/*
* Copyright (C) 2001-2006 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.
*/
/*
* This file contains address space manipulation functions.
* Roughly speaking, this is a higher-level client of
* Virtual Address Translation (VAT) subsystem.
*/
#include <mm/as.h>
#include <mm/asid.h>
#include <mm/page.h>
#include <mm/frame.h>
#include <mm/tlb.h>
#include <mm/heap.h>
#include <arch/mm/page.h>
#include <genarch/mm/page_pt.h>
#include <mm/asid.h>
#include <arch/mm/asid.h>
#include <arch/mm/as.h>
#include <arch/types.h>
#include <typedefs.h>
#include <synch/spinlock.h>
#include <config.h>
#include <list.h>
#include <panic.h>
#include <arch/asm.h>
#include <debug.h>
#include <memstr.h>
#include <arch.h>
#include <print.h>
#define KAS_START_INDEX PTL0_INDEX(KERNEL_ADDRESS_SPACE_START)
#define KAS_END_INDEX PTL0_INDEX(KERNEL_ADDRESS_SPACE_END)
#define KAS_INDICES (1+(KAS_END_INDEX-KAS_START_INDEX))
/*
* Here we assume that PFN (Physical Frame Number) space
* is smaller than the width of index_t. UNALLOCATED_PFN
* can be then used to mark mappings wich were not
* yet allocated a physical frame.
*/
#define UNALLOCATED_PFN ((index_t) -1)
/** Create address space. */
/*
* FIXME: this interface must be meaningful for all possible VAT
* (Virtual Address Translation) mechanisms.
*/
as_t *as_create(pte_t *ptl0, int flags)
{
as_t *as;
as
= (as_t
*) malloc(sizeof(as_t
)); if (as) {
list_initialize(&as->as_with_asid_link);
spinlock_initialize(&as->lock, "as_lock");
list_initialize(&as->as_area_head);
if (flags & AS_KERNEL)
as->asid = ASID_KERNEL;
else
as->asid = ASID_INVALID;
as->ptl0 = ptl0;
if (!as->ptl0) {
pte_t *src_ptl0, *dst_ptl0;
src_ptl0 = (pte_t *) PA2KA((__address) GET_PTL0_ADDRESS());
dst_ptl0 = (pte_t *) frame_alloc(FRAME_KA | FRAME_PANIC, ONE_FRAME, NULL);
// memsetb((__address) dst_ptl0, PAGE_SIZE, 0);
// memcpy((void *) &dst_ptl0[KAS_START_INDEX], (void *) &src_ptl0[KAS_START_INDEX], KAS_INDICES);
memcpy((void *) dst_ptl0
,(void *) src_ptl0
, PAGE_SIZE
);
as->ptl0 = (pte_t *) KA2PA((__address) dst_ptl0);
}
}
return as;
}
/** Create address space area of common attributes.
*
* The created address space area is added to the target address space.
*
* @param as Target address space.
* @param type Type of area.
* @param size Size of area in multiples of PAGE_SIZE.
* @param base Base address of area.
*
* @return Address space area on success or NULL on failure.
*/
as_area_t *as_area_create(as_t *as, as_area_type_t type, size_t size, __address base)
{
ipl_t ipl;
as_area_t *a;
if (base % PAGE_SIZE)
panic("addr not aligned to a page boundary");
ipl = interrupts_disable();
spinlock_lock(&as->lock);
/*
* TODO: test as_area which is to be created doesn't overlap with an existing one.
*/
a
= (as_area_t
*) malloc(sizeof(as_area_t
)); if (a) {
int i;
a
->mapping
= (index_t
*) malloc(size
* sizeof(index_t
)); if (!a->mapping) {
spinlock_unlock(&as->lock);
interrupts_restore(ipl);
return NULL;
}
for (i=0; i<size; i++) {
/*
* Frames will be allocated on-demand by
* as_page_fault() or preloaded by
* as_area_set_mapping().
*/
a->mapping[i] = UNALLOCATED_PFN;
}
spinlock_initialize(&a->lock, "as_area_lock");
link_initialize(&a->link);
a->type = type;
a->size = size;
a->base = base;
list_append(&a->link, &as->as_area_head);
}
spinlock_unlock(&as->lock);
interrupts_restore(ipl);
return a;
}
/** Load mapping for address space area.
*
* Initialize a->mapping.
*
* @param a Target address space area.
* @param vpn Page number relative to area start.
* @param pfn Frame number to map.
*/
void as_area_set_mapping(as_area_t *a, index_t vpn, index_t pfn)
{
ASSERT(vpn < a->size);
ASSERT(a->mapping[vpn] == UNALLOCATED_PFN);
ASSERT(pfn != UNALLOCATED_PFN);
ipl_t ipl;
ipl = interrupts_disable();
spinlock_lock(&a->lock);
a->mapping[vpn] = pfn;
spinlock_unlock(&a->lock);
interrupts_restore(ipl);
}
/** Handle page fault within the current address space.
*
* This is the high-level page fault handler.
* Interrupts are assumed disabled.
*
* @param page Faulting page.
*
* @return 0 on page fault, 1 on success.
*/
int as_page_fault(__address page)
{
int flags;
link_t *cur;
as_area_t *a, *area = NULL;
index_t vpn;
__address frame;
ASSERT(AS);
spinlock_lock(&AS->lock);
/*
* Search this areas of this address space for presence of 'page'.
*/
for (cur = AS->as_area_head.next; cur != &AS->as_area_head; cur = cur->next) {
a = list_get_instance(cur, as_area_t, link);
spinlock_lock(&a->lock);
if ((page >= a->base) && (page < a->base + a->size * PAGE_SIZE)) {
/*
* We found the area containing 'page'.
* TODO: access checking
*/
vpn = (page - a->base) / PAGE_SIZE;
area = a;
break;
}
spinlock_unlock(&a->lock);
}
if (!area) {
/*
* No area contained mapping for 'page'.
* Signal page fault to low-level handler.
*/
spinlock_unlock(&AS->lock);
return 0;
}
/*
* Note: area->lock is held.
*/
/*
* Decide if a frame needs to be allocated.
* If so, allocate it and adjust area->mapping map.
*/
if (area->mapping[vpn] == UNALLOCATED_PFN) {
frame = frame_alloc(0, ONE_FRAME, NULL);
memsetb(PA2KA(frame), FRAME_SIZE, 0);
area->mapping[vpn] = frame / FRAME_SIZE;
ASSERT(area->mapping[vpn] != UNALLOCATED_PFN);
} else
frame = area->mapping[vpn] * FRAME_SIZE;
switch (area->type) {
case AS_AREA_TEXT:
flags = PAGE_EXEC | PAGE_READ | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
break;
case AS_AREA_DATA:
case AS_AREA_STACK:
flags = PAGE_READ | PAGE_WRITE | PAGE_USER | PAGE_PRESENT | PAGE_CACHEABLE;
break;
default:
panic("unexpected as_area_type_t %d", area->type);
}
/*
* Map 'page' to 'frame'.
* Note that TLB shootdown is not attempted as only new information is being
* inserted into page tables.
*/
page_mapping_insert(page, AS->asid, frame, flags, (__address) AS->ptl0);
spinlock_unlock(&area->lock);
spinlock_unlock(&AS->lock);
return 1;
}
/** Install address space on CPU.
*
* @param as Address space.
*/
void as_install(as_t *as)
{
ipl_t ipl;
asid_install(as);
ipl = interrupts_disable();
spinlock_lock(&as->lock);
ASSERT(as->ptl0);
SET_PTL0_ADDRESS(as->ptl0);
spinlock_unlock(&as->lock);
interrupts_restore(ipl);
/*
* Perform architecture-specific steps.
* (e.g. write ASID to hardware register etc.)
*/
as_install_arch(as);
AS = as;
}