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