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Diffstat (limited to 'sys/vm/vm_pager.c')
| -rw-r--r-- | sys/vm/vm_pager.c | 403 |
1 files changed, 403 insertions, 0 deletions
diff --git a/sys/vm/vm_pager.c b/sys/vm/vm_pager.c new file mode 100644 index 00000000000..d832daec2fa --- /dev/null +++ b/sys/vm/vm_pager.c @@ -0,0 +1,403 @@ +/* $NetBSD: vm_pager.c,v 1.18 1995/05/07 19:27:30 cgd Exp $ */ + +/* + * 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. + * + * @(#)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. + */ + +/* + * 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 <vm/vm.h> +#include <vm/vm_page.h> +#include <vm/vm_kern.h> + +#ifdef SWAPPAGER +extern struct pagerops swappagerops; +#endif + +#ifdef VNODEPAGER +extern struct pagerops vnodepagerops; +#endif + +#ifdef DEVPAGER +extern struct pagerops devicepagerops; +#endif + +struct pagerops *pagertab[] = { +#ifdef SWAPPAGER + &swappagerops, /* PG_SWAP */ +#else + NULL, +#endif +#ifdef VNODEPAGER + &vnodepagerops, /* PG_VNODE */ +#else + NULL, +#endif +#ifdef DEVPAGER + &devicepagerops, /* PG_DEV */ +#else + NULL, +#endif +}; +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 (4 * 1024 * 1024) + +vm_map_t pager_map; +boolean_t pager_map_wanted; +vm_offset_t pager_sva, pager_eva; + +void +vm_pager_init() +{ + struct pagerops **pgops; + + /* + * Allocate a kernel submap for tracking get/put page mappings + */ + pager_map = kmem_suballoc(kernel_map, &pager_sva, &pager_eva, + PAGER_MAP_SIZE, FALSE); + /* + * Initialize known pagers + */ + for (pgops = pagertab; pgops < &pagertab[npagers]; pgops++) + if (*pgops) + (*(*pgops)->pgo_init)(); + if (dfltpagerops == NULL) + panic("no default pager"); +} + +/* + * 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, mlist, npages, sync) + vm_pager_t pager; + vm_page_t *mlist; + int npages; + boolean_t sync; +{ + int rv; + + if (pager == NULL) { + rv = VM_PAGER_OK; + while (npages--) + if (!vm_page_zero_fill(*mlist)) { + rv = VM_PAGER_FAIL; + break; + } else + mlist++; + return (rv); + } + return ((*pager->pg_ops->pgo_getpages)(pager, mlist, npages, sync)); +} + +int +vm_pager_put_pages(pager, mlist, npages, sync) + vm_pager_t pager; + vm_page_t *mlist; + int npages; + boolean_t sync; +{ + if (pager == NULL) + panic("vm_pager_put_pages: null pager"); + return ((*pager->pg_ops->pgo_putpages)(pager, mlist, npages, sync)); +} + +/* XXX compatibility*/ +int +vm_pager_get(pager, m, sync) + vm_pager_t pager; + vm_page_t m; + boolean_t sync; +{ + return vm_pager_get_pages(pager, &m, 1, sync); +} + +/* XXX compatibility*/ +int +vm_pager_put(pager, m, sync) + vm_pager_t pager; + vm_page_t m; + boolean_t sync; +{ + return vm_pager_put_pages(pager, &m, 1, sync); +} + +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_putpages)(NULL, NULL, 0, FALSE); +} + +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"); + ((*pager->pg_ops->pgo_cluster)(pager, offset, loff, hoff)); +} + +void +vm_pager_clusternull(pager, offset, loff, hoff) + vm_pager_t pager; + vm_offset_t offset; + vm_offset_t *loff; + vm_offset_t *hoff; +{ + panic("vm_pager_nullcluster called"); +} + +vm_offset_t +vm_pager_map_pages(mlist, npages, canwait) + vm_page_t *mlist; + int npages; + boolean_t canwait; +{ + vm_offset_t kva, va; + vm_size_t size; + vm_page_t m; + + /* + * Allocate space in the pager map, if none available return 0. + * This is basically an expansion of kmem_alloc_wait with optional + * blocking on no space. + */ + size = npages * PAGE_SIZE; + vm_map_lock(pager_map); + while (vm_map_findspace(pager_map, 0, size, &kva)) { + if (!canwait) { + vm_map_unlock(pager_map); + return (0); + } + pager_map_wanted = TRUE; + vm_map_unlock(pager_map); + (void) tsleep(pager_map, PVM, "pager_map", 0); + vm_map_lock(pager_map); + } + vm_map_insert(pager_map, NULL, 0, kva, kva + size); + vm_map_unlock(pager_map); + + for (va = kva; npages--; va += PAGE_SIZE) { + m = *mlist++; +#ifdef DEBUG + if ((m->flags & PG_BUSY) == 0) + panic("vm_pager_map_pages: page not busy"); + if (m->flags & PG_PAGEROWNED) + panic("vm_pager_map_pages: page already in pager"); +#endif +#ifdef DEBUG + m->flags |= PG_PAGEROWNED; +#endif + pmap_enter(vm_map_pmap(pager_map), va, VM_PAGE_TO_PHYS(m), + VM_PROT_DEFAULT, TRUE); + } + return (kva); +} + +void +vm_pager_unmap_pages(kva, npages) + vm_offset_t kva; + int npages; +{ + vm_size_t size = npages * PAGE_SIZE; + +#ifdef DEBUG + vm_offset_t va; + vm_page_t m; + int np = npages; + + for (va = kva; np--; va += PAGE_SIZE) { + m = vm_pager_atop(va); + if (m->flags & PG_PAGEROWNED) + m->flags &= ~PG_PAGEROWNED; + else + printf("vm_pager_unmap_pages: %x(%x/%x) not owned\n", + m, va, VM_PAGE_TO_PHYS(m)); + } +#endif + pmap_remove(vm_map_pmap(pager_map), kva, kva + size); + vm_map_lock(pager_map); + (void) vm_map_delete(pager_map, kva, kva + size); + if (pager_map_wanted) + wakeup(pager_map); + vm_map_unlock(pager_map); +} + +vm_page_t +vm_pager_atop(kva) + vm_offset_t kva; +{ + vm_offset_t pa; + + pa = pmap_extract(vm_map_pmap(pager_map), 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); +} |