sysroots/generic-arm32/usr/include/uapi/mm.h

/*
 * Copyright (c) 2015 Google Inc. All rights reserved
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef __UAPI_MM_H
#define __UAPI_MM_H

#include <stdint.h>

/*
 * Flags for mmap syscall
 */

/**
 * MMAP_FLAG_IO_HANDLE - map IO region rather than handle
 * When passed to mmap(), this flag causes the handle argument to be
 * interpreted as a MMIO region ID defined in the manifest rather than a
 * handle.
 *
 * An IO Mapping has fixed attributes (non-secure, strongly ordered,
 * physically contiguous, read-writable and 4k aligned) for now.
 *
 * It is an error to use this flag without %MMAP_PROT_READ and
 * %MMAP_PROT_WRITE specified, or with %MMAP_PROT_EXEC specified.
 */
#define MMAP_FLAG_IO_HANDLE (0x1 << 4)

/**
 * MMAP_FLAG_ANONYMOUS - the mapping is not backed by any handle.
 * When passed to mmap(), this flag causes the handle argument to be
 * ignored. This is analogous to MAP_ANONYMOUS in Linux.
 *
 * When this flag is used, the uaddr argument must be 0.
 */
#define MMAP_FLAG_ANONYMOUS (0x1 << 5)

/**
 * Memory Protection attributes - flags to control mmap attributes
 * %MMAP_FLAG_PROT_NONE:  specifies absence of any mmap prot flags set
 * %MMAP_FLAG_PROT_READ:  specifies that mapped region should be readable
 * %MMAP_FLAG_PROT_WRITE: specifies that mapped region should be writable
 * %MMAP_FLAG_PROT_EXEC:  specifies that mapped region should be executable
 * %MMAP_FLAG_PROT_MASK:  a combination of all possible PROT attributes
 */
#define MMAP_FLAG_PROT_NONE 0x0
#define MMAP_FLAG_PROT_READ 0x1
#define MMAP_FLAG_PROT_WRITE 0x2
#define MMAP_FLAG_PROT_EXEC 0x4

#define MMAP_FLAG_PROT_MASK \
    (MMAP_FLAG_PROT_READ | MMAP_FLAG_PROT_WRITE | MMAP_FLAG_PROT_EXEC)

/**
 * struct dma_pmem - a contiguous physical memory block
 * @paddr: start of physical address
 * @size:  size of this contiguous block
 *
 * Caller passes this struct to prepare_dma syscall, which fills in pinned
 * contiguous physical memory blocks. Caller uses DMA_MULTI_PMEM to tell
 * syscall whether it passes in a single struct or an array.
 */
struct dma_pmem {
    uint64_t paddr;
    uint32_t size;
    uint32_t pad;
};

/*
 * Flags for prepare_dma and finish_dma syscalls
 */

/*
 * DMA directions
 */
#define DMA_FLAG_TO_DEVICE (0x1 << 0)   /* memory to device */
#define DMA_FLAG_FROM_DEVICE (0x1 << 1) /* device to memory */
#define DMA_FLAG_BIDIRECTION (DMA_FLAG_TO_DEVICE | DMA_FLAG_FROM_DEVICE)

/*
 * If DMA_FLAG_MULTI_PMEM is set, caller of prepare_dma must pass an array
 * of dma_pmem struct. The array must be big enough to store all contiguous
 * physical memory blocks to match requested user space memory aperture. For
 * example, when minimum size of contiguous physical memory block is PAGE_SIZE,
 * the array must be big enough to store
 * ((uaddr + size - 1) / PAGE_SIZE - uaddr / PAGE_SIZE + 1) entries.
 * Note: using a smaller dma_pmem array would corrupt current process's memory.
 *
 * If DMA_FLAG_MULTI_PMEM is not set, caller must pass a single dma_pmem struct.
 * prepare_dma will attempt to map user space aperture into one contiguous
 * physical memory block. If user space aperture is bigger than max size of
 * contiguous physical memory block, behavior controlled by DMA_ALLOW_PARTIAL.
 */
#define DMA_FLAG_MULTI_PMEM (0x1 << 2)

/*
 * If DMA_FLAG_ALLOW_PARTIAL is set, prepare_dma allows partial mapping of user
 * requested aperture, e.g. assuming max size of one contiguous physical block
 * is PAGE_SIZE, when DMA_MULTI_PMEM is not set and [vaddr, vaddr + size) spans
 * on multiple pages, if this bit is set, kernel maps [vaddr, end of first page]
 * with a single dma_pmem struct. If not set, kernel returns ERR_BAD_LEN.
 */
#define DMA_FLAG_ALLOW_PARTIAL (0x1 << 3)

#endif /* __UAPI_MM_H */