/* $OpenBSD: uvm_map.h,v 1.42 2009/08/28 00:40:03 ariane Exp $ */ /* $NetBSD: uvm_map.h,v 1.24 2001/02/18 21:19:08 chs 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_ #include #ifdef _KERNEL /* * 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) { \ if ((VA) > (ENTRY)->start) uvm_map_clip_start(MAP,ENTRY,VA); } /* * 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) { \ if ((VA) < (ENTRY)->end) uvm_map_clip_end(MAP,ENTRY,VA); } /* * extract flags */ #define UVM_EXTRACT_REMOVE 0x1 /* remove mapping from old map */ #define UVM_EXTRACT_CONTIG 0x2 /* try to keep it contig */ #define UVM_EXTRACT_QREF 0x4 /* use quick refs */ #define UVM_EXTRACT_FIXPROT 0x8 /* set prot to maxprot as we go */ #endif /* _KERNEL */ #include /* * types defined: * * vm_map_t the high-level address map data structure. * vm_map_entry_t an entry in an address map. * vm_map_version_t a timestamp of a map, for use with vm_map_lookup */ /* * Objects which live in maps may be either VM objects, or another map * (called a "sharing map") which denotes read-write sharing with other maps. * * XXXCDC: private pager data goes here now */ union vm_map_object { struct uvm_object *uvm_obj; /* UVM OBJECT */ struct vm_map *sub_map; /* belongs to another map */ }; /* * 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 vm_map_object 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_STATIC 0x01 /* static map entry */ #define UVM_MAP_KMEM 0x02 /* from kmem entry pool */ }; /* * Marks the map entry as a guard page, using vm_map_entry.etype. */ #define MAP_ET_KVAGUARD 0x10 /* guard entry */ #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. */ struct vm_map { struct pmap * pmap; /* Physical map */ struct rwlock 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 */ simple_lock_data_t ref_lock; /* Lock for ref_count field */ vm_map_entry_t hint; /* hint for quick lookups */ simple_lock_data_t hint_lock; /* lock for hint storage */ vm_map_entry_t first_free; /* First free space hint */ int flags; /* flags */ unsigned int timestamp; /* Version number */ #define min_offset header.start #define max_offset header.end }; /* 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 */ /* XXX: number of kernel maps and entries to statically allocate */ #if !defined(MAX_KMAPENT) #define MAX_KMAPENT 1024 /* XXXCDC: no crash */ #endif /* !defined MAX_KMAPENT */ #ifdef _KERNEL #define vm_map_modflags(map, set, clear) \ do { \ (map)->flags = ((map)->flags | (set)) & ~(clear); \ } while (0) #endif /* _KERNEL */ /* * Interrupt-safe maps must also be kept on a special list, * to assist uvm_fault() in avoiding locking problems. */ struct vm_map_intrsafe { struct vm_map vmi_map; LIST_ENTRY(vm_map_intrsafe) vmi_list; }; /* * 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(vm_map_t); int uvm_map_clean(vm_map_t, vaddr_t, vaddr_t, int); void uvm_map_clip_start(vm_map_t, vm_map_entry_t, vaddr_t); void uvm_map_clip_end(vm_map_t, vm_map_entry_t, vaddr_t); vm_map_t uvm_map_create(pmap_t, vaddr_t, vaddr_t, int); int uvm_map_extract(vm_map_t, vaddr_t, vsize_t, vm_map_t, vaddr_t *, int); vm_map_entry_t uvm_map_findspace(vm_map_t, vaddr_t, vsize_t, vaddr_t *, struct uvm_object *, voff_t, vsize_t, int); vaddr_t uvm_map_pie(vaddr_t); vaddr_t uvm_map_hint(struct proc *, vm_prot_t); int uvm_map_inherit(vm_map_t, vaddr_t, vaddr_t, vm_inherit_t); int uvm_map_advice(vm_map_t, vaddr_t, vaddr_t, int); void uvm_map_init(void); boolean_t uvm_map_lookup_entry(vm_map_t, vaddr_t, vm_map_entry_t *); void uvm_map_reference(vm_map_t); int uvm_map_replace(vm_map_t, vaddr_t, vaddr_t, vm_map_entry_t, int); int uvm_map_reserve(vm_map_t, vsize_t, vaddr_t, vsize_t, vaddr_t *); void uvm_map_setup(vm_map_t, vaddr_t, vaddr_t, int); int uvm_map_submap(vm_map_t, vaddr_t, vaddr_t, vm_map_t); #define uvm_unmap(_m, _s, _e) uvm_unmap_p(_m, _s, _e, 0) void uvm_unmap_p(vm_map_t, vaddr_t, vaddr_t, struct proc *); void uvm_unmap_detach(vm_map_entry_t,int); void uvm_unmap_remove(vm_map_t, vaddr_t, vaddr_t, vm_map_entry_t *, struct proc *, boolean_t); #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 boolean_t vm_map_lock_try(vm_map_t); static __inline void vm_map_lock(vm_map_t); extern const char vmmapbsy[]; static __inline boolean_t vm_map_lock_try(struct vm_map *map) { boolean_t rv; if (map->flags & VM_MAP_INTRSAFE) { rv = TRUE; } else { if (map->flags & VM_MAP_BUSY) { return (FALSE); } rv = (rw_enter(&map->lock, RW_WRITE|RW_NOSLEEP) == 0); } if (rv) map->timestamp++; return (rv); } static __inline void vm_map_lock(struct vm_map *map) { if (map->flags & VM_MAP_INTRSAFE) return; do { while (map->flags & VM_MAP_BUSY) { map->flags |= VM_MAP_WANTLOCK; tsleep(&map->flags, PVM, (char *)vmmapbsy, 0); } } while (rw_enter(&map->lock, RW_WRITE|RW_SLEEPFAIL) != 0); map->timestamp++; } #define vm_map_lock_read(map) rw_enter_read(&(map)->lock) #define vm_map_unlock(map) \ do { \ if (((map)->flags & VM_MAP_INTRSAFE) == 0) \ rw_exit(&(map)->lock); \ } while (0) #define vm_map_unlock_read(map) rw_exit_read(&(map)->lock) #define vm_map_downgrade(map) rw_enter(&(map)->lock, RW_DOWNGRADE) #define vm_map_upgrade(map) \ do { \ rw_exit_read(&(map)->lock); \ rw_enter_write(&(map)->lock); \ } while (0) #define vm_map_busy(map) \ do { \ (map)->flags |= VM_MAP_BUSY; \ } while (0) #define vm_map_unbusy(map) \ do { \ int oflags; \ \ oflags = (map)->flags; \ (map)->flags &= ~(VM_MAP_BUSY|VM_MAP_WANTLOCK); \ if (oflags & VM_MAP_WANTLOCK) \ wakeup(&(map)->flags); \ } while (0) #endif /* _KERNEL */ /* * Functions implemented as macros */ #define vm_map_min(map) ((map)->min_offset) #define vm_map_max(map) ((map)->max_offset) #define vm_map_pmap(map) ((map)->pmap) #endif /* _UVM_UVM_MAP_H_ */