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