drivers/staging/android/ion/ion_priv.h

   1 /*
   2  * drivers/staging/android/ion/ion_priv.h
   3  *
   4  * Copyright (C) 2011 Google, Inc.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  */
  16
  17 #ifndef _ION_PRIV_H
  18 #define _ION_PRIV_H
  19
  20 #include <linux/device.h>
  21 #include <linux/dma-direction.h>
  22 #include <linux/kref.h>
  23 #include <linux/mm_types.h>
  24 #include <linux/mutex.h>
  25 #include <linux/rbtree.h>
  26 #include <linux/sched.h>
  27 #include <linux/shrinker.h>
  28 #include <linux/types.h>
  29
  30 #include "ion.h"
  31
  32 struct ion_buffer *ion_handle_buffer(struct ion_handle *handle);
  33
  34 /**
  35  * struct ion_buffer - metadata for a particular buffer
  36  * @ref:                reference count
  37  * @node:               node in the ion_device buffers tree
  38  * @dev:                back pointer to the ion_device
  39  * @heap:               back pointer to the heap the buffer came from
  40  * @flags:              buffer specific flags
  41  * @private_flags:      internal buffer specific flags
  42  * @size:               size of the buffer
  43  * @priv_virt:          private data to the buffer representable as
  44  *                      a void *
  45  * @lock:               protects the buffers cnt fields
  46  * @kmap_cnt:           number of times the buffer is mapped to the kernel
  47  * @vaddr:              the kernel mapping if kmap_cnt is not zero
  48  * @dmap_cnt:           number of times the buffer is mapped for dma
  49  * @sg_table:           the sg table for the buffer if dmap_cnt is not zero
  50  * @pages:              flat array of pages in the buffer -- used by fault
  51  *                      handler and only valid for buffers that are faulted in
  52  * @vmas:               list of vma's mapping this buffer
  53  * @handle_count:       count of handles referencing this buffer
  54  * @task_comm:          taskcomm of last client to reference this buffer in a
  55  *                      handle, used for debugging
  56  * @pid:                pid of last client to reference this buffer in a
  57  *                      handle, used for debugging
  58 */
  59 struct ion_buffer {
  60         struct kref ref;
  61         union {
  62                 struct rb_node node;
  63                 struct list_head list;
  64         };
  65         struct ion_device *dev;
  66         struct ion_heap *heap;
  67         unsigned long flags;
  68         unsigned long private_flags;
  69         size_t size;
  70         void *priv_virt;
  71         struct mutex lock;
  72         int kmap_cnt;
  73         void *vaddr;
  74         int dmap_cnt;
  75         struct sg_table *sg_table;
  76         struct page **pages;
  77         struct list_head vmas;
  78         /* used to track orphaned buffers */
  79         int handle_count;
  80         char task_comm[TASK_COMM_LEN];
  81         pid_t pid;
  82 };
  83 void ion_buffer_destroy(struct ion_buffer *buffer);
  84
  85 /**
  86  * struct ion_heap_ops - ops to operate on a given heap
  87  * @allocate:           allocate memory
  88  * @free:               free memory
  89  * @map_kernel          map memory to the kernel
  90  * @unmap_kernel        unmap memory to the kernel
  91  * @map_user            map memory to userspace
  92  *
  93  * allocate, phys, and map_user return 0 on success, -errno on error.
  94  * map_dma and map_kernel return pointer on success, ERR_PTR on
  95  * error. @free will be called with ION_PRIV_FLAG_SHRINKER_FREE set in
  96  * the buffer's private_flags when called from a shrinker. In that
  97  * case, the pages being free'd must be truly free'd back to the
  98  * system, not put in a page pool or otherwise cached.
  99  */
 100 struct ion_heap_ops {
 101         int (*allocate)(struct ion_heap *heap,
 102                         struct ion_buffer *buffer, unsigned long len,
 103                         unsigned long align, unsigned long flags);
 104         void (*free)(struct ion_buffer *buffer);
 105         void * (*map_kernel)(struct ion_heap *heap, struct ion_buffer *buffer);
 106         void (*unmap_kernel)(struct ion_heap *heap, struct ion_buffer *buffer);
 107         int (*map_user)(struct ion_heap *mapper, struct ion_buffer *buffer,
 108                         struct vm_area_struct *vma);
 109         int (*shrink)(struct ion_heap *heap, gfp_t gfp_mask, int nr_to_scan);
 110 };
 111
 112 /**
 113  * heap flags - flags between the heaps and core ion code
 114  */
 115 #define ION_HEAP_FLAG_DEFER_FREE (1 << 0)
 116
 117 /**
 118  * private flags - flags internal to ion
 119  */
 120 /*
 121  * Buffer is being freed from a shrinker function. Skip any possible
 122  * heap-specific caching mechanism (e.g. page pools). Guarantees that
 123  * any buffer storage that came from the system allocator will be
 124  * returned to the system allocator.
 125  */
 126 #define ION_PRIV_FLAG_SHRINKER_FREE (1 << 0)
 127
 128 /**
 129  * struct ion_heap - represents a heap in the system
 130  * @node:               rb node to put the heap on the device's tree of heaps
 131  * @dev:                back pointer to the ion_device
 132  * @type:               type of heap
 133  * @ops:                ops struct as above
 134  * @flags:              flags
 135  * @id:                 id of heap, also indicates priority of this heap when
 136  *                      allocating.  These are specified by platform data and
 137  *                      MUST be unique
 138  * @name:               used for debugging
 139  * @shrinker:           a shrinker for the heap
 140  * @free_list:          free list head if deferred free is used
 141  * @free_list_size      size of the deferred free list in bytes
 142  * @lock:               protects the free list
 143  * @waitqueue:          queue to wait on from deferred free thread
 144  * @task:               task struct of deferred free thread
 145  * @debug_show:         called when heap debug file is read to add any
 146  *                      heap specific debug info to output
 147  *
 148  * Represents a pool of memory from which buffers can be made.  In some
 149  * systems the only heap is regular system memory allocated via vmalloc.
 150  * On others, some blocks might require large physically contiguous buffers
 151  * that are allocated from a specially reserved heap.
 152  */
 153 struct ion_heap {
 154         struct plist_node node;
 155         struct ion_device *dev;
 156         enum ion_heap_type type;
 157         struct ion_heap_ops *ops;
 158         unsigned long flags;
 159         unsigned int id;
 160         const char *name;
 161         struct shrinker shrinker;
 162         struct list_head free_list;
 163         size_t free_list_size;
 164         spinlock_t free_lock;
 165         wait_queue_head_t waitqueue;
 166         struct task_struct *task;
 167
 168         int (*debug_show)(struct ion_heap *heap, struct seq_file *, void *);
 169 };
 170
 171 /**
 172  * ion_buffer_cached - this ion buffer is cached
 173  * @buffer:             buffer
 174  *
 175  * indicates whether this ion buffer is cached
 176  */
 177 bool ion_buffer_cached(struct ion_buffer *buffer);
 178
 179 /**
 180  * ion_buffer_fault_user_mappings - fault in user mappings of this buffer
 181  * @buffer:             buffer
 182  *
 183  * indicates whether userspace mappings of this buffer will be faulted
 184  * in, this can affect how buffers are allocated from the heap.
 185  */
 186 bool ion_buffer_fault_user_mappings(struct ion_buffer *buffer);
 187
 188 /**
 189  * ion_device_create - allocates and returns an ion device
 190  * @custom_ioctl:       arch specific ioctl function if applicable
 191  *
 192  * returns a valid device or -PTR_ERR
 193  */
 194 struct ion_device *ion_device_create(long (*custom_ioctl)
 195                                      (struct ion_client *client,
 196                                       unsigned int cmd,
 197                                       unsigned long arg));
 198
 199 /**
 200  * ion_device_destroy - free and device and it's resource
 201  * @dev:                the device
 202  */
 203 void ion_device_destroy(struct ion_device *dev);
 204
 205 /**
 206  * ion_device_add_heap - adds a heap to the ion device
 207  * @dev:                the device
 208  * @heap:               the heap to add
 209  */
 210 void ion_device_add_heap(struct ion_device *dev, struct ion_heap *heap);
 211
 212 /**
 213  * some helpers for common operations on buffers using the sg_table
 214  * and vaddr fields
 215  */
 216 void *ion_heap_map_kernel(struct ion_heap *, struct ion_buffer *);
 217 void ion_heap_unmap_kernel(struct ion_heap *, struct ion_buffer *);
 218 int ion_heap_map_user(struct ion_heap *, struct ion_buffer *,
 219                         struct vm_area_struct *);
 220 int ion_heap_buffer_zero(struct ion_buffer *buffer);
 221 int ion_heap_pages_zero(struct page *page, size_t size, pgprot_t pgprot);
 222
 223 /**
 224  * ion_heap_init_shrinker
 225  * @heap:               the heap
 226  *
 227  * If a heap sets the ION_HEAP_FLAG_DEFER_FREE flag or defines the shrink op
 228  * this function will be called to setup a shrinker to shrink the freelists
 229  * and call the heap's shrink op.
 230  */
 231 void ion_heap_init_shrinker(struct ion_heap *heap);
 232
 233 /**
 234  * ion_heap_init_deferred_free -- initialize deferred free functionality
 235  * @heap:               the heap
 236  *
 237  * If a heap sets the ION_HEAP_FLAG_DEFER_FREE flag this function will
 238  * be called to setup deferred frees. Calls to free the buffer will
 239  * return immediately and the actual free will occur some time later
 240  */
 241 int ion_heap_init_deferred_free(struct ion_heap *heap);
 242
 243 /**
 244  * ion_heap_freelist_add - add a buffer to the deferred free list
 245  * @heap:               the heap
 246  * @buffer:             the buffer
 247  *
 248  * Adds an item to the deferred freelist.
 249  */
 250 void ion_heap_freelist_add(struct ion_heap *heap, struct ion_buffer *buffer);
 251
 252 /**
 253  * ion_heap_freelist_drain - drain the deferred free list
 254  * @heap:               the heap
 255  * @size:               amount of memory to drain in bytes
 256  *
 257  * Drains the indicated amount of memory from the deferred freelist immediately.
 258  * Returns the total amount freed.  The total freed may be higher depending
 259  * on the size of the items in the list, or lower if there is insufficient
 260  * total memory on the freelist.
 261  */
 262 size_t ion_heap_freelist_drain(struct ion_heap *heap, size_t size);
 263
 264 /**
 265  * ion_heap_freelist_shrink - drain the deferred free
 266  *                              list, skipping any heap-specific
 267  *                              pooling or caching mechanisms
 268  *
 269  * @heap:               the heap
 270  * @size:               amount of memory to drain in bytes
 271  *
 272  * Drains the indicated amount of memory from the deferred freelist immediately.
 273  * Returns the total amount freed.  The total freed may be higher depending
 274  * on the size of the items in the list, or lower if there is insufficient
 275  * total memory on the freelist.
 276  *
 277  * Unlike with @ion_heap_freelist_drain, don't put any pages back into
 278  * page pools or otherwise cache the pages. Everything must be
 279  * genuinely free'd back to the system. If you're free'ing from a
 280  * shrinker you probably want to use this. Note that this relies on
 281  * the heap.ops.free callback honoring the ION_PRIV_FLAG_SHRINKER_FREE
 282  * flag.
 283  */
 284 size_t ion_heap_freelist_shrink(struct ion_heap *heap,
 285                                         size_t size);
 286
 287 /**
 288  * ion_heap_freelist_size - returns the size of the freelist in bytes
 289  * @heap:               the heap
 290  */
 291 size_t ion_heap_freelist_size(struct ion_heap *heap);
 292
 293
 294 /**
 295  * functions for creating and destroying the built in ion heaps.
 296  * architectures can add their own custom architecture specific
 297  * heaps as appropriate.
 298  */
 299
 300 struct ion_heap *ion_heap_create(struct ion_platform_heap *);
 301 void ion_heap_destroy(struct ion_heap *);
 302 struct ion_heap *ion_system_heap_create(struct ion_platform_heap *);
 303 void ion_system_heap_destroy(struct ion_heap *);
 304
 305 struct ion_heap *ion_system_contig_heap_create(struct ion_platform_heap *);
 306 void ion_system_contig_heap_destroy(struct ion_heap *);
 307
 308 struct ion_heap *ion_carveout_heap_create(struct ion_platform_heap *);
 309 void ion_carveout_heap_destroy(struct ion_heap *);
 310
 311 struct ion_heap *ion_chunk_heap_create(struct ion_platform_heap *);
 312 void ion_chunk_heap_destroy(struct ion_heap *);
 313 struct ion_heap *ion_cma_heap_create(struct ion_platform_heap *);
 314 void ion_cma_heap_destroy(struct ion_heap *);
 315
 316 /**
 317  * functions for creating and destroying a heap pool -- allows you
 318  * to keep a pool of pre allocated memory to use from your heap.  Keeping
 319  * a pool of memory that is ready for dma, ie any cached mapping have been
 320  * invalidated from the cache, provides a significant performance benefit on
 321  * many systems
 322  */
 323
 324 /**
 325  * struct ion_page_pool - pagepool struct
 326  * @high_count:         number of highmem items in the pool
 327  * @low_count:          number of lowmem items in the pool
 328  * @high_items:         list of highmem items
 329  * @low_items:          list of lowmem items
 330  * @mutex:              lock protecting this struct and especially the count
 331  *                      item list
 332  * @gfp_mask:           gfp_mask to use from alloc
 333  * @order:              order of pages in the pool
 334  * @list:               plist node for list of pools
 335  *
 336  * Allows you to keep a pool of pre allocated pages to use from your heap.
 337  * Keeping a pool of pages that is ready for dma, ie any cached mapping have
 338  * been invalidated from the cache, provides a significant performance benefit
 339  * on many systems
 340  */
 341 struct ion_page_pool {
 342         int high_count;
 343         int low_count;
 344         struct list_head high_items;
 345         struct list_head low_items;
 346         struct mutex mutex;
 347         gfp_t gfp_mask;
 348         unsigned int order;
 349         struct plist_node list;
 350 };
 351
 352 struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order);
 353 void ion_page_pool_destroy(struct ion_page_pool *);
 354 struct page *ion_page_pool_alloc(struct ion_page_pool *);
 355 void ion_page_pool_free(struct ion_page_pool *, struct page *);
 356
 357 /** ion_page_pool_shrink - shrinks the size of the memory cached in the pool
 358  * @pool:               the pool
 359  * @gfp_mask:           the memory type to reclaim
 360  * @nr_to_scan:         number of items to shrink in pages
 361  *
 362  * returns the number of items freed in pages
 363  */
 364 int ion_page_pool_shrink(struct ion_page_pool *pool, gfp_t gfp_mask,
 365                           int nr_to_scan);
 366
 367 /**
 368  * ion_pages_sync_for_device - cache flush pages for use with the specified
 369  *                             device
 370  * @dev:                the device the pages will be used with
 371  * @page:               the first page to be flushed
 372  * @size:               size in bytes of region to be flushed
 373  * @dir:                direction of dma transfer
 374  */
 375 void ion_pages_sync_for_device(struct device *dev, struct page *page,
 376                 size_t size, enum dma_data_direction dir);
 377
 378 #endif /* _ION_PRIV_H */