1 /* 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1992 OMRON Corporation. 4 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * the Systems Programming Group of the University of Utah Computer 9 * Science Department. 10 * 11 * %sccs.include.redist.c% 12 * 13 * from: Utah $Hdr: vm_machdep.c 1.21 91/04/06$ 14 * from: hp300/hp300/vm_machdep.c 7.14 (Berkeley) 12/27/92 15 * 16 * @(#)vm_machdep.c 7.4 (Berkeley) 01/03/93 17 */ 18 19 #include <sys/param.h> 20 #include <sys/systm.h> 21 #include <sys/proc.h> 22 #include <sys/malloc.h> 23 #include <sys/buf.h> 24 #include <sys/vnode.h> 25 #include <sys/user.h> 26 27 #include <machine/cpu.h> 28 29 #include <vm/vm.h> 30 #include <vm/vm_kern.h> 31 #include <luna68k/luna68k/pte.h> 32 33 /* 34 * Finish a fork operation, with process p2 nearly set up. 35 * Copy and update the kernel stack and pcb, making the child 36 * ready to run, and marking it so that it can return differently 37 * than the parent. Returns 1 in the child process, 0 in the parent. 38 * We currently double-map the user area so that the stack is at the same 39 * address in each process; in the future we will probably relocate 40 * the frame pointers on the stack after copying. 41 */ 42 cpu_fork(p1, p2) 43 register struct proc *p1, *p2; 44 { 45 register struct user *up = p2->p_addr; 46 int offset; 47 extern caddr_t getsp(); 48 extern char kstack[]; 49 50 p2->p_md.md_regs = p1->p_md.md_regs; 51 p2->p_md.md_flags = (p1->p_md.md_flags & ~(MDP_AST|MDP_HPUXTRACE)); 52 53 /* 54 * Copy pcb and stack from proc p1 to p2. 55 * We do this as cheaply as possible, copying only the active 56 * part of the stack. The stack and pcb need to agree; 57 * this is tricky, as the final pcb is constructed by savectx, 58 * but its frame isn't yet on the stack when the stack is copied. 59 * swtch compensates for this when the child eventually runs. 60 * This should be done differently, with a single call 61 * that copies and updates the pcb+stack, 62 * replacing the bcopy and savectx. 63 */ 64 p2->p_addr->u_pcb = p1->p_addr->u_pcb; 65 offset = getsp() - kstack; 66 bcopy((caddr_t)kstack + offset, (caddr_t)p2->p_addr + offset, 67 (unsigned) ctob(UPAGES) - offset); 68 69 PMAP_ACTIVATE(&p2->p_vmspace->vm_pmap, &up->u_pcb, 0); 70 71 /* 72 * Arrange for a non-local goto when the new process 73 * is started, to resume here, returning nonzero from setjmp. 74 */ 75 if (savectx(up, 1)) { 76 /* 77 * Return 1 in child. 78 */ 79 return (1); 80 } 81 return (0); 82 } 83 84 /* 85 * cpu_exit is called as the last action during exit. 86 * We release the address space and machine-dependent resources, 87 * including the memory for the user structure and kernel stack. 88 * Once finished, we call swtch_exit, which switches to a temporary 89 * pcb and stack and never returns. We block memory allocation 90 * until swtch_exit has made things safe again. 91 */ 92 cpu_exit(p) 93 struct proc *p; 94 { 95 96 vmspace_free(p->p_vmspace); 97 98 (void) splimp(); 99 kmem_free(kernel_map, (vm_offset_t)p->p_addr, ctob(UPAGES)); 100 swtch_exit(); 101 /* NOTREACHED */ 102 } 103 104 /* 105 * Dump the machine specific header information at the start of a core dump. 106 */ 107 cpu_coredump(p, vp, cred) 108 struct proc *p; 109 struct vnode *vp; 110 struct ucred *cred; 111 { 112 int error; 113 114 return (vn_rdwr(UIO_WRITE, vp, (caddr_t) p->p_addr, ctob(UPAGES), 115 (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, 116 p)); 117 } 118 119 /* 120 * Move pages from one kernel virtual address to another. 121 * Both addresses are assumed to reside in the Sysmap, 122 * and size must be a multiple of CLSIZE. 123 */ 124 pagemove(from, to, size) 125 register caddr_t from, to; 126 int size; 127 { 128 register struct pte *fpte, *tpte; 129 130 if (size % CLBYTES) 131 panic("pagemove"); 132 fpte = kvtopte(from); 133 tpte = kvtopte(to); 134 while (size > 0) { 135 *tpte++ = *fpte; 136 *(int *)fpte++ = PG_NV; 137 TBIS(from); 138 TBIS(to); 139 from += NBPG; 140 to += NBPG; 141 size -= NBPG; 142 } 143 } 144 145 /* 146 * Map `size' bytes of physical memory starting at `paddr' into 147 * kernel VA space at `vaddr'. Read/write and cache-inhibit status 148 * are specified by `prot'. 149 */ 150 physaccess(vaddr, paddr, size, prot) 151 caddr_t vaddr, paddr; 152 register int size, prot; 153 { 154 register struct pte *pte; 155 register u_int page; 156 157 pte = kvtopte(vaddr); 158 page = (u_int)paddr & PG_FRAME; 159 for (size = btoc(size); size; size--) { 160 *(int *)pte++ = PG_V | prot | page; 161 page += NBPG; 162 } 163 TBIAS(); 164 } 165 166 physunaccess(vaddr, size) 167 caddr_t vaddr; 168 register int size; 169 { 170 register struct pte *pte; 171 172 pte = kvtopte(vaddr); 173 for (size = btoc(size); size; size--) 174 *(int *)pte++ = PG_NV; 175 TBIAS(); 176 } 177 178 /* 179 * Set a red zone in the kernel stack after the u. area. 180 * We don't support a redzone right now. It really isn't clear 181 * that it is a good idea since, if the kernel stack were to roll 182 * into a write protected page, the processor would lock up (since 183 * it cannot create an exception frame) and we would get no useful 184 * post-mortem info. Currently, under the DEBUG option, we just 185 * check at every clock interrupt to see if the current k-stack has 186 * gone too far (i.e. into the "redzone" page) and if so, panic. 187 * Look at _lev6intr in locore.s for more details. 188 */ 189 /*ARGSUSED*/ 190 setredzone(pte, vaddr) 191 struct pte *pte; 192 caddr_t vaddr; 193 { 194 } 195 196 /* 197 * Convert kernel VA to physical address 198 */ 199 kvtop(addr) 200 register caddr_t addr; 201 { 202 vm_offset_t va; 203 204 va = pmap_extract(kernel_pmap, (vm_offset_t)addr); 205 if (va == 0) 206 panic("kvtop: zero page frame"); 207 return((int)va); 208 } 209 210 extern vm_map_t phys_map; 211 212 /* 213 * Map an IO request into kernel virtual address space. 214 * 215 * XXX we allocate KVA space by using kmem_alloc_wait which we know 216 * allocates space without backing physical memory. This implementation 217 * is a total crock, the multiple mappings of these physical pages should 218 * be reflected in the higher-level VM structures to avoid problems. 219 */ 220 vmapbuf(bp) 221 register struct buf *bp; 222 { 223 register int npf; 224 register caddr_t addr; 225 register long flags = bp->b_flags; 226 struct proc *p; 227 int off; 228 vm_offset_t kva; 229 register vm_offset_t pa; 230 231 if ((flags & B_PHYS) == 0) 232 panic("vmapbuf"); 233 addr = bp->b_saveaddr = bp->b_un.b_addr; 234 off = (int)addr & PGOFSET; 235 p = bp->b_proc; 236 npf = btoc(round_page(bp->b_bcount + off)); 237 kva = kmem_alloc_wait(phys_map, ctob(npf)); 238 bp->b_un.b_addr = (caddr_t) (kva + off); 239 while (npf--) { 240 pa = pmap_extract(vm_map_pmap(&p->p_vmspace->vm_map), 241 (vm_offset_t)addr); 242 if (pa == 0) 243 panic("vmapbuf: null page frame"); 244 pmap_enter(vm_map_pmap(phys_map), kva, trunc_page(pa), 245 VM_PROT_READ|VM_PROT_WRITE, TRUE); 246 addr += PAGE_SIZE; 247 kva += PAGE_SIZE; 248 } 249 } 250 251 /* 252 * Free the io map PTEs associated with this IO operation. 253 */ 254 vunmapbuf(bp) 255 register struct buf *bp; 256 { 257 register int npf; 258 register caddr_t addr = bp->b_un.b_addr; 259 vm_offset_t kva; 260 261 if ((bp->b_flags & B_PHYS) == 0) 262 panic("vunmapbuf"); 263 npf = btoc(round_page(bp->b_bcount + ((int)addr & PGOFSET))); 264 kva = (vm_offset_t)((int)addr & ~PGOFSET); 265 kmem_free_wakeup(phys_map, kva, ctob(npf)); 266 bp->b_un.b_addr = bp->b_saveaddr; 267 bp->b_saveaddr = NULL; 268 } 269