1 /* 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1992 OMRON Corporation. 4 * Copyright (c) 1982, 1986, 1990, 1993 5 * The Regents of the University of California. 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 8.4 (Berkeley) 11/14/93 15 * 16 * @(#)vm_machdep.c 8.3 (Berkeley) 12/06/93 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 * switch 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 switch_exit, which switches to a temporary 89 * pcb and stack and never returns. We block memory allocation 90 * until switch_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 switch_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 #ifdef LUNA2 144 DCIS(); 145 #endif 146 } 147 148 /* 149 * Map `size' bytes of physical memory starting at `paddr' into 150 * kernel VA space at `vaddr'. Read/write and cache-inhibit status 151 * are specified by `prot'. 152 */ 153 physaccess(vaddr, paddr, size, prot) 154 caddr_t vaddr, paddr; 155 register int size, prot; 156 { 157 register struct pte *pte; 158 register u_int page; 159 160 pte = kvtopte(vaddr); 161 page = (u_int)paddr & PG_FRAME; 162 for (size = btoc(size); size; size--) { 163 *(int *)pte++ = PG_V | prot | page; 164 page += NBPG; 165 } 166 TBIAS(); 167 } 168 169 physunaccess(vaddr, size) 170 caddr_t vaddr; 171 register int size; 172 { 173 register struct pte *pte; 174 175 pte = kvtopte(vaddr); 176 for (size = btoc(size); size; size--) 177 *(int *)pte++ = PG_NV; 178 TBIAS(); 179 } 180 181 /* 182 * Set a red zone in the kernel stack after the u. area. 183 * We don't support a redzone right now. It really isn't clear 184 * that it is a good idea since, if the kernel stack were to roll 185 * into a write protected page, the processor would lock up (since 186 * it cannot create an exception frame) and we would get no useful 187 * post-mortem info. Currently, under the DEBUG option, we just 188 * check at every clock interrupt to see if the current k-stack has 189 * gone too far (i.e. into the "redzone" page) and if so, panic. 190 * Look at _lev6intr in locore.s for more details. 191 */ 192 /*ARGSUSED*/ 193 setredzone(pte, vaddr) 194 struct pte *pte; 195 caddr_t vaddr; 196 { 197 } 198 199 /* 200 * Convert kernel VA to physical address 201 */ 202 kvtop(addr) 203 register caddr_t addr; 204 { 205 vm_offset_t va; 206 207 va = pmap_extract(kernel_pmap, (vm_offset_t)addr); 208 if (va == 0) 209 panic("kvtop: zero page frame"); 210 return((int)va); 211 } 212 213 extern vm_map_t phys_map; 214 215 /* 216 * Map an IO request into kernel virtual address space. 217 * 218 * XXX we allocate KVA space by using kmem_alloc_wait which we know 219 * allocates space without backing physical memory. This implementation 220 * is a total crock, the multiple mappings of these physical pages should 221 * be reflected in the higher-level VM structures to avoid problems. 222 */ 223 vmapbuf(bp) 224 register struct buf *bp; 225 { 226 register int npf; 227 register caddr_t addr; 228 register long flags = bp->b_flags; 229 struct proc *p; 230 int off; 231 vm_offset_t kva; 232 register vm_offset_t pa; 233 234 if ((flags & B_PHYS) == 0) 235 panic("vmapbuf"); 236 addr = bp->b_saveaddr = bp->b_data; 237 off = (int)addr & PGOFSET; 238 p = bp->b_proc; 239 npf = btoc(round_page(bp->b_bcount + off)); 240 kva = kmem_alloc_wait(phys_map, ctob(npf)); 241 bp->b_data = (caddr_t) (kva + off); 242 while (npf--) { 243 pa = pmap_extract(vm_map_pmap(&p->p_vmspace->vm_map), 244 (vm_offset_t)addr); 245 if (pa == 0) 246 panic("vmapbuf: null page frame"); 247 pmap_enter(vm_map_pmap(phys_map), kva, trunc_page(pa), 248 VM_PROT_READ|VM_PROT_WRITE, TRUE); 249 addr += PAGE_SIZE; 250 kva += PAGE_SIZE; 251 } 252 } 253 254 /* 255 * Free the io map PTEs associated with this IO operation. 256 */ 257 vunmapbuf(bp) 258 register struct buf *bp; 259 { 260 register caddr_t addr; 261 register int npf; 262 vm_offset_t kva; 263 264 if ((bp->b_flags & B_PHYS) == 0) 265 panic("vunmapbuf"); 266 addr = bp->b_data; 267 npf = btoc(round_page(bp->b_bcount + ((int)addr & PGOFSET))); 268 kva = (vm_offset_t)((int)addr & ~PGOFSET); 269 kmem_free_wakeup(phys_map, kva, ctob(npf)); 270 bp->b_data = bp->b_saveaddr; 271 bp->b_saveaddr = NULL; 272 } 273 274 #ifdef MAPPEDCOPY 275 u_int mappedcopysize = 4096; 276 277 mappedcopyin(fromp, top, count) 278 register char *fromp, *top; 279 register int count; 280 { 281 register vm_offset_t kva, upa; 282 register int off, len; 283 int alignable; 284 pmap_t upmap; 285 extern caddr_t CADDR1; 286 287 kva = (vm_offset_t) CADDR1; 288 off = (vm_offset_t)fromp & PAGE_MASK; 289 alignable = (off == ((vm_offset_t)top & PAGE_MASK)); 290 upmap = vm_map_pmap(&curproc->p_vmspace->vm_map); 291 while (count > 0) { 292 /* 293 * First access of a page, use fubyte to make sure 294 * page is faulted in and read access allowed. 295 */ 296 if (fubyte(fromp) == -1) 297 return (EFAULT); 298 /* 299 * Map in the page and bcopy data in from it 300 */ 301 upa = pmap_extract(upmap, trunc_page(fromp)); 302 if (upa == 0) 303 panic("mappedcopyin"); 304 len = min(count, PAGE_SIZE-off); 305 pmap_enter(kernel_pmap, kva, upa, VM_PROT_READ, TRUE); 306 if (len == PAGE_SIZE && alignable && off == 0) 307 copypage(kva, top); 308 else 309 bcopy((caddr_t)(kva+off), top, len); 310 fromp += len; 311 top += len; 312 count -= len; 313 off = 0; 314 } 315 pmap_remove(kernel_pmap, kva, kva+PAGE_SIZE); 316 return (0); 317 } 318 319 mappedcopyout(fromp, top, count) 320 register char *fromp, *top; 321 register int count; 322 { 323 register vm_offset_t kva, upa; 324 register int off, len; 325 int alignable; 326 pmap_t upmap; 327 extern caddr_t CADDR2; 328 329 kva = (vm_offset_t) CADDR2; 330 off = (vm_offset_t)top & PAGE_MASK; 331 alignable = (off == ((vm_offset_t)fromp & PAGE_MASK)); 332 upmap = vm_map_pmap(&curproc->p_vmspace->vm_map); 333 while (count > 0) { 334 /* 335 * First access of a page, use subyte to make sure 336 * page is faulted in and write access allowed. 337 */ 338 if (subyte(top, *fromp) == -1) 339 return (EFAULT); 340 /* 341 * Map in the page and bcopy data out to it 342 */ 343 upa = pmap_extract(upmap, trunc_page(top)); 344 if (upa == 0) 345 panic("mappedcopyout"); 346 len = min(count, PAGE_SIZE-off); 347 pmap_enter(kernel_pmap, kva, upa, 348 VM_PROT_READ|VM_PROT_WRITE, TRUE); 349 if (len == PAGE_SIZE && alignable && off == 0) 350 copypage(fromp, kva); 351 else 352 bcopy(fromp, (caddr_t)(kva+off), len); 353 fromp += len; 354 top += len; 355 count -= len; 356 off = 0; 357 } 358 pmap_remove(kernel_pmap, kva, kva+PAGE_SIZE); 359 return (0); 360 } 361 #endif 362