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 1.121 1999/04/19 14:14:13 peter Exp $ 42 */ 43 44 #include "npx.h" 45 #include "opt_user_ldt.h" 46 #ifdef PC98 47 #include "opt_pc98.h" 48 #endif 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/proc.h> 53 #include <sys/malloc.h> 54 #include <sys/buf.h> 55 #include <sys/vnode.h> 56 #include <sys/vmmeter.h> 57 #include <sys/kernel.h> 58 #include <sys/sysctl.h> 59 60 #include <machine/clock.h> 61 #include <machine/cpu.h> 62 #include <machine/md_var.h> 63 #ifdef SMP 64 #include <machine/smp.h> 65 #endif 66 #include <machine/pcb_ext.h> 67 #include <machine/vm86.h> 68 69 #include <vm/vm.h> 70 #include <vm/vm_param.h> 71 #include <vm/vm_prot.h> 72 #include <sys/lock.h> 73 #include <vm/vm_kern.h> 74 #include <vm/vm_page.h> 75 #include <vm/vm_map.h> 76 #include <vm/vm_extern.h> 77 78 #include <sys/user.h> 79 80 #ifdef PC98 81 #include <pc98/pc98/pc98.h> 82 #else 83 #include <i386/isa/isa.h> 84 #endif 85 86 static void cpu_reset_real __P((void)); 87 #ifdef SMP 88 static void cpu_reset_proxy __P((void)); 89 static u_int cpu_reset_proxyid; 90 static volatile u_int cpu_reset_proxy_active; 91 #endif 92 93 /* 94 * quick version of vm_fault 95 */ 96 void 97 vm_fault_quick(v, prot) 98 caddr_t v; 99 int prot; 100 { 101 if (prot & VM_PROT_WRITE) 102 subyte(v, fubyte(v)); 103 else 104 fubyte(v); 105 } 106 107 /* 108 * Finish a fork operation, with process p2 nearly set up. 109 * Copy and update the pcb, set up the stack so that the child 110 * ready to run and return to user mode. 111 */ 112 void 113 cpu_fork(p1, p2) 114 register struct proc *p1, *p2; 115 { 116 struct pcb *pcb2 = &p2->p_addr->u_pcb; 117 118 #if NNPX > 0 119 /* Ensure that p1's pcb is up to date. */ 120 if (npxproc == p1) 121 npxsave(&p1->p_addr->u_pcb.pcb_savefpu); 122 #endif 123 124 /* Copy p1's pcb. */ 125 p2->p_addr->u_pcb = p1->p_addr->u_pcb; 126 127 /* 128 * Create a new fresh stack for the new process. 129 * Copy the trap frame for the return to user mode as if from a 130 * syscall. This copies the user mode register values. 131 */ 132 p2->p_md.md_regs = (struct trapframe *) 133 ((int)p2->p_addr + UPAGES * PAGE_SIZE - 16) - 1; 134 *p2->p_md.md_regs = *p1->p_md.md_regs; 135 136 /* 137 * Set registers for trampoline to user mode. Leave space for the 138 * return address on stack. These are the kernel mode register values. 139 */ 140 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); 141 pcb2->pcb_edi = p2->p_md.md_regs->tf_edi; 142 pcb2->pcb_esi = (int)fork_return; 143 pcb2->pcb_ebp = p2->p_md.md_regs->tf_ebp; 144 pcb2->pcb_esp = (int)p2->p_md.md_regs - sizeof(void *); 145 pcb2->pcb_ebx = (int)p2; 146 pcb2->pcb_eip = (int)fork_trampoline; 147 /* 148 * pcb2->pcb_ldt: duplicated below, if necessary. 149 * pcb2->pcb_ldt_len: cloned above. 150 * pcb2->pcb_savefpu: cloned above. 151 * pcb2->pcb_flags: cloned above (always 0 here?). 152 * pcb2->pcb_onfault: cloned above (always NULL here?). 153 */ 154 155 #ifdef SMP 156 pcb2->pcb_mpnest = 1; 157 #endif 158 /* 159 * XXX don't copy the i/o pages. this should probably be fixed. 160 */ 161 pcb2->pcb_ext = 0; 162 163 #ifdef USER_LDT 164 /* Copy the LDT, if necessary. */ 165 if (pcb2->pcb_ldt != 0) { 166 union descriptor *new_ldt; 167 size_t len = pcb2->pcb_ldt_len * sizeof(union descriptor); 168 169 new_ldt = (union descriptor *)kmem_alloc(kernel_map, len); 170 bcopy(pcb2->pcb_ldt, new_ldt, len); 171 pcb2->pcb_ldt = (caddr_t)new_ldt; 172 } 173 #endif 174 175 /* 176 * Now, cpu_switch() can schedule the new process. 177 * pcb_esp is loaded pointing to the cpu_switch() stack frame 178 * containing the return address when exiting cpu_switch. 179 * This will normally be to proc_trampoline(), which will have 180 * %ebx loaded with the new proc's pointer. proc_trampoline() 181 * will set up a stack to call fork_return(p, frame); to complete 182 * the return to user-mode. 183 */ 184 } 185 186 /* 187 * Intercept the return address from a freshly forked process that has NOT 188 * been scheduled yet. 189 * 190 * This is needed to make kernel threads stay in kernel mode. 191 */ 192 void 193 cpu_set_fork_handler(p, func, arg) 194 struct proc *p; 195 void (*func) __P((const void *)); 196 const void *arg; 197 { 198 /* 199 * Note that the trap frame follows the args, so the function 200 * is really called like this: func(arg, frame); 201 */ 202 p->p_addr->u_pcb.pcb_esi = (int) func; /* function */ 203 p->p_addr->u_pcb.pcb_ebx = (int) arg; /* first arg */ 204 } 205 206 void 207 cpu_exit(p) 208 register struct proc *p; 209 { 210 struct pcb *pcb = &p->p_addr->u_pcb; 211 212 #if NNPX > 0 213 npxexit(p); 214 #endif /* NNPX */ 215 if (pcb->pcb_ext != 0) { 216 /* 217 * XXX do we need to move the TSS off the allocated pages 218 * before freeing them? (not done here) 219 */ 220 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext, 221 ctob(IOPAGES + 1)); 222 pcb->pcb_ext = 0; 223 } 224 #ifdef USER_LDT 225 if (pcb->pcb_ldt != 0) { 226 if (pcb == curpcb) { 227 lldt(_default_ldt); 228 currentldt = _default_ldt; 229 } 230 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ldt, 231 pcb->pcb_ldt_len * sizeof(union descriptor)); 232 pcb->pcb_ldt_len = (int)pcb->pcb_ldt = 0; 233 } 234 #endif 235 cnt.v_swtch++; 236 cpu_switch(p); 237 panic("cpu_exit"); 238 } 239 240 void 241 cpu_wait(p) 242 struct proc *p; 243 { 244 /* drop per-process resources */ 245 pmap_dispose_proc(p); 246 247 /* and clean-out the vmspace */ 248 vmspace_free(p->p_vmspace); 249 } 250 251 /* 252 * Dump the machine specific header information at the start of a core dump. 253 */ 254 int 255 cpu_coredump(p, vp, cred) 256 struct proc *p; 257 struct vnode *vp; 258 struct ucred *cred; 259 { 260 int error; 261 caddr_t tempuser; 262 263 tempuser = malloc(ctob(UPAGES), M_TEMP, M_WAITOK); 264 if (!tempuser) 265 return EINVAL; 266 267 bzero(tempuser, ctob(UPAGES)); 268 bcopy(p->p_addr, tempuser, sizeof(struct user)); 269 bcopy(p->p_md.md_regs, 270 tempuser + ((caddr_t) p->p_md.md_regs - (caddr_t) p->p_addr), 271 sizeof(struct trapframe)); 272 273 error = vn_rdwr(UIO_WRITE, vp, (caddr_t) tempuser, 274 ctob(UPAGES), 275 (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, 276 cred, (int *)NULL, p); 277 278 free(tempuser, M_TEMP); 279 280 return error; 281 } 282 283 #ifdef notyet 284 static void 285 setredzone(pte, vaddr) 286 u_short *pte; 287 caddr_t vaddr; 288 { 289 /* eventually do this by setting up an expand-down stack segment 290 for ss0: selector, allowing stack access down to top of u. 291 this means though that protection violations need to be handled 292 thru a double fault exception that must do an integral task 293 switch to a known good context, within which a dump can be 294 taken. a sensible scheme might be to save the initial context 295 used by sched (that has physical memory mapped 1:1 at bottom) 296 and take the dump while still in mapped mode */ 297 } 298 #endif 299 300 /* 301 * Convert kernel VA to physical address 302 */ 303 u_long 304 kvtop(void *addr) 305 { 306 vm_offset_t va; 307 308 va = pmap_kextract((vm_offset_t)addr); 309 if (va == 0) 310 panic("kvtop: zero page frame"); 311 return((int)va); 312 } 313 314 /* 315 * Map an IO request into kernel virtual address space. 316 * 317 * All requests are (re)mapped into kernel VA space. 318 * Notice that we use b_bufsize for the size of the buffer 319 * to be mapped. b_bcount might be modified by the driver. 320 */ 321 void 322 vmapbuf(bp) 323 register struct buf *bp; 324 { 325 register caddr_t addr, v, kva; 326 vm_offset_t pa; 327 328 if ((bp->b_flags & B_PHYS) == 0) 329 panic("vmapbuf"); 330 331 for (v = bp->b_saveaddr, addr = (caddr_t)trunc_page((vm_offset_t)bp->b_data); 332 addr < bp->b_data + bp->b_bufsize; 333 addr += PAGE_SIZE, v += PAGE_SIZE) { 334 /* 335 * Do the vm_fault if needed; do the copy-on-write thing 336 * when reading stuff off device into memory. 337 */ 338 vm_fault_quick(addr, 339 (bp->b_flags&B_READ)?(VM_PROT_READ|VM_PROT_WRITE):VM_PROT_READ); 340 pa = trunc_page(pmap_kextract((vm_offset_t) addr)); 341 if (pa == 0) 342 panic("vmapbuf: page not present"); 343 vm_page_hold(PHYS_TO_VM_PAGE(pa)); 344 pmap_kenter((vm_offset_t) v, pa); 345 } 346 347 kva = bp->b_saveaddr; 348 bp->b_saveaddr = bp->b_data; 349 bp->b_data = kva + (((vm_offset_t) bp->b_data) & PAGE_MASK); 350 } 351 352 /* 353 * Free the io map PTEs associated with this IO operation. 354 * We also invalidate the TLB entries and restore the original b_addr. 355 */ 356 void 357 vunmapbuf(bp) 358 register struct buf *bp; 359 { 360 register caddr_t addr; 361 vm_offset_t pa; 362 363 if ((bp->b_flags & B_PHYS) == 0) 364 panic("vunmapbuf"); 365 366 for (addr = (caddr_t)trunc_page((vm_offset_t)bp->b_data); 367 addr < bp->b_data + bp->b_bufsize; 368 addr += PAGE_SIZE) { 369 pa = trunc_page(pmap_kextract((vm_offset_t) addr)); 370 pmap_kremove((vm_offset_t) addr); 371 vm_page_unhold(PHYS_TO_VM_PAGE(pa)); 372 } 373 374 bp->b_data = bp->b_saveaddr; 375 } 376 377 /* 378 * Force reset the processor by invalidating the entire address space! 379 */ 380 381 #ifdef SMP 382 static void 383 cpu_reset_proxy() 384 { 385 u_int saved_mp_lock; 386 387 cpu_reset_proxy_active = 1; 388 while (cpu_reset_proxy_active == 1) 389 ; /* Wait for other cpu to disable interupts */ 390 saved_mp_lock = mp_lock; 391 mp_lock = 1; 392 printf("cpu_reset_proxy: Grabbed mp lock for BSP\n"); 393 cpu_reset_proxy_active = 3; 394 while (cpu_reset_proxy_active == 3) 395 ; /* Wait for other cpu to enable interrupts */ 396 stop_cpus((1<<cpu_reset_proxyid)); 397 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 398 DELAY(1000000); 399 cpu_reset_real(); 400 } 401 #endif 402 403 void 404 cpu_reset() 405 { 406 #ifdef SMP 407 if (smp_active == 0) { 408 cpu_reset_real(); 409 /* NOTREACHED */ 410 } else { 411 412 u_int map; 413 int cnt; 414 printf("cpu_reset called on cpu#%d\n",cpuid); 415 416 map = other_cpus & ~ stopped_cpus; 417 418 if (map != 0) { 419 printf("cpu_reset: Stopping other CPUs\n"); 420 stop_cpus(map); /* Stop all other CPUs */ 421 } 422 423 if (cpuid == 0) { 424 DELAY(1000000); 425 cpu_reset_real(); 426 /* NOTREACHED */ 427 } else { 428 /* We are not BSP (CPU #0) */ 429 430 cpu_reset_proxyid = cpuid; 431 cpustop_restartfunc = cpu_reset_proxy; 432 printf("cpu_reset: Restarting BSP\n"); 433 started_cpus = (1<<0); /* Restart CPU #0 */ 434 435 cnt = 0; 436 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 437 cnt++; /* Wait for BSP to announce restart */ 438 if (cpu_reset_proxy_active == 0) 439 printf("cpu_reset: Failed to restart BSP\n"); 440 __asm __volatile("cli" : : : "memory"); 441 cpu_reset_proxy_active = 2; 442 cnt = 0; 443 while (cpu_reset_proxy_active == 2 && cnt < 10000000) 444 cnt++; /* Do nothing */ 445 if (cpu_reset_proxy_active == 2) { 446 printf("cpu_reset: BSP did not grab mp lock\n"); 447 cpu_reset_real(); /* XXX: Bogus ? */ 448 } 449 cpu_reset_proxy_active = 4; 450 __asm __volatile("sti" : : : "memory"); 451 while (1); 452 /* NOTREACHED */ 453 } 454 } 455 #else 456 cpu_reset_real(); 457 #endif 458 } 459 460 static void 461 cpu_reset_real() 462 { 463 464 #ifdef PC98 465 /* 466 * Attempt to do a CPU reset via CPU reset port. 467 */ 468 disable_intr(); 469 if ((inb(0x35) & 0xa0) != 0xa0) { 470 outb(0x37, 0x0f); /* SHUT0 = 0. */ 471 outb(0x37, 0x0b); /* SHUT1 = 0. */ 472 } 473 outb(0xf0, 0x00); /* Reset. */ 474 #else 475 /* 476 * Attempt to do a CPU reset via the keyboard controller, 477 * do not turn of the GateA20, as any machine that fails 478 * to do the reset here would then end up in no man's land. 479 */ 480 481 #if !defined(BROKEN_KEYBOARD_RESET) 482 outb(IO_KBD + 4, 0xFE); 483 DELAY(500000); /* wait 0.5 sec to see if that did it */ 484 printf("Keyboard reset did not work, attempting CPU shutdown\n"); 485 DELAY(1000000); /* wait 1 sec for printf to complete */ 486 #endif 487 #endif /* PC98 */ 488 /* force a shutdown by unmapping entire address space ! */ 489 bzero((caddr_t) PTD, PAGE_SIZE); 490 491 /* "good night, sweet prince .... <THUNK!>" */ 492 invltlb(); 493 /* NOTREACHED */ 494 while(1); 495 } 496 497 int 498 grow_stack(p, sp) 499 struct proc *p; 500 u_int sp; 501 { 502 int rv; 503 504 rv = vm_map_growstack (p, sp); 505 if (rv != KERN_SUCCESS) 506 return (0); 507 508 return (1); 509 } 510 511 SYSCTL_DECL(_vm_stats_misc); 512 513 static int cnt_prezero; 514 515 SYSCTL_INT(_vm_stats_misc, OID_AUTO, 516 cnt_prezero, CTLFLAG_RD, &cnt_prezero, 0, ""); 517 518 /* 519 * Implement the pre-zeroed page mechanism. 520 * This routine is called from the idle loop. 521 */ 522 523 #define ZIDLE_LO(v) ((v) * 2 / 3) 524 #define ZIDLE_HI(v) ((v) * 4 / 5) 525 526 int 527 vm_page_zero_idle() 528 { 529 static int free_rover; 530 static int zero_state; 531 vm_page_t m; 532 int s; 533 534 /* 535 * Attempt to maintain approximately 1/2 of our free pages in a 536 * PG_ZERO'd state. Add some hysteresis to (attempt to) avoid 537 * generally zeroing a page when the system is near steady-state. 538 * Otherwise we might get 'flutter' during disk I/O / IPC or 539 * fast sleeps. We also do not want to be continuously zeroing 540 * pages because doing so may flush our L1 and L2 caches too much. 541 */ 542 543 if (zero_state && vm_page_zero_count >= ZIDLE_LO(cnt.v_free_count)) 544 return(0); 545 if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count)) 546 return(0); 547 548 #ifdef SMP 549 if (try_mplock()) { 550 #endif 551 s = splvm(); 552 __asm __volatile("sti" : : : "memory"); 553 zero_state = 0; 554 m = vm_page_list_find(PQ_FREE, free_rover, FALSE); 555 if (m != NULL && (m->flags & PG_ZERO) == 0) { 556 --(*vm_page_queues[m->queue].lcnt); 557 TAILQ_REMOVE(vm_page_queues[m->queue].pl, m, pageq); 558 m->queue = PQ_NONE; 559 splx(s); 560 #if 0 561 rel_mplock(); 562 #endif 563 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 564 #if 0 565 get_mplock(); 566 #endif 567 (void)splvm(); 568 vm_page_flag_set(m, PG_ZERO); 569 m->queue = PQ_FREE + m->pc; 570 ++(*vm_page_queues[m->queue].lcnt); 571 TAILQ_INSERT_TAIL(vm_page_queues[m->queue].pl, m, 572 pageq); 573 ++vm_page_zero_count; 574 ++cnt_prezero; 575 if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count)) 576 zero_state = 1; 577 } 578 free_rover = (free_rover + PQ_PRIME3) & PQ_L2_MASK; 579 splx(s); 580 __asm __volatile("cli" : : : "memory"); 581 #ifdef SMP 582 rel_mplock(); 583 #endif 584 return (1); 585 #ifdef SMP 586 } 587 #endif 588 return (0); 589 } 590 591 /* 592 * Software interrupt handler for queued VM system processing. 593 */ 594 void 595 swi_vm() 596 { 597 if (busdma_swi_pending != 0) 598 busdma_swi(); 599 } 600 601 /* 602 * Tell whether this address is in some physical memory region. 603 * Currently used by the kernel coredump code in order to avoid 604 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 605 * or other unpredictable behaviour. 606 */ 607 608 #include "isa.h" 609 610 int 611 is_physical_memory(addr) 612 vm_offset_t addr; 613 { 614 615 #if NISA > 0 616 /* The ISA ``memory hole''. */ 617 if (addr >= 0xa0000 && addr < 0x100000) 618 return 0; 619 #endif 620 621 /* 622 * stuff other tests for known memory-mapped devices (PCI?) 623 * here 624 */ 625 626 return 1; 627 } 628