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 (!*ta) {
 207                 pr_err("%s: get_free_pages failed\n", __func__);
 208                 rc = -ENOMEM;
 209                 goto rel_fw;
 210         }
 211
 212         memcpy(*ta, fw->data, fw->size);
 213 rel_fw:
 214         release_firmware(fw);
 215 unlock:
 216         mutex_unlock(&drv_mutex);
 217         return rc;
 218 }
 219
 220 static void destroy_session(struct kref *ref)
 221 {
 222         struct amdtee_session *sess = container_of(ref, struct amdtee_session,
 223                                                    refcount);
 224
 225         mutex_lock(&session_list_mutex);
 226         list_del(&sess->list_node);
 227         mutex_unlock(&session_list_mutex);
 228         kfree(sess);
 229 }
 230
 231 int amdtee_open_session(struct tee_context *ctx,
 232                         struct tee_ioctl_open_session_arg *arg,
 233                         struct tee_param *param)
 234 {
 235         struct amdtee_context_data *ctxdata = ctx->data;
 236         struct amdtee_session *sess = NULL;
 237         u32 session_info, ta_handle;
 238         size_t ta_size;
 239         int rc, i;
 240         void *ta;
 241
 242         if (arg->clnt_login != TEE_IOCTL_LOGIN_PUBLIC) {
 243                 pr_err("unsupported client login method\n");
 244                 return -EINVAL;
 245         }
 246
 247         rc = copy_ta_binary(ctx, &arg->uuid[0], &ta, &ta_size);
 248         if (rc) {
 249                 pr_err("failed to copy TA binary\n");
 250                 return rc;
 251         }
 252
 253         /* Load the TA binary into TEE environment */
 254         handle_load_ta(ta, ta_size, arg);
 255         if (arg->ret != TEEC_SUCCESS)
 256                 goto out;
 257
 258         ta_handle = get_ta_handle(arg->session);
 259
 260         mutex_lock(&session_list_mutex);
 261         sess = alloc_session(ctxdata, arg->session);
 262         mutex_unlock(&session_list_mutex);
 263
 264         if (!sess) {
 265                 handle_unload_ta(ta_handle);
 266                 rc = -ENOMEM;
 267                 goto out;
 268         }
 269
 270         /* Open session with loaded TA */
 271         handle_open_session(arg, &session_info, param);
 272         if (arg->ret != TEEC_SUCCESS) {
 273                 pr_err("open_session failed %d\n", arg->ret);
 274                 handle_unload_ta(ta_handle);
 275                 kref_put(&sess->refcount, destroy_session);
 276                 goto out;
 277         }
 278
 279         /* Find an empty session index for the given TA */
 280         spin_lock(&sess->lock);
 281         i = find_first_zero_bit(sess->sess_mask, TEE_NUM_SESSIONS);
 282         if (i < TEE_NUM_SESSIONS) {
 283                 sess->session_info[i] = session_info;
 284                 set_session_id(ta_handle, i, &arg->session);
 285                 set_bit(i, sess->sess_mask);
 286         }
 287         spin_unlock(&sess->lock);
 288
 289         if (i >= TEE_NUM_SESSIONS) {
 290                 pr_err("reached maximum session count %d\n", TEE_NUM_SESSIONS);
 291                 handle_close_session(ta_handle, session_info);
 292                 handle_unload_ta(ta_handle);
 293                 kref_put(&sess->refcount, destroy_session);
 294                 rc = -ENOMEM;
 295                 goto out;
 296         }
 297
 298 out:
 299         free_pages((u64)ta, get_order(ta_size));
 300         return rc;
 301 }
 302
 303 int amdtee_close_session(struct tee_context *ctx, u32 session)
 304 {
 305         struct amdtee_context_data *ctxdata = ctx->data;
 306         u32 i, ta_handle, session_info;
 307         struct amdtee_session *sess;
 308
 309         pr_debug("%s: sid = 0x%x\n", __func__, session);
 310
 311         /*
 312          * Check that the session is valid and clear the session
 313          * usage bit
 314          */
 315         mutex_lock(&session_list_mutex);
 316         sess = find_session(ctxdata, session);
 317         if (sess) {
 318                 ta_handle = get_ta_handle(session);
 319                 i = get_session_index(session);
 320                 session_info = sess->session_info[i];
 321                 spin_lock(&sess->lock);
 322                 clear_bit(i, sess->sess_mask);
 323                 spin_unlock(&sess->lock);
 324         }
 325         mutex_unlock(&session_list_mutex);
 326
 327         if (!sess)
 328                 return -EINVAL;
 329
 330         /* Close the session */
 331         handle_close_session(ta_handle, session_info);
 332         handle_unload_ta(ta_handle);
 333
 334         kref_put(&sess->refcount, destroy_session);
 335
 336         return 0;
 337 }
 338
 339 int amdtee_map_shmem(struct tee_shm *shm)
 340 {
 341         struct amdtee_context_data *ctxdata;
 342         struct amdtee_shm_data *shmnode;
 343         struct shmem_desc shmem;
 344         int rc, count;
 345         u32 buf_id;
 346
 347         if (!shm)
 348                 return -EINVAL;
 349
 350         shmnode = kmalloc(sizeof(*shmnode), GFP_KERNEL);
 351         if (!shmnode)
 352                 return -ENOMEM;
 353
 354         count = 1;
 355         shmem.kaddr = shm->kaddr;
 356         shmem.size = shm->size;
 357
 358         /*
 359          * Send a MAP command to TEE and get the corresponding
 360          * buffer Id
 361          */
 362         rc = handle_map_shmem(count, &shmem, &buf_id);
 363         if (rc) {
 364                 pr_err("map_shmem failed: ret = %d\n", rc);
 365                 kfree(shmnode);
 366                 return rc;
 367         }
 368
 369         shmnode->kaddr = shm->kaddr;
 370         shmnode->buf_id = buf_id;
 371         ctxdata = shm->ctx->data;
 372         mutex_lock(&ctxdata->shm_mutex);
 373         list_add(&shmnode->shm_node, &ctxdata->shm_list);
 374         mutex_unlock(&ctxdata->shm_mutex);
 375
 376         pr_debug("buf_id :[%x] kaddr[%p]\n", shmnode->buf_id, shmnode->kaddr);
 377
 378         return 0;
 379 }
 380
 381 void amdtee_unmap_shmem(struct tee_shm *shm)
 382 {
 383         struct amdtee_context_data *ctxdata;
 384         struct amdtee_shm_data *shmnode;
 385         u32 buf_id;
 386
 387         if (!shm)
 388                 return;
 389
 390         buf_id = get_buffer_id(shm);
 391         /* Unmap the shared memory from TEE */
 392         handle_unmap_shmem(buf_id);
 393
 394         ctxdata = shm->ctx->data;
 395         mutex_lock(&ctxdata->shm_mutex);
 396         list_for_each_entry(shmnode, &ctxdata->shm_list, shm_node)
 397                 if (buf_id == shmnode->buf_id) {
 398                         list_del(&shmnode->shm_node);
 399                         kfree(shmnode);
 400                         break;
 401                 }
 402         mutex_unlock(&ctxdata->shm_mutex);
 403 }
 404
 405 int amdtee_invoke_func(struct tee_context *ctx,
 406                        struct tee_ioctl_invoke_arg *arg,
 407                        struct tee_param *param)
 408 {
 409         struct amdtee_context_data *ctxdata = ctx->data;
 410         struct amdtee_session *sess;
 411         u32 i, session_info;
 412
 413         /* Check that the session is valid */
 414         mutex_lock(&session_list_mutex);
 415         sess = find_session(ctxdata, arg->session);
 416         if (sess) {
 417                 i = get_session_index(arg->session);
 418                 session_info = sess->session_info[i];
 419         }
 420         mutex_unlock(&session_list_mutex);
 421
 422         if (!sess)
 423                 return -EINVAL;
 424
 425         handle_invoke_cmd(arg, session_info, param);
 426
 427         return 0;
 428 }
 429
 430 int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
 431 {
 432         return -EINVAL;
 433 }
 434
 435 static const struct tee_driver_ops amdtee_ops = {
 436         .get_version = amdtee_get_version,
 437         .open = amdtee_open,
 438         .release = amdtee_release,
 439         .open_session = amdtee_open_session,
 440         .close_session = amdtee_close_session,
 441         .invoke_func = amdtee_invoke_func,
 442         .cancel_req = amdtee_cancel_req,
 443 };
 444
 445 static const struct tee_desc amdtee_desc = {
 446         .name = DRIVER_NAME "-clnt",
 447         .ops = &amdtee_ops,
 448         .owner = THIS_MODULE,
 449 };
 450
 451 static int __init amdtee_driver_init(void)
 452 {
 453         struct tee_device *teedev;
 454         struct tee_shm_pool *pool;
 455         struct amdtee *amdtee;
 456         int rc;
 457
 458         rc = psp_check_tee_status();
 459         if (rc) {
 460                 pr_err("amd-tee driver: tee not present\n");
 461                 return rc;
 462         }
 463
 464         drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
 465         if (!drv_data)
 466                 return -ENOMEM;
 467
 468         amdtee = kzalloc(sizeof(*amdtee), GFP_KERNEL);
 469         if (!amdtee) {
 470                 rc = -ENOMEM;
 471                 goto err_kfree_drv_data;
 472         }
 473
 474         pool = amdtee_config_shm();
 475         if (IS_ERR(pool)) {
 476                 pr_err("shared pool configuration error\n");
 477                 rc = PTR_ERR(pool);
 478                 goto err_kfree_amdtee;
 479         }
 480
 481         teedev = tee_device_alloc(&amdtee_desc, NULL, pool, amdtee);
 482         if (IS_ERR(teedev)) {
 483                 rc = PTR_ERR(teedev);
 484                 goto err_free_pool;
 485         }
 486         amdtee->teedev = teedev;
 487
 488         rc = tee_device_register(amdtee->teedev);
 489         if (rc)
 490                 goto err_device_unregister;
 491
 492         amdtee->pool = pool;
 493
 494         drv_data->amdtee = amdtee;
 495
 496         pr_info("amd-tee driver initialization successful\n");
 497         return 0;
 498
 499 err_device_unregister:
 500         tee_device_unregister(amdtee->teedev);
 501
 502 err_free_pool:
 503         tee_shm_pool_free(pool);
 504
 505 err_kfree_amdtee:
 506         kfree(amdtee);
 507
 508 err_kfree_drv_data:
 509         kfree(drv_data);
 510         drv_data = NULL;
 511
 512         pr_err("amd-tee driver initialization failed\n");
 513         return rc;
 514 }
 515 module_init(amdtee_driver_init);
 516
 517 static void __exit amdtee_driver_exit(void)
 518 {
 519         struct amdtee *amdtee;
 520
 521         if (!drv_data || !drv_data->amdtee)
 522                 return;
 523
 524         amdtee = drv_data->amdtee;
 525
 526         tee_device_unregister(amdtee->teedev);
 527         tee_shm_pool_free(amdtee->pool);
 528 }
 529 module_exit(amdtee_driver_exit);
 530
 531 MODULE_AUTHOR(DRIVER_AUTHOR);
 532 MODULE_DESCRIPTION("AMD-TEE driver");
 533 MODULE_VERSION("1.0");
 534 MODULE_LICENSE("Dual MIT/GPL");