1 /* 2 * include/linux/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_ION_H 18 #define _UAPI_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, /* 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 */ 86 struct 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 */ 104 struct 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 */ 113 struct 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 */ 125 struct ion_custom_data { 126 unsigned int cmd; 127 unsigned long arg; 128 }; 129 #define ION_IOC_MAGIC 'I' 130 131 /** 132 * DOC: ION_IOC_ALLOC - allocate memory 133 * 134 * Takes an ion_allocation_data struct and returns it with the handle field 135 * populated with the opaque handle for the allocation. 136 */ 137 #define ION_IOC_ALLOC _IOWR(ION_IOC_MAGIC, 0, \ 138 struct ion_allocation_data) 139 140 /** 141 * DOC: ION_IOC_FREE - free memory 142 * 143 * Takes an ion_handle_data struct and frees the handle. 144 */ 145 #define ION_IOC_FREE _IOWR(ION_IOC_MAGIC, 1, struct ion_handle_data) 146 147 /** 148 * DOC: ION_IOC_MAP - get a file descriptor to mmap 149 * 150 * Takes an ion_fd_data struct with the handle field populated with a valid 151 * opaque handle. Returns the struct with the fd field set to a file 152 * descriptor open in the current address space. This file descriptor 153 * can then be used as an argument to mmap. 154 */ 155 #define ION_IOC_MAP _IOWR(ION_IOC_MAGIC, 2, struct ion_fd_data) 156 157 /** 158 * DOC: ION_IOC_SHARE - creates a file descriptor to use to share an allocation 159 * 160 * Takes an ion_fd_data struct with the handle field populated with a valid 161 * opaque handle. Returns the struct with the fd field set to a file 162 * descriptor open in the current address space. This file descriptor 163 * can then be passed to another process. The corresponding opaque handle can 164 * be retrieved via ION_IOC_IMPORT. 165 */ 166 #define ION_IOC_SHARE _IOWR(ION_IOC_MAGIC, 4, struct ion_fd_data) 167 168 /** 169 * DOC: ION_IOC_IMPORT - imports a shared file descriptor 170 * 171 * Takes an ion_fd_data struct with the fd field populated with a valid file 172 * descriptor obtained from ION_IOC_SHARE and returns the struct with the handle 173 * filed set to the corresponding opaque handle. 174 */ 175 #define ION_IOC_IMPORT _IOWR(ION_IOC_MAGIC, 5, struct ion_fd_data) 176 177 /** 178 * DOC: ION_IOC_SYNC - syncs a shared file descriptors to memory 179 * 180 * Deprecated in favor of using the dma_buf api's correctly (syncing 181 * will happend automatically when the buffer is mapped to a device). 182 * If necessary should be used after touching a cached buffer from the cpu, 183 * this will make the buffer in memory coherent. 184 */ 185 #define ION_IOC_SYNC _IOWR(ION_IOC_MAGIC, 7, struct ion_fd_data) 186 187 /** 188 * DOC: ION_IOC_CUSTOM - call architecture specific ion ioctl 189 * 190 * Takes the argument of the architecture specific ioctl to call and 191 * passes appropriate userdata for that ioctl 192 */ 193 #define ION_IOC_CUSTOM _IOWR(ION_IOC_MAGIC, 6, struct ion_custom_data) 194 195 #endif /* _UAPI_ION_H */ 196