diff options
Diffstat (limited to 'sys/uvm/uvm_fault.c')
| -rw-r--r-- | sys/uvm/uvm_fault.c | 162 |
1 files changed, 161 insertions, 1 deletions
diff --git a/sys/uvm/uvm_fault.c b/sys/uvm/uvm_fault.c index be5e24d0cca..57d3fe322bf 100644 --- a/sys/uvm/uvm_fault.c +++ b/sys/uvm/uvm_fault.c @@ -1,4 +1,4 @@ -/* $OpenBSD: uvm_fault.c,v 1.51 2009/03/20 15:19:04 oga Exp $ */ +/* $OpenBSD: uvm_fault.c,v 1.52 2009/03/25 20:00:18 oga Exp $ */ /* $NetBSD: uvm_fault.c,v 1.51 2000/08/06 00:22:53 thorpej Exp $ */ /* @@ -177,6 +177,7 @@ static struct uvm_advice uvmadvice[] = { static void uvmfault_amapcopy(struct uvm_faultinfo *); static __inline void uvmfault_anonflush(struct vm_anon **, int); +void uvmfault_unlockmaps(struct uvm_faultinfo *, boolean_t); /* * inline functions @@ -1860,3 +1861,162 @@ uvm_fault_unwire_locked(vm_map_t map, vaddr_t start, vaddr_t end) uvm_unlock_pageq(); } + +/* + * uvmfault_unlockmaps: unlock the maps + */ +void +uvmfault_unlockmaps(struct uvm_faultinfo *ufi, boolean_t 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). + */ +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); + 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). + */ + +boolean_t +uvmfault_lookup(struct uvm_faultinfo *ufi, boolean_t write_lock) +{ + vm_map_t 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. + */ + + 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->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. + */ +boolean_t +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); /* got it! */ +} |