drm-lease-manager/lease-manager.c

   1 /* Copyright 2020-2021 IGEL Co., Ltd.
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License.
  14  */
  15
  16 #define _GNU_SOURCE
  17 #include "lease-manager.h"
  18
  19 #include "drm-lease.h"
  20 #include "log.h"
  21
  22 #include <assert.h>
  23 #include <errno.h>
  24 #include <fcntl.h>
  25 #include <poll.h>
  26 #include <pthread.h>
  27 #include <stdbool.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <strings.h>
  31 #include <sys/stat.h>
  32 #include <sys/sysmacros.h>
  33 #include <unistd.h>
  34 #include <xf86drm.h>
  35 #include <xf86drmMode.h>
  36
  37 /* Number of resources, to be included in a DRM lease for each connector.
  38  * Each connector needs both a CRTC and conector object:. */
  39 #define DRM_OBJECTS_PER_CONNECTOR (2)
  40
  41 #define ARRAY_LENGTH(x) (sizeof(x) / sizeof(x[0]))
  42
  43 struct lease {
  44         struct lease_handle base;
  45
  46         bool is_granted;
  47         uint32_t lessee_id;
  48         int lease_fd;
  49
  50         uint32_t *object_ids;
  51         int nobject_ids;
  52
  53         /* for lease transfer completion */
  54         uint32_t crtc_id;
  55         pthread_t transition_tid;
  56         bool transition_running;
  57 };
  58
  59 struct lm {
  60         int drm_fd;
  61         dev_t dev_id;
  62
  63         drmModeResPtr drm_resource;
  64         drmModePlaneResPtr drm_plane_resource;
  65         uint32_t available_crtcs;
  66
  67         char **connector_names;
  68         int nconnectors;
  69
  70         struct lease **leases;
  71         int nleases;
  72 };
  73
  74 static const char *const connector_type_names[] = {
  75     [DRM_MODE_CONNECTOR_Unknown] = "Unknown",
  76     [DRM_MODE_CONNECTOR_VGA] = "VGA",
  77     [DRM_MODE_CONNECTOR_DVII] = "DVI-I",
  78     [DRM_MODE_CONNECTOR_DVID] = "DVI-D",
  79     [DRM_MODE_CONNECTOR_DVIA] = "DVI-A",
  80     [DRM_MODE_CONNECTOR_Composite] = "Composite",
  81     [DRM_MODE_CONNECTOR_SVIDEO] = "SVIDEO",
  82     [DRM_MODE_CONNECTOR_LVDS] = "LVDS",
  83     [DRM_MODE_CONNECTOR_Component] = "Component",
  84     [DRM_MODE_CONNECTOR_9PinDIN] = "DIN",
  85     [DRM_MODE_CONNECTOR_DisplayPort] = "DP",
  86     [DRM_MODE_CONNECTOR_HDMIA] = "HDMI-A",
  87     [DRM_MODE_CONNECTOR_HDMIB] = "HDMI-B",
  88     [DRM_MODE_CONNECTOR_TV] = "TV",
  89     [DRM_MODE_CONNECTOR_eDP] = "eDP",
  90     [DRM_MODE_CONNECTOR_VIRTUAL] = "Virtual",
  91     [DRM_MODE_CONNECTOR_DSI] = "DSI",
  92     [DRM_MODE_CONNECTOR_DPI] = "DPI",
  93     [DRM_MODE_CONNECTOR_WRITEBACK] = "Writeback",
  94 };
  95
  96 static char *drm_create_connector_name(drmModeConnectorPtr connector)
  97 {
  98         uint32_t type = connector->connector_type;
  99         uint32_t id = connector->connector_type_id;
 100
 101         if (type >= ARRAY_LENGTH(connector_type_names))
 102                 type = DRM_MODE_CONNECTOR_Unknown;
 103
 104         /* If the type is "Unknown", use the connector_id as the identify to
 105          * guarantee that the name will be unique. */
 106         if (type == DRM_MODE_CONNECTOR_Unknown)
 107                 id = connector->connector_id;
 108
 109         char *name;
 110         if (asprintf(&name, "%s-%d", connector_type_names[type], id) < 0)
 111                 return NULL;
 112
 113         return name;
 114 }
 115
 116 static char *drm_create_default_lease_name(struct lm *lm, int cindex)
 117 {
 118         char *connector_name = lm->connector_names[cindex];
 119
 120         char *name;
 121         if (asprintf(&name, "card%d-%s", minor(lm->dev_id), connector_name) < 0)
 122                 return NULL;
 123
 124         return name;
 125 }
 126
 127 static int drm_get_encoder_crtc_index(struct lm *lm, drmModeEncoderPtr encoder)
 128 {
 129         uint32_t crtc_id = encoder->crtc_id;
 130         if (!crtc_id)
 131                 return -1;
 132
 133         // The CRTC index only makes sense if it is less than the number of
 134         // bits in the encoder possible_crtcs bitmap, which is 32.
 135         assert(lm->drm_resource->count_crtcs < 32);
 136
 137         for (int i = 0; i < lm->drm_resource->count_crtcs; i++) {
 138                 if (lm->drm_resource->crtcs[i] == crtc_id)
 139                         return i;
 140         }
 141         return -1;
 142 }
 143
 144 static int drm_get_active_crtc_index(struct lm *lm,
 145                                      drmModeConnectorPtr connector)
 146 {
 147         drmModeEncoder *encoder =
 148             drmModeGetEncoder(lm->drm_fd, connector->encoder_id);
 149         if (!encoder)
 150                 return -1;
 151
 152         int crtc_idx = drm_get_encoder_crtc_index(lm, encoder);
 153         drmModeFreeEncoder(encoder);
 154         return crtc_idx;
 155 }
 156
 157 static int drm_get_crtc_index(struct lm *lm, drmModeConnectorPtr connector)
 158 {
 159
 160         // try the active CRTC first
 161         int crtc_index = drm_get_active_crtc_index(lm, connector);
 162         if (crtc_index != -1)
 163                 return crtc_index;
 164
 165         // If not try the first available CRTC on the connector/encoder
 166         for (int i = 0; i < connector->count_encoders; i++) {
 167                 drmModeEncoder *encoder =
 168                     drmModeGetEncoder(lm->drm_fd, connector->encoders[i]);
 169
 170                 assert(encoder);
 171
 172                 uint32_t usable_crtcs =
 173                     lm->available_crtcs & encoder->possible_crtcs;
 174                 int crtc = ffs(usable_crtcs);
 175                 drmModeFreeEncoder(encoder);
 176                 if (crtc == 0)
 177                         continue;
 178                 crtc_index = crtc - 1;
 179                 lm->available_crtcs &= ~(1 << crtc_index);
 180                 break;
 181         }
 182         return crtc_index;
 183 }
 184
 185 static void drm_find_available_crtcs(struct lm *lm)
 186 {
 187         // Assume all CRTCS are available by default,
 188         lm->available_crtcs = ~0;
 189
 190         // then remove any that are in use. */
 191         for (int i = 0; i < lm->drm_resource->count_encoders; i++) {
 192                 int enc_id = lm->drm_resource->encoders[i];
 193                 drmModeEncoderPtr enc = drmModeGetEncoder(lm->drm_fd, enc_id);
 194                 if (!enc)
 195                         continue;
 196
 197                 int crtc_idx = drm_get_encoder_crtc_index(lm, enc);
 198                 if (crtc_idx >= 0)
 199                         lm->available_crtcs &= ~(1 << crtc_idx);
 200
 201                 drmModeFreeEncoder(enc);
 202         }
 203 }
 204
 205 static bool drm_find_connector(struct lm *lm, char *name, uint32_t *id)
 206 {
 207         int connectors = lm->drm_resource->count_connectors;
 208
 209         for (int i = 0; i < connectors; i++) {
 210                 if (strcmp(lm->connector_names[i], name))
 211                         continue;
 212                 if (id)
 213                         *id = lm->drm_resource->connectors[i];
 214                 return true;
 215         }
 216         return false;
 217 }
 218
 219 static bool lease_add_planes(struct lm *lm, struct lease *lease, int crtc_index)
 220 {
 221         for (uint32_t i = 0; i < lm->drm_plane_resource->count_planes; i++) {
 222                 uint32_t plane_id = lm->drm_plane_resource->planes[i];
 223                 drmModePlanePtr plane = drmModeGetPlane(lm->drm_fd, plane_id);
 224
 225                 assert(plane);
 226
 227                 // Exclude planes that can be used with multiple CRTCs for now
 228                 if (plane->possible_crtcs == (1u << crtc_index)) {
 229                         lease->object_ids[lease->nobject_ids++] = plane_id;
 230                 }
 231                 drmModeFreePlane(plane);
 232         }
 233         return true;
 234 }
 235
 236 /* Lease transition
 237  * Wait for a client to update the DRM framebuffer on the CRTC managed by
 238  * a lease.  Once the framebuffer has been updated, it is safe to close
 239  * the fd associated with the previous lease client, freeing the previous
 240  * framebuffer if there are no other references to it. */
 241 static void wait_for_fb_update(struct lease *lease, uint32_t old_fb)
 242 {
 243         uint32_t current_fb = old_fb;
 244
 245         struct pollfd drm_poll = {
 246             .fd = lease->lease_fd,
 247             .events = POLLIN,
 248         };
 249
 250         while (current_fb == old_fb) {
 251                 drmModeCrtcPtr crtc;
 252                 if (poll(&drm_poll, 1, -1) < 0) {
 253                         if (errno == EINTR)
 254                                 continue;
 255                         break;
 256                 }
 257
 258                 crtc = drmModeGetCrtc(lease->lease_fd, lease->crtc_id);
 259                 current_fb = crtc->buffer_id;
 260                 drmModeFreeCrtc(crtc);
 261         }
 262 }
 263
 264 struct transition_ctx {
 265         struct lease *lease;
 266         int close_fd;
 267         uint32_t old_fb;
 268 };
 269
 270 static void transition_done(void *arg)
 271 {
 272         struct transition_ctx *ctx = arg;
 273         close(ctx->close_fd);
 274         free(ctx);
 275 }
 276
 277 static void *finish_transition_task(void *arg)
 278 {
 279         struct transition_ctx *ctx = arg;
 280         pthread_cleanup_push(transition_done, ctx);
 281         wait_for_fb_update(ctx->lease, ctx->old_fb);
 282         pthread_cleanup_pop(true);
 283         return NULL;
 284 }
 285
 286 static void close_after_lease_transition(struct lease *lease, int close_fd)
 287 {
 288         struct transition_ctx *ctx = calloc(1, sizeof(*ctx));
 289
 290         assert(ctx);
 291
 292         drmModeCrtcPtr crtc = drmModeGetCrtc(lease->lease_fd, lease->crtc_id);
 293
 294         ctx->lease = lease;
 295         ctx->close_fd = close_fd;
 296         ctx->old_fb = crtc->buffer_id;
 297
 298         drmModeFreeCrtc(crtc);
 299
 300         int ret = pthread_create(&lease->transition_tid, NULL,
 301                                  finish_transition_task, ctx);
 302
 303         lease->transition_running = (ret == 0);
 304 }
 305
 306 static void cancel_lease_transition_thread(struct lease *lease)
 307 {
 308
 309         if (lease->transition_running) {
 310                 pthread_cancel(lease->transition_tid);
 311                 pthread_join(lease->transition_tid, NULL);
 312         }
 313
 314         lease->transition_running = false;
 315 }
 316
 317 static void lease_free(struct lease *lease)
 318 {
 319         free(lease->base.name);
 320         free(lease->object_ids);
 321         free(lease);
 322 }
 323
 324 static struct lease *lease_create(struct lm *lm,
 325                                   const struct lease_config *config)
 326 {
 327         struct lease *lease;
 328
 329         if (!config->lease_name) {
 330                 ERROR_LOG("Mising lease name\n");
 331                 return NULL;
 332         }
 333
 334         lease = calloc(1, sizeof(struct lease));
 335         if (!lease) {
 336                 DEBUG_LOG("Memory allocation failed: %s\n", strerror(errno));
 337                 return NULL;
 338         }
 339
 340         lease->base.name = strdup(config->lease_name);
 341         if (!lease->base.name) {
 342                 DEBUG_LOG("Can't create lease name: %s\n", strerror(errno));
 343                 goto err;
 344         }
 345
 346         int nconnectors = config->cnames > 0 ? config->cnames : config->ncids;
 347         int nobjects = lm->drm_plane_resource->count_planes +
 348                        nconnectors * DRM_OBJECTS_PER_CONNECTOR;
 349
 350         lease->object_ids = calloc(nobjects, sizeof(uint32_t));
 351         if (!lease->object_ids) {
 352                 DEBUG_LOG("Memory allocation failed: %s\n", strerror(errno));
 353                 goto err;
 354         }
 355
 356         for (int i = 0; i < nconnectors; i++) {
 357                 uint32_t cid;
 358
 359                 if (config->cnames > 0) {
 360                         char *connector_name = config->connector_names[i];
 361
 362                         if (!drm_find_connector(lm, connector_name, &cid)) {
 363                                 WARN_LOG("Lease: %s, "
 364                                          "unknown DRM connector: %s\n",
 365                                          config->lease_name, connector_name);
 366                                 continue;
 367                         }
 368                 } else {
 369                         cid = config->connector_ids[i];
 370                 }
 371
 372                 drmModeConnectorPtr connector =
 373                     drmModeGetConnector(lm->drm_fd, cid);
 374
 375                 if (connector == NULL) {
 376                         ERROR_LOG("Can't find connector id: %d\n", cid);
 377                         goto err;
 378                 }
 379
 380                 int crtc_index = drm_get_crtc_index(lm, connector);
 381
 382                 drmModeFreeConnector(connector);
 383
 384                 if (crtc_index < 0) {
 385                         DEBUG_LOG("No crtc found for connector: %d, lease %s\n",
 386                                   cid, lease->base.name);
 387                         goto err;
 388                 }
 389
 390                 if (!lease_add_planes(lm, lease, crtc_index))
 391                         goto err;
 392
 393                 uint32_t crtc_id = lm->drm_resource->crtcs[crtc_index];
 394                 lease->crtc_id = crtc_id;
 395                 lease->object_ids[lease->nobject_ids++] = crtc_id;
 396                 lease->object_ids[lease->nobject_ids++] = cid;
 397         }
 398         lease->is_granted = false;
 399         lease->lease_fd = -1;
 400
 401         return lease;
 402
 403 err:
 404         lease_free(lease);
 405         return NULL;
 406 }
 407
 408 static void destroy_default_lease_configs(int num_configs,
 409                                           struct lease_config *configs)
 410 {
 411         for (int i = 0; i < num_configs; i++) {
 412                 free(configs[i].connector_ids);
 413                 free(configs[i].lease_name);
 414         }
 415
 416         free(configs);
 417 }
 418
 419 static int create_default_lease_configs(struct lm *lm,
 420                                         struct lease_config **configs)
 421 {
 422         struct lease_config *def_configs;
 423         int num_configs = lm->drm_resource->count_connectors;
 424
 425         if (num_configs < 0)
 426                 return -1;
 427
 428         def_configs = calloc(num_configs, sizeof(*def_configs));
 429         if (!def_configs) {
 430                 DEBUG_LOG("Memory allocation failed: %s\n", strerror(errno));
 431                 return -1;
 432         }
 433
 434         for (int i = 0; i < num_configs; i++) {
 435                 uint32_t cid = lm->drm_resource->connectors[i];
 436
 437                 def_configs[i].connector_ids = malloc(sizeof(uint32_t));
 438                 if (!def_configs[i].connector_ids) {
 439                         DEBUG_LOG("Memory allocation failed: %s\n",
 440                                   strerror(errno));
 441                         goto err;
 442                 }
 443
 444                 def_configs[i].lease_name =
 445                     drm_create_default_lease_name(lm, i);
 446
 447                 def_configs[i].connector_ids[0] = cid;
 448                 def_configs[i].ncids = 1;
 449         }
 450
 451         *configs = def_configs;
 452         return num_configs;
 453
 454 err:
 455         destroy_default_lease_configs(num_configs, def_configs);
 456         return -1;
 457 }
 458
 459 static struct lm *drm_device_get_resources(const char *device)
 460 {
 461         struct lm *lm = calloc(1, sizeof(struct lm));
 462         if (!lm) {
 463                 DEBUG_LOG("Memory allocation failed: %s\n", strerror(errno));
 464                 return NULL;
 465         }
 466         lm->drm_fd = open(device, O_RDWR);
 467         if (lm->drm_fd < 0) {
 468                 ERROR_LOG("Cannot open DRM device (%s): %s\n", device,
 469                           strerror(errno));
 470                 goto err;
 471         }
 472
 473         lm->drm_resource = drmModeGetResources(lm->drm_fd);
 474         if (!lm->drm_resource) {
 475                 ERROR_LOG("Invalid DRM device(%s)\n", device);
 476                 DEBUG_LOG("drmModeGetResources failed: %s\n", strerror(errno));
 477                 goto err;
 478         }
 479
 480         lm->drm_plane_resource = drmModeGetPlaneResources(lm->drm_fd);
 481         if (!lm->drm_plane_resource) {
 482                 DEBUG_LOG("drmModeGetPlaneResources failed: %s\n",
 483                           strerror(errno));
 484                 goto err;
 485         }
 486
 487         struct stat st;
 488         if (fstat(lm->drm_fd, &st) < 0 || !S_ISCHR(st.st_mode)) {
 489                 DEBUG_LOG("%s is not a valid device file\n", device);
 490                 goto err;
 491         }
 492
 493         lm->dev_id = st.st_rdev;
 494
 495         lm->nconnectors = lm->drm_resource->count_connectors;
 496         lm->connector_names = calloc(lm->nconnectors, sizeof(char *));
 497
 498         for (int i = 0; i < lm->nconnectors; i++) {
 499                 drmModeConnectorPtr connector;
 500                 uint32_t cid = lm->drm_resource->connectors[i];
 501
 502                 connector = drmModeGetConnector(lm->drm_fd, cid);
 503                 lm->connector_names[i] = drm_create_connector_name(connector);
 504                 drmModeFreeConnector(connector);
 505
 506                 if (!lm->connector_names[i]) {
 507                         DEBUG_LOG("Can't create name for connector %d: %s\n",
 508                                   cid, strerror(errno));
 509                         goto err;
 510                 }
 511         }
 512         return lm;
 513 err:
 514         lm_destroy(lm);
 515         return NULL;
 516 }
 517
 518 static int lm_create_leases(struct lm *lm, int num_leases,
 519                             const struct lease_config *configs)
 520 {
 521         lm->leases = calloc(num_leases, sizeof(struct lease *));
 522         if (!lm->leases) {
 523                 DEBUG_LOG("Memory allocation failed: %s\n", strerror(errno));
 524                 return -1;
 525         }
 526
 527         drm_find_available_crtcs(lm);
 528
 529         for (int i = 0; i < num_leases; i++) {
 530                 struct lease *lease = lease_create(lm, &configs[i]);
 531                 if (!lease)
 532                         continue;
 533
 534                 lm->leases[lm->nleases] = lease;
 535                 lm->nleases++;
 536         }
 537         if (lm->nleases == 0)
 538                 return -1;
 539
 540         return 0;
 541 }
 542
 543 struct lm *lm_create_with_config(const char *device, int num_leases,
 544                                  struct lease_config *configs)
 545 {
 546         struct lease_config *default_configs = NULL;
 547         struct lm *lm = drm_device_get_resources(device);
 548
 549         if (!lm)
 550                 return NULL;
 551
 552         if (configs == NULL || num_leases == 0) {
 553                 num_leases = create_default_lease_configs(lm, &default_configs);
 554                 if (num_leases < 0) {
 555                         lm_destroy(lm);
 556                         ERROR_LOG("DRM connector enumeration failed\n");
 557                         return NULL;
 558                 }
 559                 configs = default_configs;
 560         }
 561
 562         if (lm_create_leases(lm, num_leases, configs) < 0) {
 563                 lm_destroy(lm);
 564                 lm = NULL;
 565         }
 566
 567         if (default_configs)
 568                 destroy_default_lease_configs(num_leases, default_configs);
 569         return lm;
 570 }
 571
 572 struct lm *lm_create(const char *device)
 573 {
 574         return lm_create_with_config(device, 0, NULL);
 575 }
 576
 577 void lm_destroy(struct lm *lm)
 578 {
 579         assert(lm);
 580
 581         for (int i = 0; i < lm->nleases; i++) {
 582                 struct lease_handle *lease_handle = &lm->leases[i]->base;
 583                 lm_lease_revoke(lm, lease_handle);
 584                 lm_lease_close(lease_handle);
 585                 lease_free(lm->leases[i]);
 586         }
 587
 588         free(lm->leases);
 589
 590         for (int i = 0; i < lm->nconnectors; i++)
 591                 free(lm->connector_names[i]);
 592         free(lm->connector_names);
 593
 594         drmModeFreeResources(lm->drm_resource);
 595         drmModeFreePlaneResources(lm->drm_plane_resource);
 596         close(lm->drm_fd);
 597         free(lm);
 598 }
 599
 600 int lm_get_lease_handles(struct lm *lm, struct lease_handle ***handles)
 601 {
 602         assert(lm);
 603         assert(handles);
 604
 605         *handles = (struct lease_handle **)lm->leases;
 606         return lm->nleases;
 607 }
 608
 609 int lm_lease_grant(struct lm *lm, struct lease_handle *handle)
 610 {
 611         assert(lm);
 612         assert(handle);
 613
 614         struct lease *lease = (struct lease *)handle;
 615         if (lease->is_granted) {
 616                 /* Lease is already claimed */
 617                 return -1;
 618         }
 619
 620         int lease_fd =
 621             drmModeCreateLease(lm->drm_fd, lease->object_ids,
 622                                lease->nobject_ids, 0, &lease->lessee_id);
 623         if (lease_fd < 0) {
 624                 ERROR_LOG("drmModeCreateLease failed on lease %s: %s\n",
 625                           lease->base.name, strerror(errno));
 626                 return -1;
 627         }
 628
 629         lease->is_granted = true;
 630
 631         int old_lease_fd = lease->lease_fd;
 632         lease->lease_fd = lease_fd;
 633
 634         if (old_lease_fd >= 0)
 635                 close_after_lease_transition(lease, old_lease_fd);
 636
 637         return lease_fd;
 638 }
 639
 640 int lm_lease_transfer(struct lm *lm, struct lease_handle *handle)
 641 {
 642         assert(lm);
 643         assert(handle);
 644
 645         struct lease *lease = (struct lease *)handle;
 646         if (!lease->is_granted)
 647                 return -1;
 648
 649         lm_lease_revoke(lm, handle);
 650         if (lm_lease_grant(lm, handle) < 0) {
 651                 lm_lease_close(handle);
 652                 return -1;
 653         }
 654
 655         return lease->lease_fd;
 656 }
 657
 658 void lm_lease_revoke(struct lm *lm, struct lease_handle *handle)
 659 {
 660         assert(lm);
 661         assert(handle);
 662
 663         struct lease *lease = (struct lease *)handle;
 664
 665         if (!lease->is_granted)
 666                 return;
 667
 668         drmModeRevokeLease(lm->drm_fd, lease->lessee_id);
 669         cancel_lease_transition_thread(lease);
 670         lease->is_granted = false;
 671 }
 672
 673 void lm_lease_close(struct lease_handle *handle)
 674 {
 675         assert(handle);
 676
 677         struct lease *lease = (struct lease *)handle;
 678         if (lease->lease_fd >= 0)
 679                 close(lease->lease_fd);
 680         lease->lease_fd = -1;
 681 }