1 /* $NetBSD: pmap.h,v 1.26 1997/06/12 23:57:30 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 1995 Charles M. Hannum. All rights reserved. 5 * Copyright (c) 1991 Regents of the University of California. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * the Systems Programming Group of the University of Utah Computer 10 * Science Department and William Jolitz of UUNET Technologies Inc. 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 the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 * 40 * @(#)pmap.h 7.4 (Berkeley) 5/12/91 41 */ 42 43 /* 44 * Derived from hp300 version by Mike Hibler, this version by William 45 * Jolitz uses a recursive map [a pde points to the page directory] to 46 * map the page tables using the pagetables themselves. This is done to 47 * reduce the impact on kernel virtual memory for lots of sparse address 48 * space, and to reduce the cost of memory to each process. 49 * 50 * from hp300: @(#)pmap.h 7.2 (Berkeley) 12/16/90 51 */ 52 53 #ifndef _I386_PMAP_H_ 54 #define _I386_PMAP_H_ 55 56 #include <machine/cpufunc.h> 57 #include <machine/pte.h> 58 59 /* 60 * 386 page table entry and page table directory 61 * W.Jolitz, 8/89 62 */ 63 64 /* 65 * One page directory, shared between 66 * kernel and user modes. 67 */ 68 #define PTDPTDI 0x3df /* ptd entry that points to ptd! */ 69 #define KPTDI 0x3e0 /* start of kernel virtual pde's */ 70 #define NKPDE_BASE 4 /* min. # of kernel PDEs */ 71 #define NKPDE_MAX 31 /* max. # of kernel PDEs */ 72 #define NKPDE_SCALE 1 /* # of kernel PDEs to add per meg. */ 73 #define APTDPTDI 0x3ff /* start of alternate page directory */ 74 75 /* 76 * Address of current and alternate address space page table maps 77 * and directories. 78 */ 79 #ifdef _KERNEL 80 extern pt_entry_t PTmap[], APTmap[], Upte; 81 extern pd_entry_t PTD[], APTD[], PTDpde, APTDpde, Upde; 82 extern pt_entry_t *Sysmap; 83 84 extern int PTDpaddr; /* physical address of kernel PTD */ 85 86 void pmap_bootstrap __P((vm_offset_t start)); 87 boolean_t pmap_testbit __P((vm_offset_t, int)); 88 void pmap_changebit __P((vm_offset_t, int, int)); 89 #endif 90 91 /* 92 * virtual address to page table entry and 93 * to physical address. Likewise for alternate address space. 94 * Note: these work recursively, thus vtopte of a pte will give 95 * the corresponding pde that in turn maps it. 96 */ 97 #define vtopte(va) (PTmap + i386_btop(va)) 98 #define kvtopte(va) vtopte(va) 99 #define ptetov(pt) (i386_ptob(pt - PTmap)) 100 #define vtophys(va) \ 101 ((*vtopte(va) & PG_FRAME) | ((unsigned)(va) & ~PG_FRAME)) 102 103 #define avtopte(va) (APTmap + i386_btop(va)) 104 #define ptetoav(pt) (i386_ptob(pt - APTmap)) 105 #define avtophys(va) \ 106 ((*avtopte(va) & PG_FRAME) | ((unsigned)(va) & ~PG_FRAME)) 107 108 /* 109 * macros to generate page directory/table indicies 110 */ 111 #define pdei(va) (((va) & PD_MASK) >> PDSHIFT) 112 #define ptei(va) (((va) & PT_MASK) >> PGSHIFT) 113 114 /* 115 * Pmap stuff 116 */ 117 typedef struct pmap { 118 pd_entry_t *pm_pdir; /* KVA of page directory */ 119 boolean_t pm_pdchanged; /* pdir changed */ 120 short pm_dref; /* page directory ref count */ 121 short pm_count; /* pmap reference count */ 122 simple_lock_data_t pm_lock; /* lock on pmap */ 123 struct pmap_statistics pm_stats; /* pmap statistics */ 124 long pm_ptpages; /* more stats: PT pages */ 125 } *pmap_t; 126 127 /* 128 * For each vm_page_t, there is a list of all currently valid virtual 129 * mappings of that page. An entry is a pv_entry, the list is pv_table. 130 */ 131 struct pv_entry { 132 struct pv_entry *pv_next; /* next pv_entry */ 133 pmap_t pv_pmap; /* pmap where mapping lies */ 134 vm_offset_t pv_va; /* virtual address for mapping */ 135 }; 136 137 struct pv_page; 138 139 struct pv_page_info { 140 TAILQ_ENTRY(pv_page) pgi_list; 141 struct pv_entry *pgi_freelist; 142 int pgi_nfree; 143 }; 144 145 /* 146 * This is basically: 147 * ((NBPG - sizeof(struct pv_page_info)) / sizeof(struct pv_entry)) 148 */ 149 #define NPVPPG 340 150 151 struct pv_page { 152 struct pv_page_info pvp_pgi; 153 struct pv_entry pvp_pv[NPVPPG]; 154 }; 155 156 #ifdef _KERNEL 157 extern int nkpde; /* number of kernel page dir. ents */ 158 extern struct pmap kernel_pmap_store; 159 struct pv_entry *pv_table; /* array of entries, one per page */ 160 161 #define pmap_kernel() (&kernel_pmap_store) 162 #define pmap_resident_count(pmap) ((pmap)->pm_stats.resident_count) 163 #define pmap_update() tlbflush() 164 165 vm_offset_t reserve_dumppages __P((vm_offset_t)); 166 167 static __inline void 168 pmap_clear_modify(vm_offset_t pa) 169 { 170 pmap_changebit(pa, 0, ~PG_M); 171 } 172 173 static __inline void 174 pmap_clear_reference(vm_offset_t pa) 175 { 176 pmap_changebit(pa, 0, ~PG_U); 177 } 178 179 static __inline void 180 pmap_copy_on_write(vm_offset_t pa) 181 { 182 pmap_changebit(pa, PG_RO, ~PG_RW); 183 } 184 185 static __inline boolean_t 186 pmap_is_modified(vm_offset_t pa) 187 { 188 return pmap_testbit(pa, PG_M); 189 } 190 191 static __inline boolean_t 192 pmap_is_referenced(vm_offset_t pa) 193 { 194 return pmap_testbit(pa, PG_U); 195 } 196 197 static __inline vm_offset_t 198 pmap_phys_address(int ppn) 199 { 200 return i386_ptob(ppn); 201 } 202 203 void pmap_activate __P((pmap_t, struct pcb *)); 204 205 #endif /* _KERNEL */ 206 207 #endif /* _I386_PMAP_H_ */ 208