drivers/gpu/drm/xen/xen_drm_front_kms.c

   1 // SPDX-License-Identifier: GPL-2.0 OR MIT
   2
   3 /*
   4  *  Xen para-virtual DRM device
   5  *
   6  * Copyright (C) 2016-2018 EPAM Systems Inc.
   7  *
   8  * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
   9  */
  10
  11 #include <drm/drm_atomic.h>
  12 #include <drm/drm_atomic_helper.h>
  13 #include <drm/drm_drv.h>
  14 #include <drm/drm_fourcc.h>
  15 #include <drm/drm_gem.h>
  16 #include <drm/drm_gem_atomic_helper.h>
  17 #include <drm/drm_gem_framebuffer_helper.h>
  18 #include <drm/drm_probe_helper.h>
  19 #include <drm/drm_vblank.h>
  20
  21 #include "xen_drm_front.h"
  22 #include "xen_drm_front_conn.h"
  23 #include "xen_drm_front_kms.h"
  24
  25 /*
  26  * Timeout in ms to wait for frame done event from the backend:
  27  * must be a bit more than IO time-out
  28  */
  29 #define FRAME_DONE_TO_MS        (XEN_DRM_FRONT_WAIT_BACK_MS + 100)
  30
  31 static struct xen_drm_front_drm_pipeline *
  32 to_xen_drm_pipeline(struct drm_simple_display_pipe *pipe)
  33 {
  34         return container_of(pipe, struct xen_drm_front_drm_pipeline, pipe);
  35 }
  36
  37 static void fb_destroy(struct drm_framebuffer *fb)
  38 {
  39         struct xen_drm_front_drm_info *drm_info = fb->dev->dev_private;
  40         int idx;
  41
  42         if (drm_dev_enter(fb->dev, &idx)) {
  43                 xen_drm_front_fb_detach(drm_info->front_info,
  44                                         xen_drm_front_fb_to_cookie(fb));
  45                 drm_dev_exit(idx);
  46         }
  47         drm_gem_fb_destroy(fb);
  48 }
  49
  50 static const struct drm_framebuffer_funcs fb_funcs = {
  51         .destroy = fb_destroy,
  52 };
  53
  54 static struct drm_framebuffer *
  55 fb_create(struct drm_device *dev, struct drm_file *filp,
  56           const struct drm_mode_fb_cmd2 *mode_cmd)
  57 {
  58         struct xen_drm_front_drm_info *drm_info = dev->dev_private;
  59         struct drm_framebuffer *fb;
  60         struct drm_gem_object *gem_obj;
  61         int ret;
  62
  63         fb = drm_gem_fb_create_with_funcs(dev, filp, mode_cmd, &fb_funcs);
  64         if (IS_ERR(fb))
  65                 return fb;
  66
  67         gem_obj = fb->obj[0];
  68
  69         ret = xen_drm_front_fb_attach(drm_info->front_info,
  70                                       xen_drm_front_dbuf_to_cookie(gem_obj),
  71                                       xen_drm_front_fb_to_cookie(fb),
  72                                       fb->width, fb->height,
  73                                       fb->format->format);
  74         if (ret < 0) {
  75                 DRM_ERROR("Back failed to attach FB %p: %d\n", fb, ret);
  76                 goto fail;
  77         }
  78
  79         return fb;
  80
  81 fail:
  82         drm_gem_fb_destroy(fb);
  83         return ERR_PTR(ret);
  84 }
  85
  86 static const struct drm_mode_config_funcs mode_config_funcs = {
  87         .fb_create = fb_create,
  88         .atomic_check = drm_atomic_helper_check,
  89         .atomic_commit = drm_atomic_helper_commit,
  90 };
  91
  92 static void send_pending_event(struct xen_drm_front_drm_pipeline *pipeline)
  93 {
  94         struct drm_crtc *crtc = &pipeline->pipe.crtc;
  95         struct drm_device *dev = crtc->dev;
  96         unsigned long flags;
  97
  98         spin_lock_irqsave(&dev->event_lock, flags);
  99         if (pipeline->pending_event)
 100                 drm_crtc_send_vblank_event(crtc, pipeline->pending_event);
 101         pipeline->pending_event = NULL;
 102         spin_unlock_irqrestore(&dev->event_lock, flags);
 103 }
 104
 105 static void display_enable(struct drm_simple_display_pipe *pipe,
 106                            struct drm_crtc_state *crtc_state,
 107                            struct drm_plane_state *plane_state)
 108 {
 109         struct xen_drm_front_drm_pipeline *pipeline =
 110                         to_xen_drm_pipeline(pipe);
 111         struct drm_crtc *crtc = &pipe->crtc;
 112         struct drm_framebuffer *fb = plane_state->fb;
 113         int ret, idx;
 114
 115         if (!drm_dev_enter(pipe->crtc.dev, &idx))
 116                 return;
 117
 118         ret = xen_drm_front_mode_set(pipeline, crtc->x, crtc->y,
 119                                      fb->width, fb->height,
 120                                      fb->format->cpp[0] * 8,
 121                                      xen_drm_front_fb_to_cookie(fb));
 122
 123         if (ret) {
 124                 DRM_ERROR("Failed to enable display: %d\n", ret);
 125                 pipeline->conn_connected = false;
 126         }
 127
 128         drm_dev_exit(idx);
 129 }
 130
 131 static void display_disable(struct drm_simple_display_pipe *pipe)
 132 {
 133         struct xen_drm_front_drm_pipeline *pipeline =
 134                         to_xen_drm_pipeline(pipe);
 135         int ret = 0, idx;
 136
 137         if (drm_dev_enter(pipe->crtc.dev, &idx)) {
 138                 ret = xen_drm_front_mode_set(pipeline, 0, 0, 0, 0, 0,
 139                                              xen_drm_front_fb_to_cookie(NULL));
 140                 drm_dev_exit(idx);
 141         }
 142         if (ret)
 143                 DRM_ERROR("Failed to disable display: %d\n", ret);
 144
 145         /* Make sure we can restart with enabled connector next time */
 146         pipeline->conn_connected = true;
 147
 148         /* release stalled event if any */
 149         send_pending_event(pipeline);
 150 }
 151
 152 void xen_drm_front_kms_on_frame_done(struct xen_drm_front_drm_pipeline *pipeline,
 153                                      u64 fb_cookie)
 154 {
 155         /*
 156          * This runs in interrupt context, e.g. under
 157          * drm_info->front_info->io_lock, so we cannot call _sync version
 158          * to cancel the work
 159          */
 160         cancel_delayed_work(&pipeline->pflip_to_worker);
 161
 162         send_pending_event(pipeline);
 163 }
 164
 165 static void pflip_to_worker(struct work_struct *work)
 166 {
 167         struct delayed_work *delayed_work = to_delayed_work(work);
 168         struct xen_drm_front_drm_pipeline *pipeline =
 169                         container_of(delayed_work,
 170                                      struct xen_drm_front_drm_pipeline,
 171                                      pflip_to_worker);
 172
 173         DRM_ERROR("Frame done timed-out, releasing");
 174         send_pending_event(pipeline);
 175 }
 176
 177 static bool display_send_page_flip(struct drm_simple_display_pipe *pipe,
 178                                    struct drm_plane_state *old_plane_state)
 179 {
 180         struct drm_plane_state *plane_state =
 181                         drm_atomic_get_new_plane_state(old_plane_state->state,
 182                                                        &pipe->plane);
 183
 184         /*
 185          * If old_plane_state->fb is NULL and plane_state->fb is not,
 186          * then this is an atomic commit which will enable display.
 187          * If old_plane_state->fb is not NULL and plane_state->fb is,
 188          * then this is an atomic commit which will disable display.
 189          * Ignore these and do not send page flip as this framebuffer will be
 190          * sent to the backend as a part of display_set_config call.
 191          */
 192         if (old_plane_state->fb && plane_state->fb) {
 193                 struct xen_drm_front_drm_pipeline *pipeline =
 194                                 to_xen_drm_pipeline(pipe);
 195                 struct xen_drm_front_drm_info *drm_info = pipeline->drm_info;
 196                 int ret;
 197
 198                 schedule_delayed_work(&pipeline->pflip_to_worker,
 199                                       msecs_to_jiffies(FRAME_DONE_TO_MS));
 200
 201                 ret = xen_drm_front_page_flip(drm_info->front_info,
 202                                               pipeline->index,
 203                                               xen_drm_front_fb_to_cookie(plane_state->fb));
 204                 if (ret) {
 205                         DRM_ERROR("Failed to send page flip request to backend: %d\n", ret);
 206
 207                         pipeline->conn_connected = false;
 208                         /*
 209                          * Report the flip not handled, so pending event is
 210                          * sent, unblocking user-space.
 211                          */
 212                         return false;
 213                 }
 214                 /*
 215                  * Signal that page flip was handled, pending event will be sent
 216                  * on frame done event from the backend.
 217                  */
 218                 return true;
 219         }
 220
 221         return false;
 222 }
 223
 224 static int display_check(struct drm_simple_display_pipe *pipe,
 225                          struct drm_plane_state *plane_state,
 226                          struct drm_crtc_state *crtc_state)
 227 {
 228         /*
 229          * Xen doesn't initialize vblanking via drm_vblank_init(), so
 230          * DRM helpers assume that it doesn't handle vblanking and start
 231          * sending out fake VBLANK events automatically.
 232          *
 233          * As xen contains it's own logic for sending out VBLANK events
 234          * in send_pending_event(), disable no_vblank (i.e., the xen
 235          * driver has vblanking support).
 236          */
 237         crtc_state->no_vblank = false;
 238
 239         return 0;
 240 }
 241
 242 static void display_update(struct drm_simple_display_pipe *pipe,
 243                            struct drm_plane_state *old_plane_state)
 244 {
 245         struct xen_drm_front_drm_pipeline *pipeline =
 246                         to_xen_drm_pipeline(pipe);
 247         struct drm_crtc *crtc = &pipe->crtc;
 248         struct drm_pending_vblank_event *event;
 249         int idx;
 250
 251         event = crtc->state->event;
 252         if (event) {
 253                 struct drm_device *dev = crtc->dev;
 254                 unsigned long flags;
 255
 256                 WARN_ON(pipeline->pending_event);
 257
 258                 spin_lock_irqsave(&dev->event_lock, flags);
 259                 crtc->state->event = NULL;
 260
 261                 pipeline->pending_event = event;
 262                 spin_unlock_irqrestore(&dev->event_lock, flags);
 263         }
 264
 265         if (!drm_dev_enter(pipe->crtc.dev, &idx)) {
 266                 send_pending_event(pipeline);
 267                 return;
 268         }
 269
 270         /*
 271          * Send page flip request to the backend *after* we have event cached
 272          * above, so on page flip done event from the backend we can
 273          * deliver it and there is no race condition between this code and
 274          * event from the backend.
 275          * If this is not a page flip, e.g. no flip done event from the backend
 276          * is expected, then send now.
 277          */
 278         if (!display_send_page_flip(pipe, old_plane_state))
 279                 send_pending_event(pipeline);
 280
 281         drm_dev_exit(idx);
 282 }
 283
 284 static enum drm_mode_status
 285 display_mode_valid(struct drm_simple_display_pipe *pipe,
 286                    const struct drm_display_mode *mode)
 287 {
 288         struct xen_drm_front_drm_pipeline *pipeline =
 289                         container_of(pipe, struct xen_drm_front_drm_pipeline,
 290                                      pipe);
 291
 292         if (mode->hdisplay != pipeline->width)
 293                 return MODE_ERROR;
 294
 295         if (mode->vdisplay != pipeline->height)
 296                 return MODE_ERROR;
 297
 298         return MODE_OK;
 299 }
 300
 301 static const struct drm_simple_display_pipe_funcs display_funcs = {
 302         .mode_valid = display_mode_valid,
 303         .enable = display_enable,
 304         .disable = display_disable,
 305         .check = display_check,
 306         .update = display_update,
 307 };
 308
 309 static int display_pipe_init(struct xen_drm_front_drm_info *drm_info,
 310                              int index, struct xen_drm_front_cfg_connector *cfg,
 311                              struct xen_drm_front_drm_pipeline *pipeline)
 312 {
 313         struct drm_device *dev = drm_info->drm_dev;
 314         const u32 *formats;
 315         int format_count;
 316         int ret;
 317
 318         pipeline->drm_info = drm_info;
 319         pipeline->index = index;
 320         pipeline->height = cfg->height;
 321         pipeline->width = cfg->width;
 322
 323         INIT_DELAYED_WORK(&pipeline->pflip_to_worker, pflip_to_worker);
 324
 325         ret = xen_drm_front_conn_init(drm_info, &pipeline->conn);
 326         if (ret)
 327                 return ret;
 328
 329         formats = xen_drm_front_conn_get_formats(&format_count);
 330
 331         return drm_simple_display_pipe_init(dev, &pipeline->pipe,
 332                                             &display_funcs, formats,
 333                                             format_count, NULL,
 334                                             &pipeline->conn);
 335 }
 336
 337 int xen_drm_front_kms_init(struct xen_drm_front_drm_info *drm_info)
 338 {
 339         struct drm_device *dev = drm_info->drm_dev;
 340         int i, ret;
 341
 342         drm_mode_config_init(dev);
 343
 344         dev->mode_config.min_width = 0;
 345         dev->mode_config.min_height = 0;
 346         dev->mode_config.max_width = 4095;
 347         dev->mode_config.max_height = 2047;
 348         dev->mode_config.funcs = &mode_config_funcs;
 349
 350         for (i = 0; i < drm_info->front_info->cfg.num_connectors; i++) {
 351                 struct xen_drm_front_cfg_connector *cfg =
 352                                 &drm_info->front_info->cfg.connectors[i];
 353                 struct xen_drm_front_drm_pipeline *pipeline =
 354                                 &drm_info->pipeline[i];
 355
 356                 ret = display_pipe_init(drm_info, i, cfg, pipeline);
 357                 if (ret) {
 358                         drm_mode_config_cleanup(dev);
 359                         return ret;
 360                 }
 361         }
 362
 363         drm_mode_config_reset(dev);
 364         drm_kms_helper_poll_init(dev);
 365         return 0;
 366 }
 367
 368 void xen_drm_front_kms_fini(struct xen_drm_front_drm_info *drm_info)
 369 {
 370         int i;
 371
 372         for (i = 0; i < drm_info->front_info->cfg.num_connectors; i++) {
 373                 struct xen_drm_front_drm_pipeline *pipeline =
 374                                 &drm_info->pipeline[i];
 375
 376                 cancel_delayed_work_sync(&pipeline->pflip_to_worker);
 377
 378                 send_pending_event(pipeline);
 379         }
 380 }