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/*
* Copyright (c) 1996, 1998, 1999 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
#include "svm_internal.h"
#include <oskit/lmm.h>
extern lmm_t malloc_lmm;
extern oskit_size_t svm_lowwater, svm_highwater;
/*
* Ask the lmm for a phys page. Call the pageout code if one cannot
* be found.
*/
oskit_addr_t
svm_alloc_physpage(void)
{
oskit_addr_t kvaddr, paddr;
if (svm_physmem_avail() < svm_lowwater && svm_paging)
svm_pageout();
kvaddr = (oskit_addr_t)
lmm_alloc_aligned(&malloc_lmm, PAGE_SIZE, 0, 12, 0);
if (kvaddr == NULL)
panic("svm_fault: No more physical memory");
/*
* The malloc lmm is in terms of kernel virtual addresses.
*/
paddr = kvtophys(kvaddr);
/*
* Undo the mapping that makes the phys page accessible through
* its kernel virtual address.
*/
svm_unmap_range(kvaddr, PAGE_SIZE);
ftlbentry(kvaddr);
return paddr;
}
/*
* Return a phys page to the lmm.
*/
void
svm_dealloc_physpage(oskit_addr_t paddr)
{
oskit_addr_t kvaddr;
/*
* The malloc lmm is in terms of kernel virtual addresses.
*/
kvaddr = phystokv(paddr);
/*
* Must make the physical page accessible again through its
* kernel virtual address.
*/
if (svm_map_range(kvaddr, paddr, PAGE_SIZE,
PTE_MBITS_VALID|PTE_MBITS_RW))
panic("svm_dealloc_physpage: Can't remap paddr 0x%x", paddr);
lmm_free(&malloc_lmm, (void *) kvaddr, PAGE_SIZE);
}
/*
* Return the amount of free phys memory available.
*
* NB: lmm_avail is a tad expensive to call too often.
*/
oskit_size_t
svm_physmem_avail(void)
{
return lmm_avail(&malloc_lmm, 0);
}
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