incubator-nuttx/drivers/iob/iob.h

151 lines
5.3 KiB
C

/****************************************************************************
* drivers/iob/iob.h
*
* Copyright (C) 2014, 2017 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 __DRIVERS_IOB_IOB_H
#define __DRIVERS_IOB_IOB_H 1
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <semaphore.h>
#include <debug.h>
#include <nuttx/drivers/iob.h>
#ifdef CONFIG_DRIVERS_IOB
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#if defined(CONFIG_DEBUG_FEATURES) && defined(CONFIG_IOB_DEBUG)
#ifdef CONFIG_CPP_HAVE_VARARGS
# define ioberr(format, ...) _err(format, ##__VA_ARGS__)
# define iobwarn(format, ...) _warn(format, ##__VA_ARGS__)
# define iobinfo(format, ...) _info(format, ##__VA_ARGS__)
#else
# define ioberr _err
# define iobwarn _warn
# define iobinfo _info
#endif
#else
#ifdef CONFIG_CPP_HAVE_VARARGS
# define ioberr(format, ...)
# define iobwarn(format, ...)
# define iobinfo(format, ...)
#else
# define ioberr (void)
# define iobwarn (void)
# define iobinfo (void)
#endif
#endif /* CONFIG_DEBUG_FEATURES && CONFIG_IOB_DEBUG */
/****************************************************************************
* Public Data
****************************************************************************/
/* A list of all free, unallocated I/O buffers */
extern FAR struct iob_s *g_iob_freelist;
/* A list of all free, unallocated I/O buffer queue containers */
#if CONFIG_IOB_NCHAINS > 0
extern FAR struct iob_qentry_s *g_iob_freeqlist;
#endif
/* Counting semaphores that tracks the number of free IOBs/qentries */
extern sem_t g_iob_sem; /* Counts free I/O buffers */
#if CONFIG_IOB_THROTTLE > 0
extern sem_t g_throttle_sem; /* Counts available I/O buffers when throttled */
#endif
#if CONFIG_IOB_NCHAINS > 0
extern sem_t g_qentry_sem; /* Counts free I/O buffer queue containers */
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: iob_alloc_qentry
*
* Description:
* Allocate an I/O buffer chain container by taking the buffer at the head
* of the free list. This function is intended only for internal use by
* the IOB module.
*
****************************************************************************/
FAR struct iob_qentry_s *iob_alloc_qentry(void);
/****************************************************************************
* Name: iob_tryalloc_qentry
*
* Description:
* Try to allocate an I/O buffer chain container by taking the buffer at
* the head of the free list without waiting for the container to become
* free. This function is intended only for internal use by the IOB module.
*
****************************************************************************/
FAR struct iob_qentry_s *iob_tryalloc_qentry(void);
/****************************************************************************
* Name: iob_free_qentry
*
* Description:
* Free the I/O buffer chain container by returning it to the free list.
* The link to the next I/O buffer in the chain is return.
*
****************************************************************************/
FAR struct iob_qentry_s *iob_free_qentry(FAR struct iob_qentry_s *iobq);
#endif /* CONFIG_DRIVERS_IOB */
#endif /* __DRIVERS_IOB_IOB_H */