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 7.8 (Berkeley) 04/20/91 15 */ 16 17 #include "param.h" 18 #include "systm.h" 19 #include "proc.h" 20 #include "malloc.h" 21 #include "buf.h" 22 23 #include "../include/cpu.h" 24 25 #include "vm/vm.h" 26 #include "vm/pmap.h" 27 #include "pte.h" 28 29 /* 30 * Move pages from one kernel virtual address to another. 31 * Both addresses are assumed to reside in the Sysmap, 32 * and size must be a multiple of CLSIZE. 33 */ 34 pagemove(from, to, size) 35 register caddr_t from, to; 36 int size; 37 { 38 register struct pte *fpte, *tpte; 39 40 if (size % CLBYTES) 41 panic("pagemove"); 42 fpte = kvtopte(from); 43 tpte = kvtopte(to); 44 while (size > 0) { 45 *tpte++ = *fpte; 46 *(int *)fpte++ = PG_NV; 47 TBIS(from); 48 TBIS(to); 49 from += NBPG; 50 to += NBPG; 51 size -= NBPG; 52 } 53 /* buffer pages not CI with new VM */ 54 DCIS(); 55 } 56 57 /* 58 * Set a red zone in the kernel stack after the u. area. 59 * We don't support a redzone right now. It really isn't clear 60 * that it is a good idea since, if the kernel stack were to roll 61 * into a write protected page, the processor would lock up (since 62 * it cannot create an exception frame) and we would get no useful 63 * post-mortem info. Currently, under the DEBUG option, we just 64 * check at every clock interrupt to see if the current k-stack has 65 * gone too far (i.e. into the "redzone" page) and if so, panic. 66 * Look at _lev6intr in locore.s for more details. 67 */ 68 /*ARGSUSED*/ 69 setredzone(pte, vaddr) 70 struct pte *pte; 71 caddr_t vaddr; 72 { 73 } 74 75 /* 76 * Convert kernel VA to physical address 77 */ 78 kvtop(addr) 79 register caddr_t addr; 80 { 81 vm_offset_t va; 82 83 va = pmap_extract(kernel_pmap, (vm_offset_t)addr); 84 if (va == 0) 85 panic("kvtop: zero page frame"); 86 return((int)va); 87 } 88 89 extern vm_map_t phys_map; 90 91 /* 92 * Map an IO request into kernel virtual address space. Requests fall into 93 * one of five catagories: 94 * 95 * B_PHYS|B_UAREA: User u-area swap. 96 * Address is relative to start of u-area (p_addr). 97 * B_PHYS|B_PAGET: User page table swap. 98 * Address is a kernel VA in usrpt (Usrptmap). 99 * B_PHYS|B_DIRTY: Dirty page push. 100 * Address is a VA in proc2's address space. 101 * B_PHYS|B_PGIN: Kernel pagein of user pages. 102 * Address is VA in user's address space. 103 * B_PHYS: User "raw" IO request. 104 * Address is VA in user's address space. 105 * 106 * All requests are (re)mapped into kernel VA space via the useriomap 107 * (a name with only slightly more meaning than "kernelmap") 108 */ 109 vmapbuf(bp) 110 register struct buf *bp; 111 { 112 register int npf; 113 register caddr_t addr; 114 register long flags = bp->b_flags; 115 struct proc *p; 116 int off; 117 vm_offset_t kva; 118 register vm_offset_t pa; 119 120 if ((flags & B_PHYS) == 0) 121 panic("vmapbuf"); 122 addr = bp->b_saveaddr = bp->b_un.b_addr; 123 off = (int)addr & PGOFSET; 124 p = bp->b_proc; 125 npf = btoc(round_page(bp->b_bcount + off)); 126 kva = kmem_alloc_wait(phys_map, ctob(npf)); 127 bp->b_un.b_addr = (caddr_t) (kva + off); 128 while (npf--) { 129 pa = pmap_extract(vm_map_pmap(&p->p_vmspace->vm_map), 130 (vm_offset_t)addr); 131 if (pa == 0) 132 panic("vmapbuf: null page frame"); 133 pmap_enter(vm_map_pmap(phys_map), kva, trunc_page(pa), 134 VM_PROT_READ|VM_PROT_WRITE, TRUE); 135 addr += PAGE_SIZE; 136 kva += PAGE_SIZE; 137 } 138 } 139 140 /* 141 * Free the io map PTEs associated with this IO operation. 142 * We also invalidate the TLB entries and restore the original b_addr. 143 */ 144 vunmapbuf(bp) 145 register struct buf *bp; 146 { 147 register int npf; 148 register caddr_t addr = bp->b_un.b_addr; 149 vm_offset_t kva; 150 151 if ((bp->b_flags & B_PHYS) == 0) 152 panic("vunmapbuf"); 153 npf = btoc(round_page(bp->b_bcount + ((int)addr & PGOFSET))); 154 kva = (vm_offset_t)((int)addr & ~PGOFSET); 155 kmem_free_wakeup(phys_map, kva, ctob(npf)); 156 bp->b_un.b_addr = bp->b_saveaddr; 157 bp->b_saveaddr = NULL; 158 } 159