oskit/oskit-20020317/svm/svm_pagein.c

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2016-02-19 15:02:31 +03:00
/*
* 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"
int svm_pagein_count, svm_pagein_time;
/*
* Page in a page from disk.
*
* NB: Pages are paged through the virtual address.
*/
void
svm_pagein_page(oskit_addr_t vaddr)
{
oskit_addr_t paddr;
unsigned int mbits;
int diskpage;
oskit_u64_t before, after;
before = get_tsc();
if (svm_find_mapping(vaddr, &paddr, &mbits))
panic("svm_pagein_page: Invalid vaddr:0x%x", vaddr);
if ((mbits & PTE_MBITS_PAGED) == 0)
panic("svm_pagein_page: Page not paged! vaddr:0x%x", vaddr);
diskpage = btop(paddr);
/*
* Allocate a new physical page and plug into the ptov table.
*/
paddr = svm_alloc_physpage();
SVM_PTOV(paddr) = vaddr;
#ifdef DEBUG_SVM
printf("svm_pagein_page: "
"Paging in vaddr 0x%x to paddr 0x%x from diskpage:%d\n",
vaddr, paddr, diskpage);
#endif
/*
* Change the mapping. Must be writable initially.
*/
svm_change_mapping(vaddr, paddr, PTE_MBITS_VALID|PTE_MBITS_RW);
/*
* and read the data in from disk through the virtual adress.
*/
if (svm_swapread(diskpage, vaddr))
panic("svm_pagein_page: "
"Can't pagein page! vaddr:0x%x paddr:0x%x diskpage:%d",
vaddr, paddr, diskpage);
/*
* success. Free the disk page.
*/
svm_freediskpage(diskpage);
/*
* Restore original mapping. Clear MOD/REF bits.
*/
mbits |= PTE_MBITS_VALID;
mbits &= ~(PTE_MBITS_PAGED|PTE_MBITS_MOD|PTE_MBITS_REF);
svm_change_mapping(vaddr, paddr, mbits);
after = get_tsc();
if (after > before) {
svm_pagein_time += ((int) (after - before)) / 200;
svm_pagein_count++;
}
}