1 /* SPDX-License-Identifier: GPL-2.0 */
3 * drivers/staging/android/ion/ion.h
5 * Copyright (C) 2011 Google, Inc.
11 #include <linux/device.h>
12 #include <linux/dma-direction.h>
13 #include <linux/kref.h>
14 #include <linux/mm_types.h>
15 #include <linux/mutex.h>
16 #include <linux/rbtree.h>
17 #include <linux/sched.h>
18 #include <linux/shrinker.h>
19 #include <linux/types.h>
20 #include <linux/miscdevice.h>
22 #include "../uapi/ion.h"
25 * struct ion_platform_heap - defines a heap in the given platform
26 * @type: type of the heap from ion_heap_type enum
27 * @id: unique identifier for heap. When allocating higher numb ers
28 * will be allocated from first. At allocation these are passed
29 * as a bit mask and therefore can not exceed ION_NUM_HEAP_IDS.
30 * @name: used for debug purposes
31 * @base: base address of heap in physical memory if applicable
32 * @size: size of the heap in bytes if applicable
33 * @priv: private info passed from the board file
35 * Provided by the board file.
37 struct ion_platform_heap {
38 enum ion_heap_type type;
48 * struct ion_buffer - metadata for a particular buffer
49 * @ref: reference count
50 * @node: node in the ion_device buffers tree
51 * @dev: back pointer to the ion_device
52 * @heap: back pointer to the heap the buffer came from
53 * @flags: buffer specific flags
54 * @private_flags: internal buffer specific flags
55 * @size: size of the buffer
56 * @priv_virt: private data to the buffer representable as
58 * @lock: protects the buffers cnt fields
59 * @kmap_cnt: number of times the buffer is mapped to the kernel
60 * @vaddr: the kernel mapping if kmap_cnt is not zero
61 * @sg_table: the sg table for the buffer if dmap_cnt is not zero
66 struct list_head list;
68 struct ion_device *dev;
69 struct ion_heap *heap;
71 unsigned long private_flags;
77 struct sg_table *sg_table;
78 struct list_head attachments;
81 void ion_buffer_destroy(struct ion_buffer *buffer);
84 * struct ion_device - the metadata of the ion device node
85 * @dev: the actual misc device
86 * @buffers: an rb tree of all the existing buffers
87 * @buffer_lock: lock protecting the tree of buffers
88 * @lock: rwsem protecting the tree of heaps and clients
91 struct miscdevice dev;
92 struct rb_root buffers;
93 struct mutex buffer_lock;
94 struct rw_semaphore lock;
95 struct plist_head heaps;
96 struct dentry *debug_root;
101 * struct ion_heap_ops - ops to operate on a given heap
102 * @allocate: allocate memory
104 * @map_kernel map memory to the kernel
105 * @unmap_kernel unmap memory to the kernel
106 * @map_user map memory to userspace
108 * allocate, phys, and map_user return 0 on success, -errno on error.
109 * map_dma and map_kernel return pointer on success, ERR_PTR on
110 * error. @free will be called with ION_PRIV_FLAG_SHRINKER_FREE set in
111 * the buffer's private_flags when called from a shrinker. In that
112 * case, the pages being free'd must be truly free'd back to the
113 * system, not put in a page pool or otherwise cached.
115 struct ion_heap_ops {
116 int (*allocate)(struct ion_heap *heap,
117 struct ion_buffer *buffer, unsigned long len,
118 unsigned long flags);
119 void (*free)(struct ion_buffer *buffer);
120 void * (*map_kernel)(struct ion_heap *heap, struct ion_buffer *buffer);
121 void (*unmap_kernel)(struct ion_heap *heap, struct ion_buffer *buffer);
122 int (*map_user)(struct ion_heap *mapper, struct ion_buffer *buffer,
123 struct vm_area_struct *vma);
124 int (*shrink)(struct ion_heap *heap, gfp_t gfp_mask, int nr_to_scan);
128 * heap flags - flags between the heaps and core ion code
130 #define ION_HEAP_FLAG_DEFER_FREE BIT(0)
133 * private flags - flags internal to ion
136 * Buffer is being freed from a shrinker function. Skip any possible
137 * heap-specific caching mechanism (e.g. page pools). Guarantees that
138 * any buffer storage that came from the system allocator will be
139 * returned to the system allocator.
141 #define ION_PRIV_FLAG_SHRINKER_FREE BIT(0)
144 * struct ion_heap - represents a heap in the system
145 * @node: rb node to put the heap on the device's tree of heaps
146 * @dev: back pointer to the ion_device
147 * @type: type of heap
148 * @ops: ops struct as above
150 * @id: id of heap, also indicates priority of this heap when
151 * allocating. These are specified by platform data and
153 * @name: used for debugging
154 * @shrinker: a shrinker for the heap
155 * @free_list: free list head if deferred free is used
156 * @free_list_size size of the deferred free list in bytes
157 * @lock: protects the free list
158 * @waitqueue: queue to wait on from deferred free thread
159 * @task: task struct of deferred free thread
160 * @debug_show: called when heap debug file is read to add any
161 * heap specific debug info to output
163 * Represents a pool of memory from which buffers can be made. In some
164 * systems the only heap is regular system memory allocated via vmalloc.
165 * On others, some blocks might require large physically contiguous buffers
166 * that are allocated from a specially reserved heap.
169 struct plist_node node;
170 struct ion_device *dev;
171 enum ion_heap_type type;
172 struct ion_heap_ops *ops;
176 struct shrinker shrinker;
177 struct list_head free_list;
178 size_t free_list_size;
179 spinlock_t free_lock;
180 wait_queue_head_t waitqueue;
181 struct task_struct *task;
183 int (*debug_show)(struct ion_heap *heap, struct seq_file *s,
188 * ion_device_add_heap - adds a heap to the ion device
189 * @heap: the heap to add
191 void ion_device_add_heap(struct ion_heap *heap);
194 * some helpers for common operations on buffers using the sg_table
197 void *ion_heap_map_kernel(struct ion_heap *heap, struct ion_buffer *buffer);
198 void ion_heap_unmap_kernel(struct ion_heap *heap, struct ion_buffer *buffer);
199 int ion_heap_map_user(struct ion_heap *heap, struct ion_buffer *buffer,
200 struct vm_area_struct *vma);
201 int ion_heap_buffer_zero(struct ion_buffer *buffer);
202 int ion_heap_pages_zero(struct page *page, size_t size, pgprot_t pgprot);
204 int ion_alloc(size_t len,
205 unsigned int heap_id_mask,
209 * ion_heap_init_shrinker
212 * If a heap sets the ION_HEAP_FLAG_DEFER_FREE flag or defines the shrink op
213 * this function will be called to setup a shrinker to shrink the freelists
214 * and call the heap's shrink op.
216 int ion_heap_init_shrinker(struct ion_heap *heap);
219 * ion_heap_init_deferred_free -- initialize deferred free functionality
222 * If a heap sets the ION_HEAP_FLAG_DEFER_FREE flag this function will
223 * be called to setup deferred frees. Calls to free the buffer will
224 * return immediately and the actual free will occur some time later
226 int ion_heap_init_deferred_free(struct ion_heap *heap);
229 * ion_heap_freelist_add - add a buffer to the deferred free list
231 * @buffer: the buffer
233 * Adds an item to the deferred freelist.
235 void ion_heap_freelist_add(struct ion_heap *heap, struct ion_buffer *buffer);
238 * ion_heap_freelist_drain - drain the deferred free list
240 * @size: amount of memory to drain in bytes
242 * Drains the indicated amount of memory from the deferred freelist immediately.
243 * Returns the total amount freed. The total freed may be higher depending
244 * on the size of the items in the list, or lower if there is insufficient
245 * total memory on the freelist.
247 size_t ion_heap_freelist_drain(struct ion_heap *heap, size_t size);
250 * ion_heap_freelist_shrink - drain the deferred free
251 * list, skipping any heap-specific
252 * pooling or caching mechanisms
255 * @size: amount of memory to drain in bytes
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.
262 * Unlike with @ion_heap_freelist_drain, don't put any pages back into
263 * page pools or otherwise cache the pages. Everything must be
264 * genuinely free'd back to the system. If you're free'ing from a
265 * shrinker you probably want to use this. Note that this relies on
266 * the heap.ops.free callback honoring the ION_PRIV_FLAG_SHRINKER_FREE
269 size_t ion_heap_freelist_shrink(struct ion_heap *heap,
273 * ion_heap_freelist_size - returns the size of the freelist in bytes
276 size_t ion_heap_freelist_size(struct ion_heap *heap);
279 * functions for creating and destroying a heap pool -- allows you
280 * to keep a pool of pre allocated memory to use from your heap. Keeping
281 * a pool of memory that is ready for dma, ie any cached mapping have been
282 * invalidated from the cache, provides a significant performance benefit on
287 * struct ion_page_pool - pagepool struct
288 * @high_count: number of highmem items in the pool
289 * @low_count: number of lowmem items in the pool
290 * @high_items: list of highmem items
291 * @low_items: list of lowmem items
292 * @mutex: lock protecting this struct and especially the count
294 * @gfp_mask: gfp_mask to use from alloc
295 * @order: order of pages in the pool
296 * @list: plist node for list of pools
298 * Allows you to keep a pool of pre allocated pages to use from your heap.
299 * Keeping a pool of pages that is ready for dma, ie any cached mapping have
300 * been invalidated from the cache, provides a significant performance benefit
303 struct ion_page_pool {
306 struct list_head high_items;
307 struct list_head low_items;
311 struct plist_node list;
314 struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order);
315 void ion_page_pool_destroy(struct ion_page_pool *pool);
316 struct page *ion_page_pool_alloc(struct ion_page_pool *pool);
317 void ion_page_pool_free(struct ion_page_pool *pool, struct page *page);
319 /** ion_page_pool_shrink - shrinks the size of the memory cached in the pool
321 * @gfp_mask: the memory type to reclaim
322 * @nr_to_scan: number of items to shrink in pages
324 * returns the number of items freed in pages
326 int ion_page_pool_shrink(struct ion_page_pool *pool, gfp_t gfp_mask,
329 long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
331 int ion_query_heaps(struct ion_heap_query *query);