NetBSD/sys/uvm/uvm_fault_i.h

217 lines
5.4 KiB
C

/* $NetBSD: uvm_fault_i.h,v 1.23 2007/02/22 06:05:01 thorpej Exp $ */
/*
*
* Copyright (c) 1997 Charles D. Cranor and Washington University.
* All rights reserved.
*
* 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 and
* Washington University.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* from: Id: uvm_fault_i.h,v 1.1.6.1 1997/12/08 16:07:12 chuck Exp
*/
#ifndef _UVM_UVM_FAULT_I_H_
#define _UVM_UVM_FAULT_I_H_
/*
* uvm_fault_i.h: fault inline functions
*/
/*
* uvmfault_unlockmaps: unlock the maps
*/
static __inline void
uvmfault_unlockmaps(struct uvm_faultinfo *ufi, bool write_locked)
{
/*
* ufi can be NULL when this isn't really a fault,
* but merely paging in anon data.
*/
if (ufi == NULL) {
return;
}
if (write_locked) {
vm_map_unlock(ufi->map);
} else {
vm_map_unlock_read(ufi->map);
}
}
/*
* uvmfault_unlockall: unlock everything passed in.
*
* => maps must be read-locked (not write-locked).
*/
static __inline void
uvmfault_unlockall(struct uvm_faultinfo *ufi, struct vm_amap *amap,
struct uvm_object *uobj, struct vm_anon *anon)
{
if (anon)
simple_unlock(&anon->an_lock);
if (uobj)
simple_unlock(&uobj->vmobjlock);
if (amap)
amap_unlock(amap);
uvmfault_unlockmaps(ufi, false);
}
/*
* uvmfault_lookup: lookup a virtual address in a map
*
* => caller must provide a uvm_faultinfo structure with the IN
* params properly filled in
* => we will lookup the map entry (handling submaps) as we go
* => if the lookup is a success we will return with the maps locked
* => if "write_lock" is true, we write_lock the map, otherwise we only
* get a read lock.
* => note that submaps can only appear in the kernel and they are
* required to use the same virtual addresses as the map they
* are referenced by (thus address translation between the main
* map and the submap is unnecessary).
*/
static __inline bool
uvmfault_lookup(struct uvm_faultinfo *ufi, bool write_lock)
{
struct vm_map *tmpmap;
/*
* init ufi values for lookup.
*/
ufi->map = ufi->orig_map;
ufi->size = ufi->orig_size;
/*
* keep going down levels until we are done. note that there can
* only be two levels so we won't loop very long.
*/
/*CONSTCOND*/
while (1) {
/*
* Make sure this is not an "interrupt safe" map.
* Such maps are never supposed to be involved in
* a fault.
*/
if (ufi->map->flags & VM_MAP_INTRSAFE)
return (false);
/*
* lock map
*/
if (write_lock) {
vm_map_lock(ufi->map);
} else {
vm_map_lock_read(ufi->map);
}
/*
* lookup
*/
if (!uvm_map_lookup_entry(ufi->map, ufi->orig_rvaddr,
&ufi->entry)) {
uvmfault_unlockmaps(ufi, write_lock);
return(false);
}
/*
* reduce size if necessary
*/
if (ufi->entry->end - ufi->orig_rvaddr < ufi->size)
ufi->size = ufi->entry->end - ufi->orig_rvaddr;
/*
* submap? replace map with the submap and lookup again.
* note: VAs in submaps must match VAs in main map.
*/
if (UVM_ET_ISSUBMAP(ufi->entry)) {
tmpmap = ufi->entry->object.sub_map;
if (write_lock) {
vm_map_unlock(ufi->map);
} else {
vm_map_unlock_read(ufi->map);
}
ufi->map = tmpmap;
continue;
}
/*
* got it!
*/
ufi->mapv = ufi->map->timestamp;
return(true);
} /* while loop */
/*NOTREACHED*/
}
/*
* uvmfault_relock: attempt to relock the same version of the map
*
* => fault data structures should be unlocked before calling.
* => if a success (true) maps will be locked after call.
*/
static __inline bool
uvmfault_relock(struct uvm_faultinfo *ufi)
{
/*
* ufi can be NULL when this isn't really a fault,
* but merely paging in anon data.
*/
if (ufi == NULL) {
return true;
}
uvmexp.fltrelck++;
/*
* relock map. fail if version mismatch (in which case nothing
* gets locked).
*/
vm_map_lock_read(ufi->map);
if (ufi->mapv != ufi->map->timestamp) {
vm_map_unlock_read(ufi->map);
return(false);
}
uvmexp.fltrelckok++;
return(true);
}
#endif /* _UVM_UVM_FAULT_I_H_ */