uvm_amap.h revision 1.4
1 /* $NetBSD: uvm_amap.h,v 1.4 1998/02/10 02:34:20 perry 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_amap.h,v 1.1.2.7 1998/01/05 18:12:56 chuck Exp 39 */ 40 41 #ifndef _UVM_UVM_AMAP_H_ 42 #define _UVM_UVM_AMAP_H_ 43 44 /* 45 * uvm_amap.h 46 */ 47 48 UVMHIST_DECL(maphist); 49 50 /* 51 * defines for handling of large sparce amaps. 52 * 53 * currently the kernel likes to allocate large chunks of VM to reserve 54 * them for possible use. for example, it allocates (reserves) a large 55 * chunk of user VM for possible stack growth. most of the time only 56 * a page or two of this VM is actually used. since the stack is anonymous 57 * memory it makes sense for it to live in an amap, but if we allocated 58 * an amap for the entire stack range we could end up wasting a large 59 * amount of malloc'd KVM. 60 * 61 * for example, on the i386 at boot time we allocate two amaps for the stack 62 * of /sbin/init: 63 * 1. a 7680 slot amap at protection 0 (reserve space for stack) 64 * 2. a 512 slot amap at protection 7 (top of stack) 65 * 66 * most of that VM is never mapped or used. 67 * 68 * to avoid allocating amap resources for the whole range we have the 69 * VM system look for maps that are larger than UVM_AMAP_LARGE slots 70 * (note that 1 slot = 1 vm_page). for maps that are large, we attempt 71 * to break them up into UVM_AMAP_CHUNK slot sized amaps. 72 * 73 * so, in the i386 example, the 7680 slot area is never referenced so 74 * nothing gets allocated. the 512 slot area is referenced, and it 75 * gets divided into 16 slot chunks (hopefully with one 16 slot chunk 76 * being enough to handle the whole stack...). 77 */ 78 79 #define UVM_AMAP_LARGE 256 /* # of slots in "large" amap */ 80 #define UVM_AMAP_CHUNK 16 /* # of slots to chunk large amaps in */ 81 82 83 #ifdef DIAGNOSTIC 84 #define AMAP_B2SLOT(S,B) { \ 85 if ((B) % PAGE_SIZE) \ 86 panic("AMAP_B2SLOT: invalid byte count"); \ 87 (S) = (B) / PAGE_SIZE; \ 88 } 89 #else 90 #define AMAP_B2SLOT(S,B) (S) = (B) / PAGE_SIZE 91 #endif 92 93 #ifdef VM_AMAP_PPREF 94 #define PPREF_NONE ((int *) -1) 95 #endif 96 97 /* 98 * handle inline options 99 */ 100 101 #ifdef UVM_AMAP_INLINE 102 #define AMAP_INLINE static __inline 103 #else 104 #define AMAP_INLINE /* nothing */ 105 #endif /* UVM_AMAP_INLINE */ 106 107 /* 108 * prototypes: the following prototypes define the interface to amaps 109 */ 110 111 AMAP_INLINE vm_offset_t amap_add __P((struct vm_aref *, vm_offset_t, 112 struct vm_anon *, int)); 113 struct vm_amap *amap_alloc __P((vm_offset_t, vm_offset_t, int)); 114 void amap_copy __P((vm_map_t, vm_map_entry_t, int, boolean_t, 115 vm_offset_t, vm_offset_t)); 116 void amap_cow_now __P((vm_map_t, vm_map_entry_t)); 117 void amap_extend __P((vm_map_entry_t, vm_size_t)); 118 void amap_free __P((struct vm_amap *)); 119 AMAP_INLINE struct vm_anon *amap_lookup __P((struct vm_aref *, vm_offset_t)); 120 AMAP_INLINE void amap_lookups __P((struct vm_aref *, vm_offset_t, 121 struct vm_anon **, int)); 122 #ifdef VM_AMAP_PPREF 123 void amap_pp_adjref __P((struct vm_amap *, int, vm_size_t, int)); 124 void amap_pp_establish __P((struct vm_amap *)); 125 #endif 126 AMAP_INLINE void amap_ref __P((vm_map_entry_t, int)); 127 void amap_share_protect __P((vm_map_entry_t, vm_prot_t)); 128 void amap_splitref __P((struct vm_aref *, struct vm_aref *, vm_offset_t)); 129 AMAP_INLINE void amap_unadd __P((struct vm_amap *, vm_offset_t)); 130 AMAP_INLINE void amap_unref __P((vm_map_entry_t, int)); 131 void amap_wipeout __P((struct vm_amap *)); 132 #ifdef VM_AMAP_PPREF 133 void amap_wiperange __P((struct vm_amap *, int, int)); 134 #endif 135 136 struct vm_anon *uvm_analloc __P((void)); 137 void uvm_anfree __P((struct vm_anon *)); 138 void uvm_anon_init __P((void)); 139 void uvm_anon_add __P((int)); 140 struct vm_page *uvm_anon_lockloanpg __P((struct vm_anon *)); 141 142 #endif /* _UVM_UVM_AMAP_H_ */ 143
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