/**************************************************************************** * mm/iob/iob.h * * Copyright (C) 2014, 2017 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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_IOB_IOB_H #define __MM_IOB_IOB_H 1 /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #ifdef CONFIG_MM_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 I/O buffers that are committed for allocation */ extern FAR struct iob_s *g_iob_committed; #if CONFIG_IOB_NCHAINS > 0 /* A list of all free, unallocated I/O buffer queue containers */ extern FAR struct iob_qentry_s *g_iob_freeqlist; /* A list of I/O buffer queue containers that are committed for allocation */ extern FAR struct iob_qentry_s *g_iob_qcommitted; #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); /**************************************************************************** * Name: iob_notifier_signal * * Description: * An IOB has become available. Signal all threads waiting for an IOB * that an IOB is available. * * When an IOB becomes available, *all* of the waiters in this thread will * be signaled. If there are multiple waiters then only the highest * priority thread will get the IOB. Lower priority threads will need to * call iob_notifier_setup() once again. * * Input Parameters: * None. * * Returned Value: * None. * ****************************************************************************/ #ifdef CONFIG_IOB_NOTIFIER void iob_notifier_signal(void); #endif #endif /* CONFIG_MM_IOB */ #endif /* __MM_IOB_IOB_H */