1 /* 2 * Copyright (c) 1987 Carnegie-Mellon University 3 * Copyright (c) 1991 Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * The Mach Operating System project at Carnegie-Mellon University. 8 * 9 * The CMU software License Agreement specifies the terms and conditions 10 * for use and redistribution. 11 * 12 * This version by William Jolitz for UUNET Technologies, Inc. 13 * 14 * Derived from hp300 version by Mike Hibler, this version by William 15 * Jolitz uses a recursive map [a pde points to the page directory] to 16 * map the page tables using the pagetables themselves. This is done to 17 * reduce the impact on kernel virtual memory for lots of sparse address 18 * space, and to reduce the cost of memory to each process. 19 * 20 * from hp300: @(#)pmap.h 7.2 (Berkeley) 12/16/90 21 * 22 * @(#)pmap.h 1.5 (Berkeley) 05/09/91 23 */ 24 25 #ifndef _PMAP_MACHINE_ 26 #define _PMAP_MACHINE_ 1 27 28 /* 29 * 386 page table entry and page table directory 30 * W.Jolitz, 8/89 31 */ 32 33 struct pde 34 { 35 unsigned int 36 pd_v:1, /* valid bit */ 37 pd_prot:2, /* access control */ 38 pd_mbz1:2, /* reserved, must be zero */ 39 pd_u:1, /* hardware maintained 'used' bit */ 40 :1, /* not used */ 41 pd_mbz2:2, /* reserved, must be zero */ 42 :3, /* reserved for software */ 43 pd_pfnum:20; /* physical page frame number of pte's*/ 44 }; 45 46 #define PD_MASK 0xffc00000 /* page directory address bits */ 47 #define PT_MASK 0x003ff000 /* page table address bits */ 48 #define PD_SHIFT 22 /* page directory address shift */ 49 #define PG_SHIFT 12 /* page table address shift */ 50 51 struct pte 52 { 53 unsigned int 54 pg_v:1, /* valid bit */ 55 pg_prot:2, /* access control */ 56 pg_mbz1:2, /* reserved, must be zero */ 57 pg_u:1, /* hardware maintained 'used' bit */ 58 pg_m:1, /* hardware maintained modified bit */ 59 pg_mbz2:2, /* reserved, must be zero */ 60 pg_w:1, /* software, wired down page */ 61 :1, /* software (unused) */ 62 pg_nc:1, /* 'uncacheable page' bit */ 63 pg_pfnum:20; /* physical page frame number */ 64 }; 65 66 #define PG_V 0x00000001 67 #define PG_RO 0x00000000 68 #define PG_RW 0x00000002 69 #define PG_u 0x00000004 70 #define PG_PROT 0x00000006 /* all protection bits . */ 71 #define PG_W 0x00000200 72 #define PG_N 0x00000800 /* Non-cacheable */ 73 #define PG_M 0x00000040 74 #define PG_U 0x00000020 75 #define PG_FRAME 0xfffff000 76 77 #define PG_NOACC 0 78 #define PG_KR 0x00000000 79 #define PG_KW 0x00000002 80 #define PG_URKR 0x00000004 81 #define PG_URKW 0x00000004 82 #define PG_UW 0x00000006 83 84 /* Garbage for current bastardized pager that assumes a hp300 */ 85 #define PG_NV 0 86 #define PG_CI 0 87 /* 88 * Page Protection Exception bits 89 */ 90 91 #define PGEX_P 0x01 /* Protection violation vs. not present */ 92 #define PGEX_W 0x02 /* during a Write cycle */ 93 #define PGEX_U 0x04 /* access from User mode (UPL) */ 94 95 typedef struct pde pd_entry_t; /* page directory entry */ 96 typedef struct pte pt_entry_t; /* Mach page table entry */ 97 98 #define PD_ENTRY_NULL ((pd_entry_t *) 0) 99 #define PT_ENTRY_NULL ((pt_entry_t *) 0) 100 101 /* 102 * One page directory, shared between 103 * kernel and user modes. 104 */ 105 #define I386_PAGE_SIZE NBPG 106 #define I386_PDR_SIZE NBPDR 107 108 #define I386_KPDES 8 /* KPT page directory size */ 109 #define I386_UPDES NBPDR/sizeof(struct pde)-8 /* UPT page directory size */ 110 111 #define UPTDI 0x3f6 /* ptd entry for u./kernel&user stack */ 112 #define PTDPTDI 0x3f7 /* ptd entry that points to ptd! */ 113 #define KPTDI_FIRST 0x3f8 /* start of kernel virtual pde's */ 114 #define KPTDI_LAST 0x3fA /* last of kernel virtual pde's */ 115 116 extern pt_entry_t *Sysmap; 117 118 /* 119 * Address of current and alternate address space page table maps 120 * and directories. 121 */ 122 extern struct pte PTmap[], APTmap[], Upte; 123 extern struct pde PTD[], APTD[], PTDpde, APTDpde, Upde; 124 125 extern int IdlePTD; 126 127 /* 128 * virtual address to page table entry and 129 * to physical address. Likewise for alternate address space. 130 * Note: these work recursively, thus vtopte of a pte will give 131 * the corresponding pde that in turn maps it. 132 */ 133 #define vtopte(va) (PTmap + i386_btop(va)) 134 #define kvtopte(va) vtopte(va) 135 #define ptetov(pt) (i386_ptob(pt - PTmap)) 136 #define vtophys(va) (i386_ptob(vtopte(va)->pg_pfnum) | ((int)(va) & PGOFSET)) 137 #define ispt(va) ((va) >= UPT_MIN_ADDRESS && (va) <= KPT_MAX_ADDRESS) 138 139 #define avtopte(va) (APTmap + i386_btop(va)) 140 #define ptetoav(pt) (i386_ptob(pt - APTmap)) 141 #define avtophys(va) (i386_ptob(avtopte(va)->pg_pfnum) | ((int)(va) & PGOFSET)) 142 143 /* 144 * macros to generate page directory/table indicies 145 */ 146 147 #define pdei(va) (((va)&PD_MASK)>>PD_SHIFT) 148 #define ptei(va) (((va)&PT_MASK)>>PT_SHIFT) 149 150 /* 151 * Pmap stuff 152 */ 153 154 struct pmap { 155 pd_entry_t *pm_pdir; /* KVA of page directory */ 156 boolean_t pm_pdchanged; /* pdir changed */ 157 short pm_dref; /* page directory ref count */ 158 short pm_count; /* pmap reference count */ 159 simple_lock_data_t pm_lock; /* lock on pmap */ 160 struct pmap_statistics pm_stats; /* pmap statistics */ 161 long pm_ptpages; /* more stats: PT pages */ 162 }; 163 164 typedef struct pmap *pmap_t; 165 166 extern pmap_t kernel_pmap; 167 168 /* 169 * Macros for speed 170 */ 171 #define PMAP_ACTIVATE(pmapp, pcbp) \ 172 if ((pmapp) != PMAP_NULL /*&& (pmapp)->pm_pdchanged */) { \ 173 (pcbp)->pcb_cr3 = \ 174 pmap_extract(kernel_pmap, (pmapp)->pm_pdir); \ 175 if ((pmapp) == &curproc->p_vmspace->vm_pmap) \ 176 load_cr3((pcbp)->pcb_cr3); \ 177 (pmapp)->pm_pdchanged = FALSE; \ 178 } 179 180 #define PMAP_DEACTIVATE(pmapp, pcbp) 181 182 /* 183 * For each vm_page_t, there is a list of all currently valid virtual 184 * mappings of that page. An entry is a pv_entry_t, the list is pv_table. 185 */ 186 typedef struct pv_entry { 187 struct pv_entry *pv_next; /* next pv_entry */ 188 pmap_t pv_pmap; /* pmap where mapping lies */ 189 vm_offset_t pv_va; /* virtual address for mapping */ 190 int pv_flags; /* flags */ 191 } *pv_entry_t; 192 193 #define PV_ENTRY_NULL ((pv_entry_t) 0) 194 195 #define PV_CI 0x01 /* all entries must be cache inhibited */ 196 #define PV_PTPAGE 0x02 /* entry maps a page table page */ 197 198 #ifdef KERNEL 199 200 pv_entry_t pv_table; /* array of entries, one per page */ 201 202 #define pa_index(pa) atop(pa - vm_first_phys) 203 #define pa_to_pvh(pa) (&pv_table[pa_index(pa)]) 204 205 #define pmap_resident_count(pmap) ((pmap)->pm_stats.resident_count) 206 207 #endif KERNEL 208 209 #endif _PMAP_MACHINE_ 210