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/ktr.h> 61 #include <sys/mutex.h> 62 #include <sys/sysctl.h> 63 #include <sys/unistd.h> 64 65 #include <machine/cpu.h> 66 #include <machine/md_var.h> 67 #ifdef SMP 68 #include <machine/smp.h> 69 #endif 70 #include <machine/pcb.h> 71 #include <machine/pcb_ext.h> 72 #include <machine/vm86.h> 73 74 #include <vm/vm.h> 75 #include <vm/vm_param.h> 76 #include <sys/lock.h> 77 #include <vm/vm_kern.h> 78 #include <vm/vm_page.h> 79 #include <vm/vm_map.h> 80 #include <vm/vm_extern.h> 81 82 #include <sys/user.h> 83 84 #ifdef PC98 85 #include <pc98/pc98/pc98.h> 86 #else 87 #include <i386/isa/isa.h> 88 #endif 89 90 static void cpu_reset_real __P((void)); 91 #ifdef SMP 92 static void cpu_reset_proxy __P((void)); 93 static u_int cpu_reset_proxyid; 94 static volatile u_int cpu_reset_proxy_active; 95 #endif 96 extern int _ucodesel, _udatasel; 97 98 /* 99 * quick version of vm_fault 100 */ 101 int 102 vm_fault_quick(v, prot) 103 caddr_t v; 104 int prot; 105 { 106 int r; 107 108 if (prot & VM_PROT_WRITE) 109 r = subyte(v, fubyte(v)); 110 else 111 r = fubyte(v); 112 return(r); 113 } 114 115 /* 116 * Finish a fork operation, with process p2 nearly set up. 117 * Copy and update the pcb, set up the stack so that the child 118 * ready to run and return to user mode. 119 */ 120 void 121 cpu_fork(p1, p2, flags) 122 register struct proc *p1, *p2; 123 int flags; 124 { 125 struct pcb *pcb2; 126 127 if ((flags & RFPROC) == 0) { 128 #ifdef USER_LDT 129 if ((flags & RFMEM) == 0) { 130 /* unshare user LDT */ 131 struct pcb *pcb1 = &p1->p_addr->u_pcb; 132 struct pcb_ldt *pcb_ldt = pcb1->pcb_ldt; 133 if (pcb_ldt && pcb_ldt->ldt_refcnt > 1) { 134 pcb_ldt = user_ldt_alloc(pcb1,pcb_ldt->ldt_len); 135 user_ldt_free(pcb1); 136 pcb1->pcb_ldt = pcb_ldt; 137 set_user_ldt(pcb1); 138 } 139 } 140 #endif 141 return; 142 } 143 144 #if NNPX > 0 145 /* Ensure that p1's pcb is up to date. */ 146 if (npxproc == p1) 147 npxsave(&p1->p_addr->u_pcb.pcb_savefpu); 148 #endif 149 150 /* Copy p1's pcb. */ 151 p2->p_addr->u_pcb = p1->p_addr->u_pcb; 152 pcb2 = &p2->p_addr->u_pcb; 153 154 /* 155 * Create a new fresh stack for the new process. 156 * Copy the trap frame for the return to user mode as if from a 157 * syscall. This copies the user mode register values. 158 */ 159 p2->p_md.md_regs = (struct trapframe *) 160 ((int)p2->p_addr + UPAGES * PAGE_SIZE - 16) - 1; 161 bcopy(p1->p_md.md_regs, p2->p_md.md_regs, sizeof(*p2->p_md.md_regs)); 162 163 /* 164 * Set registers for trampoline to user mode. Leave space for the 165 * return address on stack. These are the kernel mode register values. 166 */ 167 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); 168 pcb2->pcb_edi = 0; 169 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */ 170 pcb2->pcb_ebp = 0; 171 pcb2->pcb_esp = (int)p2->p_md.md_regs - sizeof(void *); 172 pcb2->pcb_ebx = (int)p2; /* fork_trampoline argument */ 173 pcb2->pcb_eip = (int)fork_trampoline; 174 /* 175 * pcb2->pcb_ldt: duplicated below, if necessary. 176 * pcb2->pcb_savefpu: cloned above. 177 * pcb2->pcb_flags: cloned above (always 0 here?). 178 * pcb2->pcb_onfault: cloned above (always NULL here?). 179 */ 180 181 pcb2->pcb_schednest = 0; 182 183 /* 184 * XXX don't copy the i/o pages. this should probably be fixed. 185 */ 186 pcb2->pcb_ext = 0; 187 188 #ifdef USER_LDT 189 /* Copy the LDT, if necessary. */ 190 if (pcb2->pcb_ldt != 0) { 191 if (flags & RFMEM) { 192 pcb2->pcb_ldt->ldt_refcnt++; 193 } else { 194 pcb2->pcb_ldt = user_ldt_alloc(pcb2, 195 pcb2->pcb_ldt->ldt_len); 196 } 197 } 198 #endif 199 200 /* 201 * Now, cpu_switch() can schedule the new process. 202 * pcb_esp is loaded pointing to the cpu_switch() stack frame 203 * containing the return address when exiting cpu_switch. 204 * This will normally be to fork_trampoline(), which will have 205 * %ebx loaded with the new proc's pointer. fork_trampoline() 206 * will set up a stack to call fork_return(p, frame); to complete 207 * the return to user-mode. 208 */ 209 } 210 211 /* 212 * Intercept the return address from a freshly forked process that has NOT 213 * been scheduled yet. 214 * 215 * This is needed to make kernel threads stay in kernel mode. 216 */ 217 void 218 cpu_set_fork_handler(p, func, arg) 219 struct proc *p; 220 void (*func) __P((void *)); 221 void *arg; 222 { 223 /* 224 * Note that the trap frame follows the args, so the function 225 * is really called like this: func(arg, frame); 226 */ 227 p->p_addr->u_pcb.pcb_esi = (int) func; /* function */ 228 p->p_addr->u_pcb.pcb_ebx = (int) arg; /* first arg */ 229 } 230 231 void 232 cpu_exit(p) 233 register struct proc *p; 234 { 235 struct pcb *pcb = &p->p_addr->u_pcb; 236 237 #if NNPX > 0 238 npxexit(p); 239 #endif /* NNPX */ 240 if (pcb->pcb_ext != 0) { 241 /* 242 * XXX do we need to move the TSS off the allocated pages 243 * before freeing them? (not done here) 244 */ 245 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext, 246 ctob(IOPAGES + 1)); 247 pcb->pcb_ext = 0; 248 } 249 #ifdef USER_LDT 250 user_ldt_free(pcb); 251 #endif 252 if (pcb->pcb_flags & PCB_DBREGS) { 253 /* 254 * disable all hardware breakpoints 255 */ 256 reset_dbregs(); 257 pcb->pcb_flags &= ~PCB_DBREGS; 258 } 259 mtx_enter(&sched_lock, MTX_SPIN); 260 mtx_exit(&Giant, MTX_DEF | MTX_NOSWITCH); 261 mtx_assert(&Giant, MA_NOTOWNED); 262 cnt.v_swtch++; 263 cpu_throw(); 264 panic("cpu_exit"); 265 } 266 267 void 268 cpu_wait(p) 269 struct proc *p; 270 { 271 /* drop per-process resources */ 272 pmap_dispose_proc(p); 273 274 /* and clean-out the vmspace */ 275 vmspace_free(p->p_vmspace); 276 } 277 278 /* 279 * Dump the machine specific header information at the start of a core dump. 280 */ 281 int 282 cpu_coredump(p, vp, cred) 283 struct proc *p; 284 struct vnode *vp; 285 struct ucred *cred; 286 { 287 int error; 288 caddr_t tempuser; 289 290 tempuser = malloc(ctob(UPAGES), M_TEMP, M_WAITOK); 291 if (!tempuser) 292 return EINVAL; 293 294 bzero(tempuser, ctob(UPAGES)); 295 bcopy(p->p_addr, tempuser, sizeof(struct user)); 296 bcopy(p->p_md.md_regs, 297 tempuser + ((caddr_t) p->p_md.md_regs - (caddr_t) p->p_addr), 298 sizeof(struct trapframe)); 299 300 error = vn_rdwr(UIO_WRITE, vp, (caddr_t) tempuser, 301 ctob(UPAGES), 302 (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, 303 cred, (int *)NULL, p); 304 305 free(tempuser, M_TEMP); 306 307 return error; 308 } 309 310 #ifdef notyet 311 static void 312 setredzone(pte, vaddr) 313 u_short *pte; 314 caddr_t vaddr; 315 { 316 /* eventually do this by setting up an expand-down stack segment 317 for ss0: selector, allowing stack access down to top of u. 318 this means though that protection violations need to be handled 319 thru a double fault exception that must do an integral task 320 switch to a known good context, within which a dump can be 321 taken. a sensible scheme might be to save the initial context 322 used by sched (that has physical memory mapped 1:1 at bottom) 323 and take the dump while still in mapped mode */ 324 } 325 #endif 326 327 /* 328 * Convert kernel VA to physical address 329 */ 330 u_long 331 kvtop(void *addr) 332 { 333 vm_offset_t va; 334 335 va = pmap_kextract((vm_offset_t)addr); 336 if (va == 0) 337 panic("kvtop: zero page frame"); 338 return((int)va); 339 } 340 341 /* 342 * Map an IO request into kernel virtual address space. 343 * 344 * All requests are (re)mapped into kernel VA space. 345 * Notice that we use b_bufsize for the size of the buffer 346 * to be mapped. b_bcount might be modified by the driver. 347 */ 348 void 349 vmapbuf(bp) 350 register struct buf *bp; 351 { 352 register caddr_t addr, v, kva; 353 vm_offset_t pa; 354 355 if ((bp->b_flags & B_PHYS) == 0) 356 panic("vmapbuf"); 357 358 for (v = bp->b_saveaddr, addr = (caddr_t)trunc_page((vm_offset_t)bp->b_data); 359 addr < bp->b_data + bp->b_bufsize; 360 addr += PAGE_SIZE, v += PAGE_SIZE) { 361 /* 362 * Do the vm_fault if needed; do the copy-on-write thing 363 * when reading stuff off device into memory. 364 */ 365 vm_fault_quick(addr, 366 (bp->b_iocmd == BIO_READ)?(VM_PROT_READ|VM_PROT_WRITE):VM_PROT_READ); 367 pa = trunc_page(pmap_kextract((vm_offset_t) addr)); 368 if (pa == 0) 369 panic("vmapbuf: page not present"); 370 vm_page_hold(PHYS_TO_VM_PAGE(pa)); 371 pmap_kenter((vm_offset_t) v, pa); 372 } 373 374 kva = bp->b_saveaddr; 375 bp->b_saveaddr = bp->b_data; 376 bp->b_data = kva + (((vm_offset_t) bp->b_data) & PAGE_MASK); 377 } 378 379 /* 380 * Free the io map PTEs associated with this IO operation. 381 * We also invalidate the TLB entries and restore the original b_addr. 382 */ 383 void 384 vunmapbuf(bp) 385 register struct buf *bp; 386 { 387 register caddr_t addr; 388 vm_offset_t pa; 389 390 if ((bp->b_flags & B_PHYS) == 0) 391 panic("vunmapbuf"); 392 393 for (addr = (caddr_t)trunc_page((vm_offset_t)bp->b_data); 394 addr < bp->b_data + bp->b_bufsize; 395 addr += PAGE_SIZE) { 396 pa = trunc_page(pmap_kextract((vm_offset_t) addr)); 397 pmap_kremove((vm_offset_t) addr); 398 vm_page_unhold(PHYS_TO_VM_PAGE(pa)); 399 } 400 401 bp->b_data = bp->b_saveaddr; 402 } 403 404 /* 405 * Force reset the processor by invalidating the entire address space! 406 */ 407 408 #ifdef SMP 409 static void 410 cpu_reset_proxy() 411 { 412 413 cpu_reset_proxy_active = 1; 414 while (cpu_reset_proxy_active == 1) 415 ; /* Wait for other cpu to see that we've started */ 416 stop_cpus((1<<cpu_reset_proxyid)); 417 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 418 DELAY(1000000); 419 cpu_reset_real(); 420 } 421 #endif 422 423 void 424 cpu_reset() 425 { 426 #ifdef SMP 427 if (smp_active == 0) { 428 cpu_reset_real(); 429 /* NOTREACHED */ 430 } else { 431 432 u_int map; 433 int cnt; 434 printf("cpu_reset called on cpu#%d\n",cpuid); 435 436 map = other_cpus & ~ stopped_cpus; 437 438 if (map != 0) { 439 printf("cpu_reset: Stopping other CPUs\n"); 440 stop_cpus(map); /* Stop all other CPUs */ 441 } 442 443 if (cpuid == 0) { 444 DELAY(1000000); 445 cpu_reset_real(); 446 /* NOTREACHED */ 447 } else { 448 /* We are not BSP (CPU #0) */ 449 450 cpu_reset_proxyid = cpuid; 451 cpustop_restartfunc = cpu_reset_proxy; 452 cpu_reset_proxy_active = 0; 453 printf("cpu_reset: Restarting BSP\n"); 454 started_cpus = (1<<0); /* Restart CPU #0 */ 455 456 cnt = 0; 457 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 458 cnt++; /* Wait for BSP to announce restart */ 459 if (cpu_reset_proxy_active == 0) 460 printf("cpu_reset: Failed to restart BSP\n"); 461 enable_intr(); 462 cpu_reset_proxy_active = 2; 463 464 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 int 511 grow_stack(p, sp) 512 struct proc *p; 513 u_int sp; 514 { 515 int rv; 516 517 rv = vm_map_growstack (p, sp); 518 if (rv != KERN_SUCCESS) 519 return (0); 520 521 return (1); 522 } 523 524 SYSCTL_DECL(_vm_stats_misc); 525 526 static int cnt_prezero; 527 528 SYSCTL_INT(_vm_stats_misc, OID_AUTO, 529 cnt_prezero, CTLFLAG_RD, &cnt_prezero, 0, ""); 530 531 /* 532 * Implement the pre-zeroed page mechanism. 533 * This routine is called from the idle loop. 534 */ 535 536 #define ZIDLE_LO(v) ((v) * 2 / 3) 537 #define ZIDLE_HI(v) ((v) * 4 / 5) 538 539 int 540 vm_page_zero_idle() 541 { 542 static int free_rover; 543 static int zero_state; 544 vm_page_t m; 545 int s; 546 547 /* 548 * Attempt to maintain approximately 1/2 of our free pages in a 549 * PG_ZERO'd state. Add some hysteresis to (attempt to) avoid 550 * generally zeroing a page when the system is near steady-state. 551 * Otherwise we might get 'flutter' during disk I/O / IPC or 552 * fast sleeps. We also do not want to be continuously zeroing 553 * pages because doing so may flush our L1 and L2 caches too much. 554 */ 555 556 if (zero_state && vm_page_zero_count >= ZIDLE_LO(cnt.v_free_count)) 557 return(0); 558 if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count)) 559 return(0); 560 561 if (mtx_try_enter(&Giant, MTX_DEF)) { 562 s = splvm(); 563 zero_state = 0; 564 m = vm_page_list_find(PQ_FREE, free_rover, FALSE); 565 if (m != NULL && (m->flags & PG_ZERO) == 0) { 566 vm_page_queues[m->queue].lcnt--; 567 TAILQ_REMOVE(&vm_page_queues[m->queue].pl, m, pageq); 568 m->queue = PQ_NONE; 569 splx(s); 570 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 571 (void)splvm(); 572 vm_page_flag_set(m, PG_ZERO); 573 m->queue = PQ_FREE + m->pc; 574 vm_page_queues[m->queue].lcnt++; 575 TAILQ_INSERT_TAIL(&vm_page_queues[m->queue].pl, m, 576 pageq); 577 ++vm_page_zero_count; 578 ++cnt_prezero; 579 if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count)) 580 zero_state = 1; 581 } 582 free_rover = (free_rover + PQ_PRIME2) & PQ_L2_MASK; 583 splx(s); 584 mtx_exit(&Giant, MTX_DEF); 585 return (1); 586 } 587 return (0); 588 } 589 590 /* 591 * Software interrupt handler for queued VM system processing. 592 */ 593 void 594 swi_vm(void *dummy) 595 { 596 if (busdma_swi_pending != 0) 597 busdma_swi(); 598 } 599 600 /* 601 * Tell whether this address is in some physical memory region. 602 * Currently used by the kernel coredump code in order to avoid 603 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 604 * or other unpredictable behaviour. 605 */ 606 607 #include "isa.h" 608 609 int 610 is_physical_memory(addr) 611 vm_offset_t addr; 612 { 613 614 #if NISA > 0 615 /* The ISA ``memory hole''. */ 616 if (addr >= 0xa0000 && addr < 0x100000) 617 return 0; 618 #endif 619 620 /* 621 * stuff other tests for known memory-mapped devices (PCI?) 622 * here 623 */ 624 625 return 1; 626 } 627