1/*
2 * drivers/staging/android/uapi/ion.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 _UAPI_LINUX_ION_H
18#define _UAPI_LINUX_ION_H
19
20#include <linux/ioctl.h>
21#include <linux/types.h>
22
23typedef int ion_user_handle_t;
24
25/**
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
31 *				 contiguous
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
36 */
37enum ion_heap_type {
38	ION_HEAP_TYPE_SYSTEM,
39	ION_HEAP_TYPE_SYSTEM_CONTIG,
40	ION_HEAP_TYPE_CARVEOUT,
41	ION_HEAP_TYPE_CHUNK,
42	ION_HEAP_TYPE_DMA,
43	ION_HEAP_TYPE_CUSTOM, /* must be last so device specific heaps always
44				 are at the end of this enum */
45	ION_NUM_HEAPS = 16,
46};
47
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)
52
53#define ION_NUM_HEAP_IDS		(sizeof(unsigned int) * 8)
54
55/**
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.
58 */
59#define ION_FLAG_CACHED 1		/* mappings of this buffer should be
60					   cached, ion will do cache
61					   maintenance when the buffer is
62					   mapped for dma */
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 */
66
67/**
68 * DOC: Ion Userspace API
69 *
70 * create a client by opening /dev/ion
71 * most operations handled via following ioctls
72 *
73 */
74
75/**
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
83 *
84 * Provided by userspace as an argument to the ioctl
85 */
86struct ion_allocation_data {
87	size_t len;
88	size_t align;
89	unsigned int heap_id_mask;
90	unsigned int flags;
91	ion_user_handle_t handle;
92};
93
94/**
95 * struct ion_fd_data - metadata passed to/from userspace for a handle/fd pair
96 * @handle:	a handle
97 * @fd:		a file descriptor representing that handle
98 *
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.
103 */
104struct ion_fd_data {
105	ion_user_handle_t handle;
106	int fd;
107};
108
109/**
110 * struct ion_handle_data - a handle passed to/from the kernel
111 * @handle:	a handle
112 */
113struct ion_handle_data {
114	ion_user_handle_t handle;
115};
116
117/**
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
122 *
123 * This works just like the regular cmd and arg fields of an ioctl.
124 */
125struct ion_custom_data {
126	unsigned int cmd;
127	unsigned long arg;
128};
129
130#define ION_IOC_MAGIC		'I'
131
132/**
133 * DOC: ION_IOC_ALLOC - allocate memory
134 *
135 * Takes an ion_allocation_data struct and returns it with the handle field
136 * populated with the opaque handle for the allocation.
137 */
138#define ION_IOC_ALLOC		_IOWR(ION_IOC_MAGIC, 0, \
139				      struct ion_allocation_data)
140
141/**
142 * DOC: ION_IOC_FREE - free memory
143 *
144 * Takes an ion_handle_data struct and frees the handle.
145 */
146#define ION_IOC_FREE		_IOWR(ION_IOC_MAGIC, 1, struct ion_handle_data)
147
148/**
149 * DOC: ION_IOC_MAP - get a file descriptor to mmap
150 *
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.
155 */
156#define ION_IOC_MAP		_IOWR(ION_IOC_MAGIC, 2, struct ion_fd_data)
157
158/**
159 * DOC: ION_IOC_SHARE - creates a file descriptor to use to share an allocation
160 *
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.
166 */
167#define ION_IOC_SHARE		_IOWR(ION_IOC_MAGIC, 4, struct ion_fd_data)
168
169/**
170 * DOC: ION_IOC_IMPORT - imports a shared file descriptor
171 *
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.
175 */
176#define ION_IOC_IMPORT		_IOWR(ION_IOC_MAGIC, 5, struct ion_fd_data)
177
178/**
179 * DOC: ION_IOC_SYNC - syncs a shared file descriptors to memory
180 *
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.
185 */
186#define ION_IOC_SYNC		_IOWR(ION_IOC_MAGIC, 7, struct ion_fd_data)
187
188/**
189 * DOC: ION_IOC_CUSTOM - call architecture specific ion ioctl
190 *
191 * Takes the argument of the architecture specific ioctl to call and
192 * passes appropriate userdata for that ioctl
193 */
194#define ION_IOC_CUSTOM		_IOWR(ION_IOC_MAGIC, 6, struct ion_custom_data)
195
196#endif /* _UAPI_LINUX_ION_H */
197