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