ion.h

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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
 * drivers/staging/android/uapi/ion.h
 *
 * Copyright (C) 2011 Google, Inc.
 */
 
#ifndef _UAPI_LINUX_ION_H
#define _UAPI_LINUX_ION_H
 
#include <linux/ioctl.h>
#include <linux/types.h>
 
/**
 * 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
                         */
};
enum ion_heap_type {…};
 
#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.
 */
 
/*
 * mappings of this buffer should be cached, ion will do cache maintenance
 * when the buffer is mapped for dma
 */
#define ION_FLAG_CACHED 1
 
/**
 * 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
 * @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 {
  __u64 len;
  __u32 heap_id_mask;
  __u32 flags;
  __u32 fd;
  __u32 unused;
};
struct ion_allocation_data {…};
 
#define MAX_HEAP_NAME 32
 
/**
 * struct ion_heap_data - data about a heap
 * @name - first 32 characters of the heap name
 * @type - heap type
 * @heap_id - heap id for the heap
 */
struct ion_heap_data {
  char name[MAX_HEAP_NAME];
  __u32 type;
  __u32 heap_id;
  __u32 reserved0;
  __u32 reserved1;
  __u32 reserved2;
};
struct ion_heap_data {…};
 
/**
 * struct ion_heap_query - collection of data about all heaps
 * @cnt - total number of heaps to be copied
 * @heaps - buffer to copy heap data
 */
struct ion_heap_query {
  __u32 cnt;       /* Total number of heaps to be copied */
  __u32 reserved0; /* align to 64bits */
  __u64 heaps;     /* buffer to be populated */
  __u32 reserved1;
  __u32 reserved2;
};
struct ion_heap_query {…};
 
#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_HEAP_QUERY - information about available heaps
 *
 * Takes an ion_heap_query structure and populates information about
 * available Ion heaps.
 */
#define ION_IOC_HEAP_QUERY _IOWR(ION_IOC_MAGIC, 8, struct ion_heap_query)
 
#endif /* _UAPI_LINUX_ION_H */