drivers/tee/amdtee/core.c

   1 // SPDX-License-Identifier: MIT
   2 /*
   3  * Copyright 2019 Advanced Micro Devices, Inc.
   4  */
   5
   6 #include <linux/errno.h>
   7 #include <linux/io.h>
   8 #include <linux/module.h>
   9 #include <linux/slab.h>
  10 #include <linux/string.h>
  11 #include <linux/device.h>
  12 #include <linux/tee_drv.h>
  13 #include <linux/types.h>
  14 #include <linux/mm.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/firmware.h>
  17 #include "amdtee_private.h"
  18 #include "../tee_private.h"
  19 #include <linux/psp-tee.h>
  20
  21 static struct amdtee_driver_data *drv_data;
  22 static DEFINE_MUTEX(session_list_mutex);
  23
  24 static void amdtee_get_version(struct tee_device *teedev,
  25                                struct tee_ioctl_version_data *vers)
  26 {
  27         struct tee_ioctl_version_data v = {
  28                 .impl_id = TEE_IMPL_ID_AMDTEE,
  29                 .impl_caps = 0,
  30                 .gen_caps = TEE_GEN_CAP_GP,
  31         };
  32         *vers = v;
  33 }
  34
  35 static int amdtee_open(struct tee_context *ctx)
  36 {
  37         struct amdtee_context_data *ctxdata;
  38
  39         ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
  40         if (!ctxdata)
  41                 return -ENOMEM;
  42
  43         INIT_LIST_HEAD(&ctxdata->sess_list);
  44         INIT_LIST_HEAD(&ctxdata->shm_list);
  45         mutex_init(&ctxdata->shm_mutex);
  46
  47         ctx->data = ctxdata;
  48         return 0;
  49 }
  50
  51 static void release_session(struct amdtee_session *sess)
  52 {
  53         int i;
  54
  55         /* Close any open session */
  56         for (i = 0; i < TEE_NUM_SESSIONS; ++i) {
  57                 /* Check if session entry 'i' is valid */
  58                 if (!test_bit(i, sess->sess_mask))
  59                         continue;
  60
  61                 handle_close_session(sess->ta_handle, sess->session_info[i]);
  62                 handle_unload_ta(sess->ta_handle);
  63         }
  64
  65         kfree(sess);
  66 }
  67
  68 static void amdtee_release(struct tee_context *ctx)
  69 {
  70         struct amdtee_context_data *ctxdata = ctx->data;
  71
  72         if (!ctxdata)
  73                 return;
  74
  75         while (true) {
  76                 struct amdtee_session *sess;
  77
  78                 sess = list_first_entry_or_null(&ctxdata->sess_list,
  79                                                 struct amdtee_session,
  80                                                 list_node);
  81
  82                 if (!sess)
  83                         break;
  84
  85                 list_del(&sess->list_node);
  86                 release_session(sess);
  87         }
  88         mutex_destroy(&ctxdata->shm_mutex);
  89         kfree(ctxdata);
  90
  91         ctx->data = NULL;
  92 }
  93
  94 /**
  95  * alloc_session() - Allocate a session structure
  96  * @ctxdata:    TEE Context data structure
  97  * @session:    Session ID for which 'struct amdtee_session' structure is to be
  98  *              allocated.
  99  *
 100  * Scans the TEE context's session list to check if TA is already loaded in to
 101  * TEE. If yes, returns the 'session' structure for that TA. Else allocates,
 102  * initializes a new 'session' structure and adds it to context's session list.
 103  *
 104  * The caller must hold a mutex.
 105  *
 106  * Returns:
 107  * 'struct amdtee_session *' on success and NULL on failure.
 108  */
 109 static struct amdtee_session *alloc_session(struct amdtee_context_data *ctxdata,
 110                                             u32 session)
 111 {
 112         struct amdtee_session *sess;
 113         u32 ta_handle = get_ta_handle(session);
 114
 115         /* Scan session list to check if TA is already loaded in to TEE */
 116         list_for_each_entry(sess, &ctxdata->sess_list, list_node)
 117                 if (sess->ta_handle == ta_handle) {
 118                         kref_get(&sess->refcount);
 119                         return sess;
 120                 }
 121
 122         /* Allocate a new session and add to list */
 123         sess = kzalloc(sizeof(*sess), GFP_KERNEL);
 124         if (sess) {
 125                 sess->ta_handle = ta_handle;
 126                 kref_init(&sess->refcount);
 127                 spin_lock_init(&sess->lock);
 128                 list_add(&sess->list_node, &ctxdata->sess_list);
 129         }
 130
 131         return sess;
 132 }
 133
 134 /* Requires mutex to be held */
 135 static struct amdtee_session *find_session(struct amdtee_context_data *ctxdata,
 136                                            u32 session)
 137 {
 138         u32 ta_handle = get_ta_handle(session);
 139         u32 index = get_session_index(session);
 140         struct amdtee_session *sess;
 141
 142         if (index >= TEE_NUM_SESSIONS)
 143                 return NULL;
 144
 145         list_for_each_entry(sess, &ctxdata->sess_list, list_node)
 146                 if (ta_handle == sess->ta_handle &&
 147                     test_bit(index, sess->sess_mask))
 148                         return sess;
 149
 150         return NULL;
 151 }
 152
 153 u32 get_buffer_id(struct tee_shm *shm)
 154 {
 155         struct amdtee_context_data *ctxdata = shm->ctx->data;
 156         struct amdtee_shm_data *shmdata;
 157         u32 buf_id = 0;
 158
 159         mutex_lock(&ctxdata->shm_mutex);
 160         list_for_each_entry(shmdata, &ctxdata->shm_list, shm_node)
 161                 if (shmdata->kaddr == shm->kaddr) {
 162                         buf_id = shmdata->buf_id;
 163                         break;
 164                 }
 165         mutex_unlock(&ctxdata->shm_mutex);
 166
 167         return buf_id;
 168 }
 169
 170 static DEFINE_MUTEX(drv_mutex);
 171 static int copy_ta_binary(struct tee_context *ctx, void *ptr, void **ta,
 172                           size_t *ta_size)
 173 {
 174         const struct firmware *fw;
 175         char fw_name[TA_PATH_MAX];
 176         struct {
 177                 u32 lo;
 178                 u16 mid;
 179                 u16 hi_ver;
 180                 u8 seq_n[8];
 181         } *uuid = ptr;
 182         int n, rc = 0;
 183
 184         n = snprintf(fw_name, TA_PATH_MAX,
 185                      "%s/%08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x.bin",
 186                      TA_LOAD_PATH, uuid->lo, uuid->mid, uuid->hi_ver,
 187                      uuid->seq_n[0], uuid->seq_n[1],
 188                      uuid->seq_n[2], uuid->seq_n[3],
 189                      uuid->seq_n[4], uuid->seq_n[5],
 190                      uuid->seq_n[6], uuid->seq_n[7]);
 191         if (n < 0 || n >= TA_PATH_MAX) {
 192                 pr_err("failed to get firmware name\n");
 193                 return -EINVAL;
 194         }
 195
 196         mutex_lock(&drv_mutex);
 197         n = request_firmware(&fw, fw_name, &ctx->teedev->dev);
 198         if (n) {
 199                 pr_err("failed to load firmware %s\n", fw_name);
 200                 rc = -ENOMEM;
 201                 goto unlock;
 202         }
 203
 204         *ta_size = roundup(fw->size, PAGE_SIZE);
 205         *ta = (void *)__get_free_pages(GFP_KERNEL, get_order(*ta_size));
 206         if (IS_ERR(*ta)) {
 207                 pr_err("%s: get_free_pages failed 0x%llx\n", __func__,
 208                        (u64)*ta);
 209                 rc = -ENOMEM;
 210                 goto rel_fw;
 211         }
 212
 213         memcpy(*ta, fw->data, fw->size);
 214 rel_fw:
 215         release_firmware(fw);
 216 unlock:
 217         mutex_unlock(&drv_mutex);
 218         return rc;
 219 }
 220
 221 static void destroy_session(struct kref *ref)
 222 {
 223         struct amdtee_session *sess = container_of(ref, struct amdtee_session,
 224                                                    refcount);
 225
 226         mutex_lock(&session_list_mutex);
 227         list_del(&sess->list_node);
 228         mutex_unlock(&session_list_mutex);
 229         kfree(sess);
 230 }
 231
 232 int amdtee_open_session(struct tee_context *ctx,
 233                         struct tee_ioctl_open_session_arg *arg,
 234                         struct tee_param *param)
 235 {
 236         struct amdtee_context_data *ctxdata = ctx->data;
 237         struct amdtee_session *sess = NULL;
 238         u32 session_info, ta_handle;
 239         size_t ta_size;
 240         int rc, i;
 241         void *ta;
 242
 243         if (arg->clnt_login != TEE_IOCTL_LOGIN_PUBLIC) {
 244                 pr_err("unsupported client login method\n");
 245                 return -EINVAL;
 246         }
 247
 248         rc = copy_ta_binary(ctx, &arg->uuid[0], &ta, &ta_size);
 249         if (rc) {
 250                 pr_err("failed to copy TA binary\n");
 251                 return rc;
 252         }
 253
 254         /* Load the TA binary into TEE environment */
 255         handle_load_ta(ta, ta_size, arg);
 256         if (arg->ret != TEEC_SUCCESS)
 257                 goto out;
 258
 259         ta_handle = get_ta_handle(arg->session);
 260
 261         mutex_lock(&session_list_mutex);
 262         sess = alloc_session(ctxdata, arg->session);
 263         mutex_unlock(&session_list_mutex);
 264
 265         if (!sess) {
 266                 handle_unload_ta(ta_handle);
 267                 rc = -ENOMEM;
 268                 goto out;
 269         }
 270
 271         /* Find an empty session index for the given TA */
 272         spin_lock(&sess->lock);
 273         i = find_first_zero_bit(sess->sess_mask, TEE_NUM_SESSIONS);
 274         if (i < TEE_NUM_SESSIONS)
 275                 set_bit(i, sess->sess_mask);
 276         spin_unlock(&sess->lock);
 277
 278         if (i >= TEE_NUM_SESSIONS) {
 279                 pr_err("reached maximum session count %d\n", TEE_NUM_SESSIONS);
 280                 handle_unload_ta(ta_handle);
 281                 kref_put(&sess->refcount, destroy_session);
 282                 rc = -ENOMEM;
 283                 goto out;
 284         }
 285
 286         /* Open session with loaded TA */
 287         handle_open_session(arg, &session_info, param);
 288         if (arg->ret != TEEC_SUCCESS) {
 289                 pr_err("open_session failed %d\n", arg->ret);
 290                 spin_lock(&sess->lock);
 291                 clear_bit(i, sess->sess_mask);
 292                 spin_unlock(&sess->lock);
 293                 handle_unload_ta(ta_handle);
 294                 kref_put(&sess->refcount, destroy_session);
 295                 goto out;
 296         }
 297
 298         sess->session_info[i] = session_info;
 299         set_session_id(ta_handle, i, &arg->session);
 300 out:
 301         free_pages((u64)ta, get_order(ta_size));
 302         return rc;
 303 }
 304
 305 int amdtee_close_session(struct tee_context *ctx, u32 session)
 306 {
 307         struct amdtee_context_data *ctxdata = ctx->data;
 308         u32 i, ta_handle, session_info;
 309         struct amdtee_session *sess;
 310
 311         pr_debug("%s: sid = 0x%x\n", __func__, session);
 312
 313         /*
 314          * Check that the session is valid and clear the session
 315          * usage bit
 316          */
 317         mutex_lock(&session_list_mutex);
 318         sess = find_session(ctxdata, session);
 319         if (sess) {
 320                 ta_handle = get_ta_handle(session);
 321                 i = get_session_index(session);
 322                 session_info = sess->session_info[i];
 323                 spin_lock(&sess->lock);
 324                 clear_bit(i, sess->sess_mask);
 325                 spin_unlock(&sess->lock);
 326         }
 327         mutex_unlock(&session_list_mutex);
 328
 329         if (!sess)
 330                 return -EINVAL;
 331
 332         /* Close the session */
 333         handle_close_session(ta_handle, session_info);
 334         handle_unload_ta(ta_handle);
 335
 336         kref_put(&sess->refcount, destroy_session);
 337
 338         return 0;
 339 }
 340
 341 int amdtee_map_shmem(struct tee_shm *shm)
 342 {
 343         struct amdtee_context_data *ctxdata;
 344         struct amdtee_shm_data *shmnode;
 345         struct shmem_desc shmem;
 346         int rc, count;
 347         u32 buf_id;
 348
 349         if (!shm)
 350                 return -EINVAL;
 351
 352         shmnode = kmalloc(sizeof(*shmnode), GFP_KERNEL);
 353         if (!shmnode)
 354                 return -ENOMEM;
 355
 356         count = 1;
 357         shmem.kaddr = shm->kaddr;
 358         shmem.size = shm->size;
 359
 360         /*
 361          * Send a MAP command to TEE and get the corresponding
 362          * buffer Id
 363          */
 364         rc = handle_map_shmem(count, &shmem, &buf_id);
 365         if (rc) {
 366                 pr_err("map_shmem failed: ret = %d\n", rc);
 367                 kfree(shmnode);
 368                 return rc;
 369         }
 370
 371         shmnode->kaddr = shm->kaddr;
 372         shmnode->buf_id = buf_id;
 373         ctxdata = shm->ctx->data;
 374         mutex_lock(&ctxdata->shm_mutex);
 375         list_add(&shmnode->shm_node, &ctxdata->shm_list);
 376         mutex_unlock(&ctxdata->shm_mutex);
 377
 378         pr_debug("buf_id :[%x] kaddr[%p]\n", shmnode->buf_id, shmnode->kaddr);
 379
 380         return 0;
 381 }
 382
 383 void amdtee_unmap_shmem(struct tee_shm *shm)
 384 {
 385         struct amdtee_context_data *ctxdata;
 386         struct amdtee_shm_data *shmnode;
 387         u32 buf_id;
 388
 389         if (!shm)
 390                 return;
 391
 392         buf_id = get_buffer_id(shm);
 393         /* Unmap the shared memory from TEE */
 394         handle_unmap_shmem(buf_id);
 395
 396         ctxdata = shm->ctx->data;
 397         mutex_lock(&ctxdata->shm_mutex);
 398         list_for_each_entry(shmnode, &ctxdata->shm_list, shm_node)
 399                 if (buf_id == shmnode->buf_id) {
 400                         list_del(&shmnode->shm_node);
 401                         kfree(shmnode);
 402                         break;
 403                 }
 404         mutex_unlock(&ctxdata->shm_mutex);
 405 }
 406
 407 int amdtee_invoke_func(struct tee_context *ctx,
 408                        struct tee_ioctl_invoke_arg *arg,
 409                        struct tee_param *param)
 410 {
 411         struct amdtee_context_data *ctxdata = ctx->data;
 412         struct amdtee_session *sess;
 413         u32 i, session_info;
 414
 415         /* Check that the session is valid */
 416         mutex_lock(&session_list_mutex);
 417         sess = find_session(ctxdata, arg->session);
 418         if (sess) {
 419                 i = get_session_index(arg->session);
 420                 session_info = sess->session_info[i];
 421         }
 422         mutex_unlock(&session_list_mutex);
 423
 424         if (!sess)
 425                 return -EINVAL;
 426
 427         handle_invoke_cmd(arg, session_info, param);
 428
 429         return 0;
 430 }
 431
 432 int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
 433 {
 434         return -EINVAL;
 435 }
 436
 437 static const struct tee_driver_ops amdtee_ops = {
 438         .get_version = amdtee_get_version,
 439         .open = amdtee_open,
 440         .release = amdtee_release,
 441         .open_session = amdtee_open_session,
 442         .close_session = amdtee_close_session,
 443         .invoke_func = amdtee_invoke_func,
 444         .cancel_req = amdtee_cancel_req,
 445 };
 446
 447 static const struct tee_desc amdtee_desc = {
 448         .name = DRIVER_NAME "-clnt",
 449         .ops = &amdtee_ops,
 450         .owner = THIS_MODULE,
 451 };
 452
 453 static int __init amdtee_driver_init(void)
 454 {
 455         struct tee_device *teedev;
 456         struct tee_shm_pool *pool;
 457         struct amdtee *amdtee;
 458         int rc;
 459
 460         rc = psp_check_tee_status();
 461         if (rc) {
 462                 pr_err("amd-tee driver: tee not present\n");
 463                 return rc;
 464         }
 465
 466         drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
 467         if (!drv_data)
 468                 return -ENOMEM;
 469
 470         amdtee = kzalloc(sizeof(*amdtee), GFP_KERNEL);
 471         if (!amdtee) {
 472                 rc = -ENOMEM;
 473                 goto err_kfree_drv_data;
 474         }
 475
 476         pool = amdtee_config_shm();
 477         if (IS_ERR(pool)) {
 478                 pr_err("shared pool configuration error\n");
 479                 rc = PTR_ERR(pool);
 480                 goto err_kfree_amdtee;
 481         }
 482
 483         teedev = tee_device_alloc(&amdtee_desc, NULL, pool, amdtee);
 484         if (IS_ERR(teedev)) {
 485                 rc = PTR_ERR(teedev);
 486                 goto err_free_pool;
 487         }
 488         amdtee->teedev = teedev;
 489
 490         rc = tee_device_register(amdtee->teedev);
 491         if (rc)
 492                 goto err_device_unregister;
 493
 494         amdtee->pool = pool;
 495
 496         drv_data->amdtee = amdtee;
 497
 498         pr_info("amd-tee driver initialization successful\n");
 499         return 0;
 500
 501 err_device_unregister:
 502         tee_device_unregister(amdtee->teedev);
 503
 504 err_free_pool:
 505         tee_shm_pool_free(pool);
 506
 507 err_kfree_amdtee:
 508         kfree(amdtee);
 509
 510 err_kfree_drv_data:
 511         kfree(drv_data);
 512         drv_data = NULL;
 513
 514         pr_err("amd-tee driver initialization failed\n");
 515         return rc;
 516 }
 517 module_init(amdtee_driver_init);
 518
 519 static void __exit amdtee_driver_exit(void)
 520 {
 521         struct amdtee *amdtee;
 522
 523         if (!drv_data || !drv_data->amdtee)
 524                 return;
 525
 526         amdtee = drv_data->amdtee;
 527
 528         tee_device_unregister(amdtee->teedev);
 529         tee_shm_pool_free(amdtee->pool);
 530 }
 531 module_exit(amdtee_driver_exit);
 532
 533 MODULE_AUTHOR(DRIVER_AUTHOR);
 534 MODULE_DESCRIPTION("AMD-TEE driver");
 535 MODULE_VERSION("1.0");
 536 MODULE_LICENSE("Dual MIT/GPL");