pte.h revision 1.7
1 /* $NetBSD: pte.h,v 1.7 1994/11/20 20:53:26 deraadt Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * All advertising materials mentioning features or use of this software 12 * must display the following acknowledgement: 13 * This product includes software developed by the University of 14 * California, Lawrence Berkeley Laboratory. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 1. Redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer. 21 * 2. Redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution. 24 * 3. All advertising materials mentioning features or use of this software 25 * must display the following acknowledgement: 26 * This product includes software developed by the University of 27 * California, Berkeley and its contributors. 28 * 4. Neither the name of the University nor the names of its contributors 29 * may be used to endorse or promote products derived from this software 30 * without specific prior written permission. 31 * 32 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 33 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 34 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 35 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 36 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 40 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 41 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 42 * SUCH DAMAGE. 43 * 44 * @(#)pte.h 8.1 (Berkeley) 6/11/93 45 */ 46 47 /* 48 * Sun-4 (sort of) and 4c (SparcStation) Page Table Entries 49 * (Sun call them `Page Map Entries'). 50 */ 51 52 #ifndef LOCORE 53 /* 54 * Segment maps contain `pmeg' (Page Map Entry Group) numbers. 55 * A PMEG is simply an index that names a group of 32 (sun4) or 56 * 64 (sun4c) PTEs. 57 */ 58 typedef u_short pmeg_t; /* 9 bits needed per Sun-4 segmap entry */ 59 #endif 60 61 /* 62 * Address translation works as follows: 63 * 64 * 1. test va<31:29> -- these must be 000 or 111 (or you get a fault) 65 * 2. concatenate context_reg<2:0> and va<29:18> to get a 15 bit number; 66 * use this to index the segment maps, yeilding a 7 or 9 bit value. 67 * (for sun4c) 68 * 3. take the value from (2) above and concatenate va<17:12> to 69 * get a `page map entry' index. This gives a 32-bit PTE. 70 * (for sun4) 71 * 3. take the value from (2) above and concatenate va<17:13> to 72 * get a `page map entry' index. This gives a 32-bit PTE. 73 * 74 * In other words: 75 * 76 * struct sun4_virtual_addr { 77 * u_int :2, (required to be the same as bit 29) 78 * va_seg:12, (virtual segment) 79 * va_pg:5, (virtual page within segment) 80 * va_off:13; (offset within page) 81 * }; 82 * struct sun4c_virtual_addr { 83 * u_int :2, (required to be the same as bit 29) 84 * va_seg:12, (virtual segment) 85 * va_pg:6, (virtual page within segment) 86 * va_off:12; (offset within page) 87 * }; 88 * 89 * Then, given any `va': 90 * 91 * extern pmeg_t segmap[8][1<<12]; ([16][1<<12] for sun4) 92 * extern int ptetable[128][1<<6]; ([512][1<<5] for sun4) 93 * 94 * (the above being in the hardware, accessed as Alternate Address Spaces) 95 * 96 * physseg = segmap[curr_ctx][va.va_seg]; 97 * pte = ptetable[physseg][va.va_pg]; 98 * if (!(pte & PG_V)) TRAP(); 99 * if (writing && !pte.pg_w) TRAP(); 100 * if (usermode && pte.pg_s) TRAP(); 101 * if (pte & PG_NC) DO_NOT_USE_CACHE_FOR_THIS_ACCESS(); 102 * pte |= PG_U; (mark used/accessed) 103 * if (writing) pte |= PG_M; (mark modified) 104 * ptetable[physseg][va.va_pg] = pte; 105 * physadr = ((pte & PG_PFNUM) << PGSHIFT) | va.va_off; 106 */ 107 108 #define NBPSG (1 << 18) /* bytes per segment */ 109 #define SGSHIFT 18 /* log2(NBPSG) */ 110 #define SGOFSET (NBPSG - 1) /* mask for segment offset */ 111 112 /* number of PTEs that map one segment (not number that fit in one segment!) */ 113 #if defined(SUN4) && defined(SUN4C) 114 extern int nptesg; 115 #define NPTESG nptesg /* (which someone will have to initialize) */ 116 #else 117 #define NPTESG (NBPSG / NBPG) 118 #endif 119 120 /* virtual address to virtual segment number */ 121 #define VA_VSEG(va) (((int)(va) >> SGSHIFT) & 0xfff) 122 123 /* virtual address to virtual page number, for Sun-4 and Sun-4c */ 124 #define VA_SUN4_VPG(va) (((int)(va) >> 13) & 31) 125 #define VA_SUN4C_VPG(va) (((int)(va) >> 12) & 63) 126 127 /* truncate virtual address to segment base */ 128 #define VA_ROUNDDOWNTOSEG(va) ((int)(va) & ~SGOFSET) 129 130 /* virtual segment to virtual address (must sign extend!) */ 131 #define VSTOVA(vseg) (((int)(vseg) << 20) >> 2) 132 133 #if defined(SUN4) && defined(SUN4C) 134 #define VA_VPG(va) (cputyp==CPU_SUN4C ? VA_SUN4C_VPG(va) : VA_SUN4_VPG(va)) 135 #endif 136 #if defined(SUN4C) && !defined(SUN4) 137 #define VA_VPG(va) VA_SUN4C_VPG(va) 138 #endif 139 #if !defined(SUN4C) && defined(SUN4) 140 #define VA_VPG(va) VA_SUN4_VPG(va) 141 #endif 142 143 /* there is no `struct pte'; we just use `int' */ 144 #define PG_V 0x80000000 145 #define PG_PROT 0x60000000 /* both protection bits */ 146 #define PG_W 0x40000000 /* allowed to write */ 147 #define PG_S 0x20000000 /* supervisor only */ 148 #define PG_NC 0x10000000 /* non-cacheable */ 149 #define PG_TYPE 0x0c000000 /* both type bits */ 150 151 #define PG_OBMEM 0x00000000 /* on board memory */ 152 #define PG_OBIO 0x04000000 /* on board I/O (incl. Sbus on 4c) */ 153 #ifdef SUN4 154 #define PG_VME16 0x08000000 /* 16-bit-data VME space */ 155 #define PG_VME32 0x0c000000 /* 32-bit-data VME space */ 156 #endif 157 158 #define PG_U 0x02000000 159 #define PG_M 0x01000000 160 #define PG_MBZ 0x00f80000 /* unused; must be zero (oh really?) */ 161 #define PG_PFNUM 0x0007ffff /* n.b.: only 16 bits on sun4c */ 162 163 #define PG_TNC_SHIFT 26 /* shift to get PG_TYPE + PG_NC */ 164 #define PG_M_SHIFT 24 /* shift to get PG_M, PG_U */ 165 166 /*efine PG_NOACC 0 ** XXX */ 167 #define PG_KR 0x20000000 168 #define PG_KW 0x60000000 169 #define PG_URKR 0 170 #define PG_UW 0x40000000 171 172 #ifdef KGDB 173 /* but we will define one for gdb anyway */ 174 struct pte { 175 u_int pg_v:1, 176 pg_w:1, 177 pg_s:1, 178 pg_nc:1; 179 enum pgtype { pg_obmem, pg_obio, pg_vme16, pg_vme32 } pg_type:2; 180 u_int pg_u:1, 181 pg_m:1, 182 pg_mbz:5, 183 pg_pfnum:19; 184 }; 185 #endif 186 187 /* 188 * These are needed in the register window code 189 * to check the validity of (ostensible) user stack PTEs. 190 */ 191 #define PG_VSHIFT 30 /* (va>>vshift)==0 or -1 => valid */ 192 /* XXX fix this name, it is a va shift not a pte bit shift! */ 193 194 #define PG_PROTSHIFT 29 195 #define PG_PROTUWRITE 6 /* PG_V,PG_W,!PG_S */ 196 #define PG_PROTUREAD 4 /* PG_V,!PG_W,!PG_S */ 197 198 /* static __inline int PG_VALID(void *va) { 199 register int t = va; t >>= PG_VSHIFT; return (t == 0 || t == -1); 200 } */ 201
Indexes created Fri Sep 26 20:09:58 GMT 2025