drivers/staging/android/uapi/ion.h

   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, /* 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 /**
  54  * allocation flags - the lower 16 bits are used by core ion, the upper 16
  55  * bits are reserved for use by the heaps themselves.
  56  */
  57 #define ION_FLAG_CACHED 1               /* mappings of this buffer should be
  58                                            cached, ion will do cache
  59                                            maintenance when the buffer is
  60                                            mapped for dma */
  61 #define ION_FLAG_CACHED_NEEDS_SYNC 2    /* mappings of this buffer will created
  62                                            at mmap time, if this is set
  63                                            caches must be managed manually */
  64
  65 /**
  66  * DOC: Ion Userspace API
  67  *
  68  * create a client by opening /dev/ion
  69  * most operations handled via following ioctls
  70  *
  71  */
  72
  73 /**
  74  * struct ion_allocation_data - metadata passed from userspace for allocations
  75  * @len:                size of the allocation
  76  * @align:              required alignment of the allocation
  77  * @heap_id_mask:       mask of heap ids to allocate from
  78  * @flags:              flags passed to heap
  79  * @handle:             pointer that will be populated with a cookie to use to
  80  *                      refer to this allocation
  81  *
  82  * Provided by userspace as an argument to the ioctl
  83  */
  84 struct ion_allocation_data {
  85         size_t len;
  86         size_t align;
  87         unsigned int heap_id_mask;
  88         unsigned int flags;
  89         ion_user_handle_t handle;
  90 };
  91
  92 /**
  93  * struct ion_fd_data - metadata passed to/from userspace for a handle/fd pair
  94  * @handle:     a handle
  95  * @fd:         a file descriptor representing that handle
  96  *
  97  * For ION_IOC_SHARE or ION_IOC_MAP userspace populates the handle field with
  98  * the handle returned from ion alloc, and the kernel returns the file
  99  * descriptor to share or map in the fd field.  For ION_IOC_IMPORT, userspace
 100  * provides the file descriptor and the kernel returns the handle.
 101  */
 102 struct ion_fd_data {
 103         ion_user_handle_t handle;
 104         int fd;
 105 };
 106
 107 /**
 108  * struct ion_handle_data - a handle passed to/from the kernel
 109  * @handle:     a handle
 110  */
 111 struct ion_handle_data {
 112         ion_user_handle_t handle;
 113 };
 114
 115 /**
 116  * struct ion_custom_data - metadata passed to/from userspace for a custom ioctl
 117  * @cmd:        the custom ioctl function to call
 118  * @arg:        additional data to pass to the custom ioctl, typically a user
 119  *              pointer to a predefined structure
 120  *
 121  * This works just like the regular cmd and arg fields of an ioctl.
 122  */
 123 struct ion_custom_data {
 124         unsigned int cmd;
 125         unsigned long arg;
 126 };
 127
 128 #define ION_IOC_MAGIC           'I'
 129
 130 /**
 131  * DOC: ION_IOC_ALLOC - allocate memory
 132  *
 133  * Takes an ion_allocation_data struct and returns it with the handle field
 134  * populated with the opaque handle for the allocation.
 135  */
 136 #define ION_IOC_ALLOC           _IOWR(ION_IOC_MAGIC, 0, \
 137                                       struct ion_allocation_data)
 138
 139 /**
 140  * DOC: ION_IOC_FREE - free memory
 141  *
 142  * Takes an ion_handle_data struct and frees the handle.
 143  */
 144 #define ION_IOC_FREE            _IOWR(ION_IOC_MAGIC, 1, struct ion_handle_data)
 145
 146 /**
 147  * DOC: ION_IOC_MAP - get a file descriptor to mmap
 148  *
 149  * Takes an ion_fd_data struct with the handle field populated with a valid
 150  * opaque handle.  Returns the struct with the fd field set to a file
 151  * descriptor open in the current address space.  This file descriptor
 152  * can then be used as an argument to mmap.
 153  */
 154 #define ION_IOC_MAP             _IOWR(ION_IOC_MAGIC, 2, struct ion_fd_data)
 155
 156 /**
 157  * DOC: ION_IOC_SHARE - creates a file descriptor to use to share an allocation
 158  *
 159  * Takes an ion_fd_data struct with the handle field populated with a valid
 160  * opaque handle.  Returns the struct with the fd field set to a file
 161  * descriptor open in the current address space.  This file descriptor
 162  * can then be passed to another process.  The corresponding opaque handle can
 163  * be retrieved via ION_IOC_IMPORT.
 164  */
 165 #define ION_IOC_SHARE           _IOWR(ION_IOC_MAGIC, 4, struct ion_fd_data)
 166
 167 /**
 168  * DOC: ION_IOC_IMPORT - imports a shared file descriptor
 169  *
 170  * Takes an ion_fd_data struct with the fd field populated with a valid file
 171  * descriptor obtained from ION_IOC_SHARE and returns the struct with the handle
 172  * filed set to the corresponding opaque handle.
 173  */
 174 #define ION_IOC_IMPORT          _IOWR(ION_IOC_MAGIC, 5, struct ion_fd_data)
 175
 176 /**
 177  * DOC: ION_IOC_SYNC - syncs a shared file descriptors to memory
 178  *
 179  * Deprecated in favor of using the dma_buf api's correctly (syncing
 180  * will happend automatically when the buffer is mapped to a device).
 181  * If necessary should be used after touching a cached buffer from the cpu,
 182  * this will make the buffer in memory coherent.
 183  */
 184 #define ION_IOC_SYNC            _IOWR(ION_IOC_MAGIC, 7, struct ion_fd_data)
 185
 186 /**
 187  * DOC: ION_IOC_CUSTOM - call architecture specific ion ioctl
 188  *
 189  * Takes the argument of the architecture specific ioctl to call and
 190  * passes appropriate userdata for that ioctl
 191  */
 192 #define ION_IOC_CUSTOM          _IOWR(ION_IOC_MAGIC, 6, struct ion_custom_data)
 193
 194 #endif /* _UAPI_LINUX_ION_H */