(i, sizeof(plane), GFP_KERNEL);
 205         if (!vkms_state->active_planes)
 206                 return -ENOMEM;
 207         vkms_state->num_active_planes = i;
 208
 209         i = 0;
 210         drm_for_each_plane_mask(plane, crtc->dev, crtc_state->plane_mask) {
 211                 plane_state = drm_atomic_get_existing_plane_state(crtc_state->state,
 212                                                                   plane);
 213
 214                 if (!plane_state->visible)
 215                         continue;
 216
 217                 vkms_state->active_planes[i++] =
 218                         to_vkms_plane_state(plane_state);
 219         }
 220
 221         return 0;
 222 }
 223
 224 static void vkms_crtc_atomic_enable(struct drm_crtc *crtc,
 225                                     struct drm_atomic_state *state)
 226 {
 227         drm_crtc_vblank_on(crtc);
 228 }
 229
 230 static void vkms_crtc_atomic_disable(struct drm_crtc *crtc,
 231                                      struct drm_atomic_state *state)
 232 {
 233         drm_crtc_vblank_off(crtc);
 234 }
 235
 236 static void vkms_crtc_atomic_begin(struct drm_crtc *crtc,
 237                                    struct drm_atomic_state *state)
 238 {
 239         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 240
 241         /* This lock is held across the atomic commit to block vblank timer
 242          * from scheduling vkms_composer_worker until the composer is updated
 243          */
 244         spin_lock_irq(&vkms_output->lock);
 245 }
 246
 247 static void vkms_crtc_atomic_flush(struct drm_crtc *crtc,
 248                                    struct drm_atomic_state *state)
 249 {
 250         struct vkms_output *vkms_output = drm_crtc_to_vkms_output(crtc);
 251
 252         if (crtc->state->event) {
 253                 spin_lock(&crtc->dev->event_lock);
 254
 255                 if (drm_crtc_vblank_get(crtc) != 0)
 256                         drm_crtc_send_vblank_event(crtc, crtc->state->event);
 257                 else
 258                         drm_crtc_arm_vblank_event(crtc, crtc->state->event);
 259
 260                 spin_unlock(&crtc->dev->event_lock);
 261
 262                 crtc->state->event = NULL;
 263         }
 264
 265         vkms_output->composer_state = to_vkms_crtc_state(crtc->state);
 266
 267         spin_unlock_irq(&vkms_output->lock);
 268 }
 269
 270 static const struct drm_crtc_helper_funcs vkms_crtc_helper_funcs = {
 271         .atomic_check   = vkms_crtc_atomic_check,
 272         .atomic_begin   = vkms_crtc_atomic_begin,
 273         .atomic_flush   = vkms_crtc_atomic_flush,
 274         .atomic_enable  = vkms_crtc_atomic_enable,
 275         .atomic_disable = vkms_crtc_atomic_disable,
 276 };
 277
 278 int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
 279                    struct drm_plane *primary, struct drm_plane *cursor)
 280 {
 281         struct vkms_output *vkms_out = drm_crtc_to_vkms_output(crtc);
 282         int ret;
 283
 284         ret = drmm_crtc_init_with_planes(dev, crtc, primary, cursor,
 285                                          &vkms_crtc_funcs, NULL);
 286         if (ret) {
 287                 DRM_ERROR("Failed to init CRTC\n");
 288                 return ret;
 289         }
 290
 291         drm_crtc_helper_add(crtc, &vkms_crtc_helper_funcs);
 292
 293         drm_mode_crtc_set_gamma_size(crtc, VKMS_LUT_SIZE);
 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         mutex_init(&vkms_out->enabled_lock);
 299
 300         vkms_out->composer_workq = alloc_ordered_workqueue("vkms_composer", 0);
 301         if (!vkms_out->composer_workq)
 302                 return -ENOMEM;
 303
 304         return ret;
 305 }