1 /* 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1982, 1986, 1990, 1993 4 * The Regents of the University of California. 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 $Hdr: vm_machdep.c 1.21 91/04/06$ 13 * 14 * @(#)vm_machdep.c 8.6 (Berkeley) 01/12/94 15 */ 16 17 #include <sys/param.h> 18 #include <sys/systm.h> 19 #include <sys/proc.h> 20 #include <sys/malloc.h> 21 #include <sys/buf.h> 22 #include <sys/vnode.h> 23 #include <sys/user.h> 24 25 #include <machine/cpu.h> 26 27 #include <vm/vm.h> 28 #include <vm/vm_kern.h> 29 #include <hp300/hp300/pte.h> 30 31 /* 32 * Finish a fork operation, with process p2 nearly set up. 33 * Copy and update the kernel stack and pcb, making the child 34 * ready to run, and marking it so that it can return differently 35 * than the parent. Returns 1 in the child process, 0 in the parent. 36 * We currently double-map the user area so that the stack is at the same 37 * address in each process; in the future we will probably relocate 38 * the frame pointers on the stack after copying. 39 */ 40 cpu_fork(p1, p2) 41 register struct proc *p1, *p2; 42 { 43 register struct user *up = p2->p_addr; 44 int offset; 45 extern caddr_t getsp(); 46 extern char kstack[]; 47 48 p2->p_md.md_regs = p1->p_md.md_regs; 49 p2->p_md.md_flags = (p1->p_md.md_flags & ~(MDP_AST|MDP_HPUXTRACE)); 50 51 /* 52 * Copy pcb and stack from proc p1 to p2. 53 * We do this as cheaply as possible, copying only the active 54 * part of the stack. The stack and pcb need to agree; 55 * this is tricky, as the final pcb is constructed by savectx, 56 * but its frame isn't yet on the stack when the stack is copied. 57 * switch compensates for this when the child eventually runs. 58 * This should be done differently, with a single call 59 * that copies and updates the pcb+stack, 60 * replacing the bcopy and savectx. 61 */ 62 p2->p_addr->u_pcb = p1->p_addr->u_pcb; 63 offset = getsp() - kstack; 64 bcopy((caddr_t)kstack + offset, (caddr_t)p2->p_addr + offset, 65 (unsigned) ctob(UPAGES) - offset); 66 67 PMAP_ACTIVATE(&p2->p_vmspace->vm_pmap, &up->u_pcb, 0); 68 69 /* 70 * Arrange for a non-local goto when the new process 71 * is started, to resume here, returning nonzero from setjmp. 72 */ 73 if (savectx(up, 1)) { 74 /* 75 * Return 1 in child. 76 */ 77 return (1); 78 } 79 return (0); 80 } 81 82 /* 83 * cpu_exit is called as the last action during exit. 84 * We release the address space and machine-dependent resources, 85 * including the memory for the user structure and kernel stack. 86 * Once finished, we call switch_exit, which switches to a temporary 87 * pcb and stack and never returns. We block memory allocation 88 * until switch_exit has made things safe again. 89 */ 90 cpu_exit(p) 91 struct proc *p; 92 { 93 94 vmspace_free(p->p_vmspace); 95 96 (void) splimp(); 97 kmem_free(kernel_map, (vm_offset_t)p->p_addr, ctob(UPAGES)); 98 switch_exit(); 99 /* NOTREACHED */ 100 } 101 102 /* 103 * Dump the machine specific header information at the start of a core dump. 104 */ 105 cpu_coredump(p, vp, cred) 106 struct proc *p; 107 struct vnode *vp; 108 struct ucred *cred; 109 { 110 #ifdef HPUXCOMPAT 111 /* 112 * If we loaded from an HP-UX format binary file we dump enough 113 * of an HP-UX style user struct so that the HP-UX debuggers can 114 * grok it. 115 */ 116 if (p->p_md.md_flags & MDP_HPUX) 117 return (hpuxdumpu(vp, cred)); 118 #endif 119 return (vn_rdwr(UIO_WRITE, vp, (caddr_t) p->p_addr, ctob(UPAGES), 120 (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, 121 p)); 122 } 123 124 /* 125 * Move pages from one kernel virtual address to another. 126 * Both addresses are assumed to reside in the Sysmap, 127 * and size must be a multiple of CLSIZE. 128 */ 129 pagemove(from, to, size) 130 register caddr_t from, to; 131 int size; 132 { 133 register vm_offset_t pa; 134 135 #ifdef DEBUG 136 if (size & CLOFSET) 137 panic("pagemove"); 138 #endif 139 while (size > 0) { 140 pa = pmap_extract(kernel_pmap, (vm_offset_t)from); 141 #ifdef DEBUG 142 if (pa == 0) 143 panic("pagemove 2"); 144 if (pmap_extract(kernel_pmap, (vm_offset_t)to) != 0) 145 panic("pagemove 3"); 146 #endif 147 pmap_remove(kernel_pmap, 148 (vm_offset_t)from, (vm_offset_t)from + PAGE_SIZE); 149 pmap_enter(kernel_pmap, 150 (vm_offset_t)to, pa, VM_PROT_READ|VM_PROT_WRITE, 1); 151 from += PAGE_SIZE; 152 to += PAGE_SIZE; 153 size -= PAGE_SIZE; 154 } 155 } 156 157 /* 158 * Map `size' bytes of physical memory starting at `paddr' into 159 * kernel VA space at `vaddr'. Read/write and cache-inhibit status 160 * are specified by `prot'. 161 */ 162 physaccess(vaddr, paddr, size, prot) 163 caddr_t vaddr, paddr; 164 register int size, prot; 165 { 166 register struct pte *pte; 167 register u_int page; 168 169 pte = kvtopte(vaddr); 170 page = (u_int)paddr & PG_FRAME; 171 for (size = btoc(size); size; size--) { 172 *(int *)pte++ = PG_V | prot | page; 173 page += NBPG; 174 } 175 TBIAS(); 176 } 177 178 physunaccess(vaddr, size) 179 caddr_t vaddr; 180 register int size; 181 { 182 register struct pte *pte; 183 184 pte = kvtopte(vaddr); 185 for (size = btoc(size); size; size--) 186 *(int *)pte++ = PG_NV; 187 TBIAS(); 188 } 189 190 /* 191 * Set a red zone in the kernel stack after the u. area. 192 * We don't support a redzone right now. It really isn't clear 193 * that it is a good idea since, if the kernel stack were to roll 194 * into a write protected page, the processor would lock up (since 195 * it cannot create an exception frame) and we would get no useful 196 * post-mortem info. Currently, under the DEBUG option, we just 197 * check at every clock interrupt to see if the current k-stack has 198 * gone too far (i.e. into the "redzone" page) and if so, panic. 199 * Look at _lev6intr in locore.s for more details. 200 */ 201 /*ARGSUSED*/ 202 setredzone(pte, vaddr) 203 struct pte *pte; 204 caddr_t vaddr; 205 { 206 } 207 208 /* 209 * Convert kernel VA to physical address 210 */ 211 kvtop(addr) 212 register caddr_t addr; 213 { 214 vm_offset_t va; 215 216 va = pmap_extract(kernel_pmap, (vm_offset_t)addr); 217 if (va == 0) 218 panic("kvtop: zero page frame"); 219 return((int)va); 220 } 221 222 extern vm_map_t phys_map; 223 224 /* 225 * Map an IO request into kernel virtual address space. 226 * 227 * XXX we allocate KVA space by using kmem_alloc_wait which we know 228 * allocates space without backing physical memory. This implementation 229 * is a total crock, the multiple mappings of these physical pages should 230 * be reflected in the higher-level VM structures to avoid problems. 231 */ 232 vmapbuf(bp) 233 register struct buf *bp; 234 { 235 register int npf; 236 register caddr_t addr; 237 register long flags = bp->b_flags; 238 struct proc *p; 239 int off; 240 vm_offset_t kva; 241 register vm_offset_t pa; 242 243 if ((flags & B_PHYS) == 0) 244 panic("vmapbuf"); 245 addr = bp->b_saveaddr = bp->b_data; 246 off = (int)addr & PGOFSET; 247 p = bp->b_proc; 248 npf = btoc(round_page(bp->b_bcount + off)); 249 kva = kmem_alloc_wait(phys_map, ctob(npf)); 250 bp->b_data = (caddr_t)(kva + off); 251 while (npf--) { 252 pa = pmap_extract(vm_map_pmap(&p->p_vmspace->vm_map), 253 (vm_offset_t)addr); 254 if (pa == 0) 255 panic("vmapbuf: null page frame"); 256 pmap_enter(vm_map_pmap(phys_map), kva, trunc_page(pa), 257 VM_PROT_READ|VM_PROT_WRITE, TRUE); 258 addr += PAGE_SIZE; 259 kva += PAGE_SIZE; 260 } 261 } 262 263 /* 264 * Free the io map PTEs associated with this IO operation. 265 */ 266 vunmapbuf(bp) 267 register struct buf *bp; 268 { 269 register caddr_t addr; 270 register int npf; 271 vm_offset_t kva; 272 273 if ((bp->b_flags & B_PHYS) == 0) 274 panic("vunmapbuf"); 275 addr = bp->b_data; 276 npf = btoc(round_page(bp->b_bcount + ((int)addr & PGOFSET))); 277 kva = (vm_offset_t)((int)addr & ~PGOFSET); 278 kmem_free_wakeup(phys_map, kva, ctob(npf)); 279 bp->b_data = bp->b_saveaddr; 280 bp->b_saveaddr = NULL; 281 } 282 283 #ifdef MAPPEDCOPY 284 u_int mappedcopysize = 4096; 285 286 mappedcopyin(fromp, top, count) 287 register char *fromp, *top; 288 register int count; 289 { 290 register vm_offset_t kva, upa; 291 register int off, len; 292 int alignable; 293 pmap_t upmap; 294 extern caddr_t CADDR1; 295 296 kva = (vm_offset_t) CADDR1; 297 off = (vm_offset_t)fromp & PAGE_MASK; 298 alignable = (off == ((vm_offset_t)top & PAGE_MASK)); 299 upmap = vm_map_pmap(&curproc->p_vmspace->vm_map); 300 while (count > 0) { 301 /* 302 * First access of a page, use fubyte to make sure 303 * page is faulted in and read access allowed. 304 */ 305 if (fubyte(fromp) == -1) 306 return (EFAULT); 307 /* 308 * Map in the page and bcopy data in from it 309 */ 310 upa = pmap_extract(upmap, trunc_page(fromp)); 311 if (upa == 0) 312 panic("mappedcopyin"); 313 len = min(count, PAGE_SIZE-off); 314 pmap_enter(kernel_pmap, kva, upa, VM_PROT_READ, TRUE); 315 if (len == PAGE_SIZE && alignable && off == 0) 316 copypage(kva, top); 317 else 318 bcopy((caddr_t)(kva+off), top, len); 319 fromp += len; 320 top += len; 321 count -= len; 322 off = 0; 323 } 324 pmap_remove(kernel_pmap, kva, kva+PAGE_SIZE); 325 return (0); 326 } 327 328 mappedcopyout(fromp, top, count) 329 register char *fromp, *top; 330 register int count; 331 { 332 register vm_offset_t kva, upa; 333 register int off, len; 334 int alignable; 335 pmap_t upmap; 336 extern caddr_t CADDR2; 337 338 kva = (vm_offset_t) CADDR2; 339 off = (vm_offset_t)top & PAGE_MASK; 340 alignable = (off == ((vm_offset_t)fromp & PAGE_MASK)); 341 upmap = vm_map_pmap(&curproc->p_vmspace->vm_map); 342 while (count > 0) { 343 /* 344 * First access of a page, use subyte to make sure 345 * page is faulted in and write access allowed. 346 */ 347 if (subyte(top, *fromp) == -1) 348 return (EFAULT); 349 /* 350 * Map in the page and bcopy data out to it 351 */ 352 upa = pmap_extract(upmap, trunc_page(top)); 353 if (upa == 0) 354 panic("mappedcopyout"); 355 len = min(count, PAGE_SIZE-off); 356 pmap_enter(kernel_pmap, kva, upa, 357 VM_PROT_READ|VM_PROT_WRITE, TRUE); 358 if (len == PAGE_SIZE && alignable && off == 0) 359 copypage(fromp, kva); 360 else 361 bcopy(fromp, (caddr_t)(kva+off), len); 362 fromp += len; 363 top += len; 364 count -= len; 365 off = 0; 366 } 367 pmap_remove(kernel_pmap, kva, kva+PAGE_SIZE); 368 return (0); 369 } 370 #endif 371