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 static struct amdtee_shm_context shmctx;
  24
  25 static void amdtee_get_version(struct tee_device *teedev,
  26                                struct tee_ioctl_version_data *vers)
  27 {
  28         struct tee_ioctl_version_data v = {
  29                 .impl_id = TEE_IMPL_ID_AMDTEE,
  30                 .impl_caps = 0,
  31                 .gen_caps = TEE_GEN_CAP_GP,
  32         };
  33         *vers = v;
  34 }
  35
  36 static int amdtee_open(struct tee_context *ctx)
  37 {
  38         struct amdtee_context_data *ctxdata;
  39
  40         ctxdata = kzalloc(sizeof(*ctxdata), GFP_KERNEL);
  41         if (!ctxdata)
  42                 return -ENOMEM;
  43
  44         INIT_LIST_HEAD(&ctxdata->sess_list);
  45         INIT_LIST_HEAD(&shmctx.shmdata_list);
  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         }
  63
  64         /* Unload Trusted Application once all sessions are closed */
  65         handle_unload_ta(sess->ta_handle);
  66         kfree(sess);
  67 }
  68
  69 static void amdtee_release(struct tee_context *ctx)
  70 {
  71         struct amdtee_context_data *ctxdata = ctx->data;
  72
  73         if (!ctxdata)
  74                 return;
  75
  76         while (true) {
  77                 struct amdtee_session *sess;
  78
  79                 sess = list_first_entry_or_null(&ctxdata->sess_list,
  80                                                 struct amdtee_session,
  81                                                 list_node);
  82
  83                 if (!sess)
  84                         break;
  85
  86                 list_del(&sess->list_node);
  87                 release_session(sess);
  88         }
  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         u32 buf_id = 0;
 156         struct amdtee_shm_data *shmdata;
 157
 158         list_for_each_entry(shmdata, &shmctx.shmdata_list, shm_node)
 159                 if (shmdata->kaddr == shm->kaddr) {
 160                         buf_id = shmdata->buf_id;
 161                         break;
 162                 }
 163
 164         return buf_id;
 165 }
 166
 167 static DEFINE_MUTEX(drv_mutex);
 168 static int copy_ta_binary(struct tee_context *ctx, void *ptr, void **ta,
 169                           size_t *ta_size)
 170 {
 171         const struct firmware *fw;
 172         char fw_name[TA_PATH_MAX];
 173         struct {
 174                 u32 lo;
 175                 u16 mid;
 176                 u16 hi_ver;
 177                 u8 seq_n[8];
 178         } *uuid = ptr;
 179         int n, rc = 0;
 180
 181         n = snprintf(fw_name, TA_PATH_MAX,
 182                      "%s/%08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x.bin",
 183                      TA_LOAD_PATH, uuid->lo, uuid->mid, uuid->hi_ver,
 184                      uuid->seq_n[0], uuid->seq_n[1],
 185                      uuid->seq_n[2], uuid->seq_n[3],
 186                      uuid->seq_n[4], uuid->seq_n[5],
 187                      uuid->seq_n[6], uuid->seq_n[7]);
 188         if (n < 0 || n >= TA_PATH_MAX) {
 189                 pr_err("failed to get firmware name\n");
 190                 return -EINVAL;
 191         }
 192
 193         mutex_lock(&drv_mutex);
 194         n = request_firmware(&fw, fw_name, &ctx->teedev->dev);
 195         if (n) {
 196                 pr_err("failed to load firmware %s\n", fw_name);
 197                 rc = -ENOMEM;
 198                 goto unlock;
 199         }
 200
 201         *ta_size = roundup(fw->size, PAGE_SIZE);
 202         *ta = (void *)__get_free_pages(GFP_KERNEL, get_order(*ta_size));
 203         if (IS_ERR(*ta)) {
 204                 pr_err("%s: get_free_pages failed 0x%llx\n", __func__,
 205                        (u64)*ta);
 206                 rc = -ENOMEM;
 207                 goto rel_fw;
 208         }
 209
 210         memcpy(*ta, fw->data, fw->size);
 211 rel_fw:
 212         release_firmware(fw);
 213 unlock:
 214         mutex_unlock(&drv_mutex);
 215         return rc;
 216 }
 217
 218 static void destroy_session(struct kref *ref)
 219 {
 220         struct amdtee_session *sess = container_of(ref, struct amdtee_session,
 221                                                    refcount);
 222
 223         /* Unload the TA from TEE */
 224         handle_unload_ta(sess->ta_handle);
 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;
 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         mutex_lock(&session_list_mutex);
 259         sess = alloc_session(ctxdata, arg->session);
 260         mutex_unlock(&session_list_mutex);
 261
 262         if (!sess) {
 263                 rc = -ENOMEM;
 264                 goto out;
 265         }
 266
 267         /* Find an empty session index for the given TA */
 268         spin_lock(&sess->lock);
 269         i = find_first_zero_bit(sess->sess_mask, TEE_NUM_SESSIONS);
 270         if (i < TEE_NUM_SESSIONS)
 271                 set_bit(i, sess->sess_mask);
 272         spin_unlock(&sess->lock);
 273
 274         if (i >= TEE_NUM_SESSIONS) {
 275                 pr_err("reached maximum session count %d\n", TEE_NUM_SESSIONS);
 276                 kref_put(&sess->refcount, destroy_session);
 277                 rc = -ENOMEM;
 278                 goto out;
 279         }
 280
 281         /* Open session with loaded TA */
 282         handle_open_session(arg, &session_info, param);
 283         if (arg->ret != TEEC_SUCCESS) {
 284                 pr_err("open_session failed %d\n", arg->ret);
 285                 spin_lock(&sess->lock);
 286                 clear_bit(i, sess->sess_mask);
 287                 spin_unlock(&sess->lock);
 288                 kref_put(&sess->refcount, destroy_session);
 289                 goto out;
 290         }
 291
 292         sess->session_info[i] = session_info;
 293         set_session_id(sess->ta_handle, i, &arg->session);
 294 out:
 295         free_pages((u64)ta, get_order(ta_size));
 296         return rc;
 297 }
 298
 299 int amdtee_close_session(struct tee_context *ctx, u32 session)
 300 {
 301         struct amdtee_context_data *ctxdata = ctx->data;
 302         u32 i, ta_handle, session_info;
 303         struct amdtee_session *sess;
 304
 305         pr_debug("%s: sid = 0x%x\n", __func__, session);
 306
 307         /*
 308          * Check that the session is valid and clear the session
 309          * usage bit
 310          */
 311         mutex_lock(&session_list_mutex);
 312         sess = find_session(ctxdata, session);
 313         if (sess) {
 314                 ta_handle = get_ta_handle(session);
 315                 i = get_session_index(session);
 316                 session_info = sess->session_info[i];
 317                 spin_lock(&sess->lock);
 318                 clear_bit(i, sess->sess_mask);
 319                 spin_unlock(&sess->lock);
 320         }
 321         mutex_unlock(&session_list_mutex);
 322
 323         if (!sess)
 324                 return -EINVAL;
 325
 326         /* Close the session */
 327         handle_close_session(ta_handle, session_info);
 328
 329         kref_put(&sess->refcount, destroy_session);
 330
 331         return 0;
 332 }
 333
 334 int amdtee_map_shmem(struct tee_shm *shm)
 335 {
 336         struct shmem_desc shmem;
 337         struct amdtee_shm_data *shmnode;
 338         int rc, count;
 339         u32 buf_id;
 340
 341         if (!shm)
 342                 return -EINVAL;
 343
 344         shmnode = kmalloc(sizeof(*shmnode), GFP_KERNEL);
 345         if (!shmnode)
 346                 return -ENOMEM;
 347
 348         count = 1;
 349         shmem.kaddr = shm->kaddr;
 350         shmem.size = shm->size;
 351
 352         /*
 353          * Send a MAP command to TEE and get the corresponding
 354          * buffer Id
 355          */
 356         rc = handle_map_shmem(count, &shmem, &buf_id);
 357         if (rc) {
 358                 pr_err("map_shmem failed: ret = %d\n", rc);
 359                 kfree(shmnode);
 360                 return rc;
 361         }
 362
 363         shmnode->kaddr = shm->kaddr;
 364         shmnode->buf_id = buf_id;
 365         list_add(&shmnode->shm_node, &shmctx.shmdata_list);
 366
 367         pr_debug("buf_id :[%x] kaddr[%p]\n", shmnode->buf_id, shmnode->kaddr);
 368
 369         return 0;
 370 }
 371
 372 void amdtee_unmap_shmem(struct tee_shm *shm)
 373 {
 374         struct amdtee_shm_data *shmnode;
 375         u32 buf_id;
 376
 377         if (!shm)
 378                 return;
 379
 380         buf_id = get_buffer_id(shm);
 381         /* Unmap the shared memory from TEE */
 382         handle_unmap_shmem(buf_id);
 383
 384         list_for_each_entry(shmnode, &shmctx.shmdata_list, shm_node)
 385                 if (buf_id == shmnode->buf_id) {
 386                         list_del(&shmnode->shm_node);
 387                         kfree(shmnode);
 388                         break;
 389                 }
 390 }
 391
 392 int amdtee_invoke_func(struct tee_context *ctx,
 393                        struct tee_ioctl_invoke_arg *arg,
 394                        struct tee_param *param)
 395 {
 396         struct amdtee_context_data *ctxdata = ctx->data;
 397         struct amdtee_session *sess;
 398         u32 i, session_info;
 399
 400         /* Check that the session is valid */
 401         mutex_lock(&session_list_mutex);
 402         sess = find_session(ctxdata, arg->session);
 403         if (sess) {
 404                 i = get_session_index(arg->session);
 405                 session_info = sess->session_info[i];
 406         }
 407         mutex_unlock(&session_list_mutex);
 408
 409         if (!sess)
 410                 return -EINVAL;
 411
 412         handle_invoke_cmd(arg, session_info, param);
 413
 414         return 0;
 415 }
 416
 417 int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
 418 {
 419         return -EINVAL;
 420 }
 421
 422 static const struct tee_driver_ops amdtee_ops = {
 423         .get_version = amdtee_get_version,
 424         .open = amdtee_open,
 425         .release = amdtee_release,
 426         .open_session = amdtee_open_session,
 427         .close_session = amdtee_close_session,
 428         .invoke_func = amdtee_invoke_func,
 429         .cancel_req = amdtee_cancel_req,
 430 };
 431
 432 static const struct tee_desc amdtee_desc = {
 433         .name = DRIVER_NAME "-clnt",
 434         .ops = &amdtee_ops,
 435         .owner = THIS_MODULE,
 436 };
 437
 438 static int __init amdtee_driver_init(void)
 439 {
 440         struct tee_device *teedev;
 441         struct tee_shm_pool *pool;
 442         struct amdtee *amdtee;
 443         int rc;
 444
 445         rc = psp_check_tee_status();
 446         if (rc) {
 447                 pr_err("amd-tee driver: tee not present\n");
 448                 return rc;
 449         }
 450
 451         drv_data = kzalloc(sizeof(*drv_data), GFP_KERNEL);
 452         if (!drv_data)
 453                 return -ENOMEM;
 454
 455         amdtee = kzalloc(sizeof(*amdtee), GFP_KERNEL);
 456         if (!amdtee) {
 457                 rc = -ENOMEM;
 458                 goto err_kfree_drv_data;
 459         }
 460
 461         pool = amdtee_config_shm();
 462         if (IS_ERR(pool)) {
 463                 pr_err("shared pool configuration error\n");
 464                 rc = PTR_ERR(pool);
 465                 goto err_kfree_amdtee;
 466         }
 467
 468         teedev = tee_device_alloc(&amdtee_desc, NULL, pool, amdtee);
 469         if (IS_ERR(teedev)) {
 470                 rc = PTR_ERR(teedev);
 471                 goto err_free_pool;
 472         }
 473         amdtee->teedev = teedev;
 474
 475         rc = tee_device_register(amdtee->teedev);
 476         if (rc)
 477                 goto err_device_unregister;
 478
 479         amdtee->pool = pool;
 480
 481         drv_data->amdtee = amdtee;
 482
 483         pr_info("amd-tee driver initialization successful\n");
 484         return 0;
 485
 486 err_device_unregister:
 487         tee_device_unregister(amdtee->teedev);
 488
 489 err_free_pool:
 490         tee_shm_pool_free(pool);
 491
 492 err_kfree_amdtee:
 493         kfree(amdtee);
 494
 495 err_kfree_drv_data:
 496         kfree(drv_data);
 497         drv_data = NULL;
 498
 499         pr_err("amd-tee driver initialization failed\n");
 500         return rc;
 501 }
 502 module_init(amdtee_driver_init);
 503
 504 static void __exit amdtee_driver_exit(void)
 505 {
 506         struct amdtee *amdtee;
 507
 508         if (!drv_data || !drv_data->amdtee)
 509                 return;
 510
 511         amdtee = drv_data->amdtee;
 512
 513         tee_device_unregister(amdtee->teedev);
 514         tee_shm_pool_free(amdtee->pool);
 515 }
 516 module_exit(amdtee_driver_exit);
 517
 518 MODULE_AUTHOR(DRIVER_AUTHOR);
 519 MODULE_DESCRIPTION("AMD-TEE driver");
 520 MODULE_VERSION("1.0");
 521 MODULE_LICENSE("Dual MIT/GPL");