1 /* $NetBSD: pmap.h,v 1.9 1994/12/10 11:44:28 pk 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 * @(#)pmap.h 8.1 (Berkeley) 6/11/93 45 */ 46 47 #ifndef _SPARC_PMAP_H_ 48 #define _SPARC_PMAP_H_ 49 50 #include <machine/pte.h> 51 52 /* 53 * Pmap structure. 54 * 55 * The pmap structure really comes in two variants, one---a single 56 * instance---for kernel virtual memory and the other---up to nproc 57 * instances---for user virtual memory. Unfortunately, we have to mash 58 * both into the same structure. Fortunately, they are almost the same. 59 * 60 * The kernel begins at 0xf8000000 and runs to 0xffffffff (although 61 * some of this is not actually used). Kernel space, including DVMA 62 * space (for now?), is mapped identically into all user contexts. 63 * There is no point in duplicating this mapping in each user process 64 * so they do not appear in the user structures. 65 * 66 * User space begins at 0x00000000 and runs through 0x1fffffff, 67 * then has a `hole', then resumes at 0xe0000000 and runs until it 68 * hits the kernel space at 0xf8000000. This can be mapped 69 * contiguously by ignorning the top two bits and pretending the 70 * space goes from 0 to 37ffffff. Typically the lower range is 71 * used for text+data and the upper for stack, but the code here 72 * makes no such distinction. 73 * 74 * Since each virtual segment covers 256 kbytes, the user space 75 * requires 3584 segments, while the kernel (including DVMA) requires 76 * only 512 segments. 77 * 78 * The segment map entry for virtual segment vseg is offset in 79 * pmap->pm_rsegmap by 0 if pmap is not the kernel pmap, or by 80 * NUSEG if it is. We keep a pointer called pmap->pm_segmap 81 * pre-offset by this value. pmap->pm_segmap thus contains the 82 * values to be loaded into the user portion of the hardware segment 83 * map so as to reach the proper PMEGs within the MMU. The kernel 84 * mappings are `set early' and are always valid in every context 85 * (every change is always propagated immediately). 86 * 87 * The PMEGs within the MMU are loaded `on demand'; when a PMEG is 88 * taken away from context `c', the pmap for context c has its 89 * corresponding pm_segmap[vseg] entry marked invalid (the MMU segment 90 * map entry is also made invalid at the same time). Thus 91 * pm_segmap[vseg] is the `invalid pmeg' number (127 or 511) whenever 92 * the corresponding PTEs are not actually in the MMU. On the other 93 * hand, pm_pte[vseg] is NULL only if no pages in that virtual segment 94 * are in core; otherwise it points to a copy of the 32 or 64 PTEs that 95 * must be loaded in the MMU in order to reach those pages. 96 * pm_npte[vseg] counts the number of valid pages in each vseg. 97 * 98 * XXX performance: faster to count valid bits? 99 * 100 * The kernel pmap cannot malloc() PTEs since malloc() will sometimes 101 * allocate a new virtual segment. Since kernel mappings are never 102 * `stolen' out of the the MMU, we just keep all its PTEs there, and 103 * have no software copies. Its mmu entries are nonetheless kept on lists 104 * so that the code that fiddles with mmu lists has something to fiddle. 105 */ 106 #define NKSEG ((int)((-(unsigned)KERNBASE) / NBPSG)) /* i.e., 512 */ 107 #define NUSEG (4096 - NKSEG) /* i.e., 3584 */ 108 109 /* data appearing in both user and kernel pmaps */ 110 struct pmap { 111 union ctxinfo *pm_ctx; /* current context, if any */ 112 int pm_ctxnum; /* current context's number */ 113 #if NCPUS > 1 114 simple_lock_data_t pm_lock; /* spinlock */ 115 #endif 116 int pm_refcount; /* just what it says */ 117 struct mmuentry *pm_mmuforw; /* pmap pmeg chain */ 118 struct mmuentry **pm_mmuback; /* (two way street) */ 119 void *pm_segstore; 120 pmeg_t *pm_segmap; /* points to pm_rsegmap per above */ 121 u_char *pm_npte; /* points to pm_rnpte */ 122 int **pm_pte; /* points to pm_rpte */ 123 int pm_gap_start; /* Starting with this vseg there's */ 124 int pm_gap_end; /* no valid mapping until here */ 125 struct pmap_statistics pm_stats; /* pmap statistics */ 126 }; 127 128 /* data appearing only in user pmaps */ 129 struct usegmap { 130 pmeg_t us_segmap[NUSEG]; /* segment map */ 131 u_char us_npte[NUSEG]; /* number of valid PTEs per seg */ 132 int *us_pte[NUSEG]; /* points to PTEs for valid segments */ 133 }; 134 135 /* data appearing only in the kernel pmap */ 136 struct ksegmap { 137 pmeg_t ks_segmap[NKSEG]; /* segment map */ 138 u_char ks_npte[NKSEG]; /* number of valid PTEs per kseg */ 139 int *ks_pte[NKSEG]; /* always NULL */ 140 }; 141 142 typedef struct pmap *pmap_t; 143 144 #ifdef KERNEL 145 146 #define PMAP_NULL ((pmap_t)0) 147 148 extern struct pmap kernel_pmap_store; 149 extern struct ksegmap kernel_segmap_store; 150 extern pmap_t kernel_pmap; 151 152 #define PMAP_ACTIVATE(pmap, pcb, iscurproc) 153 #define PMAP_DEACTIVATE(pmap, pcb) 154 155 /* 156 * Since PTEs also contain type bits, we have to have some way 157 * to tell pmap_enter `this is an IO page' or `this is not to 158 * be cached'. Since physical addresses are always aligned, we 159 * can do this with the low order bits. 160 * 161 * The ordering below is important: PMAP_PGTYPE << PG_TNC must give 162 * exactly the PG_NC and PG_TYPE bits. 163 */ 164 #define PMAP_OBIO 1 /* tells pmap_enter to use PG_OBIO */ 165 #define PMAP_VME16 2 /* etc */ 166 #define PMAP_VME32 3 /* etc */ 167 #define PMAP_NC 4 /* tells pmap_enter to set PG_NC */ 168 #define PMAP_TNC 7 /* mask to get PG_TYPE & PG_NC */ 169 170 void pmap_bootstrap __P((int nmmu, int nctx)); 171 void pmap_init __P((vm_offset_t phys_start, vm_offset_t phys_end)); 172 int pmap_count_ptes __P((struct pmap *)); 173 vm_offset_t pmap_prefer __P((vm_offset_t, vm_offset_t)); 174 175 #define pmap_resident_count(pmap) pmap_count_ptes(pmap) 176 177 #define PMAP_PREFER(pa,va) pmap_prefer((pa),(va)) 178 179 #endif /* KERNEL */ 180 181 #endif /* _SPARC_PMAP_H_ */ 182