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 _LINUX_ION_H
18 #define _LINUX_ION_H
19 
20 #include <linux/ioctl.h>
21 #include <linux/types.h>
22 
23 /**
24  * enum ion_heap_types - list of all possible types of heaps
25  * @ION_HEAP_TYPE_SYSTEM:	 memory allocated via vmalloc
26  * @ION_HEAP_TYPE_SYSTEM_CONTIG: memory allocated via kmalloc
27  * @ION_HEAP_TYPE_CARVEOUT:	 memory allocated from a prereserved
28  *				 carveout heap, allocations are physically
29  *				 contiguous
30  * @ION_HEAP_TYPE_DMA:		 memory allocated via DMA API
31  * @ION_NUM_HEAPS:		 helper for iterating over heaps, a bit mask
32  *				 is used to identify the heaps, so only 32
33  *				 total heap types are supported
34  */
35 enum ion_heap_type {
36 	ION_HEAP_TYPE_SYSTEM,
37 	ION_HEAP_TYPE_SYSTEM_CONTIG,
38 	ION_HEAP_TYPE_CARVEOUT,
39 	ION_HEAP_TYPE_CHUNK,
40 	ION_HEAP_TYPE_DMA,
41 	ION_HEAP_TYPE_CUSTOM, /*
42 			       * must be last so device specific heaps always
43 			       * are at the end of this enum
44 			       */
45 };
46 
47 #define ION_NUM_HEAP_IDS		(sizeof(unsigned int) * 8)
48 
49 /**
50  * allocation flags - the lower 16 bits are used by core ion, the upper 16
51  * bits are reserved for use by the heaps themselves.
52  */
53 
54 /*
55  * mappings of this buffer should be cached, ion will do cache maintenance
56  * when the buffer is mapped for dma
57  */
58 #define ION_FLAG_CACHED 1
59 
60 /**
61  * DOC: Ion Userspace API
62  *
63  * create a client by opening /dev/ion
64  * most operations handled via following ioctls
65  *
66  */
67 
68 /**
69  * struct ion_allocation_data - metadata passed from userspace for allocations
70  * @len:		size of the allocation
71  * @heap_id_mask:	mask of heap ids to allocate from
72  * @flags:		flags passed to heap
73  * @handle:		pointer that will be populated with a cookie to use to
74  *			refer to this allocation
75  *
76  * Provided by userspace as an argument to the ioctl
77  */
78 struct ion_allocation_data {
79 	__u64 len;
80 	__u32 heap_id_mask;
81 	__u32 flags;
82 	__u32 fd;
83 	__u32 unused;
84 };
85 
86 #define MAX_HEAP_NAME			32
87 
88 /**
89  * struct ion_heap_data - data about a heap
90  * @name - first 32 characters of the heap name
91  * @type - heap type
92  * @heap_id - heap id for the heap
93  */
94 struct ion_heap_data {
95 	char name[MAX_HEAP_NAME];
96 	__u32 type;
97 	__u32 heap_id;
98 	__u32 reserved0;
99 	__u32 reserved1;
100 	__u32 reserved2;
101 };
102 
103 /**
104  * struct ion_heap_query - collection of data about all heaps
105  * @cnt - total number of heaps to be copied
106  * @heaps - buffer to copy heap data
107  */
108 struct ion_heap_query {
109 	__u32 cnt; /* Total number of heaps to be copied */
110 	__u32 reserved0; /* align to 64bits */
111 	__u64 heaps; /* buffer to be populated */
112 	__u32 reserved1;
113 	__u32 reserved2;
114 };
115 
116 #define ION_IOC_MAGIC		'I'
117 
118 /**
119  * DOC: ION_IOC_ALLOC - allocate memory
120  *
121  * Takes an ion_allocation_data struct and returns it with the handle field
122  * populated with the opaque handle for the allocation.
123  */
124 #define ION_IOC_ALLOC		_IOWR(ION_IOC_MAGIC, 0, \
125 				      struct ion_allocation_data)
126 /**
127  * DOC: ION_IOC_HEAP_QUERY - information about available heaps
128  *
129  * Takes an ion_heap_query structure and populates information about
130  * available Ion heaps.
131  */
132 #define ION_IOC_HEAP_QUERY     _IOWR(ION_IOC_MAGIC, 8, \
133 					struct ion_heap_query)
134 
135 #endif /* _LINUX_ION_H */
136