123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160 |
- /****************************************************************************
- * mm/iob/iob_initialize.c
- *
- * 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.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <stdbool.h>
- #include <nuttx/semaphore.h>
- #include <nuttx/mm/iob.h>
- #include "iob.h"
- /****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
- #ifndef NULL
- # define NULL ((FAR void *)0)
- #endif
- /****************************************************************************
- * Private Data
- ****************************************************************************/
- /* This is a pool of pre-allocated I/O buffers */
- static struct iob_s g_iob_pool[CONFIG_IOB_NBUFFERS];
- #if CONFIG_IOB_NCHAINS > 0
- static struct iob_qentry_s g_iob_qpool[CONFIG_IOB_NCHAINS];
- #endif
- /****************************************************************************
- * Public Data
- ****************************************************************************/
- /* A list of all free, unallocated I/O buffers */
- FAR struct iob_s *g_iob_freelist;
- /* A list of I/O buffers that are committed for allocation */
- FAR struct iob_s *g_iob_committed;
- #if CONFIG_IOB_NCHAINS > 0
- /* A list of all free, unallocated I/O buffer queue containers */
- FAR struct iob_qentry_s *g_iob_freeqlist;
- /* A list of I/O buffer queue containers that are committed for allocation */
- FAR struct iob_qentry_s *g_iob_qcommitted;
- #endif
- /* Counting semaphores that tracks the number of free IOBs/qentries */
- sem_t g_iob_sem; /* Counts free I/O buffers */
- #if CONFIG_IOB_THROTTLE > 0
- sem_t g_throttle_sem; /* Counts available I/O buffers when throttled */
- #endif
- #if CONFIG_IOB_NCHAINS > 0
- sem_t g_qentry_sem; /* Counts free I/O buffer queue containers */
- #endif
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: iob_initialize
- *
- * Description:
- * Set up the I/O buffers for normal operations.
- *
- ****************************************************************************/
- void iob_initialize(void)
- {
- static bool initialized = false;
- int i;
- /* Perform one-time initialization */
- if (!initialized)
- {
- /* Add each I/O buffer to the free list */
- for (i = 0; i < CONFIG_IOB_NBUFFERS; i++)
- {
- FAR struct iob_s *iob = &g_iob_pool[i];
- /* Add the pre-allocate I/O buffer to the head of the free list */
- iob->io_flink = g_iob_freelist;
- g_iob_freelist = iob;
- }
- g_iob_committed = NULL;
- nxsem_init(&g_iob_sem, 0, CONFIG_IOB_NBUFFERS);
- #if CONFIG_IOB_THROTTLE > 0
- nxsem_init(&g_throttle_sem, 0, CONFIG_IOB_NBUFFERS - CONFIG_IOB_THROTTLE);
- #endif
- #if CONFIG_IOB_NCHAINS > 0
- /* Add each I/O buffer chain queue container to the free list */
- for (i = 0; i < CONFIG_IOB_NCHAINS; i++)
- {
- FAR struct iob_qentry_s *iobq = &g_iob_qpool[i];
- /* Add the pre-allocate buffer container to the head of the free list */
- iobq->qe_flink = g_iob_freeqlist;
- g_iob_freeqlist = iobq;
- }
- g_iob_qcommitted = NULL;
- nxsem_init(&g_qentry_sem, 0, CONFIG_IOB_NCHAINS);
- #endif
- initialized = true;
- }
- }
|