1 /* 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * the Systems Programming Group of the University of Utah Computer 7 * Science Department and William Jolitz of UUNET Technologies Inc. 8 * 9 * %sccs.include.redist.c% 10 * 11 * @(#)pmap.h 8.1 (Berkeley) 06/11/93 12 */ 13 14 /* 15 * Derived from hp300 version by Mike Hibler, this version by William 16 * Jolitz uses a recursive map [a pde points to the page directory] to 17 * map the page tables using the pagetables themselves. This is done to 18 * reduce the impact on kernel virtual memory for lots of sparse address 19 * space, and to reduce the cost of memory to each process. 20 * 21 * from hp300: @(#)pmap.h 7.2 (Berkeley) 12/16/90 22 */ 23 24 #ifndef _PMAP_MACHINE_ 25 #define _PMAP_MACHINE_ 1 26 27 /* 28 * 386 page table entry and page table directory 29 * W.Jolitz, 8/89 30 */ 31 32 struct pde 33 { 34 unsigned int 35 pd_v:1, /* valid bit */ 36 pd_prot:2, /* access control */ 37 pd_mbz1:2, /* reserved, must be zero */ 38 pd_u:1, /* hardware maintained 'used' bit */ 39 :1, /* not used */ 40 pd_mbz2:2, /* reserved, must be zero */ 41 :3, /* reserved for software */ 42 pd_pfnum:20; /* physical page frame number of pte's*/ 43 }; 44 45 #define PD_MASK 0xffc00000 /* page directory address bits */ 46 #define PT_MASK 0x003ff000 /* page table address bits */ 47 #define PD_SHIFT 22 /* page directory address shift */ 48 #define PG_SHIFT 12 /* page table address shift */ 49 50 struct pte 51 { 52 unsigned int 53 pg_v:1, /* valid bit */ 54 pg_prot:2, /* access control */ 55 pg_mbz1:2, /* reserved, must be zero */ 56 pg_u:1, /* hardware maintained 'used' bit */ 57 pg_m:1, /* hardware maintained modified bit */ 58 pg_mbz2:2, /* reserved, must be zero */ 59 pg_w:1, /* software, wired down page */ 60 :1, /* software (unused) */ 61 pg_nc:1, /* 'uncacheable page' bit */ 62 pg_pfnum:20; /* physical page frame number */ 63 }; 64 65 #define PG_V 0x00000001 66 #define PG_RO 0x00000000 67 #define PG_RW 0x00000002 68 #define PG_u 0x00000004 69 #define PG_PROT 0x00000006 /* all protection bits . */ 70 #define PG_W 0x00000200 71 #define PG_N 0x00000800 /* Non-cacheable */ 72 #define PG_M 0x00000040 73 #define PG_U 0x00000020 74 #define PG_FRAME 0xfffff000 75 76 #define PG_NOACC 0 77 #define PG_KR 0x00000000 78 #define PG_KW 0x00000002 79 #define PG_URKR 0x00000004 80 #define PG_URKW 0x00000004 81 #define PG_UW 0x00000006 82 83 /* Garbage for current bastardized pager that assumes a hp300 */ 84 #define PG_NV 0 85 #define PG_CI 0 86 /* 87 * Page Protection Exception bits 88 */ 89 90 #define PGEX_P 0x01 /* Protection violation vs. not present */ 91 #define PGEX_W 0x02 /* during a Write cycle */ 92 #define PGEX_U 0x04 /* access from User mode (UPL) */ 93 94 typedef struct pde pd_entry_t; /* page directory entry */ 95 typedef struct pte pt_entry_t; /* Mach page table entry */ 96 97 /* 98 * One page directory, shared between 99 * kernel and user modes. 100 */ 101 #define I386_PAGE_SIZE NBPG 102 #define I386_PDR_SIZE NBPDR 103 104 #define I386_KPDES 8 /* KPT page directory size */ 105 #define I386_UPDES NBPDR/sizeof(struct pde)-8 /* UPT page directory size */ 106 107 #define UPTDI 0x3f6 /* ptd entry for u./kernel&user stack */ 108 #define PTDPTDI 0x3f7 /* ptd entry that points to ptd! */ 109 #define KPTDI_FIRST 0x3f8 /* start of kernel virtual pde's */ 110 #define KPTDI_LAST 0x3fA /* last of kernel virtual pde's */ 111 112 /* 113 * Address of current and alternate address space page table maps 114 * and directories. 115 */ 116 #ifdef KERNEL 117 extern struct pte PTmap[], APTmap[], Upte; 118 extern struct pde PTD[], APTD[], PTDpde, APTDpde, Upde; 119 extern pt_entry_t *Sysmap; 120 121 extern int IdlePTD; /* physical address of "Idle" state directory */ 122 #endif 123 124 /* 125 * virtual address to page table entry and 126 * to physical address. Likewise for alternate address space. 127 * Note: these work recursively, thus vtopte of a pte will give 128 * the corresponding pde that in turn maps it. 129 */ 130 #define vtopte(va) (PTmap + i386_btop(va)) 131 #define kvtopte(va) vtopte(va) 132 #define ptetov(pt) (i386_ptob(pt - PTmap)) 133 #define vtophys(va) (i386_ptob(vtopte(va)->pg_pfnum) | ((int)(va) & PGOFSET)) 134 #define ispt(va) ((va) >= UPT_MIN_ADDRESS && (va) <= KPT_MAX_ADDRESS) 135 136 #define avtopte(va) (APTmap + i386_btop(va)) 137 #define ptetoav(pt) (i386_ptob(pt - APTmap)) 138 #define avtophys(va) (i386_ptob(avtopte(va)->pg_pfnum) | ((int)(va) & PGOFSET)) 139 140 /* 141 * macros to generate page directory/table indicies 142 */ 143 144 #define pdei(va) (((va)&PD_MASK)>>PD_SHIFT) 145 #define ptei(va) (((va)&PT_MASK)>>PT_SHIFT) 146 147 /* 148 * Pmap stuff 149 */ 150 151 struct pmap { 152 pd_entry_t *pm_pdir; /* KVA of page directory */ 153 boolean_t pm_pdchanged; /* pdir changed */ 154 short pm_dref; /* page directory ref count */ 155 short pm_count; /* pmap reference count */ 156 simple_lock_data_t pm_lock; /* lock on pmap */ 157 struct pmap_statistics pm_stats; /* pmap statistics */ 158 long pm_ptpages; /* more stats: PT pages */ 159 }; 160 161 typedef struct pmap *pmap_t; 162 163 #ifdef KERNEL 164 extern struct pmap kernel_pmap_store; 165 #define kernel_pmap (&kernel_pmap_store) 166 #endif 167 168 /* 169 * Macros for speed 170 */ 171 #define PMAP_ACTIVATE(pmapp, pcbp) \ 172 if ((pmapp) != 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 #define pmap_wired_count(pmap) ((pmap)->pm_stats.wired_count) 207 208 #endif KERNEL 209 210 #endif _PMAP_MACHINE_ 211