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Diffstat (limited to 'nuttx/mm/kmm_semaphore.c')
-rw-r--r-- | nuttx/mm/kmm_semaphore.c | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/nuttx/mm/kmm_semaphore.c b/nuttx/mm/kmm_semaphore.c new file mode 100644 index 000000000..b391e5151 --- /dev/null +++ b/nuttx/mm/kmm_semaphore.c @@ -0,0 +1,140 @@ +/************************************************************************ + * mm/kmm_semaphore.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 <nuttx/kmalloc.h> + +#if defined(CONFIG_NUTTX_KERNEL) && defined(__KERNEL__) + +/* This logic is all tentatively and, hopefully, will grow in usability. + * For now, the kernel-mode build uses the memory manager that is + * provided in the user-space build. That is awkward but reasonable for + * the current level of support: At present, only memory protection is + * provided. Kernel-mode code may call into user-mode code, but not + * vice-versa. So hosting the memory manager in user-space allows the + * memory manager to be shared in both kernel- and user-mode spaces. + * + * In the longer run, if an MMU is support that can provide virtualized + * memory, then some SLAB memory manager will be required in kernel-space + * with some kind of brk() system call to obtain mapped heap space. + * + * In the current build model, the user-space module is built first. The + * file user_map.h is generated in the first pass and contains the + * addresses of the memory manager needed in this file: + */ + +#include <arch/board/user_map.h> + +/************************************************************************ + * Pre-processor definition + ************************************************************************/ + +/* These values are obtained from user_map.h */ + +#define KTRYSEMAPHORE() ((kmtrysemaphore_t) CONFIG_USER_MMTRYSEM )() +#define KGIVESEMAPHORE() ((kmgivesemaphore_t)CONFIG_USER_MMGIVESEM)() + +/************************************************************************ + * Private Types + ************************************************************************/ + +typedef int (*kmtrysemaphore_t)(void); +typedef void (*kmgivesemaphore_t)(void); + +/************************************************************************ + * Private Functions + ************************************************************************/ + +/************************************************************************ + * Public Functions + ************************************************************************/ + +/************************************************************************ + * Name: kmm_trysemaphore + * + * Description: + * This is a simple redirection to the user-space mm_trysemaphore() + * function. + * + * Parameters: + * None + * + * Return Value: + * OK on success; a negated errno on failure + * + * Assumptions: + * 1. mm_trysemaphore() resides in user-space + * 2. The address of the user space mm_trysemaphore() is provided in + * user_map.h + * 3. The user-space mm_semaphore() is callable from kernel-space. + * + ************************************************************************/ + +int kmm_trysemaphore(void) +{ + return KTRYSEMAPHORE(); +} + +/************************************************************************ + * Name: kmm_givesemaphore + * + * Description: + * This is a simple redirection to the user-space mm_givesemaphore() + * function. + * + * Parameters: + * None + * + * Return Value: + * OK on success; a negated errno on failure + * + * Assumptions: + * 1. mm_givesemaphore() resides in user-space + * 2. The address of the user space mm_givesemaphore() is provided in + * user_map.h + * 3. The user-space mm_semaphore() is callable from kernel-space. + * + ************************************************************************/ + +void kmm_givesemaphore(void) +{ + KGIVESEMAPHORE(); +} + +#endif /* CONFIG_NUTTX_KERNEL && __KERNEL__ */ |