1 /* 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * %sccs.include.redist.c% 11 * 12 * from: Utah $Hdr: vm_machdep.c 1.18 89/08/23$ 13 * 14 * @(#)vm_machdep.c 7.7 (Berkeley) 12/16/90 15 */ 16 17 #include "sys/param.h" 18 #include "sys/systm.h" 19 #include "sys/user.h" 20 #include "sys/proc.h" 21 #include "sys/cmap.h" 22 #include "sys/malloc.h" 23 #include "sys/buf.h" 24 25 #include "../include/cpu.h" 26 27 #include "vm/vm_param.h" 28 #include "vm/pmap.h" 29 #include "vm/vm_map.h" 30 31 /* 32 * Move pages from one kernel virtual address to another. 33 * Both addresses are assumed to reside in the Sysmap, 34 * and size must be a multiple of CLSIZE. 35 */ 36 pagemove(from, to, size) 37 register caddr_t from, to; 38 int size; 39 { 40 register struct pte *fpte, *tpte; 41 42 if (size % CLBYTES) 43 panic("pagemove"); 44 fpte = kvtopte(from); 45 tpte = kvtopte(to); 46 while (size > 0) { 47 *tpte++ = *fpte; 48 *(int *)fpte++ = PG_NV; 49 TBIS(from); 50 TBIS(to); 51 from += NBPG; 52 to += NBPG; 53 size -= NBPG; 54 } 55 /* buffer pages not CI with new VM */ 56 DCIS(); 57 } 58 59 /* 60 * Set a red zone in the kernel stack after the u. area. 61 * We don't support a redzone right now. It really isn't clear 62 * that it is a good idea since, if the kernel stack were to roll 63 * into a write protected page, the processor would lock up (since 64 * it cannot create an exception frame) and we would get no useful 65 * post-mortem info. Currently, under the DEBUG option, we just 66 * check at every clock interrupt to see if the current k-stack has 67 * gone too far (i.e. into the "redzone" page) and if so, panic. 68 * Look at _lev6intr in locore.s for more details. 69 */ 70 /*ARGSUSED*/ 71 setredzone(pte, vaddr) 72 struct pte *pte; 73 caddr_t vaddr; 74 { 75 } 76 77 /* 78 * Convert kernel VA to physical address 79 */ 80 kvtop(addr) 81 register caddr_t addr; 82 { 83 vm_offset_t va; 84 85 va = pmap_extract(kernel_pmap, (vm_offset_t)addr); 86 if (va == 0) 87 panic("kvtop: zero page frame"); 88 return((int)va); 89 } 90 91 extern vm_map_t phys_map; 92 93 /* 94 * Map an IO request into kernel virtual address space. Requests fall into 95 * one of five catagories: 96 * 97 * B_PHYS|B_UAREA: User u-area swap. 98 * Address is relative to start of u-area (p_addr). 99 * B_PHYS|B_PAGET: User page table swap. 100 * Address is a kernel VA in usrpt (Usrptmap). 101 * B_PHYS|B_DIRTY: Dirty page push. 102 * Address is a VA in proc2's address space. 103 * B_PHYS|B_PGIN: Kernel pagein of user pages. 104 * Address is VA in user's address space. 105 * B_PHYS: User "raw" IO request. 106 * Address is VA in user's address space. 107 * 108 * All requests are (re)mapped into kernel VA space via the useriomap 109 * (a name with only slightly more meaning than "kernelmap") 110 */ 111 vmapbuf(bp) 112 register struct buf *bp; 113 { 114 register int npf; 115 register caddr_t addr; 116 register long flags = bp->b_flags; 117 struct proc *p; 118 int off; 119 vm_offset_t kva; 120 register vm_offset_t pa; 121 122 if ((flags & B_PHYS) == 0) 123 panic("vmapbuf"); 124 addr = bp->b_saveaddr = bp->b_un.b_addr; 125 off = (int)addr & PGOFSET; 126 p = bp->b_proc; 127 npf = btoc(round_page(bp->b_bcount + off)); 128 kva = kmem_alloc_wait(phys_map, ctob(npf)); 129 bp->b_un.b_addr = (caddr_t) (kva + off); 130 while (npf--) { 131 pa = pmap_extract(vm_map_pmap(p->p_map), (vm_offset_t)addr); 132 if (pa == 0) 133 panic("vmapbuf: null page frame"); 134 pmap_enter(vm_map_pmap(phys_map), kva, trunc_page(pa), 135 VM_PROT_READ|VM_PROT_WRITE, TRUE); 136 addr += PAGE_SIZE; 137 kva += PAGE_SIZE; 138 } 139 } 140 141 /* 142 * Free the io map PTEs associated with this IO operation. 143 * We also invalidate the TLB entries and restore the original b_addr. 144 */ 145 vunmapbuf(bp) 146 register struct buf *bp; 147 { 148 register int npf; 149 register caddr_t addr = bp->b_un.b_addr; 150 vm_offset_t kva; 151 152 if ((bp->b_flags & B_PHYS) == 0) 153 panic("vunmapbuf"); 154 npf = btoc(round_page(bp->b_bcount + ((int)addr & PGOFSET))); 155 kva = (vm_offset_t)((int)addr & ~PGOFSET); 156 kmem_free_wakeup(phys_map, kva, ctob(npf)); 157 bp->b_un.b_addr = bp->b_saveaddr; 158 bp->b_saveaddr = NULL; 159 } 160