drivers/tee/tee_core.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) "%s: " fmt, __func__
  16
  17 #include <linux/cdev.h>
  18 #include <linux/device.h>
  19 #include <linux/fs.h>
  20 #include <linux/idr.h>
  21 #include <linux/module.h>
  22 #include <linux/slab.h>
  23 #include <linux/tee_drv.h>
  24 #include <linux/uaccess.h>
  25 #include "tee_private.h"
  26
  27 #define TEE_NUM_DEVICES 32
  28
  29 #define TEE_IOCTL_PARAM_SIZE(x) (sizeof(struct tee_param) * (x))
  30
  31 /*
  32  * Unprivileged devices in the lower half range and privileged devices in
  33  * the upper half range.
  34  */
  35 static DECLARE_BITMAP(dev_mask, TEE_NUM_DEVICES);
  36 static DEFINE_SPINLOCK(driver_lock);
  37
  38 static struct class *tee_class;
  39 static dev_t tee_devt;
  40
  41 static int tee_open(struct inode *inode, struct file *filp)
  42 {
  43         int rc;
  44         struct tee_device *teedev;
  45         struct tee_context *ctx;
  46
  47         teedev = container_of(inode->i_cdev, struct tee_device, cdev);
  48         if (!tee_device_get(teedev))
  49                 return -EINVAL;
  50
  51         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
  52         if (!ctx) {
  53                 rc = -ENOMEM;
  54                 goto err;
  55         }
  56
  57         ctx->teedev = teedev;
  58         INIT_LIST_HEAD(&ctx->list_shm);
  59         filp->private_data = ctx;
  60         rc = teedev->desc->ops->open(ctx);
  61         if (rc)
  62                 goto err;
  63
  64         return 0;
  65 err:
  66         kfree(ctx);
  67         tee_device_put(teedev);
  68         return rc;
  69 }
  70
  71 static int tee_release(struct inode *inode, struct file *filp)
  72 {
  73         struct tee_context *ctx = filp->private_data;
  74         struct tee_device *teedev = ctx->teedev;
  75         struct tee_shm *shm;
  76
  77         ctx->teedev->desc->ops->release(ctx);
  78         mutex_lock(&ctx->teedev->mutex);
  79         list_for_each_entry(shm, &ctx->list_shm, link)
  80                 shm->ctx = NULL;
  81         mutex_unlock(&ctx->teedev->mutex);
  82         kfree(ctx);
  83         tee_device_put(teedev);
  84         return 0;
  85 }
  86
  87 static int tee_ioctl_version(struct tee_context *ctx,
  88                              struct tee_ioctl_version_data __user *uvers)
  89 {
  90         struct tee_ioctl_version_data vers;
  91
  92         ctx->teedev->desc->ops->get_version(ctx->teedev, &vers);
  93
  94         if (ctx->teedev->desc->flags & TEE_DESC_PRIVILEGED)
  95                 vers.gen_caps |= TEE_GEN_CAP_PRIVILEGED;
  96
  97         if (copy_to_user(uvers, &vers, sizeof(vers)))
  98                 return -EFAULT;
  99
 100         return 0;
 101 }
 102
 103 static int tee_ioctl_shm_alloc(struct tee_context *ctx,
 104                                struct tee_ioctl_shm_alloc_data __user *udata)
 105 {
 106         long ret;
 107         struct tee_ioctl_shm_alloc_data data;
 108         struct tee_shm *shm;
 109
 110         if (copy_from_user(&data, udata, sizeof(data)))
 111                 return -EFAULT;
 112
 113         /* Currently no input flags are supported */
 114         if (data.flags)
 115                 return -EINVAL;
 116
 117         data.id = -1;
 118
 119         shm = tee_shm_alloc(ctx, data.size, TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
 120         if (IS_ERR(shm))
 121                 return PTR_ERR(shm);
 122
 123         data.id = shm->id;
 124         data.flags = shm->flags;
 125         data.size = shm->size;
 126
 127         if (copy_to_user(udata, &data, sizeof(data)))
 128                 ret = -EFAULT;
 129         else
 130                 ret = tee_shm_get_fd(shm);
 131
 132         /*
 133          * When user space closes the file descriptor the shared memory
 134          * should be freed or if tee_shm_get_fd() failed then it will
 135          * be freed immediately.
 136          */
 137         tee_shm_put(shm);
 138         return ret;
 139 }
 140
 141 static int params_from_user(struct tee_context *ctx, struct tee_param *params,
 142                             size_t num_params,
 143                             struct tee_ioctl_param __user *uparams)
 144 {
 145         size_t n;
 146
 147         for (n = 0; n < num_params; n++) {
 148                 struct tee_shm *shm;
 149                 struct tee_ioctl_param ip;
 150
 151                 if (copy_from_user(&ip, uparams + n, sizeof(ip)))
 152                         return -EFAULT;
 153
 154                 /* All unused attribute bits has to be zero */
 155                 if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_TYPE_MASK)
 156                         return -EINVAL;
 157
 158                 params[n].attr = ip.attr;
 159                 switch (ip.attr) {
 160                 case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
 161                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
 162                         break;
 163                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
 164                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
 165                         params[n].u.value.a = ip.a;
 166                         params[n].u.value.b = ip.b;
 167                         params[n].u.value.c = ip.c;
 168                         break;
 169                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
 170                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
 171                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
 172                         /*
 173                          * If we fail to get a pointer to a shared memory
 174                          * object (and increase the ref count) from an
 175                          * identifier we return an error. All pointers that
 176                          * has been added in params have an increased ref
 177                          * count. It's the callers responibility to do
 178                          * tee_shm_put() on all resolved pointers.
 179                          */
 180                         shm = tee_shm_get_from_id(ctx, ip.c);
 181                         if (IS_ERR(shm))
 182                                 return PTR_ERR(shm);
 183
 184                         /*
 185                          * Ensure offset + size does not overflow offset
 186                          * and does not overflow the size of the referred
 187                          * shared memory object.
 188                          */
 189                         if ((ip.a + ip.b) < ip.a ||
 190                             (ip.a + ip.b) > shm->size) {
 191                                 tee_shm_put(shm);
 192                                 return -EINVAL;
 193                         }
 194
 195                         params[n].u.memref.shm_offs = ip.a;
 196                         params[n].u.memref.size = ip.b;
 197                         params[n].u.memref.shm = shm;
 198                         break;
 199                 default:
 200                         /* Unknown attribute */
 201                         return -EINVAL;
 202                 }
 203         }
 204         return 0;
 205 }
 206
 207 static int params_to_user(struct tee_ioctl_param __user *uparams,
 208                           size_t num_params, struct tee_param *params)
 209 {
 210         size_t n;
 211
 212         for (n = 0; n < num_params; n++) {
 213                 struct tee_ioctl_param __user *up = uparams + n;
 214                 struct tee_param *p = params + n;
 215
 216                 switch (p->attr) {
 217                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
 218                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
 219                         if (put_user(p->u.value.a, &up->a) ||
 220                             put_user(p->u.value.b, &up->b) ||
 221                             put_user(p->u.value.c, &up->c))
 222                                 return -EFAULT;
 223                         break;
 224                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
 225                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
 226                         if (put_user((u64)p->u.memref.size, &up->b))
 227                                 return -EFAULT;
 228                 default:
 229                         break;
 230                 }
 231         }
 232         return 0;
 233 }
 234
 235 static bool param_is_memref(struct tee_param *param)
 236 {
 237         switch (param->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) {
 238         case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
 239         case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
 240         case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
 241                 return true;
 242         default:
 243                 return false;
 244         }
 245 }
 246
 247 static int tee_ioctl_open_session(struct tee_context *ctx,
 248                                   struct tee_ioctl_buf_data __user *ubuf)
 249 {
 250         int rc;
 251         size_t n;
 252         struct tee_ioctl_buf_data buf;
 253         struct tee_ioctl_open_session_arg __user *uarg;
 254         struct tee_ioctl_open_session_arg arg;
 255         struct tee_ioctl_param __user *uparams = NULL;
 256         struct tee_param *params = NULL;
 257         bool have_session = false;
 258
 259         if (!ctx->teedev->desc->ops->open_session)
 260                 return -EINVAL;
 261
 262         if (copy_from_user(&buf, ubuf, sizeof(buf)))
 263                 return -EFAULT;
 264
 265         if (buf.buf_len > TEE_MAX_ARG_SIZE ||
 266             buf.buf_len < sizeof(struct tee_ioctl_open_session_arg))
 267                 return -EINVAL;
 268
 269         uarg = u64_to_user_ptr(buf.buf_ptr);
 270         if (copy_from_user(&arg, uarg, sizeof(arg)))
 271                 return -EFAULT;
 272
 273         if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
 274                 return -EINVAL;
 275
 276         if (arg.num_params) {
 277                 params = kcalloc(arg.num_params, sizeof(struct tee_param),
 278                                  GFP_KERNEL);
 279                 if (!params)
 280                         return -ENOMEM;
 281                 uparams = uarg->params;
 282                 rc = params_from_user(ctx, params, arg.num_params, uparams);
 283                 if (rc)
 284                         goto out;
 285         }
 286
 287         rc = ctx->teedev->desc->ops->open_session(ctx, &arg, params);
 288         if (rc)
 289                 goto out;
 290         have_session = true;
 291
 292         if (put_user(arg.session, &uarg->session) ||
 293             put_user(arg.ret, &uarg->ret) ||
 294             put_user(arg.ret_origin, &uarg->ret_origin)) {
 295                 rc = -EFAULT;
 296                 goto out;
 297         }
 298         rc = params_to_user(uparams, arg.num_params, params);
 299 out:
 300         /*
 301          * If we've succeeded to open the session but failed to communicate
 302          * it back to user space, close the session again to avoid leakage.
 303          */
 304         if (rc && have_session && ctx->teedev->desc->ops->close_session)
 305                 ctx->teedev->desc->ops->close_session(ctx, arg.session);
 306
 307         if (params) {
 308                 /* Decrease ref count for all valid shared memory pointers */
 309                 for (n = 0; n < arg.num_params; n++)
 310                         if (param_is_memref(params + n) &&
 311                             params[n].u.memref.shm)
 312                                 tee_shm_put(params[n].u.memref.shm);
 313                 kfree(params);
 314         }
 315
 316         return rc;
 317 }
 318
 319 static int tee_ioctl_invoke(struct tee_context *ctx,
 320                             struct tee_ioctl_buf_data __user *ubuf)
 321 {
 322         int rc;
 323         size_t n;
 324         struct tee_ioctl_buf_data buf;
 325         struct tee_ioctl_invoke_arg __user *uarg;
 326         struct tee_ioctl_invoke_arg arg;
 327         struct tee_ioctl_param __user *uparams = NULL;
 328         struct tee_param *params = NULL;
 329
 330         if (!ctx->teedev->desc->ops->invoke_func)
 331                 return -EINVAL;
 332
 333         if (copy_from_user(&buf, ubuf, sizeof(buf)))
 334                 return -EFAULT;
 335
 336         if (buf.buf_len > TEE_MAX_ARG_SIZE ||
 337             buf.buf_len < sizeof(struct tee_ioctl_invoke_arg))
 338                 return -EINVAL;
 339
 340         uarg = u64_to_user_ptr(buf.buf_ptr);
 341         if (copy_from_user(&arg, uarg, sizeof(arg)))
 342                 return -EFAULT;
 343
 344         if (sizeof(arg) + TEE_IOCTL_PARAM_SIZE(arg.num_params) != buf.buf_len)
 345                 return -EINVAL;
 346
 347         if (arg.num_params) {
 348                 params = kcalloc(arg.num_params, sizeof(struct tee_param),
 349                                  GFP_KERNEL);
 350                 if (!params)
 351                         return -ENOMEM;
 352                 uparams = uarg->params;
 353                 rc = params_from_user(ctx, params, arg.num_params, uparams);
 354                 if (rc)
 355                         goto out;
 356         }
 357
 358         rc = ctx->teedev->desc->ops->invoke_func(ctx, &arg, params);
 359         if (rc)
 360                 goto out;
 361
 362         if (put_user(arg.ret, &uarg->ret) ||
 363             put_user(arg.ret_origin, &uarg->ret_origin)) {
 364                 rc = -EFAULT;
 365                 goto out;
 366         }
 367         rc = params_to_user(uparams, arg.num_params, params);
 368 out:
 369         if (params) {
 370                 /* Decrease ref count for all valid shared memory pointers */
 371                 for (n = 0; n < arg.num_params; n++)
 372                         if (param_is_memref(params + n) &&
 373                             params[n].u.memref.shm)
 374                                 tee_shm_put(params[n].u.memref.shm);
 375                 kfree(params);
 376         }
 377         return rc;
 378 }
 379
 380 static int tee_ioctl_cancel(struct tee_context *ctx,
 381                             struct tee_ioctl_cancel_arg __user *uarg)
 382 {
 383         struct tee_ioctl_cancel_arg arg;
 384
 385         if (!ctx->teedev->desc->ops->cancel_req)
 386                 return -EINVAL;
 387
 388         if (copy_from_user(&arg, uarg, sizeof(arg)))
 389                 return -EFAULT;
 390
 391         return ctx->teedev->desc->ops->cancel_req(ctx, arg.cancel_id,
 392                                                   arg.session);
 393 }
 394
 395 static int
 396 tee_ioctl_close_session(struct tee_context *ctx,
 397                         struct tee_ioctl_close_session_arg __user *uarg)
 398 {
 399         struct tee_ioctl_close_session_arg arg;
 400
 401         if (!ctx->teedev->desc->ops->close_session)
 402                 return -EINVAL;
 403
 404         if (copy_from_user(&arg, uarg, sizeof(arg)))
 405                 return -EFAULT;
 406
 407         return ctx->teedev->desc->ops->close_session(ctx, arg.session);
 408 }
 409
 410 static int params_to_supp(struct tee_context *ctx,
 411                           struct tee_ioctl_param __user *uparams,
 412                           size_t num_params, struct tee_param *params)
 413 {
 414         size_t n;
 415
 416         for (n = 0; n < num_params; n++) {
 417                 struct tee_ioctl_param ip;
 418                 struct tee_param *p = params + n;
 419
 420                 ip.attr = p->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK;
 421                 switch (p->attr) {
 422                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
 423                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
 424                         ip.a = p->u.value.a;
 425                         ip.b = p->u.value.b;
 426                         ip.c = p->u.value.c;
 427                         break;
 428                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
 429                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
 430                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
 431                         ip.b = p->u.memref.size;
 432                         if (!p->u.memref.shm) {
 433                                 ip.a = 0;
 434                                 ip.c = (u64)-1; /* invalid shm id */
 435                                 break;
 436                         }
 437                         ip.a = p->u.memref.shm_offs;
 438                         ip.c = p->u.memref.shm->id;
 439                         break;
 440                 default:
 441                         ip.a = 0;
 442                         ip.b = 0;
 443                         ip.c = 0;
 444                         break;
 445                 }
 446
 447                 if (copy_to_user(uparams + n, &ip, sizeof(ip)))
 448                         return -EFAULT;
 449         }
 450
 451         return 0;
 452 }
 453
 454 static int tee_ioctl_supp_recv(struct tee_context *ctx,
 455                                struct tee_ioctl_buf_data __user *ubuf)
 456 {
 457         int rc;
 458         struct tee_ioctl_buf_data buf;
 459         struct tee_iocl_supp_recv_arg __user *uarg;
 460         struct tee_param *params;
 461         u32 num_params;
 462         u32 func;
 463
 464         if (!ctx->teedev->desc->ops->supp_recv)
 465                 return -EINVAL;
 466
 467         if (copy_from_user(&buf, ubuf, sizeof(buf)))
 468                 return -EFAULT;
 469
 470         if (buf.buf_len > TEE_MAX_ARG_SIZE ||
 471             buf.buf_len < sizeof(struct tee_iocl_supp_recv_arg))
 472                 return -EINVAL;
 473
 474         uarg = u64_to_user_ptr(buf.buf_ptr);
 475         if (get_user(num_params, &uarg->num_params))
 476                 return -EFAULT;
 477
 478         if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) != buf.buf_len)
 479                 return -EINVAL;
 480
 481         params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
 482         if (!params)
 483                 return -ENOMEM;
 484
 485         rc = ctx->teedev->desc->ops->supp_recv(ctx, &func, &num_params, params);
 486         if (rc)
 487                 goto out;
 488
 489         if (put_user(func, &uarg->func) ||
 490             put_user(num_params, &uarg->num_params)) {
 491                 rc = -EFAULT;
 492                 goto out;
 493         }
 494
 495         rc = params_to_supp(ctx, uarg->params, num_params, params);
 496 out:
 497         kfree(params);
 498         return rc;
 499 }
 500
 501 static int params_from_supp(struct tee_param *params, size_t num_params,
 502                             struct tee_ioctl_param __user *uparams)
 503 {
 504         size_t n;
 505
 506         for (n = 0; n < num_params; n++) {
 507                 struct tee_param *p = params + n;
 508                 struct tee_ioctl_param ip;
 509
 510                 if (copy_from_user(&ip, uparams + n, sizeof(ip)))
 511                         return -EFAULT;
 512
 513                 /* All unused attribute bits has to be zero */
 514                 if (ip.attr & ~TEE_IOCTL_PARAM_ATTR_TYPE_MASK)
 515                         return -EINVAL;
 516
 517                 p->attr = ip.attr;
 518                 switch (ip.attr) {
 519                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
 520                 case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
 521                         /* Only out and in/out values can be updated */
 522                         p->u.value.a = ip.a;
 523                         p->u.value.b = ip.b;
 524                         p->u.value.c = ip.c;
 525                         break;
 526                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
 527                 case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
 528                         /*
 529                          * Only the size of the memref can be updated.
 530                          * Since we don't have access to the original
 531                          * parameters here, only store the supplied size.
 532                          * The driver will copy the updated size into the
 533                          * original parameters.
 534                          */
 535                         p->u.memref.shm = NULL;
 536                         p->u.memref.shm_offs = 0;
 537                         p->u.memref.size = ip.b;
 538                         break;
 539                 default:
 540                         memset(&p->u, 0, sizeof(p->u));
 541                         break;
 542                 }
 543         }
 544         return 0;
 545 }
 546
 547 static int tee_ioctl_supp_send(struct tee_context *ctx,
 548                                struct tee_ioctl_buf_data __user *ubuf)
 549 {
 550         long rc;
 551         struct tee_ioctl_buf_data buf;
 552         struct tee_iocl_supp_send_arg __user *uarg;
 553         struct tee_param *params;
 554         u32 num_params;
 555         u32 ret;
 556
 557         /* Not valid for this driver */
 558         if (!ctx->teedev->desc->ops->supp_send)
 559                 return -EINVAL;
 560
 561         if (copy_from_user(&buf, ubuf, sizeof(buf)))
 562                 return -EFAULT;
 563
 564         if (buf.buf_len > TEE_MAX_ARG_SIZE ||
 565             buf.buf_len < sizeof(struct tee_iocl_supp_send_arg))
 566                 return -EINVAL;
 567
 568         uarg = u64_to_user_ptr(buf.buf_ptr);
 569         if (get_user(ret, &uarg->ret) ||
 570             get_user(num_params, &uarg->num_params))
 571                 return -EFAULT;
 572
 573         if (sizeof(*uarg) + TEE_IOCTL_PARAM_SIZE(num_params) > buf.buf_len)
 574                 return -EINVAL;
 575
 576         params = kcalloc(num_params, sizeof(struct tee_param), GFP_KERNEL);
 577         if (!params)
 578                 return -ENOMEM;
 579
 580         rc = params_from_supp(params, num_params, uarg->params);
 581         if (rc)
 582                 goto out;
 583
 584         rc = ctx->teedev->desc->ops->supp_send(ctx, ret, num_params, params);
 585 out:
 586         kfree(params);
 587         return rc;
 588 }
 589
 590 static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 591 {
 592         struct tee_context *ctx = filp->private_data;
 593         void __user *uarg = (void __user *)arg;
 594
 595         switch (cmd) {
 596         case TEE_IOC_VERSION:
 597                 return tee_ioctl_version(ctx, uarg);
 598         case TEE_IOC_SHM_ALLOC:
 599                 return tee_ioctl_shm_alloc(ctx, uarg);
 600         case TEE_IOC_OPEN_SESSION:
 601                 return tee_ioctl_open_session(ctx, uarg);
 602         case TEE_IOC_INVOKE:
 603                 return tee_ioctl_invoke(ctx, uarg);
 604         case TEE_IOC_CANCEL:
 605                 return tee_ioctl_cancel(ctx, uarg);
 606         case TEE_IOC_CLOSE_SESSION:
 607                 return tee_ioctl_close_session(ctx, uarg);
 608         case TEE_IOC_SUPPL_RECV:
 609                 return tee_ioctl_supp_recv(ctx, uarg);
 610         case TEE_IOC_SUPPL_SEND:
 611                 return tee_ioctl_supp_send(ctx, uarg);
 612         default:
 613                 return -EINVAL;
 614         }
 615 }
 616
 617 static const struct file_operations tee_fops = {
 618         .owner = THIS_MODULE,
 619         .open = tee_open,
 620         .release = tee_release,
 621         .unlocked_ioctl = tee_ioctl,
 622         .compat_ioctl = tee_ioctl,
 623 };
 624
 625 static void tee_release_device(struct device *dev)
 626 {
 627         struct tee_device *teedev = container_of(dev, struct tee_device, dev);
 628
 629         spin_lock(&driver_lock);
 630         clear_bit(teedev->id, dev_mask);
 631         spin_unlock(&driver_lock);
 632         mutex_destroy(&teedev->mutex);
 633         idr_destroy(&teedev->idr);
 634         kfree(teedev);
 635 }
 636
 637 /**
 638  * tee_device_alloc() - Allocate a new struct tee_device instance
 639  * @teedesc:    Descriptor for this driver
 640  * @dev:        Parent device for this device
 641  * @pool:       Shared memory pool, NULL if not used
 642  * @driver_data: Private driver data for this device
 643  *
 644  * Allocates a new struct tee_device instance. The device is
 645  * removed by tee_device_unregister().
 646  *
 647  * @returns a pointer to a 'struct tee_device' or an ERR_PTR on failure
 648  */
 649 struct tee_device *tee_device_alloc(const struct tee_desc *teedesc,
 650                                     struct device *dev,
 651                                     struct tee_shm_pool *pool,
 652                                     void *driver_data)
 653 {
 654         struct tee_device *teedev;
 655         void *ret;
 656         int rc;
 657         int offs = 0;
 658
 659         if (!teedesc || !teedesc->name || !teedesc->ops ||
 660             !teedesc->ops->get_version || !teedesc->ops->open ||
 661             !teedesc->ops->release || !pool)
 662                 return ERR_PTR(-EINVAL);
 663
 664         teedev = kzalloc(sizeof(*teedev), GFP_KERNEL);
 665         if (!teedev) {
 666                 ret = ERR_PTR(-ENOMEM);
 667                 goto err;
 668         }
 669
 670         if (teedesc->flags & TEE_DESC_PRIVILEGED)
 671                 offs = TEE_NUM_DEVICES / 2;
 672
 673         spin_lock(&driver_lock);
 674         teedev->id = find_next_zero_bit(dev_mask, TEE_NUM_DEVICES, offs);
 675         if (teedev->id < TEE_NUM_DEVICES)
 676                 set_bit(teedev->id, dev_mask);
 677         spin_unlock(&driver_lock);
 678
 679         if (teedev->id >= TEE_NUM_DEVICES) {
 680                 ret = ERR_PTR(-ENOMEM);
 681                 goto err;
 682         }
 683
 684         snprintf(teedev->name, sizeof(teedev->name), "tee%s%d",
 685                  teedesc->flags & TEE_DESC_PRIVILEGED ? "priv" : "",
 686                  teedev->id - offs);
 687
 688         teedev->dev.class = tee_class;
 689         teedev->dev.release = tee_release_device;
 690         teedev->dev.parent = dev;
 691
 692         teedev->dev.devt = MKDEV(MAJOR(tee_devt), teedev->id);
 693
 694         rc = dev_set_name(&teedev->dev, "%s", teedev->name);
 695         if (rc) {
 696                 ret = ERR_PTR(rc);
 697                 goto err_devt;
 698         }
 699
 700         cdev_init(&teedev->cdev, &tee_fops);
 701         teedev->cdev.owner = teedesc->owner;
 702         teedev->cdev.kobj.parent = &teedev->dev.kobj;
 703
 704         dev_set_drvdata(&teedev->dev, driver_data);
 705         device_initialize(&teedev->dev);
 706
 707         /* 1 as tee_device_unregister() does one final tee_device_put() */
 708         teedev->num_users = 1;
 709         init_completion(&teedev->c_no_users);
 710         mutex_init(&teedev->mutex);
 711         idr_init(&teedev->idr);
 712
 713         teedev->desc = teedesc;
 714         teedev->pool = pool;
 715
 716         return teedev;
 717 err_devt:
 718         unregister_chrdev_region(teedev->dev.devt, 1);
 719 err:
 720         pr_err("could not register %s driver\n",
 721                teedesc->flags & TEE_DESC_PRIVILEGED ? "privileged" : "client");
 722         if (teedev && teedev->id < TEE_NUM_DEVICES) {
 723                 spin_lock(&driver_lock);
 724                 clear_bit(teedev->id, dev_mask);
 725                 spin_unlock(&driver_lock);
 726         }
 727         kfree(teedev);
 728         return ret;
 729 }
 730 EXPORT_SYMBOL_GPL(tee_device_alloc);
 731
 732 static ssize_t implementation_id_show(struct device *dev,
 733                                       struct device_attribute *attr, char *buf)
 734 {
 735         struct tee_device *teedev = container_of(dev, struct tee_device, dev);
 736         struct tee_ioctl_version_data vers;
 737
 738         teedev->desc->ops->get_version(teedev, &vers);
 739         return scnprintf(buf, PAGE_SIZE, "%d\n", vers.impl_id);
 740 }
 741 static DEVICE_ATTR_RO(implementation_id);
 742
 743 static struct attribute *tee_dev_attrs[] = {
 744         &dev_attr_implementation_id.attr,
 745         NULL
 746 };
 747
 748 static const struct attribute_group tee_dev_group = {
 749         .attrs = tee_dev_attrs,
 750 };
 751
 752 /**
 753  * tee_device_register() - Registers a TEE device
 754  * @teedev:     Device to register
 755  *
 756  * tee_device_unregister() need to be called to remove the @teedev if
 757  * this function fails.
 758  *
 759  * @returns < 0 on failure
 760  */
 761 int tee_device_register(struct tee_device *teedev)
 762 {
 763         int rc;
 764
 765         if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
 766                 dev_err(&teedev->dev, "attempt to register twice\n");
 767                 return -EINVAL;
 768         }
 769
 770         rc = cdev_add(&teedev->cdev, teedev->dev.devt, 1);
 771         if (rc) {
 772                 dev_err(&teedev->dev,
 773                         "unable to cdev_add() %s, major %d, minor %d, err=%d\n",
 774                         teedev->name, MAJOR(teedev->dev.devt),
 775                         MINOR(teedev->dev.devt), rc);
 776                 return rc;
 777         }
 778
 779         rc = device_add(&teedev->dev);
 780         if (rc) {
 781                 dev_err(&teedev->dev,
 782                         "unable to device_add() %s, major %d, minor %d, err=%d\n",
 783                         teedev->name, MAJOR(teedev->dev.devt),
 784                         MINOR(teedev->dev.devt), rc);
 785                 goto err_device_add;
 786         }
 787
 788         rc = sysfs_create_group(&teedev->dev.kobj, &tee_dev_group);
 789         if (rc) {
 790                 dev_err(&teedev->dev,
 791                         "failed to create sysfs attributes, err=%d\n", rc);
 792                 goto err_sysfs_create_group;
 793         }
 794
 795         teedev->flags |= TEE_DEVICE_FLAG_REGISTERED;
 796         return 0;
 797
 798 err_sysfs_create_group:
 799         device_del(&teedev->dev);
 800 err_device_add:
 801         cdev_del(&teedev->cdev);
 802         return rc;
 803 }
 804 EXPORT_SYMBOL_GPL(tee_device_register);
 805
 806 void tee_device_put(struct tee_device *teedev)
 807 {
 808         mutex_lock(&teedev->mutex);
 809         /* Shouldn't put in this state */
 810         if (!WARN_ON(!teedev->desc)) {
 811                 teedev->num_users--;
 812                 if (!teedev->num_users) {
 813                         teedev->desc = NULL;
 814                         complete(&teedev->c_no_users);
 815                 }
 816         }
 817         mutex_unlock(&teedev->mutex);
 818 }
 819
 820 bool tee_device_get(struct tee_device *teedev)
 821 {
 822         mutex_lock(&teedev->mutex);
 823         if (!teedev->desc) {
 824                 mutex_unlock(&teedev->mutex);
 825                 return false;
 826         }
 827         teedev->num_users++;
 828         mutex_unlock(&teedev->mutex);
 829         return true;
 830 }
 831
 832 /**
 833  * tee_device_unregister() - Removes a TEE device
 834  * @teedev:     Device to unregister
 835  *
 836  * This function should be called to remove the @teedev even if
 837  * tee_device_register() hasn't been called yet. Does nothing if
 838  * @teedev is NULL.
 839  */
 840 void tee_device_unregister(struct tee_device *teedev)
 841 {
 842         if (!teedev)
 843                 return;
 844
 845         if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED) {
 846                 sysfs_remove_group(&teedev->dev.kobj, &tee_dev_group);
 847                 cdev_del(&teedev->cdev);
 848                 device_del(&teedev->dev);
 849         }
 850
 851         tee_device_put(teedev);
 852         wait_for_completion(&teedev->c_no_users);
 853
 854         /*
 855          * No need to take a mutex any longer now since teedev->desc was
 856          * set to NULL before teedev->c_no_users was completed.
 857          */
 858
 859         teedev->pool = NULL;
 860
 861         put_device(&teedev->dev);
 862 }
 863 EXPORT_SYMBOL_GPL(tee_device_unregister);
 864
 865 /**
 866  * tee_get_drvdata() - Return driver_data pointer
 867  * @teedev:     Device containing the driver_data pointer
 868  * @returns the driver_data pointer supplied to tee_register().
 869  */
 870 void *tee_get_drvdata(struct tee_device *teedev)
 871 {
 872         return dev_get_drvdata(&teedev->dev);
 873 }
 874 EXPORT_SYMBOL_GPL(tee_get_drvdata);
 875
 876 static int __init tee_init(void)
 877 {
 878         int rc;
 879
 880         tee_class = class_create(THIS_MODULE, "tee");
 881         if (IS_ERR(tee_class)) {
 882                 pr_err("couldn't create class\n");
 883                 return PTR_ERR(tee_class);
 884         }
 885
 886         rc = alloc_chrdev_region(&tee_devt, 0, TEE_NUM_DEVICES, "tee");
 887         if (rc) {
 888                 pr_err("failed to allocate char dev region\n");
 889                 class_destroy(tee_class);
 890                 tee_class = NULL;
 891         }
 892
 893         return rc;
 894 }
 895
 896 static void __exit tee_exit(void)
 897 {
 898         class_destroy(tee_class);
 899         tee_class = NULL;
 900         unregister_chrdev_region(tee_devt, TEE_NUM_DEVICES);
 901 }
 902
 903 subsys_initcall(tee_init);
 904 module_exit(tee_exit);
 905
 906 MODULE_AUTHOR("Linaro");
 907 MODULE_DESCRIPTION("TEE Driver");
 908 MODULE_VERSION("1.0");
 909 MODULE_LICENSE("GPL v2");