/* $NetBSD: uvm_map.h,v 1.56 2007/02/22 06:05:01 thorpej Exp $ */ /* * Copyright (c) 1997 Charles D. Cranor and Washington University. * 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 Charles D. Cranor, * Washington University, 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_map.h 8.3 (Berkeley) 3/15/94 * from: Id: uvm_map.h,v 1.1.2.3 1998/02/07 01:16:55 chs Exp * * * Copyright (c) 1987, 1990 Carnegie-Mellon University. * All rights reserved. * * 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. */ #ifndef _UVM_UVM_MAP_H_ #define _UVM_UVM_MAP_H_ /* * uvm_map.h */ #ifdef _KERNEL /* * macros */ /* * UVM_MAP_CLIP_START: ensure that the entry begins at or after * the starting address, if it doesn't we split the entry. * * => map must be locked by caller */ #define UVM_MAP_CLIP_START(MAP,ENTRY,VA,UMR) { \ if ((VA) > (ENTRY)->start) uvm_map_clip_start(MAP,ENTRY,VA,UMR); } /* * UVM_MAP_CLIP_END: ensure that the entry ends at or before * the ending address, if it does't we split the entry. * * => map must be locked by caller */ #define UVM_MAP_CLIP_END(MAP,ENTRY,VA,UMR) { \ if ((VA) < (ENTRY)->end) uvm_map_clip_end(MAP,ENTRY,VA,UMR); } /* * extract flags */ #define UVM_EXTRACT_REMOVE 0x01 /* remove mapping from old map */ #define UVM_EXTRACT_CONTIG 0x02 /* try to keep it contig */ #define UVM_EXTRACT_QREF 0x04 /* use quick refs */ #define UVM_EXTRACT_FIXPROT 0x08 /* set prot to maxprot as we go */ #define UVM_EXTRACT_RESERVED 0x10 /* caller did uvm_map_reserve() */ #endif /* _KERNEL */ #include #include #include /* * Address map entries consist of start and end addresses, * a VM object (or sharing map) and offset into that object, * and user-exported inheritance and protection information. * Also included is control information for virtual copy operations. */ struct vm_map_entry { RB_ENTRY(vm_map_entry) rb_entry; /* tree information */ vaddr_t ownspace; /* free space after */ vaddr_t space; /* space in subtree */ struct vm_map_entry *prev; /* previous entry */ struct vm_map_entry *next; /* next entry */ vaddr_t start; /* start address */ vaddr_t end; /* end address */ union { struct uvm_object *uvm_obj; /* uvm object */ struct vm_map *sub_map; /* belongs to another map */ } object; /* object I point to */ voff_t offset; /* offset into object */ int etype; /* entry type */ vm_prot_t protection; /* protection code */ vm_prot_t max_protection; /* maximum protection */ vm_inherit_t inheritance; /* inheritance */ int wired_count; /* can be paged if == 0 */ struct vm_aref aref; /* anonymous overlay */ int advice; /* madvise advice */ #define uvm_map_entry_stop_copy flags u_int8_t flags; /* flags */ #define UVM_MAP_KERNEL 0x01 /* kernel map entry */ #define UVM_MAP_KMAPENT 0x02 /* contains map entries */ #define UVM_MAP_FIRST 0x04 /* the first special entry */ #define UVM_MAP_QUANTUM 0x08 /* allocated with * UVM_FLAG_QUANTUM */ #define UVM_MAP_NOMERGE 0x10 /* this entry is not mergable */ }; #define VM_MAPENT_ISWIRED(entry) ((entry)->wired_count != 0) /* * Maps are doubly-linked lists of map entries, kept sorted * by address. A single hint is provided to start * searches again from the last successful search, * insertion, or removal. * * LOCKING PROTOCOL NOTES: * ----------------------- * * VM map locking is a little complicated. There are both shared * and exclusive locks on maps. However, it is sometimes required * to downgrade an exclusive lock to a shared lock, and upgrade to * an exclusive lock again (to perform error recovery). However, * another thread *must not* queue itself to receive an exclusive * lock while before we upgrade back to exclusive, otherwise the * error recovery becomes extremely difficult, if not impossible. * * In order to prevent this scenario, we introduce the notion of * a `busy' map. A `busy' map is read-locked, but other threads * attempting to write-lock wait for this flag to clear before * entering the lock manager. A map may only be marked busy * when the map is write-locked (and then the map must be downgraded * to read-locked), and may only be marked unbusy by the thread * which marked it busy (holding *either* a read-lock or a * write-lock, the latter being gained by an upgrade). * * Access to the map `flags' member is controlled by the `flags_lock' * simple lock. Note that some flags are static (set once at map * creation time, and never changed), and thus require no locking * to check those flags. All flags which are r/w must be set or * cleared while the `flags_lock' is asserted. Additional locking * requirements are: * * VM_MAP_PAGEABLE r/o static flag; no locking required * * VM_MAP_INTRSAFE r/o static flag; no locking required * * VM_MAP_WIREFUTURE r/w; may only be set or cleared when * map is write-locked. may be tested * without asserting `flags_lock'. * * VM_MAP_BUSY r/w; may only be set when map is * write-locked, may only be cleared by * thread which set it, map read-locked * or write-locked. must be tested * while `flags_lock' is asserted. * * VM_MAP_WANTLOCK r/w; may only be set when the map * is busy, and thread is attempting * to write-lock. must be tested * while `flags_lock' is asserted. * * VM_MAP_DYING r/o; set when a vmspace is being * destroyed to indicate that updates * to the pmap can be skipped. * * VM_MAP_TOPDOWN r/o; set when the vmspace is * created if the unspecified map * allocations are to be arranged in * a "top down" manner. */ struct vm_map { struct pmap * pmap; /* Physical map */ struct lock lock; /* Lock for map data */ RB_HEAD(uvm_tree, vm_map_entry) rbhead; /* Tree for entries */ struct vm_map_entry header; /* List of entries */ int nentries; /* Number of entries */ vsize_t size; /* virtual size */ int ref_count; /* Reference count */ struct simplelock ref_lock; /* Lock for ref_count field */ struct vm_map_entry * hint; /* hint for quick lookups */ struct simplelock hint_lock; /* lock for hint storage */ struct vm_map_entry * first_free; /* First free space hint */ int flags; /* flags */ struct simplelock flags_lock; /* Lock for flags field */ unsigned int timestamp; /* Version number */ }; #if defined(_KERNEL) #include struct vm_map_kernel { struct vm_map vmk_map; LIST_HEAD(, uvm_kmapent_hdr) vmk_kentry_free; /* Freelist of map entry */ struct vm_map_entry *vmk_merged_entries; /* Merged entries, kept for later splitting */ struct callback_head vmk_reclaim_callback; #if !defined(PMAP_MAP_POOLPAGE) struct pool vmk_vacache; /* kva cache */ struct pool_allocator vmk_vacache_allocator; /* ... and its allocator */ #endif }; #endif /* defined(_KERNEL) */ #define VM_MAP_IS_KERNEL(map) (vm_map_pmap(map) == pmap_kernel()) /* vm_map flags */ #define VM_MAP_PAGEABLE 0x01 /* ro: entries are pageable */ #define VM_MAP_INTRSAFE 0x02 /* ro: interrupt safe map */ #define VM_MAP_WIREFUTURE 0x04 /* rw: wire future mappings */ #define VM_MAP_BUSY 0x08 /* rw: map is busy */ #define VM_MAP_WANTLOCK 0x10 /* rw: want to write-lock */ #define VM_MAP_DYING 0x20 /* rw: map is being destroyed */ #define VM_MAP_TOPDOWN 0x40 /* ro: arrange map top-down */ #define VM_MAP_VACACHE 0x80 /* ro: use kva cache */ #define VM_MAP_WANTVA 0x100 /* rw: want va */ #ifdef _KERNEL struct uvm_mapent_reservation { struct vm_map_entry *umr_entries[2]; int umr_nentries; }; #define UMR_EMPTY(umr) ((umr) == NULL || (umr)->umr_nentries == 0) #define UMR_GETENTRY(umr) ((umr)->umr_entries[--(umr)->umr_nentries]) #define UMR_PUTENTRY(umr, ent) \ (umr)->umr_entries[(umr)->umr_nentries++] = (ent) struct uvm_map_args { struct vm_map_entry *uma_prev; vaddr_t uma_start; vsize_t uma_size; struct uvm_object *uma_uobj; voff_t uma_uoffset; uvm_flag_t uma_flags; }; #endif /* _KERNEL */ #ifdef _KERNEL #define vm_map_modflags(map, set, clear) \ do { \ simple_lock(&(map)->flags_lock); \ (map)->flags = ((map)->flags | (set)) & ~(clear); \ simple_unlock(&(map)->flags_lock); \ } while (/*CONSTCOND*/ 0) #endif /* _KERNEL */ /* * globals: */ #ifdef _KERNEL #ifdef PMAP_GROWKERNEL extern vaddr_t uvm_maxkaddr; #endif /* * protos: the following prototypes define the interface to vm_map */ void uvm_map_deallocate(struct vm_map *); int uvm_map_clean(struct vm_map *, vaddr_t, vaddr_t, int); void uvm_map_clip_start(struct vm_map *, struct vm_map_entry *, vaddr_t, struct uvm_mapent_reservation *); void uvm_map_clip_end(struct vm_map *, struct vm_map_entry *, vaddr_t, struct uvm_mapent_reservation *); struct vm_map *uvm_map_create(pmap_t, vaddr_t, vaddr_t, int); int uvm_map_extract(struct vm_map *, vaddr_t, vsize_t, struct vm_map *, vaddr_t *, int); struct vm_map_entry * uvm_map_findspace(struct vm_map *, vaddr_t, vsize_t, vaddr_t *, struct uvm_object *, voff_t, vsize_t, int); int uvm_map_inherit(struct vm_map *, vaddr_t, vaddr_t, vm_inherit_t); int uvm_map_advice(struct vm_map *, vaddr_t, vaddr_t, int); void uvm_map_init(void); bool uvm_map_lookup_entry(struct vm_map *, vaddr_t, struct vm_map_entry **); void uvm_map_reference(struct vm_map *); int uvm_map_replace(struct vm_map *, vaddr_t, vaddr_t, struct vm_map_entry *, int); int uvm_map_reserve(struct vm_map *, vsize_t, vaddr_t, vsize_t, vaddr_t *, uvm_flag_t); void uvm_map_setup(struct vm_map *, vaddr_t, vaddr_t, int); void uvm_map_setup_kernel(struct vm_map_kernel *, vaddr_t, vaddr_t, int); struct vm_map_kernel * vm_map_to_kernel(struct vm_map *); int uvm_map_submap(struct vm_map *, vaddr_t, vaddr_t, struct vm_map *); void uvm_unmap1(struct vm_map *, vaddr_t, vaddr_t, int); #define uvm_unmap(map, s, e) uvm_unmap1((map), (s), (e), 0) void uvm_unmap_detach(struct vm_map_entry *,int); void uvm_unmap_remove(struct vm_map *, vaddr_t, vaddr_t, struct vm_map_entry **, struct uvm_mapent_reservation *, int); int uvm_map_prepare(struct vm_map *, vaddr_t, vsize_t, struct uvm_object *, voff_t, vsize_t, uvm_flag_t, struct uvm_map_args *); int uvm_map_enter(struct vm_map *, const struct uvm_map_args *, struct vm_map_entry *); int uvm_mapent_reserve(struct vm_map *, struct uvm_mapent_reservation *, int, int); void uvm_mapent_unreserve(struct vm_map *, struct uvm_mapent_reservation *); vsize_t uvm_mapent_overhead(vsize_t, int); int uvm_mapent_trymerge(struct vm_map *, struct vm_map_entry *, int); #define UVM_MERGE_COPYING 1 #endif /* _KERNEL */ /* * VM map locking operations: * * These operations perform locking on the data portion of the * map. * * vm_map_lock_try: try to lock a map, failing if it is already locked. * * vm_map_lock: acquire an exclusive (write) lock on a map. * * vm_map_lock_read: acquire a shared (read) lock on a map. * * vm_map_unlock: release an exclusive lock on a map. * * vm_map_unlock_read: release a shared lock on a map. * * vm_map_downgrade: downgrade an exclusive lock to a shared lock. * * vm_map_upgrade: upgrade a shared lock to an exclusive lock. * * vm_map_busy: mark a map as busy. * * vm_map_unbusy: clear busy status on a map. * * Note that "intrsafe" maps use only exclusive, spin locks. We simply * use the sleep lock's interlock for this. */ #ifdef _KERNEL /* XXX: clean up later */ #include #include /* for tsleep(), wakeup() */ #include /* for panic() */ static __inline bool vm_map_lock_try(struct vm_map *); static __inline void vm_map_lock(struct vm_map *); extern const char vmmapbsy[]; static __inline bool vm_map_lock_try(struct vm_map *map) { bool rv; if (map->flags & VM_MAP_INTRSAFE) rv = simple_lock_try(&map->lock.lk_interlock); else { simple_lock(&map->flags_lock); if (map->flags & VM_MAP_BUSY) { simple_unlock(&map->flags_lock); return (false); } rv = (lockmgr(&map->lock, LK_EXCLUSIVE|LK_NOWAIT|LK_INTERLOCK, &map->flags_lock) == 0); } if (rv) map->timestamp++; return (rv); } static __inline void vm_map_lock(struct vm_map *map) { int error; if (map->flags & VM_MAP_INTRSAFE) { simple_lock(&map->lock.lk_interlock); return; } try_again: simple_lock(&map->flags_lock); while (map->flags & VM_MAP_BUSY) { map->flags |= VM_MAP_WANTLOCK; ltsleep(&map->flags, PVM, vmmapbsy, 0, &map->flags_lock); } error = lockmgr(&map->lock, LK_EXCLUSIVE|LK_SLEEPFAIL|LK_INTERLOCK, &map->flags_lock); if (error) { KASSERT(error == ENOLCK); goto try_again; } (map)->timestamp++; } #ifdef DIAGNOSTIC #define vm_map_lock_read(map) \ do { \ if ((map)->flags & VM_MAP_INTRSAFE) \ panic("vm_map_lock_read: intrsafe Map"); \ (void) lockmgr(&(map)->lock, LK_SHARED, NULL); \ } while (/*CONSTCOND*/ 0) #else #define vm_map_lock_read(map) \ (void) lockmgr(&(map)->lock, LK_SHARED, NULL) #endif #define vm_map_unlock(map) \ do { \ if ((map)->flags & VM_MAP_INTRSAFE) \ simple_unlock(&(map)->lock.lk_interlock); \ else \ (void) lockmgr(&(map)->lock, LK_RELEASE, NULL); \ } while (/*CONSTCOND*/ 0) #define vm_map_unlock_read(map) \ (void) lockmgr(&(map)->lock, LK_RELEASE, NULL) #define vm_map_downgrade(map) \ (void) lockmgr(&(map)->lock, LK_DOWNGRADE, NULL) #ifdef DIAGNOSTIC #define vm_map_upgrade(map) \ do { \ if (lockmgr(&(map)->lock, LK_UPGRADE, NULL) != 0) \ panic("vm_map_upgrade: failed to upgrade lock"); \ } while (/*CONSTCOND*/ 0) #else #define vm_map_upgrade(map) \ (void) lockmgr(&(map)->lock, LK_UPGRADE, NULL) #endif #define vm_map_busy(map) \ do { \ simple_lock(&(map)->flags_lock); \ (map)->flags |= VM_MAP_BUSY; \ simple_unlock(&(map)->flags_lock); \ } while (/*CONSTCOND*/ 0) #define vm_map_unbusy(map) \ do { \ int oflags; \ \ simple_lock(&(map)->flags_lock); \ oflags = (map)->flags; \ (map)->flags &= ~(VM_MAP_BUSY|VM_MAP_WANTLOCK); \ simple_unlock(&(map)->flags_lock); \ if (oflags & VM_MAP_WANTLOCK) \ wakeup(&(map)->flags); \ } while (/*CONSTCOND*/ 0) bool vm_map_starved_p(struct vm_map *); #endif /* _KERNEL */ /* * Functions implemented as macros */ #define vm_map_min(map) ((map)->header.end) #define vm_map_max(map) ((map)->header.start) #define vm_map_setmin(map, v) ((map)->header.end = (v)) #define vm_map_setmax(map, v) ((map)->header.start = (v)) #define vm_map_pmap(map) ((map)->pmap) #endif /* _UVM_UVM_MAP_H_ */