NetBSD/sys/uvm/uvm_fault_i.h

245 lines
6.8 KiB
C

/* $NetBSD: uvm_fault_i.h,v 1.4 1998/02/10 02:34:35 perry Exp $ */
/*
* XXXCDC: "ROUGH DRAFT" QUALITY UVM PRE-RELEASE FILE!
* >>>USE AT YOUR OWN RISK, WORK IS NOT FINISHED<<<
*/
/*
*
* 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(ufi, write_locked)
struct uvm_faultinfo *ufi;
boolean_t write_locked;
{
if (write_locked) {
vm_map_unlock(ufi->map);
if (ufi->parent_map) vm_map_unlock(ufi->parent_map);
} else {
vm_map_unlock_read(ufi->map);
if (ufi->parent_map) vm_map_unlock_read(ufi->parent_map);
}
}
/*
* uvmfault_unlockall: unlock everything passed in.
*
* => maps must be read-locked (not write-locked).
*/
static __inline void uvmfault_unlockall(ufi, amap, uobj, anon)
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)
simple_unlock(&amap->am_l);
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 and fill in parent_map, etc, 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.
* => currently we require sharemaps to have the same virtual addresses
* as the main maps they are attached to. in other words, the share
* map starts at zero and goes to the map user address. the main
* map references it by setting its offset to be the same as the
* starting virtual address. if we ever wanted to have sharemaps
* have different virtual addresses than main maps we would calculate
* it like:
* share_va = (rvaddr - entry->start) + entry->offset
* [i.e. offset from start of map entry plus offset of mapping]
* since (entry->start == entry->offset), share_va must equal rvaddr.
* if we need to change this we should store share_va in rvaddr
* and move rvaddr to orig_rvaddr.
*/
static __inline boolean_t uvmfault_lookup(ufi, write_lock)
struct uvm_faultinfo *ufi;
boolean_t write_lock;
{
vm_map_t tmpmap;
/*
* init ufi values for lookup.
*/
ufi->map = ufi->orig_map;
ufi->rvaddr = ufi->orig_rvaddr;
ufi->parent_map = NULL;
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.
*/
while (1) {
/*
* 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->rvaddr, &ufi->entry)) {
uvmfault_unlockmaps(ufi, write_lock);
return(FALSE);
}
/*
* reduce size if necessary
*/
if (ufi->entry->end - ufi->rvaddr < ufi->size)
ufi->size = ufi->entry->end - ufi->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)) {
if (ufi->parent_map)
panic("uvmfault_lookup: submap inside a sharemap (illegal)");
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;
}
/*
* share map? drop down a level. already taken care of submap case.
*/
if (UVM_ET_ISMAP(ufi->entry)) {
if (ufi->parent_map)
panic("uvmfault_lookup: sharemap inside a sharemap (illegal)");
ufi->parent_map = ufi->map;
ufi->parentv = ufi->parent_map->timestamp;
ufi->map = ufi->entry->object.share_map;
#ifdef DIAGNOSTIC
/* see note above */
if (ufi->entry->offset != ufi->entry->start)
panic("uvmfault_lookup: sharemap VA != mainmap VA (not supported)");
#endif
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 boolean_t uvmfault_relock(ufi)
struct uvm_faultinfo *ufi;
{
uvmexp.fltrelck++;
/*
* simply relock parent (if any) then map in order. fail if version
* mismatch (in which case nothing gets locked).
*/
if (ufi->parent_map) {
vm_map_lock_read(ufi->parent_map);
if (ufi->parentv != ufi->parent_map->timestamp) {
vm_map_unlock_read(ufi->parent_map);
return(FALSE);
}
}
vm_map_lock_read(ufi->map);
if (ufi->mapv != ufi->map->timestamp) {
if (ufi->parent_map)
vm_map_unlock_read(ufi->parent_map);
vm_map_unlock_read(ufi->map);
return(FALSE);
}
uvmexp.fltrelckok++;
return(TRUE); /* got it! */
}
#endif /* _UVM_UVM_FAULT_I_H_ */