/* $NetBSD: uvm_fault_i.h,v 1.33 2020/02/23 15:46:43 ad 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. * * 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 */ void uvmfault_update_stats(struct uvm_faultinfo *); /* * 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; } #ifndef __HAVE_NO_PMAP_STATS uvmfault_update_stats(ufi); #endif 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) { if (uobj) rw_exit(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. */ for (;;) { /* * 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; } cpu_count(CPU_COUNT_FLTRELCK, 1); /* * 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); } cpu_count(CPU_COUNT_FLTRELCKOK, 1); return(true); } #endif /* _UVM_UVM_FAULT_I_H_ */