drivers/tee/optee/call.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015, Linaro Limited
   4  */
   5 #include <linux/arm-smccc.h>
   6 #include <linux/device.h>
   7 #include <linux/err.h>
   8 #include <linux/errno.h>
   9 #include <linux/mm.h>
  10 #include <linux/slab.h>
  11 #include <linux/tee_drv.h>
  12 #include <linux/types.h>
  13 #include <linux/uaccess.h>
  14 #include "optee_private.h"
  15 #include "optee_smc.h"
  16
  17 struct optee_call_waiter {
  18         struct list_head list_node;
  19         struct completion c;
  20 };
  21
  22 static void optee_cq_wait_init(struct optee_call_queue *cq,
  23                                struct optee_call_waiter *w)
  24 {
  25         /*
  26          * We're preparing to make a call to secure world. In case we can't
  27          * allocate a thread in secure world we'll end up waiting in
  28          * optee_cq_wait_for_completion().
  29          *
  30          * Normally if there's no contention in secure world the call will
  31          * complete and we can cleanup directly with optee_cq_wait_final().
  32          */
  33         mutex_lock(&cq->mutex);
  34
  35         /*
  36          * We add ourselves to the queue, but we don't wait. This
  37          * guarantees that we don't lose a completion if secure world
  38          * returns busy and another thread just exited and try to complete
  39          * someone.
  40          */
  41         init_completion(&w->c);
  42         list_add_tail(&w->list_node, &cq->waiters);
  43
  44         mutex_unlock(&cq->mutex);
  45 }
  46
  47 static void optee_cq_wait_for_completion(struct optee_call_queue *cq,
  48                                          struct optee_call_waiter *w)
  49 {
  50         wait_for_completion(&w->c);
  51
  52         mutex_lock(&cq->mutex);
  53
  54         /* Move to end of list to get out of the way for other waiters */
  55         list_del(&w->list_node);
  56         reinit_completion(&w->c);
  57         list_add_tail(&w->list_node, &cq->waiters);
  58
  59         mutex_unlock(&cq->mutex);
  60 }
  61
  62 static void optee_cq_complete_one(struct optee_call_queue *cq)
  63 {
  64         struct optee_call_waiter *w;
  65
  66         list_for_each_entry(w, &cq->waiters, list_node) {
  67                 if (!completion_done(&w->c)) {
  68                         complete(&w->c);
  69                         break;
  70                 }
  71         }
  72 }
  73
  74 static void optee_cq_wait_final(struct optee_call_queue *cq,
  75                                 struct optee_call_waiter *w)
  76 {
  77         /*
  78          * We're done with the call to secure world. The thread in secure
  79          * world that was used for this call is now available for some
  80          * other task to use.
  81          */
  82         mutex_lock(&cq->mutex);
  83
  84         /* Get out of the list */
  85         list_del(&w->list_node);
  86
  87         /* Wake up one eventual waiting task */
  88         optee_cq_complete_one(cq);
  89
  90         /*
  91          * If we're completed we've got a completion from another task that
  92          * was just done with its call to secure world. Since yet another
  93          * thread now is available in secure world wake up another eventual
  94          * waiting task.
  95          */
  96         if (completion_done(&w->c))
  97                 optee_cq_complete_one(cq);
  98
  99         mutex_unlock(&cq->mutex);
 100 }
 101
 102 /* Requires the filpstate mutex to be held */
 103 static struct optee_session *find_session(struct optee_context_data *ctxdata,
 104                                           u32 session_id)
 105 {
 106         struct optee_session *sess;
 107
 108         list_for_each_entry(sess, &ctxdata->sess_list, list_node)
 109                 if (sess->session_id == session_id)
 110                         return sess;
 111
 112         return NULL;
 113 }
 114
 115 /**
 116  * optee_do_call_with_arg() - Do an SMC to OP-TEE in secure world
 117  * @ctx:        calling context
 118  * @parg:       physical address of message to pass to secure world
 119  *
 120  * Does and SMC to OP-TEE in secure world and handles eventual resulting
 121  * Remote Procedure Calls (RPC) from OP-TEE.
 122  *
 123  * Returns return code from secure world, 0 is OK
 124  */
 125 u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg)
 126 {
 127         struct optee *optee = tee_get_drvdata(ctx->teedev);
 128         struct optee_call_waiter w;
 129         struct optee_rpc_param param = { };
 130         struct optee_call_ctx call_ctx = { };
 131         u32 ret;
 132
 133         param.a0 = OPTEE_SMC_CALL_WITH_ARG;
 134         reg_pair_from_64(&param.a1, &param.a2, parg);
 135         /* Initialize waiter */
 136         optee_cq_wait_init(&optee->call_queue, &w);
 137         while (true) {
 138                 struct arm_smccc_res res;
 139
 140                 optee->invoke_fn(param.a0, param.a1, param.a2, param.a3,
 141                                  param.a4, param.a5, param.a6, param.a7,
 142                                  &res);
 143
 144                 if (res.a0 == OPTEE_SMC_RETURN_ETHREAD_LIMIT) {
 145                         /*
 146                          * Out of threads in secure world, wait for a thread
 147                          * become available.
 148                          */
 149                         optee_cq_wait_for_completion(&optee->call_queue, &w);
 150                 } else if (OPTEE_SMC_RETURN_IS_RPC(res.a0)) {
 151                         param.a0 = res.a0;
 152                         param.a1 = res.a1;
 153                         param.a2 = res.a2;
 154                         param.a3 = res.a3;
 155                         optee_handle_rpc(ctx, &param, &call_ctx);
 156                 } else {
 157                         ret = res.a0;
 158                         break;
 159                 }
 160         }
 161
 162         optee_rpc_finalize_call(&call_ctx);
 163         /*
 164          * We're done with our thread in secure world, if there's any
 165          * thread waiters wake up one.
 166          */
 167         optee_cq_wait_final(&optee->call_queue, &w);
 168
 169         return ret;
 170 }
 171
 172 static struct tee_shm *get_msg_arg(struct tee_context *ctx, size_t num_params,
 173                                    struct optee_msg_arg **msg_arg,
 174                                    phys_addr_t *msg_parg)
 175 {
 176         int rc;
 177         struct tee_shm *shm;
 178         struct optee_msg_arg *ma;
 179
 180         shm = tee_shm_alloc(ctx, OPTEE_MSG_GET_ARG_SIZE(num_params),
 181                             TEE_SHM_MAPPED);
 182         if (IS_ERR(shm))
 183                 return shm;
 184
 185         ma = tee_shm_get_va(shm, 0);
 186         if (IS_ERR(ma)) {
 187                 rc = PTR_ERR(ma);
 188                 goto out;
 189         }
 190
 191         rc = tee_shm_get_pa(shm, 0, msg_parg);
 192         if (rc)
 193                 goto out;
 194
 195         memset(ma, 0, OPTEE_MSG_GET_ARG_SIZE(num_params));
 196         ma->num_params = num_params;
 197         *msg_arg = ma;
 198 out:
 199         if (rc) {
 200                 tee_shm_free(shm);
 201                 return ERR_PTR(rc);
 202         }
 203
 204         return shm;
 205 }
 206
 207 int optee_open_session(struct tee_context *ctx,
 208                        struct tee_ioctl_open_session_arg *arg,
 209                        struct tee_param *param)
 210 {
 211         struct optee_context_data *ctxdata = ctx->data;
 212         int rc;
 213         struct tee_shm *shm;
 214         struct optee_msg_arg *msg_arg;
 215         phys_addr_t msg_parg;
 216         struct optee_session *sess = NULL;
 217
 218         /* +2 for the meta parameters added below */
 219         shm = get_msg_arg(ctx, arg->num_params + 2, &msg_arg, &msg_parg);
 220         if (IS_ERR(shm))
 221                 return PTR_ERR(shm);
 222
 223         msg_arg->cmd = OPTEE_MSG_CMD_OPEN_SESSION;
 224         msg_arg->cancel_id = arg->cancel_id;
 225
 226         /*
 227          * Initialize and add the meta parameters needed when opening a
 228          * session.
 229          */
 230         msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
 231                                   OPTEE_MSG_ATTR_META;
 232         msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
 233                                   OPTEE_MSG_ATTR_META;
 234         memcpy(&msg_arg->params[0].u.value, arg->uuid, sizeof(arg->uuid));
 235         memcpy(&msg_arg->params[1].u.value, arg->uuid, sizeof(arg->clnt_uuid));
 236         msg_arg->params[1].u.value.c = arg->clnt_login;
 237
 238         rc = optee_to_msg_param(msg_arg->params + 2, arg->num_params, param);
 239         if (rc)
 240                 goto out;
 241
 242         sess = kzalloc(sizeof(*sess), GFP_KERNEL);
 243         if (!sess) {
 244                 rc = -ENOMEM;
 245                 goto out;
 246         }
 247
 248         if (optee_do_call_with_arg(ctx, msg_parg)) {
 249                 msg_arg->ret = TEEC_ERROR_COMMUNICATION;
 250                 msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
 251         }
 252
 253         if (msg_arg->ret == TEEC_SUCCESS) {
 254                 /* A new session has been created, add it to the list. */
 255                 sess->session_id = msg_arg->session;
 256                 mutex_lock(&ctxdata->mutex);
 257                 list_add(&sess->list_node, &ctxdata->sess_list);
 258                 mutex_unlock(&ctxdata->mutex);
 259         } else {
 260                 kfree(sess);
 261         }
 262
 263         if (optee_from_msg_param(param, arg->num_params, msg_arg->params + 2)) {
 264                 arg->ret = TEEC_ERROR_COMMUNICATION;
 265                 arg->ret_origin = TEEC_ORIGIN_COMMS;
 266                 /* Close session again to avoid leakage */
 267                 optee_close_session(ctx, msg_arg->session);
 268         } else {
 269                 arg->session = msg_arg->session;
 270                 arg->ret = msg_arg->ret;
 271                 arg->ret_origin = msg_arg->ret_origin;
 272         }
 273 out:
 274         tee_shm_free(shm);
 275
 276         return rc;
 277 }
 278
 279 int optee_close_session(struct tee_context *ctx, u32 session)
 280 {
 281         struct optee_context_data *ctxdata = ctx->data;
 282         struct tee_shm *shm;
 283         struct optee_msg_arg *msg_arg;
 284         phys_addr_t msg_parg;
 285         struct optee_session *sess;
 286
 287         /* Check that the session is valid and remove it from the list */
 288         mutex_lock(&ctxdata->mutex);
 289         sess = find_session(ctxdata, session);
 290         if (sess)
 291                 list_del(&sess->list_node);
 292         mutex_unlock(&ctxdata->mutex);
 293         if (!sess)
 294                 return -EINVAL;
 295         kfree(sess);
 296
 297         shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg);
 298         if (IS_ERR(shm))
 299                 return PTR_ERR(shm);
 300
 301         msg_arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
 302         msg_arg->session = session;
 303         optee_do_call_with_arg(ctx, msg_parg);
 304
 305         tee_shm_free(shm);
 306         return 0;
 307 }
 308
 309 int optee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg,
 310                       struct tee_param *param)
 311 {
 312         struct optee_context_data *ctxdata = ctx->data;
 313         struct tee_shm *shm;
 314         struct optee_msg_arg *msg_arg;
 315         phys_addr_t msg_parg;
 316         struct optee_session *sess;
 317         int rc;
 318
 319         /* Check that the session is valid */
 320         mutex_lock(&ctxdata->mutex);
 321         sess = find_session(ctxdata, arg->session);
 322         mutex_unlock(&ctxdata->mutex);
 323         if (!sess)
 324                 return -EINVAL;
 325
 326         shm = get_msg_arg(ctx, arg->num_params, &msg_arg, &msg_parg);
 327         if (IS_ERR(shm))
 328                 return PTR_ERR(shm);
 329         msg_arg->cmd = OPTEE_MSG_CMD_INVOKE_COMMAND;
 330         msg_arg->func = arg->func;
 331         msg_arg->session = arg->session;
 332         msg_arg->cancel_id = arg->cancel_id;
 333
 334         rc = optee_to_msg_param(msg_arg->params, arg->num_params, param);
 335         if (rc)
 336                 goto out;
 337
 338         if (optee_do_call_with_arg(ctx, msg_parg)) {
 339                 msg_arg->ret = TEEC_ERROR_COMMUNICATION;
 340                 msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
 341         }
 342
 343         if (optee_from_msg_param(param, arg->num_params, msg_arg->params)) {
 344                 msg_arg->ret = TEEC_ERROR_COMMUNICATION;
 345                 msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
 346         }
 347
 348         arg->ret = msg_arg->ret;
 349         arg->ret_origin = msg_arg->ret_origin;
 350 out:
 351         tee_shm_free(shm);
 352         return rc;
 353 }
 354
 355 int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
 356 {
 357         struct optee_context_data *ctxdata = ctx->data;
 358         struct tee_shm *shm;
 359         struct optee_msg_arg *msg_arg;
 360         phys_addr_t msg_parg;
 361         struct optee_session *sess;
 362
 363         /* Check that the session is valid */
 364         mutex_lock(&ctxdata->mutex);
 365         sess = find_session(ctxdata, session);
 366         mutex_unlock(&ctxdata->mutex);
 367         if (!sess)
 368                 return -EINVAL;
 369
 370         shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg);
 371         if (IS_ERR(shm))
 372                 return PTR_ERR(shm);
 373
 374         msg_arg->cmd = OPTEE_MSG_CMD_CANCEL;
 375         msg_arg->session = session;
 376         msg_arg->cancel_id = cancel_id;
 377         optee_do_call_with_arg(ctx, msg_parg);
 378
 379         tee_shm_free(shm);
 380         return 0;
 381 }
 382
 383 /**
 384  * optee_enable_shm_cache() - Enables caching of some shared memory allocation
 385  *                            in OP-TEE
 386  * @optee:      main service struct
 387  */
 388 void optee_enable_shm_cache(struct optee *optee)
 389 {
 390         struct optee_call_waiter w;
 391
 392         /* We need to retry until secure world isn't busy. */
 393         optee_cq_wait_init(&optee->call_queue, &w);
 394         while (true) {
 395                 struct arm_smccc_res res;
 396
 397                 optee->invoke_fn(OPTEE_SMC_ENABLE_SHM_CACHE, 0, 0, 0, 0, 0, 0,
 398                                  0, &res);
 399                 if (res.a0 == OPTEE_SMC_RETURN_OK)
 400                         break;
 401                 optee_cq_wait_for_completion(&optee->call_queue, &w);
 402         }
 403         optee_cq_wait_final(&optee->call_queue, &w);
 404 }
 405
 406 /**
 407  * optee_disable_shm_cache() - Disables caching of some shared memory allocation
 408  *                            in OP-TEE
 409  * @optee:      main service struct
 410  */
 411 void optee_disable_shm_cache(struct optee *optee)
 412 {
 413         struct optee_call_waiter w;
 414
 415         /* We need to retry until secure world isn't busy. */
 416         optee_cq_wait_init(&optee->call_queue, &w);
 417         while (true) {
 418                 union {
 419                         struct arm_smccc_res smccc;
 420                         struct optee_smc_disable_shm_cache_result result;
 421                 } res;
 422
 423                 optee->invoke_fn(OPTEE_SMC_DISABLE_SHM_CACHE, 0, 0, 0, 0, 0, 0,
 424                                  0, &res.smccc);
 425                 if (res.result.status == OPTEE_SMC_RETURN_ENOTAVAIL)
 426                         break; /* All shm's freed */
 427                 if (res.result.status == OPTEE_SMC_RETURN_OK) {
 428                         struct tee_shm *shm;
 429
 430                         shm = reg_pair_to_ptr(res.result.shm_upper32,
 431                                               res.result.shm_lower32);
 432                         tee_shm_free(shm);
 433                 } else {
 434                         optee_cq_wait_for_completion(&optee->call_queue, &w);
 435                 }
 436         }
 437         optee_cq_wait_final(&optee->call_queue, &w);
 438 }
 439
 440 #define PAGELIST_ENTRIES_PER_PAGE                               \
 441         ((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1)
 442
 443 /**
 444  * optee_fill_pages_list() - write list of user pages to given shared
 445  * buffer.
 446  *
 447  * @dst: page-aligned buffer where list of pages will be stored
 448  * @pages: array of pages that represents shared buffer
 449  * @num_pages: number of entries in @pages
 450  * @page_offset: offset of user buffer from page start
 451  *
 452  * @dst should be big enough to hold list of user page addresses and
 453  *      links to the next pages of buffer
 454  */
 455 void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages,
 456                            size_t page_offset)
 457 {
 458         int n = 0;
 459         phys_addr_t optee_page;
 460         /*
 461          * Refer to OPTEE_MSG_ATTR_NONCONTIG description in optee_msg.h
 462          * for details.
 463          */
 464         struct {
 465                 u64 pages_list[PAGELIST_ENTRIES_PER_PAGE];
 466                 u64 next_page_data;
 467         } *pages_data;
 468
 469         /*
 470          * Currently OP-TEE uses 4k page size and it does not looks
 471          * like this will change in the future.  On other hand, there are
 472          * no know ARM architectures with page size < 4k.
 473          * Thus the next built assert looks redundant. But the following
 474          * code heavily relies on this assumption, so it is better be
 475          * safe than sorry.
 476          */
 477         BUILD_BUG_ON(PAGE_SIZE < OPTEE_MSG_NONCONTIG_PAGE_SIZE);
 478
 479         pages_data = (void *)dst;
 480         /*
 481          * If linux page is bigger than 4k, and user buffer offset is
 482          * larger than 4k/8k/12k/etc this will skip first 4k pages,
 483          * because they bear no value data for OP-TEE.
 484          */
 485         optee_page = page_to_phys(*pages) +
 486                 round_down(page_offset, OPTEE_MSG_NONCONTIG_PAGE_SIZE);
 487
 488         while (true) {
 489                 pages_data->pages_list[n++] = optee_page;
 490
 491                 if (n == PAGELIST_ENTRIES_PER_PAGE) {
 492                         pages_data->next_page_data =
 493                                 virt_to_phys(pages_data + 1);
 494                         pages_data++;
 495                         n = 0;
 496                 }
 497
 498                 optee_page += OPTEE_MSG_NONCONTIG_PAGE_SIZE;
 499                 if (!(optee_page & ~PAGE_MASK)) {
 500                         if (!--num_pages)
 501                                 break;
 502                         pages++;
 503                         optee_page = page_to_phys(*pages);
 504                 }
 505         }
 506 }
 507
 508 /*
 509  * The final entry in each pagelist page is a pointer to the next
 510  * pagelist page.
 511  */
 512 static size_t get_pages_list_size(size_t num_entries)
 513 {
 514         int pages = DIV_ROUND_UP(num_entries, PAGELIST_ENTRIES_PER_PAGE);
 515
 516         return pages * OPTEE_MSG_NONCONTIG_PAGE_SIZE;
 517 }
 518
 519 u64 *optee_allocate_pages_list(size_t num_entries)
 520 {
 521         return alloc_pages_exact(get_pages_list_size(num_entries), GFP_KERNEL);
 522 }
 523
 524 void optee_free_pages_list(void *list, size_t num_entries)
 525 {
 526         free_pages_exact(list, get_pages_list_size(num_entries));
 527 }
 528
 529 static bool is_normal_memory(pgprot_t p)
 530 {
 531 #if defined(CONFIG_ARM)
 532         return (pgprot_val(p) & L_PTE_MT_MASK) == L_PTE_MT_WRITEALLOC;
 533 #elif defined(CONFIG_ARM64)
 534         return (pgprot_val(p) & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL);
 535 #else
 536 #error "Unuspported architecture"
 537 #endif
 538 }
 539
 540 static int __check_mem_type(struct vm_area_struct *vma, unsigned long end)
 541 {
 542         while (vma && is_normal_memory(vma->vm_page_prot)) {
 543                 if (vma->vm_end >= end)
 544                         return 0;
 545                 vma = vma->vm_next;
 546         }
 547
 548         return -EINVAL;
 549 }
 550
 551 static int check_mem_type(unsigned long start, size_t num_pages)
 552 {
 553         struct mm_struct *mm = current->mm;
 554         int rc;
 555
 556         down_read(&mm->mmap_sem);
 557         rc = __check_mem_type(find_vma(mm, start),
 558                               start + num_pages * PAGE_SIZE);
 559         up_read(&mm->mmap_sem);
 560
 561         return rc;
 562 }
 563
 564 int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
 565                        struct page **pages, size_t num_pages,
 566                        unsigned long start)
 567 {
 568         struct tee_shm *shm_arg = NULL;
 569         struct optee_msg_arg *msg_arg;
 570         u64 *pages_list;
 571         phys_addr_t msg_parg;
 572         int rc;
 573
 574         if (!num_pages)
 575                 return -EINVAL;
 576
 577         rc = check_mem_type(start, num_pages);
 578         if (rc)
 579                 return rc;
 580
 581         pages_list = optee_allocate_pages_list(num_pages);
 582         if (!pages_list)
 583                 return -ENOMEM;
 584
 585         shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
 586         if (IS_ERR(shm_arg)) {
 587                 rc = PTR_ERR(shm_arg);
 588                 goto out;
 589         }
 590
 591         optee_fill_pages_list(pages_list, pages, num_pages,
 592                               tee_shm_get_page_offset(shm));
 593
 594         msg_arg->cmd = OPTEE_MSG_CMD_REGISTER_SHM;
 595         msg_arg->params->attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
 596                                 OPTEE_MSG_ATTR_NONCONTIG;
 597         msg_arg->params->u.tmem.shm_ref = (unsigned long)shm;
 598         msg_arg->params->u.tmem.size = tee_shm_get_size(shm);
 599         /*
 600          * In the least bits of msg_arg->params->u.tmem.buf_ptr we
 601          * store buffer offset from 4k page, as described in OP-TEE ABI.
 602          */
 603         msg_arg->params->u.tmem.buf_ptr = virt_to_phys(pages_list) |
 604           (tee_shm_get_page_offset(shm) & (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));
 605
 606         if (optee_do_call_with_arg(ctx, msg_parg) ||
 607             msg_arg->ret != TEEC_SUCCESS)
 608                 rc = -EINVAL;
 609
 610         tee_shm_free(shm_arg);
 611 out:
 612         optee_free_pages_list(pages_list, num_pages);
 613         return rc;
 614 }
 615
 616 int optee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
 617 {
 618         struct tee_shm *shm_arg;
 619         struct optee_msg_arg *msg_arg;
 620         phys_addr_t msg_parg;
 621         int rc = 0;
 622
 623         shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
 624         if (IS_ERR(shm_arg))
 625                 return PTR_ERR(shm_arg);
 626
 627         msg_arg->cmd = OPTEE_MSG_CMD_UNREGISTER_SHM;
 628
 629         msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
 630         msg_arg->params[0].u.rmem.shm_ref = (unsigned long)shm;
 631
 632         if (optee_do_call_with_arg(ctx, msg_parg) ||
 633             msg_arg->ret != TEEC_SUCCESS)
 634                 rc = -EINVAL;
 635         tee_shm_free(shm_arg);
 636         return rc;
 637 }
 638
 639 int optee_shm_register_supp(struct tee_context *ctx, struct tee_shm *shm,
 640                             struct page **pages, size_t num_pages,
 641                             unsigned long start)
 642 {
 643         /*
 644          * We don't want to register supplicant memory in OP-TEE.
 645          * Instead information about it will be passed in RPC code.
 646          */
 647         return check_mem_type(start, num_pages);
 648 }
 649
 650 int optee_shm_unregister_supp(struct tee_context *ctx, struct tee_shm *shm)
 651 {
 652         return 0;
 653 }