/*
* Copyright (C) 2006 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/** @addtogroup genarchmm
* @{
*/
/**
* @file
* @brief Address space functions for global page hash table.
*/
#include <genarch/mm/as_ht.h>
#include <genarch/mm/page_ht.h>
#include <mm/as.h>
#include <mm/frame.h>
#include <arch/types.h>
#include <typedefs.h>
#include <memstr.h>
#include <adt/hash_table.h>
#include <synch/mutex.h>
static pte_t *ht_create(int flags);
static void ht_destroy(pte_t *page_table);
static void ht_lock(as_t *as, bool lock);
static void ht_unlock(as_t *as, bool unlock);
as_operations_t as_ht_operations = {
.page_table_create = ht_create,
.page_table_destroy = ht_destroy,
.page_table_lock = ht_lock,
.page_table_unlock = ht_unlock,
};
/** Page hash table create.
*
* The page hash table will be created only once
* and will be shared by all address spaces.
*
* @param flags Ignored.
*
* @return Returns NULL.
*/
pte_t *ht_create(int flags)
{
if (flags & FLAG_AS_KERNEL) {
hash_table_create(&page_ht, PAGE_HT_ENTRIES, 2, &ht_operations);
mutex_initialize(&page_ht_lock);
}
return NULL;
}
/** Destroy page table.
*
* Actually do nothing as the global page hash table is used.
*
* @param page_table This parameter is ignored.
*/
void ht_destroy(pte_t *page_table)
{
/* No-op. */
}
/** Lock page table.
*
* Lock address space and page hash table.
* Interrupts must be disabled.
*
* @param as Address space.
* @param lock If false, do not attempt to lock the address space.
*/
void ht_lock(as_t *as, bool lock)
{
if (lock)
mutex_lock(&as->lock);
mutex_lock(&page_ht_lock);
}
/** Unlock page table.
*
* Unlock address space and page hash table.
* Interrupts must be disabled.
*
* @param as Address space.
* @param unlock If false, do not attempt to lock the address space.
*/
void ht_unlock(as_t *as, bool unlock)
{
mutex_unlock(&page_ht_lock);
if (unlock)
mutex_unlock(&as->lock);
}
/** @}
*/