drivers/tee/tee_shm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015-2016, Linaro Limited
   4  */
   5 #include <linux/device.h>
   6 #include <linux/dma-buf.h>
   7 #include <linux/fdtable.h>
   8 #include <linux/idr.h>
   9 #include <linux/sched.h>
  10 #include <linux/slab.h>
  11 #include <linux/tee_drv.h>
  12 #include <linux/uio.h>
  13 #include "tee_private.h"
  14
  15 static void release_registered_pages(struct tee_shm *shm)
  16 {
  17         if (shm->pages) {
  18                 if (shm->flags & TEE_SHM_USER_MAPPED) {
  19                         unpin_user_pages(shm->pages, shm->num_pages);
  20                 } else {
  21                         size_t n;
  22
  23                         for (n = 0; n < shm->num_pages; n++)
  24                                 put_page(shm->pages[n]);
  25                 }
  26
  27                 kfree(shm->pages);
  28         }
  29 }
  30
  31 static void tee_shm_release(struct tee_shm *shm)
  32 {
  33         struct tee_device *teedev = shm->ctx->teedev;
  34
  35         if (shm->flags & TEE_SHM_DMA_BUF) {
  36                 mutex_lock(&teedev->mutex);
  37                 idr_remove(&teedev->idr, shm->id);
  38                 mutex_unlock(&teedev->mutex);
  39         }
  40
  41         if (shm->flags & TEE_SHM_POOL) {
  42                 struct tee_shm_pool_mgr *poolm;
  43
  44                 if (shm->flags & TEE_SHM_DMA_BUF)
  45                         poolm = teedev->pool->dma_buf_mgr;
  46                 else
  47                         poolm = teedev->pool->private_mgr;
  48
  49                 poolm->ops->free(poolm, shm);
  50         } else if (shm->flags & TEE_SHM_REGISTER) {
  51                 int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
  52
  53                 if (rc)
  54                         dev_err(teedev->dev.parent,
  55                                 "unregister shm %p failed: %d", shm, rc);
  56
  57                 release_registered_pages(shm);
  58         }
  59
  60         teedev_ctx_put(shm->ctx);
  61
  62         kfree(shm);
  63
  64         tee_device_put(teedev);
  65 }
  66
  67 static struct sg_table *tee_shm_op_map_dma_buf(struct dma_buf_attachment
  68                         *attach, enum dma_data_direction dir)
  69 {
  70         return NULL;
  71 }
  72
  73 static void tee_shm_op_unmap_dma_buf(struct dma_buf_attachment *attach,
  74                                      struct sg_table *table,
  75                                      enum dma_data_direction dir)
  76 {
  77 }
  78
  79 static void tee_shm_op_release(struct dma_buf *dmabuf)
  80 {
  81         struct tee_shm *shm = dmabuf->priv;
  82
  83         tee_shm_release(shm);
  84 }
  85
  86 static int tee_shm_op_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
  87 {
  88         struct tee_shm *shm = dmabuf->priv;
  89         size_t size = vma->vm_end - vma->vm_start;
  90
  91         /* Refuse sharing shared memory provided by application */
  92         if (shm->flags & TEE_SHM_USER_MAPPED)
  93                 return -EINVAL;
  94
  95         return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
  96                                size, vma->vm_page_prot);
  97 }
  98
  99 static const struct dma_buf_ops tee_shm_dma_buf_ops = {
 100         .map_dma_buf = tee_shm_op_map_dma_buf,
 101         .unmap_dma_buf = tee_shm_op_unmap_dma_buf,
 102         .release = tee_shm_op_release,
 103         .mmap = tee_shm_op_mmap,
 104 };
 105
 106 struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
 107 {
 108         struct tee_device *teedev = ctx->teedev;
 109         struct tee_shm_pool_mgr *poolm = NULL;
 110         struct tee_shm *shm;
 111         void *ret;
 112         int rc;
 113
 114         if (!(flags & TEE_SHM_MAPPED)) {
 115                 dev_err(teedev->dev.parent,
 116                         "only mapped allocations supported\n");
 117                 return ERR_PTR(-EINVAL);
 118         }
 119
 120         if ((flags & ~(TEE_SHM_MAPPED | TEE_SHM_DMA_BUF | TEE_SHM_PRIV))) {
 121                 dev_err(teedev->dev.parent, "invalid shm flags 0x%x", flags);
 122                 return ERR_PTR(-EINVAL);
 123         }
 124
 125         if (!tee_device_get(teedev))
 126                 return ERR_PTR(-EINVAL);
 127
 128         if (!teedev->pool) {
 129                 /* teedev has been detached from driver */
 130                 ret = ERR_PTR(-EINVAL);
 131                 goto err_dev_put;
 132         }
 133
 134         shm = kzalloc(sizeof(*shm), GFP_KERNEL);
 135         if (!shm) {
 136                 ret = ERR_PTR(-ENOMEM);
 137                 goto err_dev_put;
 138         }
 139
 140         shm->flags = flags | TEE_SHM_POOL;
 141         shm->ctx = ctx;
 142         if (flags & TEE_SHM_DMA_BUF)
 143                 poolm = teedev->pool->dma_buf_mgr;
 144         else
 145                 poolm = teedev->pool->private_mgr;
 146
 147         rc = poolm->ops->alloc(poolm, shm, size);
 148         if (rc) {
 149                 ret = ERR_PTR(rc);
 150                 goto err_kfree;
 151         }
 152
 153
 154         if (flags & TEE_SHM_DMA_BUF) {
 155                 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 156
 157                 mutex_lock(&teedev->mutex);
 158                 shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
 159                 mutex_unlock(&teedev->mutex);
 160                 if (shm->id < 0) {
 161                         ret = ERR_PTR(shm->id);
 162                         goto err_pool_free;
 163                 }
 164
 165                 exp_info.ops = &tee_shm_dma_buf_ops;
 166                 exp_info.size = shm->size;
 167                 exp_info.flags = O_RDWR;
 168                 exp_info.priv = shm;
 169
 170                 shm->dmabuf = dma_buf_export(&exp_info);
 171                 if (IS_ERR(shm->dmabuf)) {
 172                         ret = ERR_CAST(shm->dmabuf);
 173                         goto err_rem;
 174                 }
 175         }
 176
 177         teedev_ctx_get(ctx);
 178
 179         return shm;
 180 err_rem:
 181         if (flags & TEE_SHM_DMA_BUF) {
 182                 mutex_lock(&teedev->mutex);
 183                 idr_remove(&teedev->idr, shm->id);
 184                 mutex_unlock(&teedev->mutex);
 185         }
 186 err_pool_free:
 187         poolm->ops->free(poolm, shm);
 188 err_kfree:
 189         kfree(shm);
 190 err_dev_put:
 191         tee_device_put(teedev);
 192         return ret;
 193 }
 194 EXPORT_SYMBOL_GPL(tee_shm_alloc);
 195
 196 /**
 197  * tee_shm_alloc_kernel_buf() - Allocate shared memory for kernel buffer
 198  * @ctx:        Context that allocates the shared memory
 199  * @size:       Requested size of shared memory
 200  *
 201  * The returned memory registered in secure world and is suitable to be
 202  * passed as a memory buffer in parameter argument to
 203  * tee_client_invoke_func(). The memory allocated is later freed with a
 204  * call to tee_shm_free().
 205  *
 206  * @returns a pointer to 'struct tee_shm'
 207  */
 208 struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
 209 {
 210         return tee_shm_alloc(ctx, size, TEE_SHM_MAPPED);
 211 }
 212 EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
 213
 214 struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
 215                                  size_t length, u32 flags)
 216 {
 217         struct tee_device *teedev = ctx->teedev;
 218         const u32 req_user_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
 219         const u32 req_kernel_flags = TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED;
 220         struct tee_shm *shm;
 221         void *ret;
 222         int rc;
 223         int num_pages;
 224         unsigned long start;
 225
 226         if (flags != req_user_flags && flags != req_kernel_flags)
 227                 return ERR_PTR(-ENOTSUPP);
 228
 229         if (!tee_device_get(teedev))
 230                 return ERR_PTR(-EINVAL);
 231
 232         if (!teedev->desc->ops->shm_register ||
 233             !teedev->desc->ops->shm_unregister) {
 234                 tee_device_put(teedev);
 235                 return ERR_PTR(-ENOTSUPP);
 236         }
 237
 238         teedev_ctx_get(ctx);
 239
 240         shm = kzalloc(sizeof(*shm), GFP_KERNEL);
 241         if (!shm) {
 242                 ret = ERR_PTR(-ENOMEM);
 243                 goto err;
 244         }
 245
 246         shm->flags = flags | TEE_SHM_REGISTER;
 247         shm->ctx = ctx;
 248         shm->id = -1;
 249         addr = untagged_addr(addr);
 250         start = rounddown(addr, PAGE_SIZE);
 251         shm->offset = addr - start;
 252         shm->size = length;
 253         num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
 254         shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
 255         if (!shm->pages) {
 256                 ret = ERR_PTR(-ENOMEM);
 257                 goto err;
 258         }
 259
 260         if (flags & TEE_SHM_USER_MAPPED) {
 261                 rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE,
 262                                          shm->pages);
 263         } else {
 264                 struct kvec *kiov;
 265                 int i;
 266
 267                 kiov = kcalloc(num_pages, sizeof(*kiov), GFP_KERNEL);
 268                 if (!kiov) {
 269                         ret = ERR_PTR(-ENOMEM);
 270                         goto err;
 271                 }
 272
 273                 for (i = 0; i < num_pages; i++) {
 274                         kiov[i].iov_base = (void *)(start + i * PAGE_SIZE);
 275                         kiov[i].iov_len = PAGE_SIZE;
 276                 }
 277
 278                 rc = get_kernel_pages(kiov, num_pages, 0, shm->pages);
 279                 kfree(kiov);
 280         }
 281         if (rc > 0)
 282                 shm->num_pages = rc;
 283         if (rc != num_pages) {
 284                 if (rc >= 0)
 285                         rc = -ENOMEM;
 286                 ret = ERR_PTR(rc);
 287                 goto err;
 288         }
 289
 290         mutex_lock(&teedev->mutex);
 291         shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
 292         mutex_unlock(&teedev->mutex);
 293
 294         if (shm->id < 0) {
 295                 ret = ERR_PTR(shm->id);
 296                 goto err;
 297         }
 298
 299         rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
 300                                              shm->num_pages, start);
 301         if (rc) {
 302                 ret = ERR_PTR(rc);
 303                 goto err;
 304         }
 305
 306         if (flags & TEE_SHM_DMA_BUF) {
 307                 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 308
 309                 exp_info.ops = &tee_shm_dma_buf_ops;
 310                 exp_info.size = shm->size;
 311                 exp_info.flags = O_RDWR;
 312                 exp_info.priv = shm;
 313
 314                 shm->dmabuf = dma_buf_export(&exp_info);
 315                 if (IS_ERR(shm->dmabuf)) {
 316                         ret = ERR_CAST(shm->dmabuf);
 317                         teedev->desc->ops->shm_unregister(ctx, shm);
 318                         goto err;
 319                 }
 320         }
 321
 322         return shm;
 323 err:
 324         if (shm) {
 325                 if (shm->id >= 0) {
 326                         mutex_lock(&teedev->mutex);
 327                         idr_remove(&teedev->idr, shm->id);
 328                         mutex_unlock(&teedev->mutex);
 329                 }
 330                 release_registered_pages(shm);
 331         }
 332         kfree(shm);
 333         teedev_ctx_put(ctx);
 334         tee_device_put(teedev);
 335         return ret;
 336 }
 337 EXPORT_SYMBOL_GPL(tee_shm_register);
 338
 339 /**
 340  * tee_shm_get_fd() - Increase reference count and return file descriptor
 341  * @shm:        Shared memory handle
 342  * @returns user space file descriptor to shared memory
 343  */
 344 int tee_shm_get_fd(struct tee_shm *shm)
 345 {
 346         int fd;
 347
 348         if (!(shm->flags & TEE_SHM_DMA_BUF))
 349                 return -EINVAL;
 350
 351         get_dma_buf(shm->dmabuf);
 352         fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
 353         if (fd < 0)
 354                 dma_buf_put(shm->dmabuf);
 355         return fd;
 356 }
 357
 358 /**
 359  * tee_shm_free() - Free shared memory
 360  * @shm:        Handle to shared memory to free
 361  */
 362 void tee_shm_free(struct tee_shm *shm)
 363 {
 364         /*
 365          * dma_buf_put() decreases the dmabuf reference counter and will
 366          * call tee_shm_release() when the last reference is gone.
 367          *
 368          * In the case of driver private memory we call tee_shm_release
 369          * directly instead as it doesn't have a reference counter.
 370          */
 371         if (shm->flags & TEE_SHM_DMA_BUF)
 372                 dma_buf_put(shm->dmabuf);
 373         else
 374                 tee_shm_release(shm);
 375 }
 376 EXPORT_SYMBOL_GPL(tee_shm_free);
 377
 378 /**
 379  * tee_shm_va2pa() - Get physical address of a virtual address
 380  * @shm:        Shared memory handle
 381  * @va:         Virtual address to tranlsate
 382  * @pa:         Returned physical address
 383  * @returns 0 on success and < 0 on failure
 384  */
 385 int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
 386 {
 387         if (!(shm->flags & TEE_SHM_MAPPED))
 388                 return -EINVAL;
 389         /* Check that we're in the range of the shm */
 390         if ((char *)va < (char *)shm->kaddr)
 391                 return -EINVAL;
 392         if ((char *)va >= ((char *)shm->kaddr + shm->size))
 393                 return -EINVAL;
 394
 395         return tee_shm_get_pa(
 396                         shm, (unsigned long)va - (unsigned long)shm->kaddr, pa);
 397 }
 398 EXPORT_SYMBOL_GPL(tee_shm_va2pa);
 399
 400 /**
 401  * tee_shm_pa2va() - Get virtual address of a physical address
 402  * @shm:        Shared memory handle
 403  * @pa:         Physical address to tranlsate
 404  * @va:         Returned virtual address
 405  * @returns 0 on success and < 0 on failure
 406  */
 407 int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
 408 {
 409         if (!(shm->flags & TEE_SHM_MAPPED))
 410                 return -EINVAL;
 411         /* Check that we're in the range of the shm */
 412         if (pa < shm->paddr)
 413                 return -EINVAL;
 414         if (pa >= (shm->paddr + shm->size))
 415                 return -EINVAL;
 416
 417         if (va) {
 418                 void *v = tee_shm_get_va(shm, pa - shm->paddr);
 419
 420                 if (IS_ERR(v))
 421                         return PTR_ERR(v);
 422                 *va = v;
 423         }
 424         return 0;
 425 }
 426 EXPORT_SYMBOL_GPL(tee_shm_pa2va);
 427
 428 /**
 429  * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
 430  * @shm:        Shared memory handle
 431  * @offs:       Offset from start of this shared memory
 432  * @returns virtual address of the shared memory + offs if offs is within
 433  *      the bounds of this shared memory, else an ERR_PTR
 434  */
 435 void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
 436 {
 437         if (!(shm->flags & TEE_SHM_MAPPED))
 438                 return ERR_PTR(-EINVAL);
 439         if (offs >= shm->size)
 440                 return ERR_PTR(-EINVAL);
 441         return (char *)shm->kaddr + offs;
 442 }
 443 EXPORT_SYMBOL_GPL(tee_shm_get_va);
 444
 445 /**
 446  * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
 447  * @shm:        Shared memory handle
 448  * @offs:       Offset from start of this shared memory
 449  * @pa:         Physical address to return
 450  * @returns 0 if offs is within the bounds of this shared memory, else an
 451  *      error code.
 452  */
 453 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
 454 {
 455         if (offs >= shm->size)
 456                 return -EINVAL;
 457         if (pa)
 458                 *pa = shm->paddr + offs;
 459         return 0;
 460 }
 461 EXPORT_SYMBOL_GPL(tee_shm_get_pa);
 462
 463 /**
 464  * tee_shm_get_from_id() - Find shared memory object and increase reference
 465  * count
 466  * @ctx:        Context owning the shared memory
 467  * @id:         Id of shared memory object
 468  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
 469  */
 470 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
 471 {
 472         struct tee_device *teedev;
 473         struct tee_shm *shm;
 474
 475         if (!ctx)
 476                 return ERR_PTR(-EINVAL);
 477
 478         teedev = ctx->teedev;
 479         mutex_lock(&teedev->mutex);
 480         shm = idr_find(&teedev->idr, id);
 481         if (!shm || shm->ctx != ctx)
 482                 shm = ERR_PTR(-EINVAL);
 483         else if (shm->flags & TEE_SHM_DMA_BUF)
 484                 get_dma_buf(shm->dmabuf);
 485         mutex_unlock(&teedev->mutex);
 486         return shm;
 487 }
 488 EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
 489
 490 /**
 491  * tee_shm_put() - Decrease reference count on a shared memory handle
 492  * @shm:        Shared memory handle
 493  */
 494 void tee_shm_put(struct tee_shm *shm)
 495 {
 496         if (shm->flags & TEE_SHM_DMA_BUF)
 497                 dma_buf_put(shm->dmabuf);
 498 }
 499 EXPORT_SYMBOL_GPL(tee_shm_put);