nuttx/mm/shm/shm.h
2014-09-23 08:46:31 -06:00

107 lines
3.8 KiB
C

/****************************************************************************
* mm/shm/shm.h
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __MM_SHM_SHM_H
#define __MM_SHM_SHM_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <stdint.h>
#include <semaphore.h>
#include <nuttx/addrenv.h>
#ifdef CONFIG_MM_SHM
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* IPC_PRIVATE is the only value for the the SHM key that is guaranteed to
* be invalid.
*/
#define SHM_INVALID_KEY IPC_PRIVATE
/****************************************************************************
* Public Types
****************************************************************************/
/* This structure represents the state of one shared memory region
* allocation. Cast compatible with struct shmid_ds.
*/
struct shm_region_s
{
struct shmid_ds sr_ds; /* Region info */
key_t sr_key; /* Lookup key. IPC_PRIVATE means unused */
sem_t sr_sem; /* Manages exclusive access to this region */
/* List of physical pages allocated for this memory region */
uintptr_t sr_pages[CONFIG_ARCH_SHM_NPAGES];
};
/* This structure represents the set of all shared memory regions.
* Access to the region
*/
struct shm_info_s
{
sem_t si_sem; /* Manages exclusive access to the region list */
struct shm_region_s si_region[CONFIG_ARCH_SHM_MAXREGIONS];
};
/****************************************************************************
* Public Data
****************************************************************************/
/* State of the all shared memory */
extern struct shm_info_s g_shminfo;
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#endif /* CONFIG_MM_SHM */
#endif /* __MM_SHM_SHM_H */