1 /*- 2 * Copyright (c) 1982, 1986 The Regents of the University of California. 3 * Copyright (c) 1989, 1990 William Jolitz 4 * Copyright (c) 1994 John Dyson 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, and William Jolitz. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. All advertising materials mentioning features or use of this software 20 * must display the following acknowledgement: 21 * This product includes software developed by the University of 22 * California, Berkeley and its contributors. 23 * 4. Neither the name of the University nor the names of its contributors 24 * may be used to endorse or promote products derived from this software 25 * without specific prior written permission. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 * 39 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91 40 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ 41 * $Id: vm_machdep.c,v 1.112 1998/10/13 08:24:33 dg Exp $ 42 */ 43 44 #include "npx.h" 45 #include "opt_user_ldt.h" 46 #include "opt_vm86.h" 47 #ifdef PC98 48 #include "opt_pc98.h" 49 #endif 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/proc.h> 54 #include <sys/malloc.h> 55 #include <sys/buf.h> 56 #include <sys/vnode.h> 57 #include <sys/vmmeter.h> 58 #include <sys/kernel.h> 59 #include <sys/sysctl.h> 60 61 #include <machine/clock.h> 62 #include <machine/cpu.h> 63 #include <machine/md_var.h> 64 #ifdef SMP 65 #include <machine/smp.h> 66 #endif 67 #ifdef VM86 68 #include <machine/pcb_ext.h> 69 #include <machine/vm86.h> 70 #endif 71 72 #include <vm/vm.h> 73 #include <vm/vm_param.h> 74 #include <vm/vm_prot.h> 75 #include <sys/lock.h> 76 #include <vm/vm_kern.h> 77 #include <vm/vm_page.h> 78 #include <vm/vm_map.h> 79 #include <vm/vm_extern.h> 80 81 #include <sys/user.h> 82 83 #ifdef PC98 84 #include <pc98/pc98/pc98.h> 85 #else 86 #include <i386/isa/isa.h> 87 #endif 88 89 static void cpu_reset_real __P((void)); 90 #ifdef SMP 91 static void cpu_reset_proxy __P((void)); 92 static u_int cpu_reset_proxyid; 93 static volatile u_int cpu_reset_proxy_active; 94 #endif 95 96 /* 97 * quick version of vm_fault 98 */ 99 void 100 vm_fault_quick(v, prot) 101 caddr_t v; 102 int prot; 103 { 104 if (prot & VM_PROT_WRITE) 105 subyte(v, fubyte(v)); 106 else 107 fubyte(v); 108 } 109 110 /* 111 * Finish a fork operation, with process p2 nearly set up. 112 * Copy and update the pcb, set up the stack so that the child 113 * ready to run and return to user mode. 114 */ 115 void 116 cpu_fork(p1, p2) 117 register struct proc *p1, *p2; 118 { 119 struct pcb *pcb2 = &p2->p_addr->u_pcb; 120 121 #if NNPX > 0 122 /* Ensure that p1's pcb is up to date. */ 123 if (npxproc == p1) 124 npxsave(&p1->p_addr->u_pcb.pcb_savefpu); 125 #endif 126 127 /* Copy p1's pcb. */ 128 p2->p_addr->u_pcb = p1->p_addr->u_pcb; 129 130 /* 131 * Create a new fresh stack for the new process. 132 * Copy the trap frame for the return to user mode as if from a 133 * syscall. This copies the user mode register values. 134 */ 135 p2->p_md.md_regs = (struct trapframe *) 136 #ifdef VM86 137 ((int)p2->p_addr + UPAGES * PAGE_SIZE - 16) - 1; 138 #else 139 ((int)p2->p_addr + UPAGES * PAGE_SIZE) - 1; 140 #endif /* VM86 */ 141 *p2->p_md.md_regs = *p1->p_md.md_regs; 142 143 /* 144 * Set registers for trampoline to user mode. Leave space for the 145 * return address on stack. These are the kernel mode register values. 146 */ 147 pcb2->pcb_cr3 = vtophys(p2->p_vmspace->vm_pmap.pm_pdir); 148 pcb2->pcb_edi = p2->p_md.md_regs->tf_edi; 149 pcb2->pcb_esi = (int)fork_return; 150 pcb2->pcb_ebp = p2->p_md.md_regs->tf_ebp; 151 pcb2->pcb_esp = (int)p2->p_md.md_regs - sizeof(void *); 152 pcb2->pcb_ebx = (int)p2; 153 pcb2->pcb_eip = (int)fork_trampoline; 154 /* 155 * pcb2->pcb_ldt: duplicated below, if necessary. 156 * pcb2->pcb_ldt_len: cloned above. 157 * pcb2->pcb_savefpu: cloned above. 158 * pcb2->pcb_flags: cloned above (always 0 here?). 159 * pcb2->pcb_onfault: cloned above (always NULL here?). 160 */ 161 162 #ifdef SMP 163 pcb2->pcb_mpnest = 1; 164 #endif 165 #ifdef VM86 166 /* 167 * XXX don't copy the i/o pages. this should probably be fixed. 168 */ 169 pcb2->pcb_ext = 0; 170 #endif 171 172 #ifdef USER_LDT 173 /* Copy the LDT, if necessary. */ 174 if (pcb2->pcb_ldt != 0) { 175 union descriptor *new_ldt; 176 size_t len = pcb2->pcb_ldt_len * sizeof(union descriptor); 177 178 new_ldt = (union descriptor *)kmem_alloc(kernel_map, len); 179 bcopy(pcb2->pcb_ldt, new_ldt, len); 180 pcb2->pcb_ldt = (caddr_t)new_ldt; 181 } 182 #endif 183 184 /* 185 * Now, cpu_switch() can schedule the new process. 186 * pcb_esp is loaded pointing to the cpu_switch() stack frame 187 * containing the return address when exiting cpu_switch. 188 * This will normally be to proc_trampoline(), which will have 189 * %ebx loaded with the new proc's pointer. proc_trampoline() 190 * will set up a stack to call fork_return(p, frame); to complete 191 * the return to user-mode. 192 */ 193 } 194 195 /* 196 * Intercept the return address from a freshly forked process that has NOT 197 * been scheduled yet. 198 * 199 * This is needed to make kernel threads stay in kernel mode. 200 */ 201 void 202 cpu_set_fork_handler(p, func, arg) 203 struct proc *p; 204 void (*func) __P((void *)); 205 void *arg; 206 { 207 /* 208 * Note that the trap frame follows the args, so the function 209 * is really called like this: func(arg, frame); 210 */ 211 p->p_addr->u_pcb.pcb_esi = (int) func; /* function */ 212 p->p_addr->u_pcb.pcb_ebx = (int) arg; /* first arg */ 213 } 214 215 void 216 cpu_exit(p) 217 register struct proc *p; 218 { 219 #if defined(USER_LDT) || defined(VM86) 220 struct pcb *pcb = &p->p_addr->u_pcb; 221 #endif 222 223 #if NNPX > 0 224 npxexit(p); 225 #endif /* NNPX */ 226 #ifdef VM86 227 if (pcb->pcb_ext != 0) { 228 /* 229 * XXX do we need to move the TSS off the allocated pages 230 * before freeing them? (not done here) 231 */ 232 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext, 233 ctob(IOPAGES + 1)); 234 pcb->pcb_ext = 0; 235 } 236 #endif 237 #ifdef USER_LDT 238 if (pcb->pcb_ldt != 0) { 239 if (pcb == curpcb) { 240 lldt(_default_ldt); 241 currentldt = _default_ldt; 242 } 243 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ldt, 244 pcb->pcb_ldt_len * sizeof(union descriptor)); 245 pcb->pcb_ldt_len = (int)pcb->pcb_ldt = 0; 246 } 247 #endif 248 cnt.v_swtch++; 249 cpu_switch(p); 250 panic("cpu_exit"); 251 } 252 253 void 254 cpu_wait(p) 255 struct proc *p; 256 { 257 /* drop per-process resources */ 258 pmap_dispose_proc(p); 259 260 /* and clean-out the vmspace */ 261 vmspace_free(p->p_vmspace); 262 } 263 264 /* 265 * Dump the machine specific header information at the start of a core dump. 266 */ 267 int 268 cpu_coredump(p, vp, cred) 269 struct proc *p; 270 struct vnode *vp; 271 struct ucred *cred; 272 { 273 int error; 274 caddr_t tempuser; 275 276 tempuser = malloc(ctob(UPAGES), M_TEMP, M_WAITOK); 277 if (!tempuser) 278 return EINVAL; 279 280 bzero(tempuser, ctob(UPAGES)); 281 bcopy(p->p_addr, tempuser, sizeof(struct user)); 282 bcopy(p->p_md.md_regs, 283 tempuser + ((caddr_t) p->p_md.md_regs - (caddr_t) p->p_addr), 284 sizeof(struct trapframe)); 285 286 error = vn_rdwr(UIO_WRITE, vp, (caddr_t) tempuser, 287 ctob(UPAGES), 288 (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, 289 cred, (int *)NULL, p); 290 291 free(tempuser, M_TEMP); 292 293 return error; 294 } 295 296 #ifdef notyet 297 static void 298 setredzone(pte, vaddr) 299 u_short *pte; 300 caddr_t vaddr; 301 { 302 /* eventually do this by setting up an expand-down stack segment 303 for ss0: selector, allowing stack access down to top of u. 304 this means though that protection violations need to be handled 305 thru a double fault exception that must do an integral task 306 switch to a known good context, within which a dump can be 307 taken. a sensible scheme might be to save the initial context 308 used by sched (that has physical memory mapped 1:1 at bottom) 309 and take the dump while still in mapped mode */ 310 } 311 #endif 312 313 /* 314 * Convert kernel VA to physical address 315 */ 316 u_long 317 kvtop(void *addr) 318 { 319 vm_offset_t va; 320 321 va = pmap_kextract((vm_offset_t)addr); 322 if (va == 0) 323 panic("kvtop: zero page frame"); 324 return((int)va); 325 } 326 327 /* 328 * Map an IO request into kernel virtual address space. 329 * 330 * All requests are (re)mapped into kernel VA space. 331 * Notice that we use b_bufsize for the size of the buffer 332 * to be mapped. b_bcount might be modified by the driver. 333 */ 334 void 335 vmapbuf(bp) 336 register struct buf *bp; 337 { 338 register caddr_t addr, v, kva; 339 vm_offset_t pa; 340 341 if ((bp->b_flags & B_PHYS) == 0) 342 panic("vmapbuf"); 343 344 for (v = bp->b_saveaddr, addr = (caddr_t)trunc_page((vm_offset_t)bp->b_data); 345 addr < bp->b_data + bp->b_bufsize; 346 addr += PAGE_SIZE, v += PAGE_SIZE) { 347 /* 348 * Do the vm_fault if needed; do the copy-on-write thing 349 * when reading stuff off device into memory. 350 */ 351 vm_fault_quick(addr, 352 (bp->b_flags&B_READ)?(VM_PROT_READ|VM_PROT_WRITE):VM_PROT_READ); 353 pa = trunc_page(pmap_kextract((vm_offset_t) addr)); 354 if (pa == 0) 355 panic("vmapbuf: page not present"); 356 vm_page_hold(PHYS_TO_VM_PAGE(pa)); 357 pmap_kenter((vm_offset_t) v, pa); 358 } 359 360 kva = bp->b_saveaddr; 361 bp->b_saveaddr = bp->b_data; 362 bp->b_data = kva + (((vm_offset_t) bp->b_data) & PAGE_MASK); 363 } 364 365 /* 366 * Free the io map PTEs associated with this IO operation. 367 * We also invalidate the TLB entries and restore the original b_addr. 368 */ 369 void 370 vunmapbuf(bp) 371 register struct buf *bp; 372 { 373 register caddr_t addr; 374 vm_offset_t pa; 375 376 if ((bp->b_flags & B_PHYS) == 0) 377 panic("vunmapbuf"); 378 379 for (addr = (caddr_t)trunc_page((vm_offset_t)bp->b_data); 380 addr < bp->b_data + bp->b_bufsize; 381 addr += PAGE_SIZE) { 382 pa = trunc_page(pmap_kextract((vm_offset_t) addr)); 383 pmap_kremove((vm_offset_t) addr); 384 vm_page_unhold(PHYS_TO_VM_PAGE(pa)); 385 } 386 387 bp->b_data = bp->b_saveaddr; 388 } 389 390 /* 391 * Force reset the processor by invalidating the entire address space! 392 */ 393 394 #ifdef SMP 395 static void 396 cpu_reset_proxy() 397 { 398 u_int saved_mp_lock; 399 400 cpu_reset_proxy_active = 1; 401 while (cpu_reset_proxy_active == 1) 402 ; /* Wait for other cpu to disable interupts */ 403 saved_mp_lock = mp_lock; 404 mp_lock = 1; 405 printf("cpu_reset_proxy: Grabbed mp lock for BSP\n"); 406 cpu_reset_proxy_active = 3; 407 while (cpu_reset_proxy_active == 3) 408 ; /* Wait for other cpu to enable interrupts */ 409 stop_cpus((1<<cpu_reset_proxyid)); 410 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 411 DELAY(1000000); 412 cpu_reset_real(); 413 } 414 #endif 415 416 void 417 cpu_reset() 418 { 419 #ifdef SMP 420 if (smp_active == 0) { 421 cpu_reset_real(); 422 /* NOTREACHED */ 423 } else { 424 425 u_int map; 426 int cnt; 427 printf("cpu_reset called on cpu#%d\n",cpuid); 428 429 map = other_cpus & ~ stopped_cpus; 430 431 if (map != 0) { 432 printf("cpu_reset: Stopping other CPUs\n"); 433 stop_cpus(map); /* Stop all other CPUs */ 434 } 435 436 if (cpuid == 0) { 437 DELAY(1000000); 438 cpu_reset_real(); 439 /* NOTREACHED */ 440 } else { 441 /* We are not BSP (CPU #0) */ 442 443 cpu_reset_proxyid = cpuid; 444 cpustop_restartfunc = cpu_reset_proxy; 445 printf("cpu_reset: Restarting BSP\n"); 446 started_cpus = (1<<0); /* Restart CPU #0 */ 447 448 cnt = 0; 449 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 450 cnt++; /* Wait for BSP to announce restart */ 451 if (cpu_reset_proxy_active == 0) 452 printf("cpu_reset: Failed to restart BSP\n"); 453 __asm __volatile("cli" : : : "memory"); 454 cpu_reset_proxy_active = 2; 455 cnt = 0; 456 while (cpu_reset_proxy_active == 2 && cnt < 10000000) 457 cnt++; /* Do nothing */ 458 if (cpu_reset_proxy_active == 2) { 459 printf("cpu_reset: BSP did not grab mp lock\n"); 460 cpu_reset_real(); /* XXX: Bogus ? */ 461 } 462 cpu_reset_proxy_active = 4; 463 __asm __volatile("sti" : : : "memory"); 464 while (1); 465 /* NOTREACHED */ 466 } 467 } 468 #else 469 cpu_reset_real(); 470 #endif 471 } 472 473 static void 474 cpu_reset_real() 475 { 476 477 #ifdef PC98 478 /* 479 * Attempt to do a CPU reset via CPU reset port. 480 */ 481 disable_intr(); 482 if ((inb(0x35) & 0xa0) != 0xa0) { 483 outb(0x37, 0x0f); /* SHUT0 = 0. */ 484 outb(0x37, 0x0b); /* SHUT1 = 0. */ 485 } 486 outb(0xf0, 0x00); /* Reset. */ 487 #else 488 /* 489 * Attempt to do a CPU reset via the keyboard controller, 490 * do not turn of the GateA20, as any machine that fails 491 * to do the reset here would then end up in no man's land. 492 */ 493 494 #if !defined(BROKEN_KEYBOARD_RESET) 495 outb(IO_KBD + 4, 0xFE); 496 DELAY(500000); /* wait 0.5 sec to see if that did it */ 497 printf("Keyboard reset did not work, attempting CPU shutdown\n"); 498 DELAY(1000000); /* wait 1 sec for printf to complete */ 499 #endif 500 #endif /* PC98 */ 501 /* force a shutdown by unmapping entire address space ! */ 502 bzero((caddr_t) PTD, PAGE_SIZE); 503 504 /* "good night, sweet prince .... <THUNK!>" */ 505 invltlb(); 506 /* NOTREACHED */ 507 while(1); 508 } 509 510 /* 511 * Grow the user stack to allow for 'sp'. This version grows the stack in 512 * chunks of SGROWSIZ. 513 */ 514 int 515 grow(p, sp) 516 struct proc *p; 517 u_int sp; 518 { 519 unsigned int nss; 520 caddr_t v; 521 struct vmspace *vm = p->p_vmspace; 522 523 if ((caddr_t)sp <= vm->vm_maxsaddr || (unsigned)sp >= (unsigned)USRSTACK) 524 return (1); 525 526 nss = roundup(USRSTACK - (unsigned)sp, PAGE_SIZE); 527 528 if (nss > p->p_rlimit[RLIMIT_STACK].rlim_cur) 529 return (0); 530 531 if (vm->vm_ssize && roundup(vm->vm_ssize << PAGE_SHIFT, 532 SGROWSIZ) < nss) { 533 int grow_amount; 534 /* 535 * If necessary, grow the VM that the stack occupies 536 * to allow for the rlimit. This allows us to not have 537 * to allocate all of the VM up-front in execve (which 538 * is expensive). 539 * Grow the VM by the amount requested rounded up to 540 * the nearest SGROWSIZ to provide for some hysteresis. 541 */ 542 grow_amount = roundup((nss - (vm->vm_ssize << PAGE_SHIFT)), SGROWSIZ); 543 v = (char *)USRSTACK - roundup(vm->vm_ssize << PAGE_SHIFT, 544 SGROWSIZ) - grow_amount; 545 /* 546 * If there isn't enough room to extend by SGROWSIZ, then 547 * just extend to the maximum size 548 */ 549 if (v < vm->vm_maxsaddr) { 550 v = vm->vm_maxsaddr; 551 grow_amount = MAXSSIZ - (vm->vm_ssize << PAGE_SHIFT); 552 } 553 if ((grow_amount == 0) || (vm_map_find(&vm->vm_map, NULL, 0, (vm_offset_t *)&v, 554 grow_amount, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0) != KERN_SUCCESS)) { 555 return (0); 556 } 557 vm->vm_ssize += grow_amount >> PAGE_SHIFT; 558 } 559 560 return (1); 561 } 562 563 static int cnt_prezero; 564 565 SYSCTL_INT(_vm_stats_misc, OID_AUTO, 566 cnt_prezero, CTLFLAG_RD, &cnt_prezero, 0, ""); 567 568 /* 569 * Implement the pre-zeroed page mechanism. 570 * This routine is called from the idle loop. 571 */ 572 int 573 vm_page_zero_idle() 574 { 575 static int free_rover; 576 vm_page_t m; 577 int s; 578 579 /* 580 * XXX 581 * We stop zeroing pages when there are sufficent prezeroed pages. 582 * This threshold isn't really needed, except we want to 583 * bypass unneeded calls to vm_page_list_find, and the 584 * associated cache flush and latency. The pre-zero will 585 * still be called when there are significantly more 586 * non-prezeroed pages than zeroed pages. The threshold 587 * of half the number of reserved pages is arbitrary, but 588 * approximately the right amount. Eventually, we should 589 * perhaps interrupt the zero operation when a process 590 * is found to be ready to run. 591 */ 592 if (cnt.v_free_count - vm_page_zero_count <= cnt.v_free_reserved / 2) 593 return (0); 594 #ifdef SMP 595 if (try_mplock()) { 596 #endif 597 s = splvm(); 598 __asm __volatile("sti" : : : "memory"); 599 m = vm_page_list_find(PQ_FREE, free_rover); 600 if (m != NULL) { 601 --(*vm_page_queues[m->queue].lcnt); 602 TAILQ_REMOVE(vm_page_queues[m->queue].pl, m, pageq); 603 m->queue = PQ_NONE; 604 splx(s); 605 #if 0 606 rel_mplock(); 607 #endif 608 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 609 #if 0 610 get_mplock(); 611 #endif 612 (void)splvm(); 613 m->queue = PQ_ZERO + m->pc; 614 ++(*vm_page_queues[m->queue].lcnt); 615 TAILQ_INSERT_HEAD(vm_page_queues[m->queue].pl, m, 616 pageq); 617 free_rover = (free_rover + PQ_PRIME3) & PQ_L2_MASK; 618 ++vm_page_zero_count; 619 ++cnt_prezero; 620 } 621 splx(s); 622 __asm __volatile("cli" : : : "memory"); 623 #ifdef SMP 624 rel_mplock(); 625 #endif 626 return (1); 627 #ifdef SMP 628 } 629 #endif 630 return (0); 631 } 632 633 /* 634 * Software interrupt handler for queued VM system processing. 635 */ 636 void 637 swi_vm() 638 { 639 if (busdma_swi_pending != 0) 640 busdma_swi(); 641 } 642 643 /* 644 * Tell whether this address is in some physical memory region. 645 * Currently used by the kernel coredump code in order to avoid 646 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 647 * or other unpredictable behaviour. 648 */ 649 650 #include "isa.h" 651 652 int 653 is_physical_memory(addr) 654 vm_offset_t addr; 655 { 656 657 #if NISA > 0 658 /* The ISA ``memory hole''. */ 659 if (addr >= 0xa0000 && addr < 0x100000) 660 return 0; 661 #endif 662 663 /* 664 * stuff other tests for known memory-mapped devices (PCI?) 665 * here 666 */ 667 668 return 1; 669 } 670