1 /*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * the University of Utah, and William Jolitz. 7 * 8 * %sccs.include.386.c% 9 * 10 * @(#)vm_machdep.c 5.7 (Berkeley) 05/02/91 11 */ 12 13 /* 14 * Copyright (c) 1989, 1990 William F. Jolitz 15 */ 16 17 /* 18 * Copyright (c) 1988 University of Utah. 19 * All rights reserved. The Utah Software License Agreement 20 * specifies the terms and conditions for redistribution. 21 * 22 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ 23 */ 24 /* 25 * Copyright (c) 1982, 1986 Regents of the University of California. 26 * All rights reserved. The Berkeley software License Agreement 27 * specifies the terms and conditions for redistribution. 28 * 29 * @(#)vm_machdep.c 7.1 (Berkeley) 6/5/86 30 */ 31 32 #include "sys/param.h" 33 #include "sys/systm.h" 34 #include "sys/user.h" 35 #include "sys/proc.h" 36 #include "sys/cmap.h" 37 #include "sys/malloc.h" 38 #include "sys/buf.h" 39 40 #include "machine/cpu.h" 41 42 #include "vm/vm_param.h" 43 #include "vm/pmap.h" 44 #include "vm/vm_map.h" 45 46 /* 47 * Set a red zone in the kernel stack after the u. area. 48 */ 49 setredzone(pte, vaddr) 50 u_short *pte; 51 caddr_t vaddr; 52 { 53 /* eventually do this by setting up an expand-down stack segment 54 for ss0: selector, allowing stack access down to top of u. 55 this means though that protection violations need to be handled 56 thru a double fault exception that must do an integral task 57 switch to a known good context, within which a dump can be 58 taken. a sensible scheme might be to save the initial context 59 used by sched (that has physical memory mapped 1:1 at bottom) 60 and take the dump while still in mapped mode */ 61 } 62 63 /* 64 * Move pages from one kernel virtual address to another. 65 * Both addresses are assumed to reside in the Sysmap, 66 * and size must be a multiple of CLSIZE. 67 */ 68 pagemove(from, to, size) 69 register caddr_t from, to; 70 int size; 71 { 72 register struct pte *fpte, *tpte; 73 74 if (size % CLBYTES) 75 panic("pagemove"); 76 fpte = kvtopte(from); 77 tpte = kvtopte(to); 78 while (size > 0) { 79 *tpte++ = *fpte; 80 *(int *)fpte++ = 0; 81 from += NBPG; 82 to += NBPG; 83 size -= NBPG; 84 } 85 load_cr3(u.u_pcb.pcb_cr3); 86 } 87 88 /* 89 * Convert kernel VA to physical address 90 */ 91 kvtop(addr) 92 register caddr_t addr; 93 { 94 vm_offset_t va; 95 96 va = pmap_extract(kernel_pmap, (vm_offset_t)addr); 97 if (va == 0) 98 panic("kvtop: zero page frame"); 99 return((int)va); 100 } 101 102 #ifdef notdef 103 /* 104 * The probe[rw] routines should probably be redone in assembler 105 * for efficiency. 106 */ 107 prober(addr) 108 register u_int addr; 109 { 110 register int page; 111 register struct proc *p; 112 113 if (addr >= USRSTACK) 114 return(0); 115 p = u.u_procp; 116 page = btop(addr); 117 if (page < dptov(p, p->p_dsize) || page > sptov(p, p->p_ssize)) 118 return(1); 119 return(0); 120 } 121 122 probew(addr) 123 register u_int addr; 124 { 125 register int page; 126 register struct proc *p; 127 128 if (addr >= USRSTACK) 129 return(0); 130 p = u.u_procp; 131 page = btop(addr); 132 if (page < dptov(p, p->p_dsize) || page > sptov(p, p->p_ssize)) 133 return((*(int *)vtopte(p, page) & PG_PROT) == PG_UW); 134 return(0); 135 } 136 137 /* 138 * NB: assumes a physically contiguous kernel page table 139 * (makes life a LOT simpler). 140 */ 141 kernacc(addr, count, rw) 142 register u_int addr; 143 int count, rw; 144 { 145 register struct pde *pde; 146 register struct pte *pte; 147 register int ix, cnt; 148 extern long Syssize; 149 150 if (count <= 0) 151 return(0); 152 pde = (struct pde *)((u_int)u.u_procp->p_p0br + u.u_procp->p_szpt * NBPG); 153 ix = (addr & PD_MASK) >> PD_SHIFT; 154 cnt = ((addr + count + (1 << PD_SHIFT) - 1) & PD_MASK) >> PD_SHIFT; 155 cnt -= ix; 156 for (pde += ix; cnt; cnt--, pde++) 157 if (pde->pd_v == 0) 158 return(0); 159 ix = btop(addr-0xfe000000); 160 cnt = btop(addr-0xfe000000+count+NBPG-1); 161 if (cnt > (int)&Syssize) 162 return(0); 163 cnt -= ix; 164 for (pte = &Sysmap[ix]; cnt; cnt--, pte++) 165 if (pte->pg_v == 0 /*|| (rw == B_WRITE && pte->pg_prot == 1)*/) 166 return(0); 167 return(1); 168 } 169 170 useracc(addr, count, rw) 171 register u_int addr; 172 int count, rw; 173 { 174 register int (*func)(); 175 register u_int addr2; 176 extern int prober(), probew(); 177 178 if (count <= 0) 179 return(0); 180 addr2 = addr; 181 addr += count; 182 func = (rw == B_READ) ? prober : probew; 183 do { 184 if ((*func)(addr2) == 0) 185 return(0); 186 addr2 = (addr2 + NBPG) & ~PGOFSET; 187 } while (addr2 < addr); 188 return(1); 189 } 190 #endif 191 192 extern vm_map_t phys_map; 193 194 /* 195 * Map an IO request into kernel virtual address space. Requests fall into 196 * one of five catagories: 197 * 198 * B_PHYS|B_UAREA: User u-area swap. 199 * Address is relative to start of u-area (p_addr). 200 * B_PHYS|B_PAGET: User page table swap. 201 * Address is a kernel VA in usrpt (Usrptmap). 202 * B_PHYS|B_DIRTY: Dirty page push. 203 * Address is a VA in proc2's address space. 204 * B_PHYS|B_PGIN: Kernel pagein of user pages. 205 * Address is VA in user's address space. 206 * B_PHYS: User "raw" IO request. 207 * Address is VA in user's address space. 208 * 209 * All requests are (re)mapped into kernel VA space via the useriomap 210 * (a name with only slightly more meaning than "kernelmap") 211 */ 212 vmapbuf(bp) 213 register struct buf *bp; 214 { 215 register int npf; 216 register caddr_t addr; 217 register long flags = bp->b_flags; 218 struct proc *p; 219 int off; 220 vm_offset_t kva; 221 register vm_offset_t pa; 222 223 if ((flags & B_PHYS) == 0) 224 panic("vmapbuf"); 225 addr = bp->b_saveaddr = bp->b_un.b_addr; 226 off = (int)addr & PGOFSET; 227 p = bp->b_proc; 228 npf = btoc(round_page(bp->b_bcount + off)); 229 kva = kmem_alloc_wait(phys_map, ctob(npf)); 230 bp->b_un.b_addr = (caddr_t) (kva + off); 231 while (npf--) { 232 pa = pmap_extract(vm_map_pmap(p->p_map), (vm_offset_t)addr); 233 if (pa == 0) 234 panic("vmapbuf: null page frame"); 235 pmap_enter(vm_map_pmap(phys_map), kva, trunc_page(pa), 236 VM_PROT_READ|VM_PROT_WRITE, TRUE); 237 addr += PAGE_SIZE; 238 kva += PAGE_SIZE; 239 } 240 } 241 242 /* 243 * Free the io map PTEs associated with this IO operation. 244 * We also invalidate the TLB entries and restore the original b_addr. 245 */ 246 vunmapbuf(bp) 247 register struct buf *bp; 248 { 249 register int npf; 250 register caddr_t addr = bp->b_un.b_addr; 251 vm_offset_t kva; 252 253 if ((bp->b_flags & B_PHYS) == 0) 254 panic("vunmapbuf"); 255 npf = btoc(round_page(bp->b_bcount + ((int)addr & PGOFSET))); 256 kva = (vm_offset_t)((int)addr & ~PGOFSET); 257 kmem_free_wakeup(phys_map, kva, ctob(npf)); 258 bp->b_un.b_addr = bp->b_saveaddr; 259 bp->b_saveaddr = NULL; 260 } 261