2 * drivers/staging/android/uapi/ion.h
4 * Copyright (C) 2011 Google, Inc.
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.
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.
17 #ifndef _UAPI_LINUX_ION_H
18 #define _UAPI_LINUX_ION_H
20 #include <linux/ioctl.h>
21 #include <linux/types.h>
23 typedef int ion_user_handle_t;
26 * enum ion_heap_types - list of all possible types of heaps
27 * @ION_HEAP_TYPE_SYSTEM: memory allocated via vmalloc
28 * @ION_HEAP_TYPE_SYSTEM_CONTIG: memory allocated via kmalloc
29 * @ION_HEAP_TYPE_CARVEOUT: memory allocated from a prereserved
30 * carveout heap, allocations are physically
32 * @ION_HEAP_TYPE_DMA: memory allocated via DMA API
33 * @ION_NUM_HEAPS: helper for iterating over heaps, a bit mask
34 * is used to identify the heaps, so only 32
35 * total heap types are supported
39 ION_HEAP_TYPE_SYSTEM_CONTIG,
40 ION_HEAP_TYPE_CARVEOUT,
43 ION_HEAP_TYPE_CUSTOM, /* must be last so device specific heaps always
44 are at the end of this enum */
48 #define ION_HEAP_SYSTEM_MASK (1 << ION_HEAP_TYPE_SYSTEM)
49 #define ION_HEAP_SYSTEM_CONTIG_MASK (1 << ION_HEAP_TYPE_SYSTEM_CONTIG)
50 #define ION_HEAP_CARVEOUT_MASK (1 << ION_HEAP_TYPE_CARVEOUT)
51 #define ION_HEAP_TYPE_DMA_MASK (1 << ION_HEAP_TYPE_DMA)
53 #define ION_NUM_HEAP_IDS sizeof(unsigned int) * 8
56 * allocation flags - the lower 16 bits are used by core ion, the upper 16
57 * bits are reserved for use by the heaps themselves.
59 #define ION_FLAG_CACHED 1 /* mappings of this buffer should be
60 cached, ion will do cache
61 maintenance when the buffer is
63 #define ION_FLAG_CACHED_NEEDS_SYNC 2 /* mappings of this buffer will created
64 at mmap time, if this is set
65 caches must be managed manually */
68 * DOC: Ion Userspace API
70 * create a client by opening /dev/ion
71 * most operations handled via following ioctls
76 * struct ion_allocation_data - metadata passed from userspace for allocations
77 * @len: size of the allocation
78 * @align: required alignment of the allocation
79 * @heap_id_mask: mask of heap ids to allocate from
80 * @flags: flags passed to heap
81 * @handle: pointer that will be populated with a cookie to use to
82 * refer to this allocation
84 * Provided by userspace as an argument to the ioctl
86 struct ion_allocation_data {
89 unsigned int heap_id_mask;
91 ion_user_handle_t handle;
95 * struct ion_fd_data - metadata passed to/from userspace for a handle/fd pair
97 * @fd: a file descriptor representing that handle
99 * For ION_IOC_SHARE or ION_IOC_MAP userspace populates the handle field with
100 * the handle returned from ion alloc, and the kernel returns the file
101 * descriptor to share or map in the fd field. For ION_IOC_IMPORT, userspace
102 * provides the file descriptor and the kernel returns the handle.
105 ion_user_handle_t handle;
110 * struct ion_handle_data - a handle passed to/from the kernel
113 struct ion_handle_data {
114 ion_user_handle_t handle;
118 * struct ion_custom_data - metadata passed to/from userspace for a custom ioctl
119 * @cmd: the custom ioctl function to call
120 * @arg: additional data to pass to the custom ioctl, typically a user
121 * pointer to a predefined structure
123 * This works just like the regular cmd and arg fields of an ioctl.
125 struct ion_custom_data {
130 #define ION_IOC_MAGIC 'I'
133 * DOC: ION_IOC_ALLOC - allocate memory
135 * Takes an ion_allocation_data struct and returns it with the handle field
136 * populated with the opaque handle for the allocation.
138 #define ION_IOC_ALLOC _IOWR(ION_IOC_MAGIC, 0, \
139 struct ion_allocation_data)
142 * DOC: ION_IOC_FREE - free memory
144 * Takes an ion_handle_data struct and frees the handle.
146 #define ION_IOC_FREE _IOWR(ION_IOC_MAGIC, 1, struct ion_handle_data)
149 * DOC: ION_IOC_MAP - get a file descriptor to mmap
151 * Takes an ion_fd_data struct with the handle field populated with a valid
152 * opaque handle. Returns the struct with the fd field set to a file
153 * descriptor open in the current address space. This file descriptor
154 * can then be used as an argument to mmap.
156 #define ION_IOC_MAP _IOWR(ION_IOC_MAGIC, 2, struct ion_fd_data)
159 * DOC: ION_IOC_SHARE - creates a file descriptor to use to share an allocation
161 * Takes an ion_fd_data struct with the handle field populated with a valid
162 * opaque handle. Returns the struct with the fd field set to a file
163 * descriptor open in the current address space. This file descriptor
164 * can then be passed to another process. The corresponding opaque handle can
165 * be retrieved via ION_IOC_IMPORT.
167 #define ION_IOC_SHARE _IOWR(ION_IOC_MAGIC, 4, struct ion_fd_data)
170 * DOC: ION_IOC_IMPORT - imports a shared file descriptor
172 * Takes an ion_fd_data struct with the fd field populated with a valid file
173 * descriptor obtained from ION_IOC_SHARE and returns the struct with the handle
174 * filed set to the corresponding opaque handle.
176 #define ION_IOC_IMPORT _IOWR(ION_IOC_MAGIC, 5, struct ion_fd_data)
179 * DOC: ION_IOC_SYNC - syncs a shared file descriptors to memory
181 * Deprecated in favor of using the dma_buf api's correctly (syncing
182 * will happend automatically when the buffer is mapped to a device).
183 * If necessary should be used after touching a cached buffer from the cpu,
184 * this will make the buffer in memory coherent.
186 #define ION_IOC_SYNC _IOWR(ION_IOC_MAGIC, 7, struct ion_fd_data)
189 * DOC: ION_IOC_CUSTOM - call architecture specific ion ioctl
191 * Takes the argument of the architecture specific ioctl to call and
192 * passes appropriate userdata for that ioctl
194 #define ION_IOC_CUSTOM _IOWR(ION_IOC_MAGIC, 6, struct ion_custom_data)
196 #endif /* _UAPI_LINUX_ION_H */