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Diffstat (limited to 'nuttx/fs/mmap/fs_munmap.c')
| -rw-r--r-- | nuttx/fs/mmap/fs_munmap.c | 212 |
1 files changed, 0 insertions, 212 deletions
diff --git a/nuttx/fs/mmap/fs_munmap.c b/nuttx/fs/mmap/fs_munmap.c deleted file mode 100644 index 5d9416d45..000000000 --- a/nuttx/fs/mmap/fs_munmap.c +++ /dev/null @@ -1,212 +0,0 @@ -/**************************************************************************** - * fs/mmap/fs_munmap.c - * - * Copyright (C) 2011 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 <sys/types.h> -#include <sys/mman.h> - -#include <stdint.h> -#include <errno.h> -#include <assert.h> -#include <debug.h> - -#include <nuttx/kmalloc.h> - -#include "fs_internal.h" -#include "fs_rammap.h" - -#ifdef CONFIG_FS_RAMMAP - -/**************************************************************************** - * Global Functions - ****************************************************************************/ - -/**************************************************************************** - * Name: munmap - * - * Description: - * - * munmap() system call deletes mappings for the specified address range. - * All memory starting with 'start' and continuing for a length of 'length' - * bytes are removed. - * - * NuttX operates in a flat open address space. Therefore, it generally - * does not require mmap() and, hence, munmap functionality. There are - * two exceptions where mmap() is available: - * - * 1. mmap() is the API that is used to support direct access to random - * access media under the following very restrictive conditions: - * - * a. The filesystem supports the FIOC_MMAP ioctl command. Any file - * system that maps files contiguously on the media should support - * this ioctl. (vs. file system that scatter files over the media - * in non-contiguous sectors). As of this writing, ROMFS is the - * only file system that meets this requirement. - * b. The underlying block driver supports the BIOC_XIPBASE ioctl - * command that maps the underlying media to a randomly accessible - * address. At present, only the RAM/ROM disk driver does this. - * - * munmap() is still not required in this first case. In this first - * The mapped address is a static address in the MCUs address space - * does not need to be munmapped. Support for munmap() in this case - * provided by the simple definition in sys/mman.h: - * - * #define munmap(start, length) - * - * 2. If CONFIG_FS_RAMMAP is defined in the configuration, then mmap() will - * support simulation of memory mapped files by copying files whole - * into RAM. munmap() is required in this case to free the allocated - * memory holding the shared copy of the file. - * - * Parameters: - * start The start address of the mapping to delete. For this - * simplified munmap() implementation, the *must* be the start - * address of the memory region (the same address returned by - * mmap()). - * length The length region to be umapped. - * - * Returned Value: - * On success, munmap() returns 0, on failure -1, and errno is set - * (probably to EINVAL). - * - ****************************************************************************/ - -int munmap(FAR void *start, size_t length) -{ - FAR struct fs_rammap_s *prev; - FAR struct fs_rammap_s *curr; - FAR void *newaddr; - unsigned int offset; - int ret; - int err; - - /* Find a region containing this start and length in the list of regions */ - - rammap_initialize(); - ret = sem_wait(&g_rammaps.exclsem); - if (ret < 0) - { - return ERROR; - } - - /* Seach the list of regions */ - - for (prev = NULL, curr = g_rammaps.head; curr; prev = curr, curr = curr->flink) - { - /* Does this region include any part of the specified range? */ - - if ((uintptr_t)start < (uintptr_t)curr->addr + curr->length && - (uintptr_t)start + length >= (uintptr_t)curr->addr) - { - break; - } - } - - /* Did we find the region */ - - if (!curr) - { - fdbg("Region not found\n"); - err = EINVAL; - goto errout_with_semaphore; - } - - /* Get the offset from the beginning of the region and the actual number - * of bytes to "unmap". All mappings must extend to the end of the region. - * There is no support for free a block of memory but leaving a block of - * memory at the end. This is a consequence of using realloc() to - * simulate the unmapping. - */ - - offset = start - curr->addr; - if (offset + length < curr->length) - { - fdbg("Cannot umap without unmapping to the end\n"); - err = ENOSYS; - goto errout_with_semaphore; - } - - /* Okay.. the region is beging umapped to the end. Make sure the length - * indicates that. - */ - - length = curr->length - offset; - - /* Are we unmapping the entire region (offset == 0)? */ - - if (length >= curr->length) - { - /* Yes.. remove the mapping from the list */ - - if (prev) - { - prev->flink = curr->flink; - } - else - { - g_rammaps.head = curr->flink; - } - - /* Then free the region */ - - kfree(curr); - } - - /* No.. We have been asked to "unmap' only a portion of the memory - * (offset > 0). - */ - - else - { - newaddr = krealloc(curr->addr, sizeof(struct fs_rammap_s) + length); - DEBUGASSERT(newaddr == (FAR void*)(curr->addr)); - curr->length = length; - } - - sem_post(&g_rammaps.exclsem); - return OK; - -errout_with_semaphore: - sem_post(&g_rammaps.exclsem); - errno = err; - return ERROR; -} - -#endif /* CONFIG_FS_RAMMAP */ |