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