drivers/tee/optee/core.c

   1 /*
   2  * Copyright (c) 2015, Linaro Limited
   3  *
   4  * This software is licensed under the terms of the GNU General Public
   5  * License version 2, as published by the Free Software Foundation, and
   6  * may be copied, distributed, and modified under those terms.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  */
  14
  15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  16
  17 #include <linux/arm-smccc.h>
  18 #include <linux/errno.h>
  19 #include <linux/io.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22 #include <linux/of_platform.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/slab.h>
  25 #include <linux/string.h>
  26 #include <linux/tee_drv.h>
  27 #include <linux/types.h>
  28 #include <linux/uaccess.h>
  29 #include "optee_private.h"
  30 #include "optee_smc.h"
  31
  32 #define DRIVER_NAME "optee"
  33
  34 #define OPTEE_SHM_NUM_PRIV_PAGES        1
  35
  36 /**
  37  * optee_from_msg_param() - convert from OPTEE_MSG parameters to
  38  *                          struct tee_param
  39  * @params:     subsystem internal parameter representation
  40  * @num_params: number of elements in the parameter arrays
  41  * @msg_params: OPTEE_MSG parameters
  42  * Returns 0 on success or <0 on failure
  43  */
  44 int optee_from_msg_param(struct tee_param *params, size_t num_params,
  45                          const struct optee_msg_param *msg_params)
  46 {
  47         int rc;
  48         size_t n;
  49         struct tee_shm *shm;
  50         phys_addr_t pa;
  51
  52         for (n = 0; n < num_params; n++) {
  53                 struct tee_param *p = params + n;
  54                 const struct optee_msg_param *mp = msg_params + n;
  55                 u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;
  56
  57                 switch (attr) {
  58                 case OPTEE_MSG_ATTR_TYPE_NONE:
  59                         p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
  60                         memset(&p->u, 0, sizeof(p->u));
  61                         break;
  62                 case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
  63                 case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
  64                 case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
  65                         p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT +
  66                                   attr - OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
  67                         p->u.value.a = mp->u.value.a;
  68                         p->u.value.b = mp->u.value.b;
  69                         p->u.value.c = mp->u.value.c;
  70                         break;
  71                 case OPTEE_MSG_ATTR_TYPE_TMEM_INPUT:
  72                 case OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT:
  73                 case OPTEE_MSG_ATTR_TYPE_TMEM_INOUT:
  74                         p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
  75                                   attr - OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
  76                         p->u.memref.size = mp->u.tmem.size;
  77                         shm = (struct tee_shm *)(unsigned long)
  78                                 mp->u.tmem.shm_ref;
  79                         if (!shm) {
  80                                 p->u.memref.shm_offs = 0;
  81                                 p->u.memref.shm = NULL;
  82                                 break;
  83                         }
  84                         rc = tee_shm_get_pa(shm, 0, &pa);
  85                         if (rc)
  86                                 return rc;
  87                         p->u.memref.shm_offs = mp->u.tmem.buf_ptr - pa;
  88                         p->u.memref.shm = shm;
  89                         break;
  90                 default:
  91                         return -EINVAL;
  92                 }
  93         }
  94         return 0;
  95 }
  96
  97 /**
  98  * optee_to_msg_param() - convert from struct tee_params to OPTEE_MSG parameters
  99  * @msg_params: OPTEE_MSG parameters
 100  * @num_params: number of elements in the parameter arrays
 101  * @params:     subsystem itnernal parameter representation
 102  * Returns 0 on success or <0 on failure
 103  */
 104 int optee_to_msg_param(struct optee_msg_param *msg_params, size_t num_params,
 105                        const struct tee_param *params)
 106 {
 107         int rc;
 108         size_t n;
 109         phys_addr_t pa;
 110
 111         for (n = 0; n < num_params; n++) {
 112                 const struct tee_param *p = params + n;
 113                 struct optee_msg_param *mp = msg_params + n;
 114
 115                 switch (p->attr) {
 116                 case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
 117                         mp->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
 118                         memset(&mp->u, 0, sizeof(mp->u));
 119                         break;
 120                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
 121                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
 122                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
 123                         mp->attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT + p->attr -
 124                                    TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
 125                         mp->u.value.a = p->u.value.a;
 126                         mp->u.value.b = p->u.value.b;
 127                         mp->u.value.c = p->u.value.c;
 128                         break;
 129                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
 130                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
 131                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
 132                         mp->attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT +
 133                                    p->attr -
 134                                    TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
 135                         mp->u.tmem.shm_ref = (unsigned long)p->u.memref.shm;
 136                         mp->u.tmem.size = p->u.memref.size;
 137                         if (!p->u.memref.shm) {
 138                                 mp->u.tmem.buf_ptr = 0;
 139                                 break;
 140                         }
 141                         rc = tee_shm_get_pa(p->u.memref.shm,
 142                                             p->u.memref.shm_offs, &pa);
 143                         if (rc)
 144                                 return rc;
 145                         mp->u.tmem.buf_ptr = pa;
 146                         mp->attr |= OPTEE_MSG_ATTR_CACHE_PREDEFINED <<
 147                                         OPTEE_MSG_ATTR_CACHE_SHIFT;
 148                         break;
 149                 default:
 150                         return -EINVAL;
 151                 }
 152         }
 153         return 0;
 154 }
 155
 156 static void optee_get_version(struct tee_device *teedev,
 157                               struct tee_ioctl_version_data *vers)
 158 {
 159         struct tee_ioctl_version_data v = {
 160                 .impl_id = TEE_IMPL_ID_OPTEE,
 161                 .impl_caps = TEE_OPTEE_CAP_TZ,
 162                 .gen_caps = TEE_GEN_CAP_GP,
 163         };
 164         *vers = v;
 165 }
 166
 167 static int optee_open(struct tee_context *ctx)
 168 {
 169         struct optee_context_data *ctxdata;
 170         struct tee_device *teedev = ctx->teedev;
 171         struct optee *optee = tee_get_drvdata(teedev);
 172
 173         ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
 174         if (!ctxdata)
 175                 return -ENOMEM;
 176
 177         if (teedev == optee->supp_teedev) {
 178                 bool busy = true;
 179
 180                 mutex_lock(&optee->supp.ctx_mutex);
 181                 if (!optee->supp.ctx) {
 182                         busy = false;
 183                         optee->supp.ctx = ctx;
 184                 }
 185                 mutex_unlock(&optee->supp.ctx_mutex);
 186                 if (busy) {
 187                         kfree(ctxdata);
 188                         return -EBUSY;
 189                 }
 190         }
 191
 192         mutex_init(&ctxdata->mutex);
 193         INIT_LIST_HEAD(&ctxdata->sess_list);
 194
 195         ctx->data = ctxdata;
 196         return 0;
 197 }
 198
 199 static void optee_release(struct tee_context *ctx)
 200 {
 201         struct optee_context_data *ctxdata = ctx->data;
 202         struct tee_device *teedev = ctx->teedev;
 203         struct optee *optee = tee_get_drvdata(teedev);
 204         struct tee_shm *shm;
 205         struct optee_msg_arg *arg = NULL;
 206         phys_addr_t parg;
 207         struct optee_session *sess;
 208         struct optee_session *sess_tmp;
 209
 210         if (!ctxdata)
 211                 return;
 212
 213         shm = tee_shm_alloc(ctx, sizeof(struct optee_msg_arg), TEE_SHM_MAPPED);
 214         if (!IS_ERR(shm)) {
 215                 arg = tee_shm_get_va(shm, 0);
 216                 /*
 217                  * If va2pa fails for some reason, we can't call into
 218                  * secure world, only free the memory. Secure OS will leak
 219                  * sessions and finally refuse more sessions, but we will
 220                  * at least let normal world reclaim its memory.
 221                  */
 222                 if (!IS_ERR(arg))
 223                         if (tee_shm_va2pa(shm, arg, &parg))
 224                                 arg = NULL; /* prevent usage of parg below */
 225         }
 226
 227         list_for_each_entry_safe(sess, sess_tmp, &ctxdata->sess_list,
 228                                  list_node) {
 229                 list_del(&sess->list_node);
 230                 if (!IS_ERR_OR_NULL(arg)) {
 231                         memset(arg, 0, sizeof(*arg));
 232                         arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
 233                         arg->session = sess->session_id;
 234                         optee_do_call_with_arg(ctx, parg);
 235                 }
 236                 kfree(sess);
 237         }
 238         kfree(ctxdata);
 239
 240         if (!IS_ERR(shm))
 241                 tee_shm_free(shm);
 242
 243         ctx->data = NULL;
 244
 245         if (teedev == optee->supp_teedev) {
 246                 mutex_lock(&optee->supp.ctx_mutex);
 247                 optee->supp.ctx = NULL;
 248                 mutex_unlock(&optee->supp.ctx_mutex);
 249         }
 250 }
 251
 252 static const struct tee_driver_ops optee_ops = {
 253         .get_version = optee_get_version,
 254         .open = optee_open,
 255         .release = optee_release,
 256         .open_session = optee_open_session,
 257         .close_session = optee_close_session,
 258         .invoke_func = optee_invoke_func,
 259         .cancel_req = optee_cancel_req,
 260 };
 261
 262 static const struct tee_desc optee_desc = {
 263         .name = DRIVER_NAME "-clnt",
 264         .ops = &optee_ops,
 265         .owner = THIS_MODULE,
 266 };
 267
 268 static const struct tee_driver_ops optee_supp_ops = {
 269         .get_version = optee_get_version,
 270         .open = optee_open,
 271         .release = optee_release,
 272         .supp_recv = optee_supp_recv,
 273         .supp_send = optee_supp_send,
 274 };
 275
 276 static const struct tee_desc optee_supp_desc = {
 277         .name = DRIVER_NAME "-supp",
 278         .ops = &optee_supp_ops,
 279         .owner = THIS_MODULE,
 280         .flags = TEE_DESC_PRIVILEGED,
 281 };
 282
 283 static bool optee_msg_api_uid_is_optee_api(optee_invoke_fn *invoke_fn)
 284 {
 285         struct arm_smccc_res res;
 286
 287         invoke_fn(OPTEE_SMC_CALLS_UID, 0, 0, 0, 0, 0, 0, 0, &res);
 288
 289         if (res.a0 == OPTEE_MSG_UID_0 && res.a1 == OPTEE_MSG_UID_1 &&
 290             res.a2 == OPTEE_MSG_UID_2 && res.a3 == OPTEE_MSG_UID_3)
 291                 return true;
 292         return false;
 293 }
 294
 295 static bool optee_msg_api_revision_is_compatible(optee_invoke_fn *invoke_fn)
 296 {
 297         union {
 298                 struct arm_smccc_res smccc;
 299                 struct optee_smc_calls_revision_result result;
 300         } res;
 301
 302         invoke_fn(OPTEE_SMC_CALLS_REVISION, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
 303
 304         if (res.result.major == OPTEE_MSG_REVISION_MAJOR &&
 305             (int)res.result.minor >= OPTEE_MSG_REVISION_MINOR)
 306                 return true;
 307         return false;
 308 }
 309
 310 static bool optee_msg_exchange_capabilities(optee_invoke_fn *invoke_fn,
 311                                             u32 *sec_caps)
 312 {
 313         union {
 314                 struct arm_smccc_res smccc;
 315                 struct optee_smc_exchange_capabilities_result result;
 316         } res;
 317         u32 a1 = 0;
 318
 319         /*
 320          * TODO This isn't enough to tell if it's UP system (from kernel
 321          * point of view) or not, is_smp() returns the the information
 322          * needed, but can't be called directly from here.
 323          */
 324         if (!IS_ENABLED(CONFIG_SMP) || nr_cpu_ids == 1)
 325                 a1 |= OPTEE_SMC_NSEC_CAP_UNIPROCESSOR;
 326
 327         invoke_fn(OPTEE_SMC_EXCHANGE_CAPABILITIES, a1, 0, 0, 0, 0, 0, 0,
 328                   &res.smccc);
 329
 330         if (res.result.status != OPTEE_SMC_RETURN_OK)
 331                 return false;
 332
 333         *sec_caps = res.result.capabilities;
 334         return true;
 335 }
 336
 337 static struct tee_shm_pool *
 338 optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm)
 339 {
 340         union {
 341                 struct arm_smccc_res smccc;
 342                 struct optee_smc_get_shm_config_result result;
 343         } res;
 344         struct tee_shm_pool *pool;
 345         unsigned long vaddr;
 346         phys_addr_t paddr;
 347         size_t size;
 348         phys_addr_t begin;
 349         phys_addr_t end;
 350         void *va;
 351         struct tee_shm_pool_mem_info priv_info;
 352         struct tee_shm_pool_mem_info dmabuf_info;
 353
 354         invoke_fn(OPTEE_SMC_GET_SHM_CONFIG, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
 355         if (res.result.status != OPTEE_SMC_RETURN_OK) {
 356                 pr_info("shm service not available\n");
 357                 return ERR_PTR(-ENOENT);
 358         }
 359
 360         if (res.result.settings != OPTEE_SMC_SHM_CACHED) {
 361                 pr_err("only normal cached shared memory supported\n");
 362                 return ERR_PTR(-EINVAL);
 363         }
 364
 365         begin = roundup(res.result.start, PAGE_SIZE);
 366         end = rounddown(res.result.start + res.result.size, PAGE_SIZE);
 367         paddr = begin;
 368         size = end - begin;
 369
 370         if (size < 2 * OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE) {
 371                 pr_err("too small shared memory area\n");
 372                 return ERR_PTR(-EINVAL);
 373         }
 374
 375         va = memremap(paddr, size, MEMREMAP_WB);
 376         if (!va) {
 377                 pr_err("shared memory ioremap failed\n");
 378                 return ERR_PTR(-EINVAL);
 379         }
 380         vaddr = (unsigned long)va;
 381
 382         priv_info.vaddr = vaddr;
 383         priv_info.paddr = paddr;
 384         priv_info.size = OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
 385         dmabuf_info.vaddr = vaddr + OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
 386         dmabuf_info.paddr = paddr + OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
 387         dmabuf_info.size = size - OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
 388
 389         pool = tee_shm_pool_alloc_res_mem(&priv_info, &dmabuf_info);
 390         if (IS_ERR(pool)) {
 391                 memunmap(va);
 392                 goto out;
 393         }
 394
 395         *memremaped_shm = va;
 396 out:
 397         return pool;
 398 }
 399
 400 /* Simple wrapper functions to be able to use a function pointer */
 401 static void optee_smccc_smc(unsigned long a0, unsigned long a1,
 402                             unsigned long a2, unsigned long a3,
 403                             unsigned long a4, unsigned long a5,
 404                             unsigned long a6, unsigned long a7,
 405                             struct arm_smccc_res *res)
 406 {
 407         arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res);
 408 }
 409
 410 static void optee_smccc_hvc(unsigned long a0, unsigned long a1,
 411                             unsigned long a2, unsigned long a3,
 412                             unsigned long a4, unsigned long a5,
 413                             unsigned long a6, unsigned long a7,
 414                             struct arm_smccc_res *res)
 415 {
 416         arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res);
 417 }
 418
 419 static optee_invoke_fn *get_invoke_func(struct device_node *np)
 420 {
 421         const char *method;
 422
 423         pr_info("probing for conduit method from DT.\n");
 424
 425         if (of_property_read_string(np, "method", &method)) {
 426                 pr_warn("missing \"method\" property\n");
 427                 return ERR_PTR(-ENXIO);
 428         }
 429
 430         if (!strcmp("hvc", method))
 431                 return optee_smccc_hvc;
 432         else if (!strcmp("smc", method))
 433                 return optee_smccc_smc;
 434
 435         pr_warn("invalid \"method\" property: %s\n", method);
 436         return ERR_PTR(-EINVAL);
 437 }
 438
 439 static struct optee *optee_probe(struct device_node *np)
 440 {
 441         optee_invoke_fn *invoke_fn;
 442         struct tee_shm_pool *pool;
 443         struct optee *optee = NULL;
 444         void *memremaped_shm = NULL;
 445         struct tee_device *teedev;
 446         u32 sec_caps;
 447         int rc;
 448
 449         invoke_fn = get_invoke_func(np);
 450         if (IS_ERR(invoke_fn))
 451                 return (void *)invoke_fn;
 452
 453         if (!optee_msg_api_uid_is_optee_api(invoke_fn)) {
 454                 pr_warn("api uid mismatch\n");
 455                 return ERR_PTR(-EINVAL);
 456         }
 457
 458         if (!optee_msg_api_revision_is_compatible(invoke_fn)) {
 459                 pr_warn("api revision mismatch\n");
 460                 return ERR_PTR(-EINVAL);
 461         }
 462
 463         if (!optee_msg_exchange_capabilities(invoke_fn, &sec_caps)) {
 464                 pr_warn("capabilities mismatch\n");
 465                 return ERR_PTR(-EINVAL);
 466         }
 467
 468         /*
 469          * We have no other option for shared memory, if secure world
 470          * doesn't have any reserved memory we can use we can't continue.
 471          */
 472         if (!(sec_caps & OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM))
 473                 return ERR_PTR(-EINVAL);
 474
 475         pool = optee_config_shm_memremap(invoke_fn, &memremaped_shm);
 476         if (IS_ERR(pool))
 477                 return (void *)pool;
 478
 479         optee = kzalloc(sizeof(*optee), GFP_KERNEL);
 480         if (!optee) {
 481                 rc = -ENOMEM;
 482                 goto err;
 483         }
 484
 485         optee->invoke_fn = invoke_fn;
 486
 487         teedev = tee_device_alloc(&optee_desc, NULL, pool, optee);
 488         if (IS_ERR(teedev)) {
 489                 rc = PTR_ERR(teedev);
 490                 goto err;
 491         }
 492         optee->teedev = teedev;
 493
 494         teedev = tee_device_alloc(&optee_supp_desc, NULL, pool, optee);
 495         if (IS_ERR(teedev)) {
 496                 rc = PTR_ERR(teedev);
 497                 goto err;
 498         }
 499         optee->supp_teedev = teedev;
 500
 501         rc = tee_device_register(optee->teedev);
 502         if (rc)
 503                 goto err;
 504
 505         rc = tee_device_register(optee->supp_teedev);
 506         if (rc)
 507                 goto err;
 508
 509         mutex_init(&optee->call_queue.mutex);
 510         INIT_LIST_HEAD(&optee->call_queue.waiters);
 511         optee_wait_queue_init(&optee->wait_queue);
 512         optee_supp_init(&optee->supp);
 513         optee->memremaped_shm = memremaped_shm;
 514         optee->pool = pool;
 515
 516         optee_enable_shm_cache(optee);
 517
 518         pr_info("initialized driver\n");
 519         return optee;
 520 err:
 521         if (optee) {
 522                 /*
 523                  * tee_device_unregister() is safe to call even if the
 524                  * devices hasn't been registered with
 525                  * tee_device_register() yet.
 526                  */
 527                 tee_device_unregister(optee->supp_teedev);
 528                 tee_device_unregister(optee->teedev);
 529                 kfree(optee);
 530         }
 531         if (pool)
 532                 tee_shm_pool_free(pool);
 533         if (memremaped_shm)
 534                 memunmap(memremaped_shm);
 535         return ERR_PTR(rc);
 536 }
 537
 538 static void optee_remove(struct optee *optee)
 539 {
 540         /*
 541          * Ask OP-TEE to free all cached shared memory objects to decrease
 542          * reference counters and also avoid wild pointers in secure world
 543          * into the old shared memory range.
 544          */
 545         optee_disable_shm_cache(optee);
 546
 547         /*
 548          * The two devices has to be unregistered before we can free the
 549          * other resources.
 550          */
 551         tee_device_unregister(optee->supp_teedev);
 552         tee_device_unregister(optee->teedev);
 553
 554         tee_shm_pool_free(optee->pool);
 555         if (optee->memremaped_shm)
 556                 memunmap(optee->memremaped_shm);
 557         optee_wait_queue_exit(&optee->wait_queue);
 558         optee_supp_uninit(&optee->supp);
 559         mutex_destroy(&optee->call_queue.mutex);
 560
 561         kfree(optee);
 562 }
 563
 564 static const struct of_device_id optee_match[] = {
 565         { .compatible = "linaro,optee-tz" },
 566         {},
 567 };
 568
 569 static struct optee *optee_svc;
 570
 571 static int __init optee_driver_init(void)
 572 {
 573         struct device_node *fw_np;
 574         struct device_node *np;
 575         struct optee *optee;
 576
 577         /* Node is supposed to be below /firmware */
 578         fw_np = of_find_node_by_name(NULL, "firmware");
 579         if (!fw_np)
 580                 return -ENODEV;
 581
 582         np = of_find_matching_node(fw_np, optee_match);
 583         if (!np || !of_device_is_available(np)) {
 584                 of_node_put(np);
 585                 return -ENODEV;
 586         }
 587
 588         optee = optee_probe(np);
 589         of_node_put(np);
 590
 591         if (IS_ERR(optee))
 592                 return PTR_ERR(optee);
 593
 594         optee_svc = optee;
 595
 596         return 0;
 597 }
 598 module_init(optee_driver_init);
 599
 600 static void __exit optee_driver_exit(void)
 601 {
 602         struct optee *optee = optee_svc;
 603
 604         optee_svc = NULL;
 605         if (optee)
 606                 optee_remove(optee);
 607 }
 608 module_exit(optee_driver_exit);
 609
 610 MODULE_AUTHOR("Linaro");
 611 MODULE_DESCRIPTION("OP-TEE driver");
 612 MODULE_SUPPORTED_DEVICE("");
 613 MODULE_VERSION("1.0");
 614 MODULE_LICENSE("GPL v2");