drivers/staging/android/ion/ion.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * drivers/staging/android/ion/ion.c
   4  *
   5  * Copyright (C) 2011 Google, Inc.
   6  */
   7
   8 #include <linux/anon_inodes.h>
   9 #include <linux/debugfs.h>
  10 #include <linux/device.h>
  11 #include <linux/dma-buf.h>
  12 #include <linux/err.h>
  13 #include <linux/export.h>
  14 #include <linux/file.h>
  15 #include <linux/freezer.h>
  16 #include <linux/fs.h>
  17 #include <linux/idr.h>
  18 #include <linux/kthread.h>
  19 #include <linux/list.h>
  20 #include <linux/memblock.h>
  21 #include <linux/miscdevice.h>
  22 #include <linux/mm.h>
  23 #include <linux/mm_types.h>
  24 #include <linux/rbtree.h>
  25 #include <linux/sched/task.h>
  26 #include <linux/seq_file.h>
  27 #include <linux/slab.h>
  28 #include <linux/uaccess.h>
  29 #include <linux/vmalloc.h>
  30
  31 #include "ion.h"
  32
  33 static struct ion_device *internal_dev;
  34 static int heap_id;
  35
  36 /* this function should only be called while dev->lock is held */
  37 static void ion_buffer_add(struct ion_device *dev,
  38                            struct ion_buffer *buffer)
  39 {
  40         struct rb_node **p = &dev->buffers.rb_node;
  41         struct rb_node *parent = NULL;
  42         struct ion_buffer *entry;
  43
  44         while (*p) {
  45                 parent = *p;
  46                 entry = rb_entry(parent, struct ion_buffer, node);
  47
  48                 if (buffer < entry) {
  49                         p = &(*p)->rb_left;
  50                 } else if (buffer > entry) {
  51                         p = &(*p)->rb_right;
  52                 } else {
  53                         pr_err("%s: buffer already found.", __func__);
  54                         BUG();
  55                 }
  56         }
  57
  58         rb_link_node(&buffer->node, parent, p);
  59         rb_insert_color(&buffer->node, &dev->buffers);
  60 }
  61
  62 /* this function should only be called while dev->lock is held */
  63 static struct ion_buffer *ion_buffer_create(struct ion_heap *heap,
  64                                             struct ion_device *dev,
  65                                             unsigned long len,
  66                                             unsigned long flags)
  67 {
  68         struct ion_buffer *buffer;
  69         int ret;
  70
  71         buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
  72         if (!buffer)
  73                 return ERR_PTR(-ENOMEM);
  74
  75         buffer->heap = heap;
  76         buffer->flags = flags;
  77         buffer->dev = dev;
  78         buffer->size = len;
  79
  80         ret = heap->ops->allocate(heap, buffer, len, flags);
  81
  82         if (ret) {
  83                 if (!(heap->flags & ION_HEAP_FLAG_DEFER_FREE))
  84                         goto err2;
  85
  86                 ion_heap_freelist_drain(heap, 0);
  87                 ret = heap->ops->allocate(heap, buffer, len, flags);
  88                 if (ret)
  89                         goto err2;
  90         }
  91
  92         if (!buffer->sg_table) {
  93                 WARN_ONCE(1, "This heap needs to set the sgtable");
  94                 ret = -EINVAL;
  95                 goto err1;
  96         }
  97
  98         INIT_LIST_HEAD(&buffer->attachments);
  99         mutex_init(&buffer->lock);
 100         mutex_lock(&dev->buffer_lock);
 101         ion_buffer_add(dev, buffer);
 102         mutex_unlock(&dev->buffer_lock);
 103         return buffer;
 104
 105 err1:
 106         heap->ops->free(buffer);
 107 err2:
 108         kfree(buffer);
 109         return ERR_PTR(ret);
 110 }
 111
 112 void ion_buffer_destroy(struct ion_buffer *buffer)
 113 {
 114         if (buffer->kmap_cnt > 0) {
 115                 pr_warn_once("%s: buffer still mapped in the kernel\n",
 116                              __func__);
 117                 buffer->heap->ops->unmap_kernel(buffer->heap, buffer);
 118         }
 119         buffer->heap->ops->free(buffer);
 120         kfree(buffer);
 121 }
 122
 123 static void _ion_buffer_destroy(struct ion_buffer *buffer)
 124 {
 125         struct ion_heap *heap = buffer->heap;
 126         struct ion_device *dev = buffer->dev;
 127
 128         mutex_lock(&dev->buffer_lock);
 129         rb_erase(&buffer->node, &dev->buffers);
 130         mutex_unlock(&dev->buffer_lock);
 131
 132         if (heap->flags & ION_HEAP_FLAG_DEFER_FREE)
 133                 ion_heap_freelist_add(heap, buffer);
 134         else
 135                 ion_buffer_destroy(buffer);
 136 }
 137
 138 static void *ion_buffer_kmap_get(struct ion_buffer *buffer)
 139 {
 140         void *vaddr;
 141
 142         if (buffer->kmap_cnt) {
 143                 buffer->kmap_cnt++;
 144                 return buffer->vaddr;
 145         }
 146         vaddr = buffer->heap->ops->map_kernel(buffer->heap, buffer);
 147         if (WARN_ONCE(!vaddr,
 148                       "heap->ops->map_kernel should return ERR_PTR on error"))
 149                 return ERR_PTR(-EINVAL);
 150         if (IS_ERR(vaddr))
 151                 return vaddr;
 152         buffer->vaddr = vaddr;
 153         buffer->kmap_cnt++;
 154         return vaddr;
 155 }
 156
 157 static void ion_buffer_kmap_put(struct ion_buffer *buffer)
 158 {
 159         buffer->kmap_cnt--;
 160         if (!buffer->kmap_cnt) {
 161                 buffer->heap->ops->unmap_kernel(buffer->heap, buffer);
 162                 buffer->vaddr = NULL;
 163         }
 164 }
 165
 166 static struct sg_table *dup_sg_table(struct sg_table *table)
 167 {
 168         struct sg_table *new_table;
 169         int ret, i;
 170         struct scatterlist *sg, *new_sg;
 171
 172         new_table = kzalloc(sizeof(*new_table), GFP_KERNEL);
 173         if (!new_table)
 174                 return ERR_PTR(-ENOMEM);
 175
 176         ret = sg_alloc_table(new_table, table->nents, GFP_KERNEL);
 177         if (ret) {
 178                 kfree(new_table);
 179                 return ERR_PTR(-ENOMEM);
 180         }
 181
 182         new_sg = new_table->sgl;
 183         for_each_sg(table->sgl, sg, table->nents, i) {
 184                 memcpy(new_sg, sg, sizeof(*sg));
 185                 new_sg->dma_address = 0;
 186                 new_sg = sg_next(new_sg);
 187         }
 188
 189         return new_table;
 190 }
 191
 192 static void free_duped_table(struct sg_table *table)
 193 {
 194         sg_free_table(table);
 195         kfree(table);
 196 }
 197
 198 struct ion_dma_buf_attachment {
 199         struct device *dev;
 200         struct sg_table *table;
 201         struct list_head list;
 202 };
 203
 204 static int ion_dma_buf_attach(struct dma_buf *dmabuf,
 205                               struct dma_buf_attachment *attachment)
 206 {
 207         struct ion_dma_buf_attachment *a;
 208         struct sg_table *table;
 209         struct ion_buffer *buffer = dmabuf->priv;
 210
 211         a = kzalloc(sizeof(*a), GFP_KERNEL);
 212         if (!a)
 213                 return -ENOMEM;
 214
 215         table = dup_sg_table(buffer->sg_table);
 216         if (IS_ERR(table)) {
 217                 kfree(a);
 218                 return -ENOMEM;
 219         }
 220
 221         a->table = table;
 222         a->dev = attachment->dev;
 223         INIT_LIST_HEAD(&a->list);
 224
 225         attachment->priv = a;
 226
 227         mutex_lock(&buffer->lock);
 228         list_add(&a->list, &buffer->attachments);
 229         mutex_unlock(&buffer->lock);
 230
 231         return 0;
 232 }
 233
 234 static void ion_dma_buf_detatch(struct dma_buf *dmabuf,
 235                                 struct dma_buf_attachment *attachment)
 236 {
 237         struct ion_dma_buf_attachment *a = attachment->priv;
 238         struct ion_buffer *buffer = dmabuf->priv;
 239
 240         free_duped_table(a->table);
 241         mutex_lock(&buffer->lock);
 242         list_del(&a->list);
 243         mutex_unlock(&buffer->lock);
 244
 245         kfree(a);
 246 }
 247
 248 static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment *attachment,
 249                                         enum dma_data_direction direction)
 250 {
 251         struct ion_dma_buf_attachment *a = attachment->priv;
 252         struct sg_table *table;
 253
 254         table = a->table;
 255
 256         if (!dma_map_sg(attachment->dev, table->sgl, table->nents,
 257                         direction))
 258                 return ERR_PTR(-ENOMEM);
 259
 260         return table;
 261 }
 262
 263 static void ion_unmap_dma_buf(struct dma_buf_attachment *attachment,
 264                               struct sg_table *table,
 265                               enum dma_data_direction direction)
 266 {
 267         dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction);
 268 }
 269
 270 static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
 271 {
 272         struct ion_buffer *buffer = dmabuf->priv;
 273         int ret = 0;
 274
 275         if (!buffer->heap->ops->map_user) {
 276                 pr_err("%s: this heap does not define a method for mapping to userspace\n",
 277                        __func__);
 278                 return -EINVAL;
 279         }
 280
 281         if (!(buffer->flags & ION_FLAG_CACHED))
 282                 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 283
 284         mutex_lock(&buffer->lock);
 285         /* now map it to userspace */
 286         ret = buffer->heap->ops->map_user(buffer->heap, buffer, vma);
 287         mutex_unlock(&buffer->lock);
 288
 289         if (ret)
 290                 pr_err("%s: failure mapping buffer to userspace\n",
 291                        __func__);
 292
 293         return ret;
 294 }
 295
 296 static void ion_dma_buf_release(struct dma_buf *dmabuf)
 297 {
 298         struct ion_buffer *buffer = dmabuf->priv;
 299
 300         _ion_buffer_destroy(buffer);
 301 }
 302
 303 static void *ion_dma_buf_kmap(struct dma_buf *dmabuf, unsigned long offset)
 304 {
 305         struct ion_buffer *buffer = dmabuf->priv;
 306
 307         return buffer->vaddr + offset * PAGE_SIZE;
 308 }
 309
 310 static void ion_dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long offset,
 311                                void *ptr)
 312 {
 313 }
 314
 315 static int ion_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
 316                                         enum dma_data_direction direction)
 317 {
 318         struct ion_buffer *buffer = dmabuf->priv;
 319         void *vaddr;
 320         struct ion_dma_buf_attachment *a;
 321         int ret = 0;
 322
 323         /*
 324          * TODO: Move this elsewhere because we don't always need a vaddr
 325          */
 326         if (buffer->heap->ops->map_kernel) {
 327                 mutex_lock(&buffer->lock);
 328                 vaddr = ion_buffer_kmap_get(buffer);
 329                 if (IS_ERR(vaddr)) {
 330                         ret = PTR_ERR(vaddr);
 331                         goto unlock;
 332                 }
 333                 mutex_unlock(&buffer->lock);
 334         }
 335
 336         mutex_lock(&buffer->lock);
 337         list_for_each_entry(a, &buffer->attachments, list) {
 338                 dma_sync_sg_for_cpu(a->dev, a->table->sgl, a->table->nents,
 339                                     direction);
 340         }
 341
 342 unlock:
 343         mutex_unlock(&buffer->lock);
 344         return ret;
 345 }
 346
 347 static int ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
 348                                       enum dma_data_direction direction)
 349 {
 350         struct ion_buffer *buffer = dmabuf->priv;
 351         struct ion_dma_buf_attachment *a;
 352
 353         if (buffer->heap->ops->map_kernel) {
 354                 mutex_lock(&buffer->lock);
 355                 ion_buffer_kmap_put(buffer);
 356                 mutex_unlock(&buffer->lock);
 357         }
 358
 359         mutex_lock(&buffer->lock);
 360         list_for_each_entry(a, &buffer->attachments, list) {
 361                 dma_sync_sg_for_device(a->dev, a->table->sgl, a->table->nents,
 362                                        direction);
 363         }
 364         mutex_unlock(&buffer->lock);
 365
 366         return 0;
 367 }
 368
 369 static const struct dma_buf_ops dma_buf_ops = {
 370         .map_dma_buf = ion_map_dma_buf,
 371         .unmap_dma_buf = ion_unmap_dma_buf,
 372         .mmap = ion_mmap,
 373         .release = ion_dma_buf_release,
 374         .attach = ion_dma_buf_attach,
 375         .detach = ion_dma_buf_detatch,
 376         .begin_cpu_access = ion_dma_buf_begin_cpu_access,
 377         .end_cpu_access = ion_dma_buf_end_cpu_access,
 378         .map = ion_dma_buf_kmap,
 379         .unmap = ion_dma_buf_kunmap,
 380 };
 381
 382 int ion_alloc(size_t len, unsigned int heap_id_mask, unsigned int flags)
 383 {
 384         struct ion_device *dev = internal_dev;
 385         struct ion_buffer *buffer = NULL;
 386         struct ion_heap *heap;
 387         DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 388         int fd;
 389         struct dma_buf *dmabuf;
 390
 391         pr_debug("%s: len %zu heap_id_mask %u flags %x\n", __func__,
 392                  len, heap_id_mask, flags);
 393         /*
 394          * traverse the list of heaps available in this system in priority
 395          * order.  If the heap type is supported by the client, and matches the
 396          * request of the caller allocate from it.  Repeat until allocate has
 397          * succeeded or all heaps have been tried
 398          */
 399         len = PAGE_ALIGN(len);
 400
 401         if (!len)
 402                 return -EINVAL;
 403
 404         down_read(&dev->lock);
 405         plist_for_each_entry(heap, &dev->heaps, node) {
 406                 /* if the caller didn't specify this heap id */
 407                 if (!((1 << heap->id) & heap_id_mask))
 408                         continue;
 409                 buffer = ion_buffer_create(heap, dev, len, flags);
 410                 if (!IS_ERR(buffer))
 411                         break;
 412         }
 413         up_read(&dev->lock);
 414
 415         if (!buffer)
 416                 return -ENODEV;
 417
 418         if (IS_ERR(buffer))
 419                 return PTR_ERR(buffer);
 420
 421         exp_info.ops = &dma_buf_ops;
 422         exp_info.size = buffer->size;
 423         exp_info.flags = O_RDWR;
 424         exp_info.priv = buffer;
 425
 426         dmabuf = dma_buf_export(&exp_info);
 427         if (IS_ERR(dmabuf)) {
 428                 _ion_buffer_destroy(buffer);
 429                 return PTR_ERR(dmabuf);
 430         }
 431
 432         fd = dma_buf_fd(dmabuf, O_CLOEXEC);
 433         if (fd < 0)
 434                 dma_buf_put(dmabuf);
 435
 436         return fd;
 437 }
 438
 439 int ion_query_heaps(struct ion_heap_query *query)
 440 {
 441         struct ion_device *dev = internal_dev;
 442         struct ion_heap_data __user *buffer = u64_to_user_ptr(query->heaps);
 443         int ret = -EINVAL, cnt = 0, max_cnt;
 444         struct ion_heap *heap;
 445         struct ion_heap_data hdata;
 446
 447         memset(&hdata, 0, sizeof(hdata));
 448
 449         down_read(&dev->lock);
 450         if (!buffer) {
 451                 query->cnt = dev->heap_cnt;
 452                 ret = 0;
 453                 goto out;
 454         }
 455
 456         if (query->cnt <= 0)
 457                 goto out;
 458
 459         max_cnt = query->cnt;
 460
 461         plist_for_each_entry(heap, &dev->heaps, node) {
 462                 strncpy(hdata.name, heap->name, MAX_HEAP_NAME);
 463                 hdata.name[sizeof(hdata.name) - 1] = '\0';
 464                 hdata.type = heap->type;
 465                 hdata.heap_id = heap->id;
 466
 467                 if (copy_to_user(&buffer[cnt], &hdata, sizeof(hdata))) {
 468                         ret = -EFAULT;
 469                         goto out;
 470                 }
 471
 472                 cnt++;
 473                 if (cnt >= max_cnt)
 474                         break;
 475         }
 476
 477         query->cnt = cnt;
 478         ret = 0;
 479 out:
 480         up_read(&dev->lock);
 481         return ret;
 482 }
 483
 484 static const struct file_operations ion_fops = {
 485         .owner          = THIS_MODULE,
 486         .unlocked_ioctl = ion_ioctl,
 487 #ifdef CONFIG_COMPAT
 488         .compat_ioctl   = ion_ioctl,
 489 #endif
 490 };
 491
 492 static int debug_shrink_set(void *data, u64 val)
 493 {
 494         struct ion_heap *heap = data;
 495         struct shrink_control sc;
 496         int objs;
 497
 498         sc.gfp_mask = GFP_HIGHUSER;
 499         sc.nr_to_scan = val;
 500
 501         if (!val) {
 502                 objs = heap->shrinker.count_objects(&heap->shrinker, &sc);
 503                 sc.nr_to_scan = objs;
 504         }
 505
 506         heap->shrinker.scan_objects(&heap->shrinker, &sc);
 507         return 0;
 508 }
 509
 510 static int debug_shrink_get(void *data, u64 *val)
 511 {
 512         struct ion_heap *heap = data;
 513         struct shrink_control sc;
 514         int objs;
 515
 516         sc.gfp_mask = GFP_HIGHUSER;
 517         sc.nr_to_scan = 0;
 518
 519         objs = heap->shrinker.count_objects(&heap->shrinker, &sc);
 520         *val = objs;
 521         return 0;
 522 }
 523
 524 DEFINE_SIMPLE_ATTRIBUTE(debug_shrink_fops, debug_shrink_get,
 525                         debug_shrink_set, "%llu\n");
 526
 527 void ion_device_add_heap(struct ion_heap *heap)
 528 {
 529         struct ion_device *dev = internal_dev;
 530         int ret;
 531
 532         if (!heap->ops->allocate || !heap->ops->free)
 533                 pr_err("%s: can not add heap with invalid ops struct.\n",
 534                        __func__);
 535
 536         spin_lock_init(&heap->free_lock);
 537         heap->free_list_size = 0;
 538
 539         if (heap->flags & ION_HEAP_FLAG_DEFER_FREE)
 540                 ion_heap_init_deferred_free(heap);
 541
 542         if ((heap->flags & ION_HEAP_FLAG_DEFER_FREE) || heap->ops->shrink) {
 543                 ret = ion_heap_init_shrinker(heap);
 544                 if (ret)
 545                         pr_err("%s: Failed to register shrinker\n", __func__);
 546         }
 547
 548         heap->dev = dev;
 549         down_write(&dev->lock);
 550         heap->id = heap_id++;
 551         /*
 552          * use negative heap->id to reverse the priority -- when traversing
 553          * the list later attempt higher id numbers first
 554          */
 555         plist_node_init(&heap->node, -heap->id);
 556         plist_add(&heap->node, &dev->heaps);
 557
 558         if (heap->shrinker.count_objects && heap->shrinker.scan_objects) {
 559                 char debug_name[64];
 560
 561                 snprintf(debug_name, 64, "%s_shrink", heap->name);
 562                 debugfs_create_file(debug_name, 0644, dev->debug_root,
 563                                     heap, &debug_shrink_fops);
 564         }
 565
 566         dev->heap_cnt++;
 567         up_write(&dev->lock);
 568 }
 569 EXPORT_SYMBOL(ion_device_add_heap);
 570
 571 static int ion_device_create(void)
 572 {
 573         struct ion_device *idev;
 574         int ret;
 575
 576         idev = kzalloc(sizeof(*idev), GFP_KERNEL);
 577         if (!idev)
 578                 return -ENOMEM;
 579
 580         idev->dev.minor = MISC_DYNAMIC_MINOR;
 581         idev->dev.name = "ion";
 582         idev->dev.fops = &ion_fops;
 583         idev->dev.parent = NULL;
 584         ret = misc_register(&idev->dev);
 585         if (ret) {
 586                 pr_err("ion: failed to register misc device.\n");
 587                 kfree(idev);
 588                 return ret;
 589         }
 590
 591         idev->debug_root = debugfs_create_dir("ion", NULL);
 592         idev->buffers = RB_ROOT;
 593         mutex_init(&idev->buffer_lock);
 594         init_rwsem(&idev->lock);
 595         plist_head_init(&idev->heaps);
 596         internal_dev = idev;
 597         return 0;
 598 }
 599 subsys_initcall(ion_device_create);