/*
* drivers/staging/android/uapi/ion.h
*
* Copyright (C) 2011 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#ifndef _LINUX_ION_H
#define _LINUX_ION_H
#include <linux/ioctl.h>
#include <linux/types.h>
typedef int ion_user_handle_t;
/**
* enum ion_heap_types - list of all possible types of heaps
* @ION_HEAP_TYPE_SYSTEM: memory allocated via vmalloc
* @ION_HEAP_TYPE_SYSTEM_CONTIG: memory allocated via kmalloc
* @ION_HEAP_TYPE_CARVEOUT: memory allocated from a prereserved
* carveout heap, allocations are physically
* contiguous
* @ION_HEAP_TYPE_DMA: memory allocated via DMA API
* @ION_NUM_HEAPS: helper for iterating over heaps, a bit mask
* is used to identify the heaps, so only 32
* total heap types are supported
*/
enum ion_heap_type {
ION_HEAP_TYPE_SYSTEM,
ION_HEAP_TYPE_SYSTEM_CONTIG,
ION_HEAP_TYPE_CARVEOUT,
ION_HEAP_TYPE_CHUNK,
ION_HEAP_TYPE_DMA,
ION_HEAP_TYPE_CUSTOM, /*
* must be last so device specific heaps always
* are at the end of this enum
*/
ION_NUM_HEAPS = 16,
};
#define ION_HEAP_SYSTEM_MASK (1 << ION_HEAP_TYPE_SYSTEM)
#define ION_HEAP_SYSTEM_CONTIG_MASK (1 << ION_HEAP_TYPE_SYSTEM_CONTIG)
#define ION_HEAP_CARVEOUT_MASK (1 << ION_HEAP_TYPE_CARVEOUT)
#define ION_HEAP_TYPE_DMA_MASK (1 << ION_HEAP_TYPE_DMA)
#define ION_NUM_HEAP_IDS (sizeof(unsigned int) * 8)
/**
* allocation flags - the lower 16 bits are used by core ion, the upper 16
* bits are reserved for use by the heaps themselves.
*/
#define ION_FLAG_CACHED 1 /*
* mappings of this buffer should be
* cached, ion will do cache
* maintenance when the buffer is
* mapped for dma
*/
#define ION_FLAG_CACHED_NEEDS_SYNC 2 /*
* mappings of this buffer will created
* at mmap time, if this is set
* caches must be managed
* manually
*/
/**
* DOC: Ion Userspace API
*
* create a client by opening /dev/ion
* most operations handled via following ioctls
*
*/
/**
* struct ion_allocation_data - metadata passed from userspace for allocations
* @len: size of the allocation
* @align: required alignment of the allocation
* @heap_id_mask: mask of heap ids to allocate from
* @flags: flags passed to heap
* @handle: pointer that will be populated with a cookie to use to
* refer to this allocation
*
* Provided by userspace as an argument to the ioctl
*/
struct ion_allocation_data {
size_t len;
size_t align;
unsigned int heap_id_mask;
unsigned int flags;
ion_user_handle_t handle;
};
/**
* struct ion_fd_data - metadata passed to/from userspace for a handle/fd pair
* @handle: a handle
* @fd: a file descriptor representing that handle
*
* For ION_IOC_SHARE or ION_IOC_MAP userspace populates the handle field with
* the handle returned from ion alloc, and the kernel returns the file
* descriptor to share or map in the fd field. For ION_IOC_IMPORT, userspace
* provides the file descriptor and the kernel returns the handle.
*/
struct ion_fd_data {
ion_user_handle_t handle;
int fd;
};
/**
* struct ion_handle_data - a handle passed to/from the kernel
* @handle: a handle
*/
struct ion_handle_data {
ion_user_handle_t handle;
};
/**
* struct ion_custom_data - metadata passed to/from userspace for a custom ioctl
* @cmd: the custom ioctl function to call
* @arg: additional data to pass to the custom ioctl, typically a user
* pointer to a predefined structure
*
* This works just like the regular cmd and arg fields of an ioctl.
*/
struct ion_custom_data {
unsigned int cmd;
unsigned long arg;
};
#define ION_IOC_MAGIC 'I'
/**
* DOC: ION_IOC_ALLOC - allocate memory
*
* Takes an ion_allocation_data struct and returns it with the handle field
* populated with the opaque handle for the allocation.
*/
#define ION_IOC_ALLOC _IOWR(ION_IOC_MAGIC, 0, \
struct ion_allocation_data)
/**
* DOC: ION_IOC_FREE - free memory
*
* Takes an ion_handle_data struct and frees the handle.
*/
#define ION_IOC_FREE _IOWR(ION_IOC_MAGIC, 1, struct ion_handle_data)
/**
* DOC: ION_IOC_MAP - get a file descriptor to mmap
*
* Takes an ion_fd_data struct with the handle field populated with a valid
* opaque handle. Returns the struct with the fd field set to a file
* descriptor open in the current address space. This file descriptor
* can then be used as an argument to mmap.
*/
#define ION_IOC_MAP _IOWR(ION_IOC_MAGIC, 2, struct ion_fd_data)
/**
* DOC: ION_IOC_SHARE - creates a file descriptor to use to share an allocation
*
* Takes an ion_fd_data struct with the handle field populated with a valid
* opaque handle. Returns the struct with the fd field set to a file
* descriptor open in the current address space. This file descriptor
* can then be passed to another process. The corresponding opaque handle can
* be retrieved via ION_IOC_IMPORT.
*/
#define ION_IOC_SHARE _IOWR(ION_IOC_MAGIC, 4, struct ion_fd_data)
/**
* DOC: ION_IOC_IMPORT - imports a shared file descriptor
*
* Takes an ion_fd_data struct with the fd field populated with a valid file
* descriptor obtained from ION_IOC_SHARE and returns the struct with the handle
* filed set to the corresponding opaque handle.
*/
#define ION_IOC_IMPORT _IOWR(ION_IOC_MAGIC, 5, struct ion_fd_data)
/**
* DOC: ION_IOC_SYNC - syncs a shared file descriptors to memory
*
* Deprecated in favor of using the dma_buf api's correctly (syncing
* will happen automatically when the buffer is mapped to a device).
* If necessary should be used after touching a cached buffer from the cpu,
* this will make the buffer in memory coherent.
*/
#define ION_IOC_SYNC _IOWR(ION_IOC_MAGIC, 7, struct ion_fd_data)
/**
* DOC: ION_IOC_CUSTOM - call architecture specific ion ioctl
*
* Takes the argument of the architecture specific ioctl to call and
* passes appropriate userdata for that ioctl
*/
#define ION_IOC_CUSTOM _IOWR(ION_IOC_MAGIC, 6, struct ion_custom_data)
#endif /* _LINUX_ION_H */