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/*
* Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
* All rights reserved.
*
* 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 of Hyra 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.
*/
#include <sys/types.h>
#include <sys/sched.h>
#include <vm/fault.h>
#include <vm/map.h>
#include <vm/pmap.h>
#include <vm/vm.h>
#include <vm/physseg.h>
static struct vm_mapping *
vm_mapq_search(vm_mapq_t *mq, vaddr_t addr)
{
struct vm_mapping *mapping;
const struct vm_range *range;
TAILQ_FOREACH(mapping, mq, link) {
range = &mapping->range;
if (addr >= range->start && addr <= range->end) {
return mapping;
}
}
return NULL;
}
static struct vm_mapping *
vm_find_mapping(vaddr_t addr)
{
struct vm_mapping *mapping;
struct proc *td = this_td();
vm_mapq_t *mapq;
mapping = vm_mapping_fetch(&td->mapspace, addr);
if (mapping != NULL)
return mapping;
/* Need to search other maps */
for (size_t i = 0; i < MTAB_ENTRIES; ++i) {
mapq = &td->mapspace.mtab[i];
mapping = vm_mapq_search(mapq, addr);
if (mapping != NULL)
return mapping;
}
return NULL;
}
static int
vm_demand_page(struct vm_mapping *mapping, vaddr_t va, vm_prot_t access_type)
{
struct proc *td;
paddr_t pa_base;
int s;
size_t granule = vm_get_page_size();
/* Allocate physical memory if needed */
if (mapping->physmem_base == 0) {
pa_base = vm_alloc_pageframe(1);
mapping->physmem_base = pa_base;
} else {
pa_base = mapping->physmem_base;
}
td = this_td();
s = vm_map_create(td->addrsp, va, pa_base, access_type, granule);
return s;
}
int
vm_fault(vaddr_t va, vm_prot_t access_type)
{
struct vm_mapping *mapping;
struct vm_object *vmobj;
int s = 0;
size_t granule = vm_get_page_size();
vaddr_t va_base = va & ~(granule - 1);
mapping = vm_find_mapping(va_base);
if (mapping == NULL)
return -1;
if ((vmobj = mapping->vmobj) == NULL)
/* Virtual memory object non-existent */
return -1;
if ((access_type & ~mapping->prot) != 0)
/* Invalid access type */
return -1;
vm_object_ref(vmobj);
/* Can we perform demand paging? */
if (vmobj->demand) {
s = vm_demand_page(mapping, va_base, access_type);
if (s != 0)
goto done;
}
done:
/* Drop the vmobj ref */
vm_object_unref(vmobj);
return s;
}
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