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uvm_fault_i.h revision 1.7 
      1 /*	$NetBSD: uvm_fault_i.h,v 1.7 1999/01/24 23:53:15 chuck Exp $	*/
      2 
      3 /*
      4  * XXXCDC: "ROUGH DRAFT" QUALITY UVM PRE-RELEASE FILE!
      5  *	   >>>USE AT YOUR OWN RISK, WORK IS NOT FINISHED<<<
      6  */
      7 /*
      8  *
      9  * Copyright (c) 1997 Charles D. Cranor and Washington University.
     10  * All rights reserved.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. All advertising materials mentioning features or use of this software
     21  *    must display the following acknowledgement:
     22  *      This product includes software developed by Charles D. Cranor and
     23  *      Washington University.
     24  * 4. The name of the author may not be used to endorse or promote products
     25  *    derived from this software without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     28  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     29  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     30  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     31  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     32  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     33  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     34  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     35  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     36  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     37  *
     38  * from: Id: uvm_fault_i.h,v 1.1.6.1 1997/12/08 16:07:12 chuck Exp
     39  */
     40 
     41 #ifndef _UVM_UVM_FAULT_I_H_
     42 #define _UVM_UVM_FAULT_I_H_
     43 
     44 /*
     45  * uvm_fault_i.h: fault inline functions
     46  */
     47 
     48 /*
     49  * uvmfault_unlockmaps: unlock the maps
     50  */
     51 
     52 static __inline void
     53 uvmfault_unlockmaps(ufi, write_locked)
     54 	struct uvm_faultinfo *ufi;
     55 	boolean_t write_locked;
     56 {
     57 
     58 	if (write_locked) {
     59 		vm_map_unlock(ufi->map);
     60 	} else {
     61 		vm_map_unlock_read(ufi->map);
     62 	}
     63 }
     64 
     65 /*
     66  * uvmfault_unlockall: unlock everything passed in.
     67  *
     68  * => maps must be read-locked (not write-locked).
     69  */
     70 
     71 static __inline void
     72 uvmfault_unlockall(ufi, amap, uobj, anon)
     73 	struct uvm_faultinfo *ufi;
     74 	struct vm_amap *amap;
     75 	struct uvm_object *uobj;
     76 	struct vm_anon *anon;
     77 {
     78 
     79 	if (anon)
     80 		simple_unlock(&anon->an_lock);
     81 	if (uobj)
     82 		simple_unlock(&uobj->vmobjlock);
     83 	if (amap)
     84 		amap_unlock(amap);
     85 	uvmfault_unlockmaps(ufi, FALSE);
     86 }
     87 
     88 /*
     89  * uvmfault_lookup: lookup a virtual address in a map
     90  *
     91  * => caller must provide a uvm_faultinfo structure with the IN
     92  *	params properly filled in
     93  * => we will lookup the map entry (handling submaps) as we go
     94  * => if the lookup is a success we will return with the maps locked
     95  * => if "write_lock" is TRUE, we write_lock the map, otherwise we only
     96  *	get a read lock.
     97  * => note that submaps can only appear in the kernel and they are
     98  *	required to use the same virtual addresses as the map they
     99  *	are referenced by (thus address translation between the main
    100  *	map and the submap is unnecessary).
    101  */
    102 
    103 static __inline boolean_t
    104 uvmfault_lookup(ufi, write_lock)
    105 	struct uvm_faultinfo *ufi;
    106 	boolean_t write_lock;
    107 {
    108 	vm_map_t tmpmap;
    109 
    110 	/*
    111 	 * init ufi values for lookup.
    112 	 */
    113 
    114 	ufi->map = ufi->orig_map;
    115 	ufi->size = ufi->orig_size;
    116 
    117 	/*
    118 	 * keep going down levels until we are done.   note that there can
    119 	 * only be two levels so we won't loop very long.
    120 	 */
    121 
    122 	while (1) {
    123 
    124 		/*
    125 		 * lock map
    126 		 */
    127 		if (write_lock) {
    128 			vm_map_lock(ufi->map);
    129 		} else {
    130 			vm_map_lock_read(ufi->map);
    131 		}
    132 
    133 		/*
    134 		 * lookup
    135 		 */
    136 		if (!uvm_map_lookup_entry(ufi->map, ufi->orig_rvaddr,
    137 								&ufi->entry)) {
    138 			uvmfault_unlockmaps(ufi, write_lock);
    139 			return(FALSE);
    140 		}
    141 
    142 		/*
    143 		 * reduce size if necessary
    144 		 */
    145 		if (ufi->entry->end - ufi->orig_rvaddr < ufi->size)
    146 			ufi->size = ufi->entry->end - ufi->orig_rvaddr;
    147 
    148 		/*
    149 		 * submap?    replace map with the submap and lookup again.
    150 		 * note: VAs in submaps must match VAs in main map.
    151 		 */
    152 		if (UVM_ET_ISSUBMAP(ufi->entry)) {
    153 			tmpmap = ufi->entry->object.sub_map;
    154 			if (write_lock) {
    155 				vm_map_unlock(ufi->map);
    156 			} else {
    157 				vm_map_unlock_read(ufi->map);
    158 			}
    159 			ufi->map = tmpmap;
    160 			continue;
    161 		}
    162 
    163 		/*
    164 		 * got it!
    165 		 */
    166 
    167 		ufi->mapv = ufi->map->timestamp;
    168 		return(TRUE);
    169 
    170 	}	/* while loop */
    171 
    172 	/*NOTREACHED*/
    173 }
    174 
    175 /*
    176  * uvmfault_relock: attempt to relock the same version of the map
    177  *
    178  * => fault data structures should be unlocked before calling.
    179  * => if a success (TRUE) maps will be locked after call.
    180  */
    181 
    182 static __inline boolean_t
    183 uvmfault_relock(ufi)
    184 	struct uvm_faultinfo *ufi;
    185 {
    186 
    187 	uvmexp.fltrelck++;
    188 	/*
    189 	 * relock map.   fail if version mismatch (in which case nothing
    190 	 * gets locked).
    191 	 */
    192 
    193 	vm_map_lock_read(ufi->map);
    194 	if (ufi->mapv != ufi->map->timestamp) {
    195 		vm_map_unlock_read(ufi->map);
    196 		return(FALSE);
    197 	}
    198 
    199 	uvmexp.fltrelckok++;
    200 	return(TRUE);		/* got it! */
    201 }
    202 
    203 #endif /* _UVM_UVM_FAULT_I_H_ */
    204