metalsvm/include/metalsvm/mmu.h
2013-11-18 15:47:26 +01:00

90 lines
2.2 KiB
C

/*
* Copyright 2010 Stefan Lankes, Chair for Operating Systems,
* RWTH Aachen University
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of MetalSVM.
*/
/**
* @author Stefan Lankes
* @file include/metalsvm/mmu.h
* @brief Memory management related
*
* This file contains memory management related
* functions for use in kernel space
*/
#ifndef __MMU_H__
#define __MMU_H__
#include <metalsvm/stddef.h>
#include <asm/atomic.h>
#ifdef __cplusplus
extern "C" {
#endif
extern atomic_int32_t total_pages;
extern atomic_int32_t total_allocated_pages;
extern atomic_int32_t total_available_pages;
/** @brief Initialize MMU subsystem
*
* This function finds out which pageframes are
* used by the kernel already before the paging
* was initialized, marks it as used and starts
* the paging subsystem.
*/
int mmu_init(void);
/** @brief Get continuous pages
*
* Use first fit algorithm to find a suitable, continous physical memory region
*
* @param npages Desired number of pages
* @return
* - physical address on success
* - 0 on failure
*/
size_t get_pages(uint32_t npages);
/** @brief Get a single page
*
* Convenience function: uses get_pages(1);
*/
static inline size_t get_page(void) { return get_pages(1); }
/** @brief Put back a sequence of continous pages
*
* @param phyaddr Physical address of the first page
* @param npages Number of pages
*
* @return
* - 0 on success
* - -EINVAL (-22) on failure
*/
int put_pages(size_t phyaddr, size_t npages);
/** @brief Put a single page
*
* Convenience function: uses put_pages(1);
*/
static inline int put_page(size_t phyaddr) { return put_pages(phyaddr, 1); }
#ifdef __cplusplus
}
#endif
#endif