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+/*
+ * Copyright (c) 1991, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * The Mach Operating System project at Carnegie-Mellon University.
+ *
+ * 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. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
+ *
+ * from: @(#)vm_pager.c 8.6 (Berkeley) 1/12/94
+ *
+ *
+ * Copyright (c) 1987, 1990 Carnegie-Mellon University.
+ * All rights reserved.
+ *
+ * Authors: Avadis Tevanian, Jr., Michael Wayne Young
+ *
+ * Permission to use, copy, modify and distribute this software and
+ * its documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ *
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
+ * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ *
+ * Carnegie Mellon requests users of this software to return to
+ *
+ * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
+ * School of Computer Science
+ * Carnegie Mellon University
+ * Pittsburgh PA 15213-3890
+ *
+ * any improvements or extensions that they make and grant Carnegie the
+ * rights to redistribute these changes.
+ *
+ * $Id: vm_pager.c,v 1.6 1994/08/07 14:53:27 davidg Exp $
+ */
+
+/*
+ * Paging space routine stubs. Emulates a matchmaker-like interface
+ * for builtin pagers.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/malloc.h>
+#include <sys/buf.h>
+#include <sys/ucred.h>
+
+#include <vm/vm.h>
+#include <vm/vm_page.h>
+#include <vm/vm_kern.h>
+
+extern struct pagerops swappagerops;
+extern struct pagerops vnodepagerops;
+extern struct pagerops devicepagerops;
+
+struct pagerops *pagertab[] = {
+ &swappagerops, /* PG_SWAP */
+ &vnodepagerops, /* PG_VNODE */
+ &devicepagerops, /* PG_DEV */
+};
+int npagers = sizeof (pagertab) / sizeof (pagertab[0]);
+
+struct pagerops *dfltpagerops = NULL; /* default pager */
+
+/*
+ * Kernel address space for mapping pages.
+ * Used by pagers where KVAs are needed for IO.
+ *
+ * XXX needs to be large enough to support the number of pending async
+ * cleaning requests (NPENDINGIO == 64) * the maximum swap cluster size
+ * (MAXPHYS == 64k) if you want to get the most efficiency.
+ */
+#define PAGER_MAP_SIZE (8 * 1024 * 1024)
+
+int pager_map_size = PAGER_MAP_SIZE;
+vm_map_t pager_map;
+boolean_t pager_map_wanted;
+vm_offset_t pager_sva, pager_eva;
+int bswneeded;
+vm_offset_t swapbkva; /* swap buffers kva */
+
+void
+vm_pager_init()
+{
+ struct pagerops **pgops;
+
+ /*
+ * Initialize known pagers
+ */
+ for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
+ if (pgops)
+ (*(*pgops)->pgo_init)();
+ if (dfltpagerops == NULL)
+ panic("no default pager");
+}
+
+void
+vm_pager_bufferinit()
+{
+ struct buf *bp;
+ int i;
+ bp = swbuf;
+ /*
+ * Now set up swap and physical I/O buffer headers.
+ */
+ for (i = 0; i < nswbuf - 1; i++, bp++) {
+ TAILQ_INSERT_HEAD(&bswlist, bp, b_freelist);
+ bp->b_rcred = bp->b_wcred = NOCRED;
+ bp->b_vnbufs.le_next = NOLIST;
+ }
+ bp->b_rcred = bp->b_wcred = NOCRED;
+ bp->b_vnbufs.le_next = NOLIST;
+ bp->b_actf = NULL;
+
+ swapbkva = kmem_alloc_pageable( pager_map, nswbuf * MAXPHYS);
+ if( !swapbkva)
+ panic("Not enough pager_map VM space for physical buffers");
+}
+
+/*
+ * Allocate an instance of a pager of the given type.
+ * Size, protection and offset parameters are passed in for pagers that
+ * need to perform page-level validation (e.g. the device pager).
+ */
+vm_pager_t
+vm_pager_allocate(type, handle, size, prot, off)
+ int type;
+ caddr_t handle;
+ vm_size_t size;
+ vm_prot_t prot;
+ vm_offset_t off;
+{
+ struct pagerops *ops;
+
+ ops = (type == PG_DFLT) ? dfltpagerops : pagertab[type];
+ if (ops)
+ return ((*ops->pgo_alloc)(handle, size, prot, off));
+ return (NULL);
+}
+
+void
+vm_pager_deallocate(pager)
+ vm_pager_t pager;
+{
+ if (pager == NULL)
+ panic("vm_pager_deallocate: null pager");
+
+ (*pager->pg_ops->pgo_dealloc)(pager);
+}
+
+
+int
+vm_pager_get_pages(pager, m, count, reqpage, sync)
+ vm_pager_t pager;
+ vm_page_t *m;
+ int count;
+ int reqpage;
+ boolean_t sync;
+{
+ extern int vm_pageout_count;
+ int i;
+
+ if (pager == NULL) {
+ for (i=0;i<count;i++) {
+ if( i != reqpage) {
+ PAGE_WAKEUP(m[i]);
+ vm_page_free(m[i]);
+ }
+ }
+ vm_page_zero_fill(m[reqpage]);
+ return VM_PAGER_OK;
+ }
+
+ if( pager->pg_ops->pgo_getpages == 0) {
+ for(i=0;i<count;i++) {
+ if( i != reqpage) {
+ PAGE_WAKEUP(m[i]);
+ vm_page_free(m[i]);
+ }
+ }
+ return(VM_PAGER_GET(pager, m[reqpage], sync));
+ } else {
+ return(VM_PAGER_GET_MULTI(pager, m, count, reqpage, sync));
+ }
+}
+
+int
+vm_pager_put_pages(pager, m, count, sync, rtvals)
+ vm_pager_t pager;
+ vm_page_t *m;
+ int count;
+ boolean_t sync;
+ int *rtvals;
+{
+ int i;
+
+ if( pager->pg_ops->pgo_putpages)
+ return(VM_PAGER_PUT_MULTI(pager, m, count, sync, rtvals));
+ else {
+ for(i=0;i<count;i++) {
+ rtvals[i] = VM_PAGER_PUT( pager, m[i], sync);
+ }
+ return rtvals[0];
+ }
+}
+
+boolean_t
+vm_pager_has_page(pager, offset)
+ vm_pager_t pager;
+ vm_offset_t offset;
+{
+ if (pager == NULL)
+ panic("vm_pager_has_page: null pager");
+ return ((*pager->pg_ops->pgo_haspage)(pager, offset));
+}
+
+/*
+ * Called by pageout daemon before going back to sleep.
+ * Gives pagers a chance to clean up any completed async pageing operations.
+ */
+void
+vm_pager_sync()
+{
+ struct pagerops **pgops;
+
+ for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++)
+ if (pgops)
+ (*(*pgops)->pgo_putpage)(NULL, NULL, 0);
+}
+
+#if 0
+void
+vm_pager_cluster(pager, offset, loff, hoff)
+ vm_pager_t pager;
+ vm_offset_t offset;
+ vm_offset_t *loff;
+ vm_offset_t *hoff;
+{
+ if (pager == NULL)
+ panic("vm_pager_cluster: null pager");
+ return ((*pager->pg_ops->pgo_cluster)(pager, offset, loff, hoff));
+}
+#endif
+
+vm_offset_t
+vm_pager_map_page(m)
+ vm_page_t m;
+{
+ vm_offset_t kva;
+
+ kva = kmem_alloc_wait(pager_map, PAGE_SIZE);
+ pmap_kenter(kva, VM_PAGE_TO_PHYS(m));
+ return(kva);
+}
+
+void
+vm_pager_unmap_page(kva)
+ vm_offset_t kva;
+{
+ pmap_kremove(kva);
+ kmem_free_wakeup(pager_map, kva, PAGE_SIZE);
+}
+
+vm_page_t
+vm_pager_atop(kva)
+ vm_offset_t kva;
+{
+ vm_offset_t pa;
+
+ pa = pmap_kextract( kva);
+ if (pa == 0)
+ panic("vm_pager_atop");
+ return (PHYS_TO_VM_PAGE(pa));
+}
+
+vm_pager_t
+vm_pager_lookup(pglist, handle)
+ register struct pagerlst *pglist;
+ caddr_t handle;
+{
+ register vm_pager_t pager;
+
+ for (pager = pglist->tqh_first; pager; pager = pager->pg_list.tqe_next)
+ if (pager->pg_handle == handle)
+ return (pager);
+ return (NULL);
+}
+
+/*
+ * This routine gains a reference to the object.
+ * Explicit deallocation is necessary.
+ */
+int
+pager_cache(object, should_cache)
+ vm_object_t object;
+ boolean_t should_cache;
+{
+ if (object == NULL)
+ return (KERN_INVALID_ARGUMENT);
+
+ vm_object_cache_lock();
+ vm_object_lock(object);
+ if (should_cache)
+ object->flags |= OBJ_CANPERSIST;
+ else
+ object->flags &= ~OBJ_CANPERSIST;
+ vm_object_unlock(object);
+ vm_object_cache_unlock();
+
+ vm_object_deallocate(object);
+
+ return (KERN_SUCCESS);
+}
+
+/*
+ * allocate a physical buffer
+ */
+struct buf *
+getpbuf() {
+ int s;
+ struct buf *bp;
+
+ s = splbio();
+ /* get a bp from the swap buffer header pool */
+ while ((bp = bswlist.tqh_first) == NULL) {
+ bswneeded = 1;
+ tsleep((caddr_t)&bswneeded, PVM, "wswbuf", 0);
+ }
+ TAILQ_REMOVE(&bswlist, bp, b_freelist);
+ splx(s);
+
+ bzero(bp, sizeof *bp);
+ bp->b_rcred = NOCRED;
+ bp->b_wcred = NOCRED;
+ bp->b_data = (caddr_t) (MAXPHYS * (bp-swbuf)) + swapbkva;
+ return bp;
+}
+
+/*
+ * allocate a physical buffer, if one is available
+ */
+struct buf *
+trypbuf() {
+ int s;
+ struct buf *bp;
+
+ s = splbio();
+ if ((bp = bswlist.tqh_first) == NULL) {
+ splx(s);
+ return NULL;
+ }
+ TAILQ_REMOVE(&bswlist, bp, b_freelist);
+ splx(s);
+
+ bzero(bp, sizeof *bp);
+ bp->b_rcred = NOCRED;
+ bp->b_wcred = NOCRED;
+ bp->b_data = (caddr_t) (MAXPHYS * (bp-swbuf)) + swapbkva;
+ return bp;
+}
+
+/*
+ * release a physical buffer
+ */
+void
+relpbuf(bp)
+ struct buf *bp;
+{
+ int s;
+
+ s = splbio();
+
+ if (bp->b_rcred != NOCRED) {
+ crfree(bp->b_rcred);
+ bp->b_rcred = NOCRED;
+ }
+ if (bp->b_wcred != NOCRED) {
+ crfree(bp->b_wcred);
+ bp->b_wcred = NOCRED;
+ }
+
+ if (bp->b_vp)
+ brelvp(bp);
+
+ TAILQ_INSERT_HEAD(&bswlist, bp, b_freelist);
+
+ if (bswneeded) {
+ bswneeded = 0;
+ wakeup((caddr_t)&bswlist);
+ }
+ splx(s);
+}
+
+
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