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NetBSD/sys/uvm/uvm_map.h

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/* $NetBSD: uvm_map.h,v 1.31 2001/10/03 13:32:23 christos 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) { \
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 <uvm/uvm_anon.h>
/*
* 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 {
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_STATIC 0x01 /* static map entry */
#define UVM_MAP_KMEM 0x02 /* from kmem entry pool */
};
#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 lock lock; /* Lock for map data */
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 */
#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)
#if (50 + (2 * NPROC) > 1000)
#define MAX_KMAPENT (50 + (2 * NPROC))
#else
#define MAX_KMAPENT 1000 /* XXXCDC: no crash */
#endif
#endif /* !defined MAX_KMAPENT */
#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 (0)
#endif /* _KERNEL */
/*
* handle inline options
*/
#ifdef UVM_MAP_INLINE
#define MAP_INLINE static __inline
#else
#define MAP_INLINE /* nothing */
#endif /* UVM_MAP_INLINE */
/*
* globals:
*/
#ifdef _KERNEL
#ifdef PMAP_GROWKERNEL
extern vaddr_t uvm_maxkaddr;
#endif
/*
* protos: the following prototypes define the interface to vm_map
*/
MAP_INLINE
void uvm_map_deallocate __P((struct vm_map *));
int uvm_map_clean __P((struct vm_map *, vaddr_t, vaddr_t, int));
void uvm_map_clip_start __P((struct vm_map *, struct vm_map_entry *,
vaddr_t));
void uvm_map_clip_end __P((struct vm_map *, struct vm_map_entry *,
vaddr_t));
MAP_INLINE
struct vm_map *uvm_map_create __P((pmap_t, vaddr_t, vaddr_t, int));
int uvm_map_extract __P((struct vm_map *, vaddr_t, vsize_t,
struct vm_map *, vaddr_t *, int));
struct vm_map_entry *uvm_map_findspace __P((struct vm_map *, vaddr_t, vsize_t,
vaddr_t *, struct uvm_object *, voff_t, vsize_t, int));
int uvm_map_inherit __P((struct vm_map *, vaddr_t, vaddr_t,
vm_inherit_t));
int uvm_map_advice __P((struct vm_map *, vaddr_t, vaddr_t, int));
void uvm_map_init __P((void));
boolean_t uvm_map_lookup_entry __P((struct vm_map *, vaddr_t,
struct vm_map_entry **));
MAP_INLINE
void uvm_map_reference __P((struct vm_map *));
int uvm_map_replace __P((struct vm_map *, vaddr_t, vaddr_t,
struct vm_map_entry *, int));
int uvm_map_reserve __P((struct vm_map *, vsize_t, vaddr_t, vsize_t,
vaddr_t *));
void uvm_map_setup __P((struct vm_map *, vaddr_t, vaddr_t, int));
int uvm_map_submap __P((struct vm_map *, vaddr_t, vaddr_t,
struct vm_map *));
MAP_INLINE
void uvm_unmap __P((struct vm_map *, vaddr_t, vaddr_t));
void uvm_unmap_detach __P((struct vm_map_entry *,int));
void uvm_unmap_remove __P((struct vm_map *, vaddr_t, vaddr_t,
struct vm_map_entry **));
#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 <sys/time.h>
#include <sys/proc.h> /* for tsleep(), wakeup() */
#include <sys/systm.h> /* for panic() */
static __inline boolean_t vm_map_lock_try __P((struct vm_map *));
static __inline void vm_map_lock __P((struct vm_map *));
extern const char vmmapbsy[];
static __inline boolean_t
vm_map_lock_try(map)
struct vm_map *map;
{
boolean_t 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(map)
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 (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 (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 (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 (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 (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_ */
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