drivers/tee/tee_shm.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 #include <linux/device.h>
  15 #include <linux/dma-buf.h>
  16 #include <linux/fdtable.h>
  17 #include <linux/idr.h>
  18 #include <linux/sched.h>
  19 #include <linux/slab.h>
  20 #include <linux/tee_drv.h>
  21 #include "tee_private.h"
  22
  23 static void tee_shm_release(struct tee_shm *shm)
  24 {
  25         struct tee_device *teedev = shm->teedev;
  26
  27         mutex_lock(&teedev->mutex);
  28         idr_remove(&teedev->idr, shm->id);
  29         if (shm->ctx)
  30                 list_del(&shm->link);
  31         mutex_unlock(&teedev->mutex);
  32
  33         if (shm->flags & TEE_SHM_POOL) {
  34                 struct tee_shm_pool_mgr *poolm;
  35
  36                 if (shm->flags & TEE_SHM_DMA_BUF)
  37                         poolm = teedev->pool->dma_buf_mgr;
  38                 else
  39                         poolm = teedev->pool->private_mgr;
  40
  41                 poolm->ops->free(poolm, shm);
  42         } else if (shm->flags & TEE_SHM_REGISTER) {
  43                 size_t n;
  44                 int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
  45
  46                 if (rc)
  47                         dev_err(teedev->dev.parent,
  48                                 "unregister shm %p failed: %d", shm, rc);
  49
  50                 for (n = 0; n < shm->num_pages; n++)
  51                         put_page(shm->pages[n]);
  52
  53                 kfree(shm->pages);
  54         }
  55
  56         if (shm->ctx)
  57                 teedev_ctx_put(shm->ctx);
  58
  59         kfree(shm);
  60
  61         tee_device_put(teedev);
  62 }
  63
  64 static struct sg_table *tee_shm_op_map_dma_buf(struct dma_buf_attachment
  65                         *attach, enum dma_data_direction dir)
  66 {
  67         return NULL;
  68 }
  69
  70 static void tee_shm_op_unmap_dma_buf(struct dma_buf_attachment *attach,
  71                                      struct sg_table *table,
  72                                      enum dma_data_direction dir)
  73 {
  74 }
  75
  76 static void tee_shm_op_release(struct dma_buf *dmabuf)
  77 {
  78         struct tee_shm *shm = dmabuf->priv;
  79
  80         tee_shm_release(shm);
  81 }
  82
  83 static void *tee_shm_op_map(struct dma_buf *dmabuf, unsigned long pgnum)
  84 {
  85         return NULL;
  86 }
  87
  88 static int tee_shm_op_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
  89 {
  90         struct tee_shm *shm = dmabuf->priv;
  91         size_t size = vma->vm_end - vma->vm_start;
  92
  93         /* Refuse sharing shared memory provided by application */
  94         if (shm->flags & TEE_SHM_REGISTER)
  95                 return -EINVAL;
  96
  97         return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
  98                                size, vma->vm_page_prot);
  99 }
 100
 101 static const struct dma_buf_ops tee_shm_dma_buf_ops = {
 102         .map_dma_buf = tee_shm_op_map_dma_buf,
 103         .unmap_dma_buf = tee_shm_op_unmap_dma_buf,
 104         .release = tee_shm_op_release,
 105         .map = tee_shm_op_map,
 106         .mmap = tee_shm_op_mmap,
 107 };
 108
 109 static struct tee_shm *__tee_shm_alloc(struct tee_context *ctx,
 110                                        struct tee_device *teedev,
 111                                        size_t size, u32 flags)
 112 {
 113         struct tee_shm_pool_mgr *poolm = NULL;
 114         struct tee_shm *shm;
 115         void *ret;
 116         int rc;
 117
 118         if (ctx && ctx->teedev != teedev) {
 119                 dev_err(teedev->dev.parent, "ctx and teedev mismatch\n");
 120                 return ERR_PTR(-EINVAL);
 121         }
 122
 123         if (!(flags & TEE_SHM_MAPPED)) {
 124                 dev_err(teedev->dev.parent,
 125                         "only mapped allocations supported\n");
 126                 return ERR_PTR(-EINVAL);
 127         }
 128
 129         if ((flags & ~(TEE_SHM_MAPPED | TEE_SHM_DMA_BUF))) {
 130                 dev_err(teedev->dev.parent, "invalid shm flags 0x%x", flags);
 131                 return ERR_PTR(-EINVAL);
 132         }
 133
 134         if (!tee_device_get(teedev))
 135                 return ERR_PTR(-EINVAL);
 136
 137         if (!teedev->pool) {
 138                 /* teedev has been detached from driver */
 139                 ret = ERR_PTR(-EINVAL);
 140                 goto err_dev_put;
 141         }
 142
 143         shm = kzalloc(sizeof(*shm), GFP_KERNEL);
 144         if (!shm) {
 145                 ret = ERR_PTR(-ENOMEM);
 146                 goto err_dev_put;
 147         }
 148
 149         shm->flags = flags | TEE_SHM_POOL;
 150         shm->teedev = teedev;
 151         shm->ctx = ctx;
 152         if (flags & TEE_SHM_DMA_BUF)
 153                 poolm = teedev->pool->dma_buf_mgr;
 154         else
 155                 poolm = teedev->pool->private_mgr;
 156
 157         rc = poolm->ops->alloc(poolm, shm, size);
 158         if (rc) {
 159                 ret = ERR_PTR(rc);
 160                 goto err_kfree;
 161         }
 162
 163         mutex_lock(&teedev->mutex);
 164         shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
 165         mutex_unlock(&teedev->mutex);
 166         if (shm->id < 0) {
 167                 ret = ERR_PTR(shm->id);
 168                 goto err_pool_free;
 169         }
 170
 171         if (flags & TEE_SHM_DMA_BUF) {
 172                 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 173
 174                 exp_info.ops = &tee_shm_dma_buf_ops;
 175                 exp_info.size = shm->size;
 176                 exp_info.flags = O_RDWR;
 177                 exp_info.priv = shm;
 178
 179                 shm->dmabuf = dma_buf_export(&exp_info);
 180                 if (IS_ERR(shm->dmabuf)) {
 181                         ret = ERR_CAST(shm->dmabuf);
 182                         goto err_rem;
 183                 }
 184         }
 185
 186         if (ctx) {
 187                 teedev_ctx_get(ctx);
 188                 mutex_lock(&teedev->mutex);
 189                 list_add_tail(&shm->link, &ctx->list_shm);
 190                 mutex_unlock(&teedev->mutex);
 191         }
 192
 193         return shm;
 194 err_rem:
 195         mutex_lock(&teedev->mutex);
 196         idr_remove(&teedev->idr, shm->id);
 197         mutex_unlock(&teedev->mutex);
 198 err_pool_free:
 199         poolm->ops->free(poolm, shm);
 200 err_kfree:
 201         kfree(shm);
 202 err_dev_put:
 203         tee_device_put(teedev);
 204         return ret;
 205 }
 206
 207 /**
 208  * tee_shm_alloc() - Allocate shared memory
 209  * @ctx:        Context that allocates the shared memory
 210  * @size:       Requested size of shared memory
 211  * @flags:      Flags setting properties for the requested shared memory.
 212  *
 213  * Memory allocated as global shared memory is automatically freed when the
 214  * TEE file pointer is closed. The @flags field uses the bits defined by
 215  * TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
 216  * set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
 217  * associated with a dma-buf handle, else driver private memory.
 218  */
 219 struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
 220 {
 221         return __tee_shm_alloc(ctx, ctx->teedev, size, flags);
 222 }
 223 EXPORT_SYMBOL_GPL(tee_shm_alloc);
 224
 225 struct tee_shm *tee_shm_priv_alloc(struct tee_device *teedev, size_t size)
 226 {
 227         return __tee_shm_alloc(NULL, teedev, size, TEE_SHM_MAPPED);
 228 }
 229 EXPORT_SYMBOL_GPL(tee_shm_priv_alloc);
 230
 231 struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
 232                                  size_t length, u32 flags)
 233 {
 234         struct tee_device *teedev = ctx->teedev;
 235         const u32 req_flags = TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED;
 236         struct tee_shm *shm;
 237         void *ret;
 238         int rc;
 239         int num_pages;
 240         unsigned long start;
 241
 242         if (flags != req_flags)
 243                 return ERR_PTR(-ENOTSUPP);
 244
 245         if (!tee_device_get(teedev))
 246                 return ERR_PTR(-EINVAL);
 247
 248         if (!teedev->desc->ops->shm_register ||
 249             !teedev->desc->ops->shm_unregister) {
 250                 tee_device_put(teedev);
 251                 return ERR_PTR(-ENOTSUPP);
 252         }
 253
 254         teedev_ctx_get(ctx);
 255
 256         shm = kzalloc(sizeof(*shm), GFP_KERNEL);
 257         if (!shm) {
 258                 ret = ERR_PTR(-ENOMEM);
 259                 goto err;
 260         }
 261
 262         shm->flags = flags | TEE_SHM_REGISTER;
 263         shm->teedev = teedev;
 264         shm->ctx = ctx;
 265         shm->id = -1;
 266         start = rounddown(addr, PAGE_SIZE);
 267         shm->offset = addr - start;
 268         shm->size = length;
 269         num_pages = (roundup(addr + length, PAGE_SIZE) - start) / PAGE_SIZE;
 270         shm->pages = kcalloc(num_pages, sizeof(*shm->pages), GFP_KERNEL);
 271         if (!shm->pages) {
 272                 ret = ERR_PTR(-ENOMEM);
 273                 goto err;
 274         }
 275
 276         rc = get_user_pages_fast(start, num_pages, 1, shm->pages);
 277         if (rc > 0)
 278                 shm->num_pages = rc;
 279         if (rc != num_pages) {
 280                 if (rc >= 0)
 281                         rc = -ENOMEM;
 282                 ret = ERR_PTR(rc);
 283                 goto err;
 284         }
 285
 286         mutex_lock(&teedev->mutex);
 287         shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
 288         mutex_unlock(&teedev->mutex);
 289
 290         if (shm->id < 0) {
 291                 ret = ERR_PTR(shm->id);
 292                 goto err;
 293         }
 294
 295         rc = teedev->desc->ops->shm_register(ctx, shm, shm->pages,
 296                                              shm->num_pages, start);
 297         if (rc) {
 298                 ret = ERR_PTR(rc);
 299                 goto err;
 300         }
 301
 302         if (flags & TEE_SHM_DMA_BUF) {
 303                 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 304
 305                 exp_info.ops = &tee_shm_dma_buf_ops;
 306                 exp_info.size = shm->size;
 307                 exp_info.flags = O_RDWR;
 308                 exp_info.priv = shm;
 309
 310                 shm->dmabuf = dma_buf_export(&exp_info);
 311                 if (IS_ERR(shm->dmabuf)) {
 312                         ret = ERR_CAST(shm->dmabuf);
 313                         teedev->desc->ops->shm_unregister(ctx, shm);
 314                         goto err;
 315                 }
 316         }
 317
 318         mutex_lock(&teedev->mutex);
 319         list_add_tail(&shm->link, &ctx->list_shm);
 320         mutex_unlock(&teedev->mutex);
 321
 322         return shm;
 323 err:
 324         if (shm) {
 325                 size_t n;
 326
 327                 if (shm->id >= 0) {
 328                         mutex_lock(&teedev->mutex);
 329                         idr_remove(&teedev->idr, shm->id);
 330                         mutex_unlock(&teedev->mutex);
 331                 }
 332                 if (shm->pages) {
 333                         for (n = 0; n < shm->num_pages; n++)
 334                                 put_page(shm->pages[n]);
 335                         kfree(shm->pages);
 336                 }
 337         }
 338         kfree(shm);
 339         teedev_ctx_put(ctx);
 340         tee_device_put(teedev);
 341         return ret;
 342 }
 343 EXPORT_SYMBOL_GPL(tee_shm_register);
 344
 345 /**
 346  * tee_shm_get_fd() - Increase reference count and return file descriptor
 347  * @shm:        Shared memory handle
 348  * @returns user space file descriptor to shared memory
 349  */
 350 int tee_shm_get_fd(struct tee_shm *shm)
 351 {
 352         int fd;
 353
 354         if (!(shm->flags & TEE_SHM_DMA_BUF))
 355                 return -EINVAL;
 356
 357         get_dma_buf(shm->dmabuf);
 358         fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
 359         if (fd < 0)
 360                 dma_buf_put(shm->dmabuf);
 361         return fd;
 362 }
 363
 364 /**
 365  * tee_shm_free() - Free shared memory
 366  * @shm:        Handle to shared memory to free
 367  */
 368 void tee_shm_free(struct tee_shm *shm)
 369 {
 370         /*
 371          * dma_buf_put() decreases the dmabuf reference counter and will
 372          * call tee_shm_release() when the last reference is gone.
 373          *
 374          * In the case of driver private memory we call tee_shm_release
 375          * directly instead as it doesn't have a reference counter.
 376          */
 377         if (shm->flags & TEE_SHM_DMA_BUF)
 378                 dma_buf_put(shm->dmabuf);
 379         else
 380                 tee_shm_release(shm);
 381 }
 382 EXPORT_SYMBOL_GPL(tee_shm_free);
 383
 384 /**
 385  * tee_shm_va2pa() - Get physical address of a virtual address
 386  * @shm:        Shared memory handle
 387  * @va:         Virtual address to tranlsate
 388  * @pa:         Returned physical address
 389  * @returns 0 on success and < 0 on failure
 390  */
 391 int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
 392 {
 393         if (!(shm->flags & TEE_SHM_MAPPED))
 394                 return -EINVAL;
 395         /* Check that we're in the range of the shm */
 396         if ((char *)va < (char *)shm->kaddr)
 397                 return -EINVAL;
 398         if ((char *)va >= ((char *)shm->kaddr + shm->size))
 399                 return -EINVAL;
 400
 401         return tee_shm_get_pa(
 402                         shm, (unsigned long)va - (unsigned long)shm->kaddr, pa);
 403 }
 404 EXPORT_SYMBOL_GPL(tee_shm_va2pa);
 405
 406 /**
 407  * tee_shm_pa2va() - Get virtual address of a physical address
 408  * @shm:        Shared memory handle
 409  * @pa:         Physical address to tranlsate
 410  * @va:         Returned virtual address
 411  * @returns 0 on success and < 0 on failure
 412  */
 413 int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
 414 {
 415         if (!(shm->flags & TEE_SHM_MAPPED))
 416                 return -EINVAL;
 417         /* Check that we're in the range of the shm */
 418         if (pa < shm->paddr)
 419                 return -EINVAL;
 420         if (pa >= (shm->paddr + shm->size))
 421                 return -EINVAL;
 422
 423         if (va) {
 424                 void *v = tee_shm_get_va(shm, pa - shm->paddr);
 425
 426                 if (IS_ERR(v))
 427                         return PTR_ERR(v);
 428                 *va = v;
 429         }
 430         return 0;
 431 }
 432 EXPORT_SYMBOL_GPL(tee_shm_pa2va);
 433
 434 /**
 435  * tee_shm_get_va() - Get virtual address of a shared memory plus an offset
 436  * @shm:        Shared memory handle
 437  * @offs:       Offset from start of this shared memory
 438  * @returns virtual address of the shared memory + offs if offs is within
 439  *      the bounds of this shared memory, else an ERR_PTR
 440  */
 441 void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
 442 {
 443         if (!(shm->flags & TEE_SHM_MAPPED))
 444                 return ERR_PTR(-EINVAL);
 445         if (offs >= shm->size)
 446                 return ERR_PTR(-EINVAL);
 447         return (char *)shm->kaddr + offs;
 448 }
 449 EXPORT_SYMBOL_GPL(tee_shm_get_va);
 450
 451 /**
 452  * tee_shm_get_pa() - Get physical address of a shared memory plus an offset
 453  * @shm:        Shared memory handle
 454  * @offs:       Offset from start of this shared memory
 455  * @pa:         Physical address to return
 456  * @returns 0 if offs is within the bounds of this shared memory, else an
 457  *      error code.
 458  */
 459 int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
 460 {
 461         if (offs >= shm->size)
 462                 return -EINVAL;
 463         if (pa)
 464                 *pa = shm->paddr + offs;
 465         return 0;
 466 }
 467 EXPORT_SYMBOL_GPL(tee_shm_get_pa);
 468
 469 /**
 470  * tee_shm_get_from_id() - Find shared memory object and increase reference
 471  * count
 472  * @ctx:        Context owning the shared memory
 473  * @id:         Id of shared memory object
 474  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
 475  */
 476 struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
 477 {
 478         struct tee_device *teedev;
 479         struct tee_shm *shm;
 480
 481         if (!ctx)
 482                 return ERR_PTR(-EINVAL);
 483
 484         teedev = ctx->teedev;
 485         mutex_lock(&teedev->mutex);
 486         shm = idr_find(&teedev->idr, id);
 487         if (!shm || shm->ctx != ctx)
 488                 shm = ERR_PTR(-EINVAL);
 489         else if (shm->flags & TEE_SHM_DMA_BUF)
 490                 get_dma_buf(shm->dmabuf);
 491         mutex_unlock(&teedev->mutex);
 492         return shm;
 493 }
 494 EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
 495
 496 /**
 497  * tee_shm_put() - Decrease reference count on a shared memory handle
 498  * @shm:        Shared memory handle
 499  */
 500 void tee_shm_put(struct tee_shm *shm)
 501 {
 502         if (shm->flags & TEE_SHM_DMA_BUF)
 503                 dma_buf_put(shm->dmabuf);
 504 }
 505 EXPORT_SYMBOL_GPL(tee_shm_put);