drivers/gpu/drm/i915/gt/uc/intel_huc.c

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright © 2016-2019 Intel Corporation
   4  */
   5
   6 #include <linux/types.h>
   7
   8 #include "gt/intel_gt.h"
   9 #include "intel_guc_reg.h"
  10 #include "intel_huc.h"
  11 #include "i915_drv.h"
  12
  13 #include <linux/device/bus.h>
  14 #include <linux/mei_aux.h>
  15
  16 /**
  17  * DOC: HuC
  18  *
  19  * The HuC is a dedicated microcontroller for usage in media HEVC (High
  20  * Efficiency Video Coding) operations. Userspace can directly use the firmware
  21  * capabilities by adding HuC specific commands to batch buffers.
  22  *
  23  * The kernel driver is only responsible for loading the HuC firmware and
  24  * triggering its security authentication, which is performed by the GuC on
  25  * older platforms and by the GSC on newer ones. For the GuC to correctly
  26  * perform the authentication, the HuC binary must be loaded before the GuC one.
  27  * Loading the HuC is optional; however, not using the HuC might negatively
  28  * impact power usage and/or performance of media workloads, depending on the
  29  * use-cases.
  30  * HuC must be reloaded on events that cause the WOPCM to lose its contents
  31  * (S3/S4, FLR); GuC-authenticated HuC must also be reloaded on GuC/GT reset,
  32  * while GSC-managed HuC will survive that.
  33  *
  34  * See https://github.com/intel/media-driver for the latest details on HuC
  35  * functionality.
  36  */
  37
  38 /**
  39  * DOC: HuC Memory Management
  40  *
  41  * Similarly to the GuC, the HuC can't do any memory allocations on its own,
  42  * with the difference being that the allocations for HuC usage are handled by
  43  * the userspace driver instead of the kernel one. The HuC accesses the memory
  44  * via the PPGTT belonging to the context loaded on the VCS executing the
  45  * HuC-specific commands.
  46  */
  47
  48 /*
  49  * MEI-GSC load is an async process. The probing of the exposed aux device
  50  * (see intel_gsc.c) usually happens a few seconds after i915 probe, depending
  51  * on when the kernel schedules it. Unless something goes terribly wrong, we're
  52  * guaranteed for this to happen during boot, so the big timeout is a safety net
  53  * that we never expect to need.
  54  * MEI-PXP + HuC load usually takes ~300ms, but if the GSC needs to be resumed
  55  * and/or reset, this can take longer. Note that the kernel might schedule
  56  * other work between the i915 init/resume and the MEI one, which can add to
  57  * the delay.
  58  */
  59 #define GSC_INIT_TIMEOUT_MS 10000
  60 #define PXP_INIT_TIMEOUT_MS 5000
  61
  62 static int sw_fence_dummy_notify(struct i915_sw_fence *sf,
  63                                  enum i915_sw_fence_notify state)
  64 {
  65         return NOTIFY_DONE;
  66 }
  67
  68 static void __delayed_huc_load_complete(struct intel_huc *huc)
  69 {
  70         if (!i915_sw_fence_done(&huc->delayed_load.fence))
  71                 i915_sw_fence_complete(&huc->delayed_load.fence);
  72 }
  73
  74 static void delayed_huc_load_complete(struct intel_huc *huc)
  75 {
  76         hrtimer_cancel(&huc->delayed_load.timer);
  77         __delayed_huc_load_complete(huc);
  78 }
  79
  80 static void __gsc_init_error(struct intel_huc *huc)
  81 {
  82         huc->delayed_load.status = INTEL_HUC_DELAYED_LOAD_ERROR;
  83         __delayed_huc_load_complete(huc);
  84 }
  85
  86 static void gsc_init_error(struct intel_huc *huc)
  87 {
  88         hrtimer_cancel(&huc->delayed_load.timer);
  89         __gsc_init_error(huc);
  90 }
  91
  92 static void gsc_init_done(struct intel_huc *huc)
  93 {
  94         hrtimer_cancel(&huc->delayed_load.timer);
  95
  96         /* MEI-GSC init is done, now we wait for MEI-PXP to bind */
  97         huc->delayed_load.status = INTEL_HUC_WAITING_ON_PXP;
  98         if (!i915_sw_fence_done(&huc->delayed_load.fence))
  99                 hrtimer_start(&huc->delayed_load.timer,
 100                               ms_to_ktime(PXP_INIT_TIMEOUT_MS),
 101                               HRTIMER_MODE_REL);
 102 }
 103
 104 static enum hrtimer_restart huc_delayed_load_timer_callback(struct hrtimer *hrtimer)
 105 {
 106         struct intel_huc *huc = container_of(hrtimer, struct intel_huc, delayed_load.timer);
 107
 108         if (!intel_huc_is_authenticated(huc)) {
 109                 if (huc->delayed_load.status == INTEL_HUC_WAITING_ON_GSC)
 110                         drm_notice(&huc_to_gt(huc)->i915->drm,
 111                                    "timed out waiting for MEI GSC init to load HuC\n");
 112                 else if (huc->delayed_load.status == INTEL_HUC_WAITING_ON_PXP)
 113                         drm_notice(&huc_to_gt(huc)->i915->drm,
 114                                    "timed out waiting for MEI PXP init to load HuC\n");
 115                 else
 116                         MISSING_CASE(huc->delayed_load.status);
 117
 118                 __gsc_init_error(huc);
 119         }
 120
 121         return HRTIMER_NORESTART;
 122 }
 123
 124 static void huc_delayed_load_start(struct intel_huc *huc)
 125 {
 126         ktime_t delay;
 127
 128         GEM_BUG_ON(intel_huc_is_authenticated(huc));
 129
 130         /*
 131          * On resume we don't have to wait for MEI-GSC to be re-probed, but we
 132          * do need to wait for MEI-PXP to reset & re-bind
 133          */
 134         switch (huc->delayed_load.status) {
 135         case INTEL_HUC_WAITING_ON_GSC:
 136                 delay = ms_to_ktime(GSC_INIT_TIMEOUT_MS);
 137                 break;
 138         case INTEL_HUC_WAITING_ON_PXP:
 139                 delay = ms_to_ktime(PXP_INIT_TIMEOUT_MS);
 140                 break;
 141         default:
 142                 gsc_init_error(huc);
 143                 return;
 144         }
 145
 146         /*
 147          * This fence is always complete unless we're waiting for the
 148          * GSC device to come up to load the HuC. We arm the fence here
 149          * and complete it when we confirm that the HuC is loaded from
 150          * the PXP bind callback.
 151          */
 152         GEM_BUG_ON(!i915_sw_fence_done(&huc->delayed_load.fence));
 153         i915_sw_fence_fini(&huc->delayed_load.fence);
 154         i915_sw_fence_reinit(&huc->delayed_load.fence);
 155         i915_sw_fence_await(&huc->delayed_load.fence);
 156         i915_sw_fence_commit(&huc->delayed_load.fence);
 157
 158         hrtimer_start(&huc->delayed_load.timer, delay, HRTIMER_MODE_REL);
 159 }
 160
 161 static int gsc_notifier(struct notifier_block *nb, unsigned long action, void *data)
 162 {
 163         struct device *dev = data;
 164         struct intel_huc *huc = container_of(nb, struct intel_huc, delayed_load.nb);
 165         struct intel_gsc_intf *intf = &huc_to_gt(huc)->gsc.intf[0];
 166
 167         if (!intf->adev || &intf->adev->aux_dev.dev != dev)
 168                 return 0;
 169
 170         switch (action) {
 171         case BUS_NOTIFY_BOUND_DRIVER: /* mei driver bound to aux device */
 172                 gsc_init_done(huc);
 173                 break;
 174
 175         case BUS_NOTIFY_DRIVER_NOT_BOUND: /* mei driver fails to be bound */
 176         case BUS_NOTIFY_UNBIND_DRIVER: /* mei driver about to be unbound */
 177                 drm_info(&huc_to_gt(huc)->i915->drm,
 178                          "mei driver not bound, disabling HuC load\n");
 179                 gsc_init_error(huc);
 180                 break;
 181         }
 182
 183         return 0;
 184 }
 185
 186 void intel_huc_register_gsc_notifier(struct intel_huc *huc, struct bus_type *bus)
 187 {
 188         int ret;
 189
 190         if (!intel_huc_is_loaded_by_gsc(huc))
 191                 return;
 192
 193         huc->delayed_load.nb.notifier_call = gsc_notifier;
 194         ret = bus_register_notifier(bus, &huc->delayed_load.nb);
 195         if (ret) {
 196                 drm_err(&huc_to_gt(huc)->i915->drm,
 197                         "failed to register GSC notifier\n");
 198                 huc->delayed_load.nb.notifier_call = NULL;
 199                 gsc_init_error(huc);
 200         }
 201 }
 202
 203 void intel_huc_unregister_gsc_notifier(struct intel_huc *huc, struct bus_type *bus)
 204 {
 205         if (!huc->delayed_load.nb.notifier_call)
 206                 return;
 207
 208         delayed_huc_load_complete(huc);
 209
 210         bus_unregister_notifier(bus, &huc->delayed_load.nb);
 211         huc->delayed_load.nb.notifier_call = NULL;
 212 }
 213
 214 static void delayed_huc_load_init(struct intel_huc *huc)
 215 {
 216         /*
 217          * Initialize fence to be complete as this is expected to be complete
 218          * unless there is a delayed HuC load in progress.
 219          */
 220         i915_sw_fence_init(&huc->delayed_load.fence,
 221                            sw_fence_dummy_notify);
 222         i915_sw_fence_commit(&huc->delayed_load.fence);
 223
 224         hrtimer_init(&huc->delayed_load.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 225         huc->delayed_load.timer.function = huc_delayed_load_timer_callback;
 226 }
 227
 228 static void delayed_huc_load_fini(struct intel_huc *huc)
 229 {
 230         /*
 231          * the fence is initialized in init_early, so we need to clean it up
 232          * even if HuC loading is off.
 233          */
 234         delayed_huc_load_complete(huc);
 235         i915_sw_fence_fini(&huc->delayed_load.fence);
 236 }
 237
 238 static bool vcs_supported(struct intel_gt *gt)
 239 {
 240         intel_engine_mask_t mask = gt->info.engine_mask;
 241
 242         /*
 243          * We reach here from i915_driver_early_probe for the primary GT before
 244          * its engine mask is set, so we use the device info engine mask for it;
 245          * this means we're not taking VCS fusing into account, but if the
 246          * primary GT supports VCS engines we expect at least one of them to
 247          * remain unfused so we're fine.
 248          * For other GTs we expect the GT-specific mask to be set before we
 249          * call this function.
 250          */
 251         GEM_BUG_ON(!gt_is_root(gt) && !gt->info.engine_mask);
 252
 253         if (gt_is_root(gt))
 254                 mask = RUNTIME_INFO(gt->i915)->platform_engine_mask;
 255         else
 256                 mask = gt->info.engine_mask;
 257
 258         return __ENGINE_INSTANCES_MASK(mask, VCS0, I915_MAX_VCS);
 259 }
 260
 261 void intel_huc_init_early(struct intel_huc *huc)
 262 {
 263         struct drm_i915_private *i915 = huc_to_gt(huc)->i915;
 264         struct intel_gt *gt = huc_to_gt(huc);
 265
 266         intel_uc_fw_init_early(&huc->fw, INTEL_UC_FW_TYPE_HUC);
 267
 268         /*
 269          * we always init the fence as already completed, even if HuC is not
 270          * supported. This way we don't have to distinguish between HuC not
 271          * supported/disabled or already loaded, and can focus on if the load
 272          * is currently in progress (fence not complete) or not, which is what
 273          * we care about for stalling userspace submissions.
 274          */
 275         delayed_huc_load_init(huc);
 276
 277         if (!vcs_supported(gt)) {
 278                 intel_uc_fw_change_status(&huc->fw, INTEL_UC_FIRMWARE_NOT_SUPPORTED);
 279                 return;
 280         }
 281
 282         if (GRAPHICS_VER(i915) >= 11) {
 283                 huc->status.reg = GEN11_HUC_KERNEL_LOAD_INFO;
 284                 huc->status.mask = HUC_LOAD_SUCCESSFUL;
 285                 huc->status.value = HUC_LOAD_SUCCESSFUL;
 286         } else {
 287                 huc->status.reg = HUC_STATUS2;
 288                 huc->status.mask = HUC_FW_VERIFIED;
 289                 huc->status.value = HUC_FW_VERIFIED;
 290         }
 291 }
 292
 293 #define HUC_LOAD_MODE_STRING(x) (x ? "GSC" : "legacy")
 294 static int check_huc_loading_mode(struct intel_huc *huc)
 295 {
 296         struct intel_gt *gt = huc_to_gt(huc);
 297         bool fw_needs_gsc = intel_huc_is_loaded_by_gsc(huc);
 298         bool hw_uses_gsc = false;
 299
 300         /*
 301          * The fuse for HuC load via GSC is only valid on platforms that have
 302          * GuC deprivilege.
 303          */
 304         if (HAS_GUC_DEPRIVILEGE(gt->i915))
 305                 hw_uses_gsc = intel_uncore_read(gt->uncore, GUC_SHIM_CONTROL2) &
 306                               GSC_LOADS_HUC;
 307
 308         if (fw_needs_gsc != hw_uses_gsc) {
 309                 drm_err(&gt->i915->drm,
 310                         "mismatch between HuC FW (%s) and HW (%s) load modes\n",
 311                         HUC_LOAD_MODE_STRING(fw_needs_gsc),
 312                         HUC_LOAD_MODE_STRING(hw_uses_gsc));
 313                 return -ENOEXEC;
 314         }
 315
 316         /* make sure we can access the GSC via the mei driver if we need it */
 317         if (!(IS_ENABLED(CONFIG_INTEL_MEI_PXP) && IS_ENABLED(CONFIG_INTEL_MEI_GSC)) &&
 318             fw_needs_gsc) {
 319                 drm_info(&gt->i915->drm,
 320                          "Can't load HuC due to missing MEI modules\n");
 321                 return -EIO;
 322         }
 323
 324         drm_dbg(&gt->i915->drm, "GSC loads huc=%s\n", str_yes_no(fw_needs_gsc));
 325
 326         return 0;
 327 }
 328
 329 int intel_huc_init(struct intel_huc *huc)
 330 {
 331         struct drm_i915_private *i915 = huc_to_gt(huc)->i915;
 332         int err;
 333
 334         err = check_huc_loading_mode(huc);
 335         if (err)
 336                 goto out;
 337
 338         err = intel_uc_fw_init(&huc->fw);
 339         if (err)
 340                 goto out;
 341
 342         intel_uc_fw_change_status(&huc->fw, INTEL_UC_FIRMWARE_LOADABLE);
 343
 344         return 0;
 345
 346 out:
 347         intel_uc_fw_change_status(&huc->fw, INTEL_UC_FIRMWARE_INIT_FAIL);
 348         drm_info(&i915->drm, "HuC init failed with %d\n", err);
 349         return err;
 350 }
 351
 352 void intel_huc_fini(struct intel_huc *huc)
 353 {
 354         /*
 355          * the fence is initialized in init_early, so we need to clean it up
 356          * even if HuC loading is off.
 357          */
 358         delayed_huc_load_fini(huc);
 359
 360         if (intel_uc_fw_is_loadable(&huc->fw))
 361                 intel_uc_fw_fini(&huc->fw);
 362 }
 363
 364 void intel_huc_suspend(struct intel_huc *huc)
 365 {
 366         if (!intel_uc_fw_is_loadable(&huc->fw))
 367                 return;
 368
 369         /*
 370          * in the unlikely case that we're suspending before the GSC has
 371          * completed its loading sequence, just stop waiting. We'll restart
 372          * on resume.
 373          */
 374         delayed_huc_load_complete(huc);
 375 }
 376
 377 int intel_huc_wait_for_auth_complete(struct intel_huc *huc)
 378 {
 379         struct intel_gt *gt = huc_to_gt(huc);
 380         int ret;
 381
 382         ret = __intel_wait_for_register(gt->uncore,
 383                                         huc->status.reg,
 384                                         huc->status.mask,
 385                                         huc->status.value,
 386                                         2, 50, NULL);
 387
 388         /* mark the load process as complete even if the wait failed */
 389         delayed_huc_load_complete(huc);
 390
 391         if (ret) {
 392                 drm_err(&gt->i915->drm, "HuC: Firmware not verified %d\n", ret);
 393                 intel_uc_fw_change_status(&huc->fw, INTEL_UC_FIRMWARE_LOAD_FAIL);
 394                 return ret;
 395         }
 396
 397         intel_uc_fw_change_status(&huc->fw, INTEL_UC_FIRMWARE_RUNNING);
 398         drm_info(&gt->i915->drm, "HuC authenticated\n");
 399         return 0;
 400 }
 401
 402 /**
 403  * intel_huc_auth() - Authenticate HuC uCode
 404  * @huc: intel_huc structure
 405  *
 406  * Called after HuC and GuC firmware loading during intel_uc_init_hw().
 407  *
 408  * This function invokes the GuC action to authenticate the HuC firmware,
 409  * passing the offset of the RSA signature to intel_guc_auth_huc(). It then
 410  * waits for up to 50ms for firmware verification ACK.
 411  */
 412 int intel_huc_auth(struct intel_huc *huc)
 413 {
 414         struct intel_gt *gt = huc_to_gt(huc);
 415         struct intel_guc *guc = &gt->uc.guc;
 416         int ret;
 417
 418         if (!intel_uc_fw_is_loaded(&huc->fw))
 419                 return -ENOEXEC;
 420
 421         /* GSC will do the auth */
 422         if (intel_huc_is_loaded_by_gsc(huc))
 423                 return -ENODEV;
 424
 425         ret = i915_inject_probe_error(gt->i915, -ENXIO);
 426         if (ret)
 427                 goto fail;
 428
 429         GEM_BUG_ON(intel_uc_fw_is_running(&huc->fw));
 430
 431         ret = intel_guc_auth_huc(guc, intel_guc_ggtt_offset(guc, huc->fw.rsa_data));
 432         if (ret) {
 433                 DRM_ERROR("HuC: GuC did not ack Auth request %d\n", ret);
 434                 goto fail;
 435         }
 436
 437         /* Check authentication status, it should be done by now */
 438         ret = intel_huc_wait_for_auth_complete(huc);
 439         if (ret)
 440                 goto fail;
 441
 442         return 0;
 443
 444 fail:
 445         i915_probe_error(gt->i915, "HuC: Authentication failed %d\n", ret);
 446         return ret;
 447 }
 448
 449 bool intel_huc_is_authenticated(struct intel_huc *huc)
 450 {
 451         struct intel_gt *gt = huc_to_gt(huc);
 452         intel_wakeref_t wakeref;
 453         u32 status = 0;
 454
 455         with_intel_runtime_pm(gt->uncore->rpm, wakeref)
 456                 status = intel_uncore_read(gt->uncore, huc->status.reg);
 457
 458         return (status & huc->status.mask) == huc->status.value;
 459 }
 460
 461 /**
 462  * intel_huc_check_status() - check HuC status
 463  * @huc: intel_huc structure
 464  *
 465  * This function reads status register to verify if HuC
 466  * firmware was successfully loaded.
 467  *
 468  * The return values match what is expected for the I915_PARAM_HUC_STATUS
 469  * getparam.
 470  */
 471 int intel_huc_check_status(struct intel_huc *huc)
 472 {
 473         switch (__intel_uc_fw_status(&huc->fw)) {
 474         case INTEL_UC_FIRMWARE_NOT_SUPPORTED:
 475                 return -ENODEV;
 476         case INTEL_UC_FIRMWARE_DISABLED:
 477                 return -EOPNOTSUPP;
 478         case INTEL_UC_FIRMWARE_MISSING:
 479                 return -ENOPKG;
 480         case INTEL_UC_FIRMWARE_ERROR:
 481                 return -ENOEXEC;
 482         case INTEL_UC_FIRMWARE_INIT_FAIL:
 483                 return -ENOMEM;
 484         case INTEL_UC_FIRMWARE_LOAD_FAIL:
 485                 return -EIO;
 486         default:
 487                 break;
 488         }
 489
 490         return intel_huc_is_authenticated(huc);
 491 }
 492
 493 static bool huc_has_delayed_load(struct intel_huc *huc)
 494 {
 495         return intel_huc_is_loaded_by_gsc(huc) &&
 496                (huc->delayed_load.status != INTEL_HUC_DELAYED_LOAD_ERROR);
 497 }
 498
 499 void intel_huc_update_auth_status(struct intel_huc *huc)
 500 {
 501         if (!intel_uc_fw_is_loadable(&huc->fw))
 502                 return;
 503
 504         if (intel_huc_is_authenticated(huc))
 505                 intel_uc_fw_change_status(&huc->fw,
 506                                           INTEL_UC_FIRMWARE_RUNNING);
 507         else if (huc_has_delayed_load(huc))
 508                 huc_delayed_load_start(huc);
 509 }
 510
 511 /**
 512  * intel_huc_load_status - dump information about HuC load status
 513  * @huc: the HuC
 514  * @p: the &drm_printer
 515  *
 516  * Pretty printer for HuC load status.
 517  */
 518 void intel_huc_load_status(struct intel_huc *huc, struct drm_printer *p)
 519 {
 520         struct intel_gt *gt = huc_to_gt(huc);
 521         intel_wakeref_t wakeref;
 522
 523         if (!intel_huc_is_supported(huc)) {
 524                 drm_printf(p, "HuC not supported\n");
 525                 return;
 526         }
 527
 528         if (!intel_huc_is_wanted(huc)) {
 529                 drm_printf(p, "HuC disabled\n");
 530                 return;
 531         }
 532
 533         intel_uc_fw_dump(&huc->fw, p);
 534
 535         with_intel_runtime_pm(gt->uncore->rpm, wakeref)
 536                 drm_printf(p, "HuC status: 0x%08x\n",
 537                            intel_uncore_read(gt->uncore, huc->status.reg));
 538 }