drivers/tee/optee/rpc.c

   1 /*
   2  * Copyright (c) 2015-2016, 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/delay.h>
  18 #include <linux/device.h>
  19 #include <linux/slab.h>
  20 #include <linux/tee_drv.h>
  21 #include "optee_private.h"
  22 #include "optee_smc.h"
  23
  24 struct wq_entry {
  25         struct list_head link;
  26         struct completion c;
  27         u32 key;
  28 };
  29
  30 void optee_wait_queue_init(struct optee_wait_queue *priv)
  31 {
  32         mutex_init(&priv->mu);
  33         INIT_LIST_HEAD(&priv->db);
  34 }
  35
  36 void optee_wait_queue_exit(struct optee_wait_queue *priv)
  37 {
  38         mutex_destroy(&priv->mu);
  39 }
  40
  41 static void handle_rpc_func_cmd_get_time(struct optee_msg_arg *arg)
  42 {
  43         struct timespec64 ts;
  44
  45         if (arg->num_params != 1)
  46                 goto bad;
  47         if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
  48                         OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT)
  49                 goto bad;
  50
  51         ktime_get_real_ts64(&ts);
  52         arg->params[0].u.value.a = ts.tv_sec;
  53         arg->params[0].u.value.b = ts.tv_nsec;
  54
  55         arg->ret = TEEC_SUCCESS;
  56         return;
  57 bad:
  58         arg->ret = TEEC_ERROR_BAD_PARAMETERS;
  59 }
  60
  61 static struct wq_entry *wq_entry_get(struct optee_wait_queue *wq, u32 key)
  62 {
  63         struct wq_entry *w;
  64
  65         mutex_lock(&wq->mu);
  66
  67         list_for_each_entry(w, &wq->db, link)
  68                 if (w->key == key)
  69                         goto out;
  70
  71         w = kmalloc(sizeof(*w), GFP_KERNEL);
  72         if (w) {
  73                 init_completion(&w->c);
  74                 w->key = key;
  75                 list_add_tail(&w->link, &wq->db);
  76         }
  77 out:
  78         mutex_unlock(&wq->mu);
  79         return w;
  80 }
  81
  82 static void wq_sleep(struct optee_wait_queue *wq, u32 key)
  83 {
  84         struct wq_entry *w = wq_entry_get(wq, key);
  85
  86         if (w) {
  87                 wait_for_completion(&w->c);
  88                 mutex_lock(&wq->mu);
  89                 list_del(&w->link);
  90                 mutex_unlock(&wq->mu);
  91                 kfree(w);
  92         }
  93 }
  94
  95 static void wq_wakeup(struct optee_wait_queue *wq, u32 key)
  96 {
  97         struct wq_entry *w = wq_entry_get(wq, key);
  98
  99         if (w)
 100                 complete(&w->c);
 101 }
 102
 103 static void handle_rpc_func_cmd_wq(struct optee *optee,
 104                                    struct optee_msg_arg *arg)
 105 {
 106         if (arg->num_params != 1)
 107                 goto bad;
 108
 109         if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
 110                         OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
 111                 goto bad;
 112
 113         switch (arg->params[0].u.value.a) {
 114         case OPTEE_MSG_RPC_WAIT_QUEUE_SLEEP:
 115                 wq_sleep(&optee->wait_queue, arg->params[0].u.value.b);
 116                 break;
 117         case OPTEE_MSG_RPC_WAIT_QUEUE_WAKEUP:
 118                 wq_wakeup(&optee->wait_queue, arg->params[0].u.value.b);
 119                 break;
 120         default:
 121                 goto bad;
 122         }
 123
 124         arg->ret = TEEC_SUCCESS;
 125         return;
 126 bad:
 127         arg->ret = TEEC_ERROR_BAD_PARAMETERS;
 128 }
 129
 130 static void handle_rpc_func_cmd_wait(struct optee_msg_arg *arg)
 131 {
 132         u32 msec_to_wait;
 133
 134         if (arg->num_params != 1)
 135                 goto bad;
 136
 137         if ((arg->params[0].attr & OPTEE_MSG_ATTR_TYPE_MASK) !=
 138                         OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
 139                 goto bad;
 140
 141         msec_to_wait = arg->params[0].u.value.a;
 142
 143         /* Go to interruptible sleep */
 144         msleep_interruptible(msec_to_wait);
 145
 146         arg->ret = TEEC_SUCCESS;
 147         return;
 148 bad:
 149         arg->ret = TEEC_ERROR_BAD_PARAMETERS;
 150 }
 151
 152 static void handle_rpc_supp_cmd(struct tee_context *ctx,
 153                                 struct optee_msg_arg *arg)
 154 {
 155         struct tee_param *params;
 156
 157         arg->ret_origin = TEEC_ORIGIN_COMMS;
 158
 159         params = kmalloc_array(arg->num_params, sizeof(struct tee_param),
 160                                GFP_KERNEL);
 161         if (!params) {
 162                 arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
 163                 return;
 164         }
 165
 166         if (optee_from_msg_param(params, arg->num_params, arg->params)) {
 167                 arg->ret = TEEC_ERROR_BAD_PARAMETERS;
 168                 goto out;
 169         }
 170
 171         arg->ret = optee_supp_thrd_req(ctx, arg->cmd, arg->num_params, params);
 172
 173         if (optee_to_msg_param(arg->params, arg->num_params, params))
 174                 arg->ret = TEEC_ERROR_BAD_PARAMETERS;
 175 out:
 176         kfree(params);
 177 }
 178
 179 static struct tee_shm *cmd_alloc_suppl(struct tee_context *ctx, size_t sz)
 180 {
 181         u32 ret;
 182         struct tee_param param;
 183         struct optee *optee = tee_get_drvdata(ctx->teedev);
 184         struct tee_shm *shm;
 185
 186         param.attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
 187         param.u.value.a = OPTEE_MSG_RPC_SHM_TYPE_APPL;
 188         param.u.value.b = sz;
 189         param.u.value.c = 0;
 190
 191         ret = optee_supp_thrd_req(ctx, OPTEE_MSG_RPC_CMD_SHM_ALLOC, 1, &param);
 192         if (ret)
 193                 return ERR_PTR(-ENOMEM);
 194
 195         mutex_lock(&optee->supp.mutex);
 196         /* Increases count as secure world doesn't have a reference */
 197         shm = tee_shm_get_from_id(optee->supp.ctx, param.u.value.c);
 198         mutex_unlock(&optee->supp.mutex);
 199         return shm;
 200 }
 201
 202 static void handle_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
 203                                           struct optee_msg_arg *arg,
 204                                           struct optee_call_ctx *call_ctx)
 205 {
 206         phys_addr_t pa;
 207         struct tee_shm *shm;
 208         size_t sz;
 209         size_t n;
 210
 211         arg->ret_origin = TEEC_ORIGIN_COMMS;
 212
 213         if (!arg->num_params ||
 214             arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
 215                 arg->ret = TEEC_ERROR_BAD_PARAMETERS;
 216                 return;
 217         }
 218
 219         for (n = 1; n < arg->num_params; n++) {
 220                 if (arg->params[n].attr != OPTEE_MSG_ATTR_TYPE_NONE) {
 221                         arg->ret = TEEC_ERROR_BAD_PARAMETERS;
 222                         return;
 223                 }
 224         }
 225
 226         sz = arg->params[0].u.value.b;
 227         switch (arg->params[0].u.value.a) {
 228         case OPTEE_MSG_RPC_SHM_TYPE_APPL:
 229                 shm = cmd_alloc_suppl(ctx, sz);
 230                 break;
 231         case OPTEE_MSG_RPC_SHM_TYPE_KERNEL:
 232                 shm = tee_shm_alloc(ctx, sz, TEE_SHM_MAPPED);
 233                 break;
 234         default:
 235                 arg->ret = TEEC_ERROR_BAD_PARAMETERS;
 236                 return;
 237         }
 238
 239         if (IS_ERR(shm)) {
 240                 arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
 241                 return;
 242         }
 243
 244         if (tee_shm_get_pa(shm, 0, &pa)) {
 245                 arg->ret = TEEC_ERROR_BAD_PARAMETERS;
 246                 goto bad;
 247         }
 248
 249         sz = tee_shm_get_size(shm);
 250
 251         if (tee_shm_is_registered(shm)) {
 252                 struct page **pages;
 253                 u64 *pages_list;
 254                 size_t page_num;
 255
 256                 pages = tee_shm_get_pages(shm, &page_num);
 257                 if (!pages || !page_num) {
 258                         arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
 259                         goto bad;
 260                 }
 261
 262                 pages_list = optee_allocate_pages_list(page_num);
 263                 if (!pages_list) {
 264                         arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
 265                         goto bad;
 266                 }
 267
 268                 call_ctx->pages_list = pages_list;
 269                 call_ctx->num_entries = page_num;
 270
 271                 arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
 272                                       OPTEE_MSG_ATTR_NONCONTIG;
 273                 /*
 274                  * In the least bits of u.tmem.buf_ptr we store buffer offset
 275                  * from 4k page, as described in OP-TEE ABI.
 276                  */
 277                 arg->params[0].u.tmem.buf_ptr = virt_to_phys(pages_list) |
 278                         (tee_shm_get_page_offset(shm) &
 279                          (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));
 280                 arg->params[0].u.tmem.size = tee_shm_get_size(shm);
 281                 arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
 282
 283                 optee_fill_pages_list(pages_list, pages, page_num,
 284                                       tee_shm_get_page_offset(shm));
 285         } else {
 286                 arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT;
 287                 arg->params[0].u.tmem.buf_ptr = pa;
 288                 arg->params[0].u.tmem.size = sz;
 289                 arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
 290         }
 291
 292         arg->ret = TEEC_SUCCESS;
 293         return;
 294 bad:
 295         tee_shm_free(shm);
 296 }
 297
 298 static void cmd_free_suppl(struct tee_context *ctx, struct tee_shm *shm)
 299 {
 300         struct tee_param param;
 301
 302         param.attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
 303         param.u.value.a = OPTEE_MSG_RPC_SHM_TYPE_APPL;
 304         param.u.value.b = tee_shm_get_id(shm);
 305         param.u.value.c = 0;
 306
 307         /*
 308          * Match the tee_shm_get_from_id() in cmd_alloc_suppl() as secure
 309          * world has released its reference.
 310          *
 311          * It's better to do this before sending the request to supplicant
 312          * as we'd like to let the process doing the initial allocation to
 313          * do release the last reference too in order to avoid stacking
 314          * many pending fput() on the client process. This could otherwise
 315          * happen if secure world does many allocate and free in a single
 316          * invoke.
 317          */
 318         tee_shm_put(shm);
 319
 320         optee_supp_thrd_req(ctx, OPTEE_MSG_RPC_CMD_SHM_FREE, 1, &param);
 321 }
 322
 323 static void handle_rpc_func_cmd_shm_free(struct tee_context *ctx,
 324                                          struct optee_msg_arg *arg)
 325 {
 326         struct tee_shm *shm;
 327
 328         arg->ret_origin = TEEC_ORIGIN_COMMS;
 329
 330         if (arg->num_params != 1 ||
 331             arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
 332                 arg->ret = TEEC_ERROR_BAD_PARAMETERS;
 333                 return;
 334         }
 335
 336         shm = (struct tee_shm *)(unsigned long)arg->params[0].u.value.b;
 337         switch (arg->params[0].u.value.a) {
 338         case OPTEE_MSG_RPC_SHM_TYPE_APPL:
 339                 cmd_free_suppl(ctx, shm);
 340                 break;
 341         case OPTEE_MSG_RPC_SHM_TYPE_KERNEL:
 342                 tee_shm_free(shm);
 343                 break;
 344         default:
 345                 arg->ret = TEEC_ERROR_BAD_PARAMETERS;
 346         }
 347         arg->ret = TEEC_SUCCESS;
 348 }
 349
 350 static void free_pages_list(struct optee_call_ctx *call_ctx)
 351 {
 352         if (call_ctx->pages_list) {
 353                 optee_free_pages_list(call_ctx->pages_list,
 354                                       call_ctx->num_entries);
 355                 call_ctx->pages_list = NULL;
 356                 call_ctx->num_entries = 0;
 357         }
 358 }
 359
 360 void optee_rpc_finalize_call(struct optee_call_ctx *call_ctx)
 361 {
 362         free_pages_list(call_ctx);
 363 }
 364
 365 static void handle_rpc_func_cmd(struct tee_context *ctx, struct optee *optee,
 366                                 struct tee_shm *shm,
 367                                 struct optee_call_ctx *call_ctx)
 368 {
 369         struct optee_msg_arg *arg;
 370
 371         arg = tee_shm_get_va(shm, 0);
 372         if (IS_ERR(arg)) {
 373                 pr_err("%s: tee_shm_get_va %p failed\n", __func__, shm);
 374                 return;
 375         }
 376
 377         switch (arg->cmd) {
 378         case OPTEE_MSG_RPC_CMD_GET_TIME:
 379                 handle_rpc_func_cmd_get_time(arg);
 380                 break;
 381         case OPTEE_MSG_RPC_CMD_WAIT_QUEUE:
 382                 handle_rpc_func_cmd_wq(optee, arg);
 383                 break;
 384         case OPTEE_MSG_RPC_CMD_SUSPEND:
 385                 handle_rpc_func_cmd_wait(arg);
 386                 break;
 387         case OPTEE_MSG_RPC_CMD_SHM_ALLOC:
 388                 free_pages_list(call_ctx);
 389                 handle_rpc_func_cmd_shm_alloc(ctx, arg, call_ctx);
 390                 break;
 391         case OPTEE_MSG_RPC_CMD_SHM_FREE:
 392                 handle_rpc_func_cmd_shm_free(ctx, arg);
 393                 break;
 394         default:
 395                 handle_rpc_supp_cmd(ctx, arg);
 396         }
 397 }
 398
 399 /**
 400  * optee_handle_rpc() - handle RPC from secure world
 401  * @ctx:        context doing the RPC
 402  * @param:      value of registers for the RPC
 403  * @call_ctx:   call context. Preserved during one OP-TEE invocation
 404  *
 405  * Result of RPC is written back into @param.
 406  */
 407 void optee_handle_rpc(struct tee_context *ctx, struct optee_rpc_param *param,
 408                       struct optee_call_ctx *call_ctx)
 409 {
 410         struct tee_device *teedev = ctx->teedev;
 411         struct optee *optee = tee_get_drvdata(teedev);
 412         struct tee_shm *shm;
 413         phys_addr_t pa;
 414
 415         switch (OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0)) {
 416         case OPTEE_SMC_RPC_FUNC_ALLOC:
 417                 shm = tee_shm_alloc(ctx, param->a1, TEE_SHM_MAPPED);
 418                 if (!IS_ERR(shm) && !tee_shm_get_pa(shm, 0, &pa)) {
 419                         reg_pair_from_64(&param->a1, &param->a2, pa);
 420                         reg_pair_from_64(&param->a4, &param->a5,
 421                                          (unsigned long)shm);
 422                 } else {
 423                         param->a1 = 0;
 424                         param->a2 = 0;
 425                         param->a4 = 0;
 426                         param->a5 = 0;
 427                 }
 428                 break;
 429         case OPTEE_SMC_RPC_FUNC_FREE:
 430                 shm = reg_pair_to_ptr(param->a1, param->a2);
 431                 tee_shm_free(shm);
 432                 break;
 433         case OPTEE_SMC_RPC_FUNC_FOREIGN_INTR:
 434                 /*
 435                  * A foreign interrupt was raised while secure world was
 436                  * executing, since they are handled in Linux a dummy RPC is
 437                  * performed to let Linux take the interrupt through the normal
 438                  * vector.
 439                  */
 440                 break;
 441         case OPTEE_SMC_RPC_FUNC_CMD:
 442                 shm = reg_pair_to_ptr(param->a1, param->a2);
 443                 handle_rpc_func_cmd(ctx, optee, shm, call_ctx);
 444                 break;
 445         default:
 446                 pr_warn("Unknown RPC func 0x%x\n",
 447                         (u32)OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0));
 448                 break;
 449         }
 450
 451         param->a0 = OPTEE_SMC_CALL_RETURN_FROM_RPC;
 452 }