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 * $FreeBSD$ 42 */ 43 44 #include "npx.h" 45 #include "opt_user_ldt.h" 46 #ifdef PC98 47 #include "opt_pc98.h" 48 #endif 49 #include "opt_reset.h" 50 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/malloc.h> 54 #include <sys/proc.h> 55 #include <sys/bio.h> 56 #include <sys/buf.h> 57 #include <sys/vnode.h> 58 #include <sys/vmmeter.h> 59 #include <sys/kernel.h> 60 #include <sys/sysctl.h> 61 #include <sys/unistd.h> 62 63 #include <machine/clock.h> 64 #include <machine/cpu.h> 65 #include <machine/md_var.h> 66 #ifdef SMP 67 #include <machine/smp.h> 68 #endif 69 #include <machine/pcb.h> 70 #include <machine/pcb_ext.h> 71 #include <machine/vm86.h> 72 73 #include <vm/vm.h> 74 #include <vm/vm_param.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 int 100 vm_fault_quick(v, prot) 101 caddr_t v; 102 int prot; 103 { 104 int r; 105 106 if (prot & VM_PROT_WRITE) 107 r = subyte(v, fubyte(v)); 108 else 109 r = fubyte(v); 110 return(r); 111 } 112 113 /* 114 * Finish a fork operation, with process p2 nearly set up. 115 * Copy and update the pcb, set up the stack so that the child 116 * ready to run and return to user mode. 117 */ 118 void 119 cpu_fork(p1, p2, flags) 120 register struct proc *p1, *p2; 121 int flags; 122 { 123 struct pcb *pcb2; 124 125 if ((flags & RFPROC) == 0) { 126 #ifdef USER_LDT 127 if ((flags & RFMEM) == 0) { 128 /* unshare user LDT */ 129 struct pcb *pcb1 = &p1->p_addr->u_pcb; 130 struct pcb_ldt *pcb_ldt = pcb1->pcb_ldt; 131 if (pcb_ldt && pcb_ldt->ldt_refcnt > 1) { 132 pcb_ldt = user_ldt_alloc(pcb1,pcb_ldt->ldt_len); 133 user_ldt_free(pcb1); 134 pcb1->pcb_ldt = pcb_ldt; 135 set_user_ldt(pcb1); 136 } 137 } 138 #endif 139 return; 140 } 141 142 #if NNPX > 0 143 /* Ensure that p1's pcb is up to date. */ 144 if (npxproc == p1) 145 npxsave(&p1->p_addr->u_pcb.pcb_savefpu); 146 #endif 147 148 /* Copy p1's pcb. */ 149 p2->p_addr->u_pcb = p1->p_addr->u_pcb; 150 pcb2 = &p2->p_addr->u_pcb; 151 152 /* 153 * Create a new fresh stack for the new process. 154 * Copy the trap frame for the return to user mode as if from a 155 * syscall. This copies the user mode register values. 156 */ 157 p2->p_md.md_regs = (struct trapframe *) 158 ((int)p2->p_addr + UPAGES * PAGE_SIZE - 16) - 1; 159 *p2->p_md.md_regs = *p1->p_md.md_regs; 160 161 /* 162 * Set registers for trampoline to user mode. Leave space for the 163 * return address on stack. These are the kernel mode register values. 164 */ 165 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); 166 pcb2->pcb_edi = p2->p_md.md_regs->tf_edi; 167 pcb2->pcb_esi = (int)fork_return; 168 pcb2->pcb_ebp = p2->p_md.md_regs->tf_ebp; 169 pcb2->pcb_esp = (int)p2->p_md.md_regs - sizeof(void *); 170 pcb2->pcb_ebx = (int)p2; 171 pcb2->pcb_eip = (int)fork_trampoline; 172 /* 173 * pcb2->pcb_ldt: duplicated below, if necessary. 174 * pcb2->pcb_savefpu: cloned above. 175 * pcb2->pcb_flags: cloned above (always 0 here?). 176 * pcb2->pcb_onfault: cloned above (always NULL here?). 177 */ 178 179 #ifdef SMP 180 pcb2->pcb_mpnest = 1; 181 #endif 182 /* 183 * XXX don't copy the i/o pages. this should probably be fixed. 184 */ 185 pcb2->pcb_ext = 0; 186 187 #ifdef USER_LDT 188 /* Copy the LDT, if necessary. */ 189 if (pcb2->pcb_ldt != 0) { 190 if (flags & RFMEM) { 191 pcb2->pcb_ldt->ldt_refcnt++; 192 } else { 193 pcb2->pcb_ldt = user_ldt_alloc(pcb2, 194 pcb2->pcb_ldt->ldt_len); 195 } 196 } 197 #endif 198 199 /* 200 * Now, cpu_switch() can schedule the new process. 201 * pcb_esp is loaded pointing to the cpu_switch() stack frame 202 * containing the return address when exiting cpu_switch. 203 * This will normally be to proc_trampoline(), which will have 204 * %ebx loaded with the new proc's pointer. proc_trampoline() 205 * will set up a stack to call fork_return(p, frame); to complete 206 * the return to user-mode. 207 */ 208 } 209 210 /* 211 * Intercept the return address from a freshly forked process that has NOT 212 * been scheduled yet. 213 * 214 * This is needed to make kernel threads stay in kernel mode. 215 */ 216 void 217 cpu_set_fork_handler(p, func, arg) 218 struct proc *p; 219 void (*func) __P((void *)); 220 void *arg; 221 { 222 /* 223 * Note that the trap frame follows the args, so the function 224 * is really called like this: func(arg, frame); 225 */ 226 p->p_addr->u_pcb.pcb_esi = (int) func; /* function */ 227 p->p_addr->u_pcb.pcb_ebx = (int) arg; /* first arg */ 228 } 229 230 void 231 cpu_exit(p) 232 register struct proc *p; 233 { 234 struct pcb *pcb = &p->p_addr->u_pcb; 235 236 #if NNPX > 0 237 npxexit(p); 238 #endif /* NNPX */ 239 if (pcb->pcb_ext != 0) { 240 /* 241 * XXX do we need to move the TSS off the allocated pages 242 * before freeing them? (not done here) 243 */ 244 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext, 245 ctob(IOPAGES + 1)); 246 pcb->pcb_ext = 0; 247 } 248 #ifdef USER_LDT 249 user_ldt_free(pcb); 250 #endif 251 if (pcb->pcb_flags & PCB_DBREGS) { 252 /* 253 * disable all hardware breakpoints 254 */ 255 reset_dbregs(); 256 pcb->pcb_flags &= ~PCB_DBREGS; 257 } 258 cnt.v_swtch++; 259 cpu_switch(p); 260 panic("cpu_exit"); 261 } 262 263 void 264 cpu_wait(p) 265 struct proc *p; 266 { 267 /* drop per-process resources */ 268 pmap_dispose_proc(p); 269 270 /* and clean-out the vmspace */ 271 vmspace_free(p->p_vmspace); 272 } 273 274 /* 275 * Dump the machine specific header information at the start of a core dump. 276 */ 277 int 278 cpu_coredump(p, vp, cred) 279 struct proc *p; 280 struct vnode *vp; 281 struct ucred *cred; 282 { 283 int error; 284 caddr_t tempuser; 285 286 tempuser = malloc(ctob(UPAGES), M_TEMP, M_WAITOK); 287 if (!tempuser) 288 return EINVAL; 289 290 bzero(tempuser, ctob(UPAGES)); 291 bcopy(p->p_addr, tempuser, sizeof(struct user)); 292 bcopy(p->p_md.md_regs, 293 tempuser + ((caddr_t) p->p_md.md_regs - (caddr_t) p->p_addr), 294 sizeof(struct trapframe)); 295 296 error = vn_rdwr(UIO_WRITE, vp, (caddr_t) tempuser, 297 ctob(UPAGES), 298 (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, 299 cred, (int *)NULL, p); 300 301 free(tempuser, M_TEMP); 302 303 return error; 304 } 305 306 #ifdef notyet 307 static void 308 setredzone(pte, vaddr) 309 u_short *pte; 310 caddr_t vaddr; 311 { 312 /* eventually do this by setting up an expand-down stack segment 313 for ss0: selector, allowing stack access down to top of u. 314 this means though that protection violations need to be handled 315 thru a double fault exception that must do an integral task 316 switch to a known good context, within which a dump can be 317 taken. a sensible scheme might be to save the initial context 318 used by sched (that has physical memory mapped 1:1 at bottom) 319 and take the dump while still in mapped mode */ 320 } 321 #endif 322 323 /* 324 * Convert kernel VA to physical address 325 */ 326 u_long 327 kvtop(void *addr) 328 { 329 vm_offset_t va; 330 331 va = pmap_kextract((vm_offset_t)addr); 332 if (va == 0) 333 panic("kvtop: zero page frame"); 334 return((int)va); 335 } 336 337 /* 338 * Map an IO request into kernel virtual address space. 339 * 340 * All requests are (re)mapped into kernel VA space. 341 * Notice that we use b_bufsize for the size of the buffer 342 * to be mapped. b_bcount might be modified by the driver. 343 */ 344 void 345 vmapbuf(bp) 346 register struct buf *bp; 347 { 348 register caddr_t addr, v, kva; 349 vm_offset_t pa; 350 351 if ((bp->b_flags & B_PHYS) == 0) 352 panic("vmapbuf"); 353 354 for (v = bp->b_saveaddr, addr = (caddr_t)trunc_page((vm_offset_t)bp->b_data); 355 addr < bp->b_data + bp->b_bufsize; 356 addr += PAGE_SIZE, v += PAGE_SIZE) { 357 /* 358 * Do the vm_fault if needed; do the copy-on-write thing 359 * when reading stuff off device into memory. 360 */ 361 vm_fault_quick(addr, 362 (bp->b_iocmd == BIO_READ)?(VM_PROT_READ|VM_PROT_WRITE):VM_PROT_READ); 363 pa = trunc_page(pmap_kextract((vm_offset_t) addr)); 364 if (pa == 0) 365 panic("vmapbuf: page not present"); 366 vm_page_hold(PHYS_TO_VM_PAGE(pa)); 367 pmap_kenter((vm_offset_t) v, pa); 368 } 369 370 kva = bp->b_saveaddr; 371 bp->b_saveaddr = bp->b_data; 372 bp->b_data = kva + (((vm_offset_t) bp->b_data) & PAGE_MASK); 373 } 374 375 /* 376 * Free the io map PTEs associated with this IO operation. 377 * We also invalidate the TLB entries and restore the original b_addr. 378 */ 379 void 380 vunmapbuf(bp) 381 register struct buf *bp; 382 { 383 register caddr_t addr; 384 vm_offset_t pa; 385 386 if ((bp->b_flags & B_PHYS) == 0) 387 panic("vunmapbuf"); 388 389 for (addr = (caddr_t)trunc_page((vm_offset_t)bp->b_data); 390 addr < bp->b_data + bp->b_bufsize; 391 addr += PAGE_SIZE) { 392 pa = trunc_page(pmap_kextract((vm_offset_t) addr)); 393 pmap_kremove((vm_offset_t) addr); 394 vm_page_unhold(PHYS_TO_VM_PAGE(pa)); 395 } 396 397 bp->b_data = bp->b_saveaddr; 398 } 399 400 /* 401 * Force reset the processor by invalidating the entire address space! 402 */ 403 404 #ifdef SMP 405 static void 406 cpu_reset_proxy() 407 { 408 u_int saved_mp_lock; 409 410 cpu_reset_proxy_active = 1; 411 while (cpu_reset_proxy_active == 1) 412 ; /* Wait for other cpu to disable interupts */ 413 saved_mp_lock = mp_lock; 414 mp_lock = 1; 415 printf("cpu_reset_proxy: Grabbed mp lock for BSP\n"); 416 cpu_reset_proxy_active = 3; 417 while (cpu_reset_proxy_active == 3) 418 ; /* Wait for other cpu to enable interrupts */ 419 stop_cpus((1<<cpu_reset_proxyid)); 420 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 421 DELAY(1000000); 422 cpu_reset_real(); 423 } 424 #endif 425 426 void 427 cpu_reset() 428 { 429 #ifdef SMP 430 if (smp_active == 0) { 431 cpu_reset_real(); 432 /* NOTREACHED */ 433 } else { 434 435 u_int map; 436 int cnt; 437 printf("cpu_reset called on cpu#%d\n",cpuid); 438 439 map = other_cpus & ~ stopped_cpus; 440 441 if (map != 0) { 442 printf("cpu_reset: Stopping other CPUs\n"); 443 stop_cpus(map); /* Stop all other CPUs */ 444 } 445 446 if (cpuid == 0) { 447 DELAY(1000000); 448 cpu_reset_real(); 449 /* NOTREACHED */ 450 } else { 451 /* We are not BSP (CPU #0) */ 452 453 cpu_reset_proxyid = cpuid; 454 cpustop_restartfunc = cpu_reset_proxy; 455 printf("cpu_reset: Restarting BSP\n"); 456 started_cpus = (1<<0); /* Restart CPU #0 */ 457 458 cnt = 0; 459 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 460 cnt++; /* Wait for BSP to announce restart */ 461 if (cpu_reset_proxy_active == 0) 462 printf("cpu_reset: Failed to restart BSP\n"); 463 __asm __volatile("cli" : : : "memory"); 464 cpu_reset_proxy_active = 2; 465 cnt = 0; 466 while (cpu_reset_proxy_active == 2 && cnt < 10000000) 467 cnt++; /* Do nothing */ 468 if (cpu_reset_proxy_active == 2) { 469 printf("cpu_reset: BSP did not grab mp lock\n"); 470 cpu_reset_real(); /* XXX: Bogus ? */ 471 } 472 cpu_reset_proxy_active = 4; 473 __asm __volatile("sti" : : : "memory"); 474 while (1); 475 /* NOTREACHED */ 476 } 477 } 478 #else 479 cpu_reset_real(); 480 #endif 481 } 482 483 static void 484 cpu_reset_real() 485 { 486 487 #ifdef PC98 488 /* 489 * Attempt to do a CPU reset via CPU reset port. 490 */ 491 disable_intr(); 492 if ((inb(0x35) & 0xa0) != 0xa0) { 493 outb(0x37, 0x0f); /* SHUT0 = 0. */ 494 outb(0x37, 0x0b); /* SHUT1 = 0. */ 495 } 496 outb(0xf0, 0x00); /* Reset. */ 497 #else 498 /* 499 * Attempt to do a CPU reset via the keyboard controller, 500 * do not turn of the GateA20, as any machine that fails 501 * to do the reset here would then end up in no man's land. 502 */ 503 504 #if !defined(BROKEN_KEYBOARD_RESET) 505 outb(IO_KBD + 4, 0xFE); 506 DELAY(500000); /* wait 0.5 sec to see if that did it */ 507 printf("Keyboard reset did not work, attempting CPU shutdown\n"); 508 DELAY(1000000); /* wait 1 sec for printf to complete */ 509 #endif 510 #endif /* PC98 */ 511 /* force a shutdown by unmapping entire address space ! */ 512 bzero((caddr_t) PTD, PAGE_SIZE); 513 514 /* "good night, sweet prince .... <THUNK!>" */ 515 invltlb(); 516 /* NOTREACHED */ 517 while(1); 518 } 519 520 int 521 grow_stack(p, sp) 522 struct proc *p; 523 u_int sp; 524 { 525 int rv; 526 527 rv = vm_map_growstack (p, sp); 528 if (rv != KERN_SUCCESS) 529 return (0); 530 531 return (1); 532 } 533 534 SYSCTL_DECL(_vm_stats_misc); 535 536 static int cnt_prezero; 537 538 SYSCTL_INT(_vm_stats_misc, OID_AUTO, 539 cnt_prezero, CTLFLAG_RD, &cnt_prezero, 0, ""); 540 541 /* 542 * Implement the pre-zeroed page mechanism. 543 * This routine is called from the idle loop. 544 */ 545 546 #define ZIDLE_LO(v) ((v) * 2 / 3) 547 #define ZIDLE_HI(v) ((v) * 4 / 5) 548 549 int 550 vm_page_zero_idle() 551 { 552 static int free_rover; 553 static int zero_state; 554 vm_page_t m; 555 int s; 556 557 /* 558 * Attempt to maintain approximately 1/2 of our free pages in a 559 * PG_ZERO'd state. Add some hysteresis to (attempt to) avoid 560 * generally zeroing a page when the system is near steady-state. 561 * Otherwise we might get 'flutter' during disk I/O / IPC or 562 * fast sleeps. We also do not want to be continuously zeroing 563 * pages because doing so may flush our L1 and L2 caches too much. 564 */ 565 566 if (zero_state && vm_page_zero_count >= ZIDLE_LO(cnt.v_free_count)) 567 return(0); 568 if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count)) 569 return(0); 570 571 #ifdef SMP 572 if (try_mplock()) { 573 #endif 574 s = splvm(); 575 __asm __volatile("sti" : : : "memory"); 576 zero_state = 0; 577 m = vm_page_list_find(PQ_FREE, free_rover, FALSE); 578 if (m != NULL && (m->flags & PG_ZERO) == 0) { 579 vm_page_queues[m->queue].lcnt--; 580 TAILQ_REMOVE(&vm_page_queues[m->queue].pl, m, pageq); 581 m->queue = PQ_NONE; 582 splx(s); 583 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 584 (void)splvm(); 585 vm_page_flag_set(m, PG_ZERO); 586 m->queue = PQ_FREE + m->pc; 587 vm_page_queues[m->queue].lcnt++; 588 TAILQ_INSERT_TAIL(&vm_page_queues[m->queue].pl, m, 589 pageq); 590 ++vm_page_zero_count; 591 ++cnt_prezero; 592 if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count)) 593 zero_state = 1; 594 } 595 free_rover = (free_rover + PQ_PRIME2) & PQ_L2_MASK; 596 splx(s); 597 __asm __volatile("cli" : : : "memory"); 598 #ifdef SMP 599 rel_mplock(); 600 #endif 601 return (1); 602 #ifdef SMP 603 } 604 #endif 605 /* 606 * We have to enable interrupts for a moment if the try_mplock fails 607 * in order to potentially take an IPI. XXX this should be in 608 * swtch.s 609 */ 610 __asm __volatile("sti; nop; cli" : : : "memory"); 611 return (0); 612 } 613 614 /* 615 * Software interrupt handler for queued VM system processing. 616 */ 617 void 618 swi_vm() 619 { 620 if (busdma_swi_pending != 0) 621 busdma_swi(); 622 } 623 624 /* 625 * Tell whether this address is in some physical memory region. 626 * Currently used by the kernel coredump code in order to avoid 627 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 628 * or other unpredictable behaviour. 629 */ 630 631 #include "isa.h" 632 633 int 634 is_physical_memory(addr) 635 vm_offset_t addr; 636 { 637 638 #if NISA > 0 639 /* The ISA ``memory hole''. */ 640 if (addr >= 0xa0000 && addr < 0x100000) 641 return 0; 642 #endif 643 644 /* 645 * stuff other tests for known memory-mapped devices (PCI?) 646 * here 647 */ 648 649 return 1; 650 } 651