/* * 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. * * %sccs.include.redist.c% * * @(#)vm_pager.c 8.7 (Berkeley) 07/07/94 * * * 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 #include #include #include #include #include #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); }