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))) {
 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 struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
 197                                  size_t length, u32 flags)
 198 {
 199         struct tee_device *teedev = ctx->teedev;
 200         const u32 req_user_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
 201         const u32 req_kernel_flags = TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED;
 202         struct tee_shm *shm;
 203         void *ret;
 204         int rc;
 205         int num_pages;
 206         unsigned long start;
 207
 208         if (flags != req_user_flags && flags != req_kernel_flags)
 209                 return ERR_PTR(-ENOTSUPP);
 210
 211         if (!tee_device_get(teedev))
 212                 return ERR_PTR(-EINVAL);
 213
 214         if (!teedev->desc->ops->shm_register ||
 215             !teedev->desc->ops->shm_unregister) {
 216                 tee_device_put(teedev);
 217                 return ERR_PTR(-ENOTSUPP);
 218         }
 219
 220         teedev_ctx_get(ctx);
 221
 222         shm = kzalloc(sizeof(*shm), GFP_KERNEL);
 223         if (!shm) {
 224                 ret = ERR_PTR(-ENOMEM);
 225                 goto err;
 226         }
 227
 228         shm->flags = flags | TEE_SHM_REGISTER;
 229         shm->ctx = ctx;
 230         shm->id = -1;
 231         addr = untagged_addr(addr);
 232         start = rounddown(addr, PAGE_SIZE);
 233         shm->offset = addr - start;
 234         shm->size = length;
 235         num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
 236         shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
 237         if (!shm->pages) {
 238                 ret = ERR_PTR(-ENOMEM);
 239                 goto err;
 240         }
 241
 242         if (flags & TEE_SHM_USER_MAPPED) {
 243                 rc = pin_user_pages_fast(start, num_pages, FOLL_WRITE,
 244                                          shm->pages);
 245         } else {
 246                 struct kvec *kiov;
 247                 int i;
 248
 249                 kiov = kcalloc(num_pages, sizeof(*kiov), GFP_KERNEL);
 250                 if (!kiov) {
 251                         ret = ERR_PTR(-ENOMEM);
 252                         goto err;
 253                 }
 254
 255                 for (i = 0; i < num_pages; i++) {
 256                         kiov[i].iov_base = (void *)(start + i * PAGE_SIZE);
 257                         kiov[i].iov_len = PAGE_SIZE;
 258                 }
 259
 260                 rc = get_kernel_pages(kiov, num_pages, 0, shm->pages);
 261                 kfree(kiov);
 262         }
 263         if (rc > 0)
 264                 shm->num_pages = rc;
 265         if (rc != num_pages) {
 266                 if (rc >= 0)
 267                         rc = -ENOMEM;
 268                 ret = ERR_PTR(rc);
 269                 goto err;
 270         }
 271
 272         mutex_lock(&teedev->mutex);
 273         shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
 274         mutex_unlock(&teedev->mutex);
 275
 276         if (shm->id < 0) {
 277                 ret = ERR_PTR(shm->id);
 278                 goto err;
 279         }
 280
 281         rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
 282                                              shm->num_pages, start);
 283         if (rc) {
 284                 ret = ERR_PTR(rc);
 285                 goto err;
 286         }
 287
 288         if (flags & TEE_SHM_DMA_BUF) {
 289                 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 290
 291                 exp_info.ops = &tee_shm_dma_buf_ops;
 292                 exp_info.size = shm->size;
 293                 exp_info.flags = O_RDWR;
 294                 exp_info.priv = shm;
 295
 296                 shm->dmabuf = dma_buf_export(&exp_info);
 297                 if (IS_ERR(shm->dmabuf)) {
 298                         ret = ERR_CAST(shm->dmabuf);
 299                         teedev->desc->ops->shm_unregister(ctx, shm);
 300                         goto err;
 301                 }
 302         }
 303
 304         return shm;
 305 err:
 306         if (shm) {
 307                 if (shm->id >= 0) {
 308                         mutex_lock(&teedev->mutex);
 309                         idr_remove(&teedev->idr, shm->id);
 310                         mutex_unlock(&teedev->mutex);
 311                 }
 312                 release_registered_pages(shm);
 313         }
 314         kfree(shm);
 315         teedev_ctx_put(ctx);
 316         tee_device_put(teedev);
 317         return ret;
 318 }
 319 EXPORT_SYMBOL_GPL(tee_shm_register);
 320
 321 /**
 322  * tee_shm_get_fd() - Increase reference count and return file descriptor
 323  * @shm:        Shared memory handle
 324  * @returns user space file descriptor to shared memory
 325  */
 326 int tee_shm_get_fd(struct tee_shm *shm)
 327 {
 328         int fd;
 329
 330         if (!(shm->flags & TEE_SHM_DMA_BUF))
 331                 return -EINVAL;
 332
 333         get_dma_buf(shm->dmabuf);
 334         fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
 335         if (fd < 0)
 336                 dma_buf_put(shm->dmabuf);
 337         return fd;
 338 }
 339
 340 /**
 341  * tee_shm_free() - Free shared memory
 342  * @shm:        Handle to shared memory to free
 343  */
 344 void tee_shm_free(struct tee_shm *shm)
 345 {
 346         /*
 347          * dma_buf_put() decreases the dmabuf reference counter and will
 348          * call tee_shm_release() when the last reference is gone.
 349          *
 350          * In the case of driver private memory we call tee_shm_release
 351          * directly instead as it doesn't have a reference counter.
 352          */
 353         if (shm->flags & TEE_SHM_DMA_BUF)
 354                 dma_buf_put(shm->dmabuf);
 355         else
 356                 tee_shm_release(shm);
 357 }
 358 EXPORT_SYMBOL_GPL(tee_shm_free);
 359
 360 /**
 361  * tee_shm_va2pa() - Get physical address of a virtual address
 362  * @shm:        Shared memory handle
 363  * @va:         Virtual address to tranlsate
 364  * @pa:         Returned physical address
 365  * @returns 0 on success and < 0 on failure
 366  */
 367 int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
 368 {
 369         if (!(shm->flags & TEE_SHM_MAPPED))
 370                 return -EINVAL;
 371         /* Check that we're in the range of the shm */
 372         if ((char *)va < (char *)shm->kaddr)
 373                 return -EINVAL;
 374         if ((char *)va >= ((char *)shm->kaddr + shm->size))
 375                 return -EINVAL;
 376
 377         return tee_shm_get_pa(
 378                         shm, (unsigned long)va - (unsigned long)shm->kaddr, pa);
 379 }
 380 EXPORT_SYMBOL_GPL(tee_shm_va2pa);
 381
 382 /**
 383  * tee_shm_pa2va() - Get virtual address of a physical address
 384  * @shm:        Shared memory handle
 385  * @pa:         Physical address to tranlsate
 386  * @va:         Returned virtual address
 387  * @returns 0 on success and < 0 on failure
 388  */
 389 int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
 390 {
 391         if (!(shm->flags & TEE_SHM_MAPPED))
 392                 return -EINVAL;
 393         /* Check that we're in the range of the shm */
 394         if (pa < shm->paddr)
 395                 return -EINVAL;
 396         if (pa >= (shm->paddr + shm->size))
 397                 return -EINVAL;
 398
 399         if (va) {
 400                 void *v = tee_shm_get_va(shm, pa - shm->paddr);
 401
 402                 if (IS_ERR(v))
 403                         return PTR_ERR(v);
 404                 *va = v;
 405         }
 406         return 0;
 407 }
 408 EXPORT_SYMBOL_GPL(tee_shm_pa2va);
 409
 410 /**
 411  * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
 412  * @shm:        Shared memory handle
 413  * @offs:       Offset from start of this shared memory
 414  * @returns virtual address of the shared memory + offs if offs is within
 415  *      the bounds of this shared memory, else an ERR_PTR
 416  */
 417 void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
 418 {
 419         if (!(shm->flags & TEE_SHM_MAPPED))
 420                 return ERR_PTR(-EINVAL);
 421         if (offs >= shm->size)
 422                 return ERR_PTR(-EINVAL);
 423         return (char *)shm->kaddr + offs;
 424 }
 425 EXPORT_SYMBOL_GPL(tee_shm_get_va);
 426
 427 /**
 428  * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
 429  * @shm:        Shared memory handle
 430  * @offs:       Offset from start of this shared memory
 431  * @pa:         Physical address to return
 432  * @returns 0 if offs is within the bounds of this shared memory, else an
 433  *      error code.
 434  */
 435 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
 436 {
 437         if (offs >= shm->size)
 438                 return -EINVAL;
 439         if (pa)
 440                 *pa = shm->paddr + offs;
 441         return 0;
 442 }
 443 EXPORT_SYMBOL_GPL(tee_shm_get_pa);
 444
 445 /**
 446  * tee_shm_get_from_id() - Find shared memory object and increase reference
 447  * count
 448  * @ctx:        Context owning the shared memory
 449  * @id:         Id of shared memory object
 450  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
 451  */
 452 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
 453 {
 454         struct tee_device *teedev;
 455         struct tee_shm *shm;
 456
 457         if (!ctx)
 458                 return ERR_PTR(-EINVAL);
 459
 460         teedev = ctx->teedev;
 461         mutex_lock(&teedev->mutex);
 462         shm = idr_find(&teedev->idr, id);
 463         if (!shm || shm->ctx != ctx)
 464                 shm = ERR_PTR(-EINVAL);
 465         else if (shm->flags & TEE_SHM_DMA_BUF)
 466                 get_dma_buf(shm->dmabuf);
 467         mutex_unlock(&teedev->mutex);
 468         return shm;
 469 }
 470 EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
 471
 472 /**
 473  * tee_shm_put() - Decrease reference count on a shared memory handle
 474  * @shm:        Shared memory handle
 475  */
 476 void tee_shm_put(struct tee_shm *shm)
 477 {
 478         if (shm->flags & TEE_SHM_DMA_BUF)
 479                 dma_buf_put(shm->dmabuf);
 480 }
 481 EXPORT_SYMBOL_GPL(tee_shm_put);