/*
* 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 kernel_genarch_mm
* @{
*/
/**
* @file
* @brief Address space functions for 4-level hierarchical pagetables.
*/
#include <genarch/mm/page_pt.h>
#include <mm/page.h>
#include <mm/frame.h>
#include <mm/as.h>
#include <synch/mutex.h>
#include <arch/mm/page.h>
#include <arch/mm/as.h>
#include <typedefs.h>
#include <memw.h>
#include <arch.h>
static pte_t *ptl0_create(unsigned int);
static void ptl0_destroy(pte_t *);
static void pt_lock(as_t *, bool);
static void pt_unlock(as_t *, bool);
static bool pt_locked(as_t *);
const as_operations_t as_pt_operations = {
.page_table_create = ptl0_create,
.page_table_destroy = ptl0_destroy,
.page_table_lock = pt_lock,
.page_table_unlock = pt_unlock,
.page_table_locked = pt_locked,
};
/** Create PTL0.
*
* PTL0 of 4-level page table will be created for each address space.
*
* @param flags Flags can specify whether ptl0 is for the kernel address space.
*
* @return New PTL0.
*
*/
pte_t *ptl0_create(unsigned int flags)
{
pte_t *dst_ptl0 = (pte_t *)
PA2KA(frame_alloc(PTL0_FRAMES, FRAME_LOWMEM, PTL0_SIZE - 1));
memsetb(dst_ptl0, PTL0_SIZE, 0);
if (!KERNEL_SEPARATE_PTL0 && !(flags & FLAG_AS_KERNEL)) {
/*
* Copy the kernel address space portion to new PTL0.
*/
mutex_lock(&AS_KERNEL->lock);
pte_t *src_ptl0 =
(pte_t *) PA2KA((uintptr_t) AS_KERNEL->genarch.page_table);
uintptr_t src = (uintptr_t)
&src_ptl0[PTL0_INDEX(KERNEL_ADDRESS_SPACE_START)];
uintptr_t dst = (uintptr_t)
&dst_ptl0[PTL0_INDEX(KERNEL_ADDRESS_SPACE_START)];
memcpy((void *) dst, (void *) src,
PTL0_SIZE - (src - (uintptr_t) src_ptl0));
mutex_unlock(&AS_KERNEL->lock);
}
return (pte_t *) KA2PA((uintptr_t) dst_ptl0);
}
/** Destroy page table.
*
* Destroy PTL0, other levels are expected to be already deallocated.
*
* @param page_table Physical address of PTL0.
*
*/
void ptl0_destroy(pte_t *page_table)
{
frame_free((uintptr_t) page_table, PTL0_FRAMES);
}
/** Lock page tables.
*
* Lock only the address space.
* Interrupts must be disabled.
*
* @param as Address space.
* @param lock If false, do not attempt to lock the address space.
*
*/
void pt_lock(as_t *as, bool lock)
{
if (lock)
mutex_lock(&as->lock);
}
/** Unlock page tables.
*
* Unlock the address space.
* Interrupts must be disabled.
*
* @param as Address space.
* @param unlock If false, do not attempt to unlock the address space.
*
*/
void pt_unlock(as_t *as, bool unlock)
{
if (unlock)
mutex_unlock(&as->lock);
}
/** Test whether page tables are locked.
*
* @param as Address space where the page tables belong.
*
* @return True if the page tables belonging to the address soace
* are locked, otherwise false.
*/
bool pt_locked(as_t *as)
{
return mutex_locked(&as->lock);
}
/** @}
*/