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, /*
44 * must be last so device specific heaps always
45 * are at the end of this enum
49 #define ION_NUM_HEAP_IDS (sizeof(unsigned int) * 8)
52 * allocation flags - the lower 16 bits are used by core ion, the upper 16
53 * bits are reserved for use by the heaps themselves.
57 * mappings of this buffer should be cached, ion will do cache maintenance
58 * when the buffer is mapped for dma
60 #define ION_FLAG_CACHED 1
63 * mappings of this buffer will created at mmap time, if this is set
64 * caches must be managed manually
66 #define ION_FLAG_CACHED_NEEDS_SYNC 2
69 * DOC: Ion Userspace API
71 * create a client by opening /dev/ion
72 * most operations handled via following ioctls
77 * struct ion_allocation_data - metadata passed from userspace for allocations
78 * @len: size of the allocation
79 * @align: required alignment of the allocation
80 * @heap_id_mask: mask of heap ids to allocate from
81 * @flags: flags passed to heap
82 * @handle: pointer that will be populated with a cookie to use to
83 * refer to this allocation
85 * Provided by userspace as an argument to the ioctl
87 struct ion_allocation_data {
90 unsigned int heap_id_mask;
92 ion_user_handle_t handle;
96 * struct ion_fd_data - metadata passed to/from userspace for a handle/fd pair
98 * @fd: a file descriptor representing that handle
100 * For ION_IOC_SHARE or ION_IOC_MAP userspace populates the handle field with
101 * the handle returned from ion alloc, and the kernel returns the file
102 * descriptor to share or map in the fd field. For ION_IOC_IMPORT, userspace
103 * provides the file descriptor and the kernel returns the handle.
106 ion_user_handle_t handle;
111 * struct ion_handle_data - a handle passed to/from the kernel
114 struct ion_handle_data {
115 ion_user_handle_t handle;
119 * struct ion_custom_data - metadata passed to/from userspace for a custom ioctl
120 * @cmd: the custom ioctl function to call
121 * @arg: additional data to pass to the custom ioctl, typically a user
122 * pointer to a predefined structure
124 * This works just like the regular cmd and arg fields of an ioctl.
126 struct ion_custom_data {
131 #define MAX_HEAP_NAME 32
134 * struct ion_heap_data - data about a heap
135 * @name - first 32 characters of the heap name
137 * @heap_id - heap id for the heap
139 struct ion_heap_data {
140 char name[MAX_HEAP_NAME];
149 * struct ion_heap_query - collection of data about all heaps
150 * @cnt - total number of heaps to be copied
151 * @heaps - buffer to copy heap data
153 struct ion_heap_query {
154 __u32 cnt; /* Total number of heaps to be copied */
155 __u32 reserved0; /* align to 64bits */
156 __u64 heaps; /* buffer to be populated */
161 #define ION_IOC_MAGIC 'I'
164 * DOC: ION_IOC_ALLOC - allocate memory
166 * Takes an ion_allocation_data struct and returns it with the handle field
167 * populated with the opaque handle for the allocation.
169 #define ION_IOC_ALLOC _IOWR(ION_IOC_MAGIC, 0, \
170 struct ion_allocation_data)
173 * DOC: ION_IOC_FREE - free memory
175 * Takes an ion_handle_data struct and frees the handle.
177 #define ION_IOC_FREE _IOWR(ION_IOC_MAGIC, 1, struct ion_handle_data)
180 * DOC: ION_IOC_MAP - get a file descriptor to mmap
182 * Takes an ion_fd_data struct with the handle field populated with a valid
183 * opaque handle. Returns the struct with the fd field set to a file
184 * descriptor open in the current address space. This file descriptor
185 * can then be used as an argument to mmap.
187 #define ION_IOC_MAP _IOWR(ION_IOC_MAGIC, 2, struct ion_fd_data)
190 * DOC: ION_IOC_SHARE - creates a file descriptor to use to share an allocation
192 * Takes an ion_fd_data struct with the handle field populated with a valid
193 * opaque handle. Returns the struct with the fd field set to a file
194 * descriptor open in the current address space. This file descriptor
195 * can then be passed to another process. The corresponding opaque handle can
196 * be retrieved via ION_IOC_IMPORT.
198 #define ION_IOC_SHARE _IOWR(ION_IOC_MAGIC, 4, struct ion_fd_data)
201 * DOC: ION_IOC_IMPORT - imports a shared file descriptor
203 * Takes an ion_fd_data struct with the fd field populated with a valid file
204 * descriptor obtained from ION_IOC_SHARE and returns the struct with the handle
205 * filed set to the corresponding opaque handle.
207 #define ION_IOC_IMPORT _IOWR(ION_IOC_MAGIC, 5, struct ion_fd_data)
210 * DOC: ION_IOC_CUSTOM - call architecture specific ion ioctl
212 * Takes the argument of the architecture specific ioctl to call and
213 * passes appropriate userdata for that ioctl
215 #define ION_IOC_CUSTOM _IOWR(ION_IOC_MAGIC, 6, struct ion_custom_data)
218 * DOC: ION_IOC_HEAP_QUERY - information about available heaps
220 * Takes an ion_heap_query structure and populates information about
221 * available Ion heaps.
223 #define ION_IOC_HEAP_QUERY _IOWR(ION_IOC_MAGIC, 8, \
224 struct ion_heap_query)
226 #endif /* _UAPI_LINUX_ION_H */