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 
23 typedef 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  */
37 enum 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, /*
44 			       * must be last so device specific heaps always
45 			       * are at the end of this enum
46 			       */
47 };
48 
49 #define ION_NUM_HEAP_IDS		(sizeof(unsigned int) * 8)
50 
51 /**
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.
54  */
55 
56 /*
57  * mappings of this buffer should be cached, ion will do cache maintenance
58  * when the buffer is mapped for dma
59  */
60 #define ION_FLAG_CACHED 1
61 
62 /*
63  * mappings of this buffer will created at mmap time, if this is set
64  * caches must be managed manually
65  */
66 #define ION_FLAG_CACHED_NEEDS_SYNC 2
67 
68 /**
69  * DOC: Ion Userspace API
70  *
71  * create a client by opening /dev/ion
72  * most operations handled via following ioctls
73  *
74  */
75 
76 /**
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
84  *
85  * Provided by userspace as an argument to the ioctl
86  */
87 struct ion_allocation_data {
88 	size_t len;
89 	size_t align;
90 	unsigned int heap_id_mask;
91 	unsigned int flags;
92 	ion_user_handle_t handle;
93 };
94 
95 /**
96  * struct ion_fd_data - metadata passed to/from userspace for a handle/fd pair
97  * @handle:	a handle
98  * @fd:		a file descriptor representing that handle
99  *
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.
104  */
105 struct ion_fd_data {
106 	ion_user_handle_t handle;
107 	int fd;
108 };
109 
110 /**
111  * struct ion_handle_data - a handle passed to/from the kernel
112  * @handle:	a handle
113  */
114 struct ion_handle_data {
115 	ion_user_handle_t handle;
116 };
117 
118 /**
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
123  *
124  * This works just like the regular cmd and arg fields of an ioctl.
125  */
126 struct ion_custom_data {
127 	unsigned int cmd;
128 	unsigned long arg;
129 };
130 
131 #define MAX_HEAP_NAME			32
132 
133 /**
134  * struct ion_heap_data - data about a heap
135  * @name - first 32 characters of the heap name
136  * @type - heap type
137  * @heap_id - heap id for the heap
138  */
139 struct ion_heap_data {
140 	char name[MAX_HEAP_NAME];
141 	__u32 type;
142 	__u32 heap_id;
143 	__u32 reserved0;
144 	__u32 reserved1;
145 	__u32 reserved2;
146 };
147 
148 /**
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
152  */
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 */
157 	__u32 reserved1;
158 	__u32 reserved2;
159 };
160 
161 #define ION_IOC_MAGIC		'I'
162 
163 /**
164  * DOC: ION_IOC_ALLOC - allocate memory
165  *
166  * Takes an ion_allocation_data struct and returns it with the handle field
167  * populated with the opaque handle for the allocation.
168  */
169 #define ION_IOC_ALLOC		_IOWR(ION_IOC_MAGIC, 0, \
170 				      struct ion_allocation_data)
171 
172 /**
173  * DOC: ION_IOC_FREE - free memory
174  *
175  * Takes an ion_handle_data struct and frees the handle.
176  */
177 #define ION_IOC_FREE		_IOWR(ION_IOC_MAGIC, 1, struct ion_handle_data)
178 
179 /**
180  * DOC: ION_IOC_MAP - get a file descriptor to mmap
181  *
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.
186  */
187 #define ION_IOC_MAP		_IOWR(ION_IOC_MAGIC, 2, struct ion_fd_data)
188 
189 /**
190  * DOC: ION_IOC_SHARE - creates a file descriptor to use to share an allocation
191  *
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.
197  */
198 #define ION_IOC_SHARE		_IOWR(ION_IOC_MAGIC, 4, struct ion_fd_data)
199 
200 /**
201  * DOC: ION_IOC_IMPORT - imports a shared file descriptor
202  *
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.
206  */
207 #define ION_IOC_IMPORT		_IOWR(ION_IOC_MAGIC, 5, struct ion_fd_data)
208 
209 /**
210  * DOC: ION_IOC_SYNC - syncs a shared file descriptors to memory
211  *
212  * Deprecated in favor of using the dma_buf api's correctly (syncing
213  * will happen automatically when the buffer is mapped to a device).
214  * If necessary should be used after touching a cached buffer from the cpu,
215  * this will make the buffer in memory coherent.
216  */
217 #define ION_IOC_SYNC		_IOWR(ION_IOC_MAGIC, 7, struct ion_fd_data)
218 
219 /**
220  * DOC: ION_IOC_CUSTOM - call architecture specific ion ioctl
221  *
222  * Takes the argument of the architecture specific ioctl to call and
223  * passes appropriate userdata for that ioctl
224  */
225 #define ION_IOC_CUSTOM		_IOWR(ION_IOC_MAGIC, 6, struct ion_custom_data)
226 
227 /**
228  * DOC: ION_IOC_HEAP_QUERY - information about available heaps
229  *
230  * Takes an ion_heap_query structure and populates information about
231  * available Ion heaps.
232  */
233 #define ION_IOC_HEAP_QUERY     _IOWR(ION_IOC_MAGIC, 8, \
234 					struct ion_heap_query)
235 
236 #endif /* _UAPI_LINUX_ION_H */
237