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 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/malloc.h> 53 #include <sys/proc.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 #include <sys/unistd.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 #include <machine/pcb.h> 68 #include <machine/pcb_ext.h> 69 #include <machine/vm86.h> 70 71 #include <vm/vm.h> 72 #include <vm/vm_param.h> 73 #include <sys/lock.h> 74 #include <vm/vm_kern.h> 75 #include <vm/vm_page.h> 76 #include <vm/vm_map.h> 77 #include <vm/vm_extern.h> 78 79 #include <sys/user.h> 80 81 #ifdef PC98 82 #include <pc98/pc98/pc98.h> 83 #else 84 #include <i386/isa/isa.h> 85 #endif 86 87 static void cpu_reset_real __P((void)); 88 #ifdef SMP 89 static void cpu_reset_proxy __P((void)); 90 static u_int cpu_reset_proxyid; 91 static volatile u_int cpu_reset_proxy_active; 92 #endif 93 94 /* 95 * quick version of vm_fault 96 */ 97 int 98 vm_fault_quick(v, prot) 99 caddr_t v; 100 int prot; 101 { 102 int r; 103 104 if (prot & VM_PROT_WRITE) 105 r = subyte(v, fubyte(v)); 106 else 107 r = fubyte(v); 108 return(r); 109 } 110 111 /* 112 * Finish a fork operation, with process p2 nearly set up. 113 * Copy and update the pcb, set up the stack so that the child 114 * ready to run and return to user mode. 115 */ 116 void 117 cpu_fork(p1, p2, flags) 118 register struct proc *p1, *p2; 119 int flags; 120 { 121 struct pcb *pcb2; 122 123 if ((flags & RFPROC) == 0) { 124 #ifdef USER_LDT 125 if ((flags & RFMEM) == 0) { 126 /* unshare user LDT */ 127 struct pcb *pcb1 = &p1->p_addr->u_pcb; 128 struct pcb_ldt *pcb_ldt = pcb1->pcb_ldt; 129 if (pcb_ldt && pcb_ldt->ldt_refcnt > 1) { 130 pcb_ldt = user_ldt_alloc(pcb1,pcb_ldt->ldt_len); 131 user_ldt_free(pcb1); 132 pcb1->pcb_ldt = pcb_ldt; 133 set_user_ldt(pcb1); 134 } 135 } 136 #endif 137 return; 138 } 139 140 #if NNPX > 0 141 /* Ensure that p1's pcb is up to date. */ 142 if (npxproc == p1) 143 npxsave(&p1->p_addr->u_pcb.pcb_savefpu); 144 #endif 145 146 /* Copy p1's pcb. */ 147 p2->p_addr->u_pcb = p1->p_addr->u_pcb; 148 pcb2 = &p2->p_addr->u_pcb; 149 150 /* 151 * Create a new fresh stack for the new process. 152 * Copy the trap frame for the return to user mode as if from a 153 * syscall. This copies the user mode register values. 154 */ 155 p2->p_md.md_regs = (struct trapframe *) 156 ((int)p2->p_addr + UPAGES * PAGE_SIZE - 16) - 1; 157 *p2->p_md.md_regs = *p1->p_md.md_regs; 158 159 /* 160 * Set registers for trampoline to user mode. Leave space for the 161 * return address on stack. These are the kernel mode register values. 162 */ 163 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); 164 pcb2->pcb_edi = p2->p_md.md_regs->tf_edi; 165 pcb2->pcb_esi = (int)fork_return; 166 pcb2->pcb_ebp = p2->p_md.md_regs->tf_ebp; 167 pcb2->pcb_esp = (int)p2->p_md.md_regs - sizeof(void *); 168 pcb2->pcb_ebx = (int)p2; 169 pcb2->pcb_eip = (int)fork_trampoline; 170 /* 171 * pcb2->pcb_ldt: duplicated below, if necessary. 172 * pcb2->pcb_savefpu: cloned above. 173 * pcb2->pcb_flags: cloned above (always 0 here?). 174 * pcb2->pcb_onfault: cloned above (always NULL here?). 175 */ 176 177 #ifdef SMP 178 pcb2->pcb_mpnest = 1; 179 #endif 180 /* 181 * XXX don't copy the i/o pages. this should probably be fixed. 182 */ 183 pcb2->pcb_ext = 0; 184 185 #ifdef USER_LDT 186 /* Copy the LDT, if necessary. */ 187 if (pcb2->pcb_ldt != 0) { 188 if (flags & RFMEM) { 189 pcb2->pcb_ldt->ldt_refcnt++; 190 } else { 191 pcb2->pcb_ldt = user_ldt_alloc(pcb2, 192 pcb2->pcb_ldt->ldt_len); 193 } 194 } 195 #endif 196 197 /* 198 * Now, cpu_switch() can schedule the new process. 199 * pcb_esp is loaded pointing to the cpu_switch() stack frame 200 * containing the return address when exiting cpu_switch. 201 * This will normally be to proc_trampoline(), which will have 202 * %ebx loaded with the new proc's pointer. proc_trampoline() 203 * will set up a stack to call fork_return(p, frame); to complete 204 * the return to user-mode. 205 */ 206 } 207 208 /* 209 * Intercept the return address from a freshly forked process that has NOT 210 * been scheduled yet. 211 * 212 * This is needed to make kernel threads stay in kernel mode. 213 */ 214 void 215 cpu_set_fork_handler(p, func, arg) 216 struct proc *p; 217 void (*func) __P((void *)); 218 void *arg; 219 { 220 /* 221 * Note that the trap frame follows the args, so the function 222 * is really called like this: func(arg, frame); 223 */ 224 p->p_addr->u_pcb.pcb_esi = (int) func; /* function */ 225 p->p_addr->u_pcb.pcb_ebx = (int) arg; /* first arg */ 226 } 227 228 void 229 cpu_exit(p) 230 register struct proc *p; 231 { 232 struct pcb *pcb = &p->p_addr->u_pcb; 233 234 #if NNPX > 0 235 npxexit(p); 236 #endif /* NNPX */ 237 if (pcb->pcb_ext != 0) { 238 /* 239 * XXX do we need to move the TSS off the allocated pages 240 * before freeing them? (not done here) 241 */ 242 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext, 243 ctob(IOPAGES + 1)); 244 pcb->pcb_ext = 0; 245 } 246 #ifdef USER_LDT 247 user_ldt_free(pcb); 248 #endif 249 if (pcb->pcb_flags & PCB_DBREGS) { 250 /* 251 * disable all hardware breakpoints 252 */ 253 reset_dbregs(); 254 pcb->pcb_flags &= ~PCB_DBREGS; 255 } 256 cnt.v_swtch++; 257 cpu_switch(p); 258 panic("cpu_exit"); 259 } 260 261 void 262 cpu_wait(p) 263 struct proc *p; 264 { 265 /* drop per-process resources */ 266 pmap_dispose_proc(p); 267 268 /* and clean-out the vmspace */ 269 vmspace_free(p->p_vmspace); 270 } 271 272 /* 273 * Dump the machine specific header information at the start of a core dump. 274 */ 275 int 276 cpu_coredump(p, vp, cred) 277 struct proc *p; 278 struct vnode *vp; 279 struct ucred *cred; 280 { 281 int error; 282 caddr_t tempuser; 283 284 tempuser = malloc(ctob(UPAGES), M_TEMP, M_WAITOK); 285 if (!tempuser) 286 return EINVAL; 287 288 bzero(tempuser, ctob(UPAGES)); 289 bcopy(p->p_addr, tempuser, sizeof(struct user)); 290 bcopy(p->p_md.md_regs, 291 tempuser + ((caddr_t) p->p_md.md_regs - (caddr_t) p->p_addr), 292 sizeof(struct trapframe)); 293 294 error = vn_rdwr(UIO_WRITE, vp, (caddr_t) tempuser, 295 ctob(UPAGES), 296 (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, 297 cred, (int *)NULL, p); 298 299 free(tempuser, M_TEMP); 300 301 return error; 302 } 303 304 #ifdef notyet 305 static void 306 setredzone(pte, vaddr) 307 u_short *pte; 308 caddr_t vaddr; 309 { 310 /* eventually do this by setting up an expand-down stack segment 311 for ss0: selector, allowing stack access down to top of u. 312 this means though that protection violations need to be handled 313 thru a double fault exception that must do an integral task 314 switch to a known good context, within which a dump can be 315 taken. a sensible scheme might be to save the initial context 316 used by sched (that has physical memory mapped 1:1 at bottom) 317 and take the dump while still in mapped mode */ 318 } 319 #endif 320 321 /* 322 * Convert kernel VA to physical address 323 */ 324 u_long 325 kvtop(void *addr) 326 { 327 vm_offset_t va; 328 329 va = pmap_kextract((vm_offset_t)addr); 330 if (va == 0) 331 panic("kvtop: zero page frame"); 332 return((int)va); 333 } 334 335 /* 336 * Map an IO request into kernel virtual address space. 337 * 338 * All requests are (re)mapped into kernel VA space. 339 * Notice that we use b_bufsize for the size of the buffer 340 * to be mapped. b_bcount might be modified by the driver. 341 */ 342 void 343 vmapbuf(bp) 344 register struct buf *bp; 345 { 346 register caddr_t addr, v, kva; 347 vm_offset_t pa; 348 349 if ((bp->b_flags & B_PHYS) == 0) 350 panic("vmapbuf"); 351 352 for (v = bp->b_saveaddr, addr = (caddr_t)trunc_page((vm_offset_t)bp->b_data); 353 addr < bp->b_data + bp->b_bufsize; 354 addr += PAGE_SIZE, v += PAGE_SIZE) { 355 /* 356 * Do the vm_fault if needed; do the copy-on-write thing 357 * when reading stuff off device into memory. 358 */ 359 vm_fault_quick(addr, 360 (bp->b_iocmd == BIO_READ)?(VM_PROT_READ|VM_PROT_WRITE):VM_PROT_READ); 361 pa = trunc_page(pmap_kextract((vm_offset_t) addr)); 362 if (pa == 0) 363 panic("vmapbuf: page not present"); 364 vm_page_hold(PHYS_TO_VM_PAGE(pa)); 365 pmap_kenter((vm_offset_t) v, pa); 366 } 367 368 kva = bp->b_saveaddr; 369 bp->b_saveaddr = bp->b_data; 370 bp->b_data = kva + (((vm_offset_t) bp->b_data) & PAGE_MASK); 371 } 372 373 /* 374 * Free the io map PTEs associated with this IO operation. 375 * We also invalidate the TLB entries and restore the original b_addr. 376 */ 377 void 378 vunmapbuf(bp) 379 register struct buf *bp; 380 { 381 register caddr_t addr; 382 vm_offset_t pa; 383 384 if ((bp->b_flags & B_PHYS) == 0) 385 panic("vunmapbuf"); 386 387 for (addr = (caddr_t)trunc_page((vm_offset_t)bp->b_data); 388 addr < bp->b_data + bp->b_bufsize; 389 addr += PAGE_SIZE) { 390 pa = trunc_page(pmap_kextract((vm_offset_t) addr)); 391 pmap_kremove((vm_offset_t) addr); 392 vm_page_unhold(PHYS_TO_VM_PAGE(pa)); 393 } 394 395 bp->b_data = bp->b_saveaddr; 396 } 397 398 /* 399 * Force reset the processor by invalidating the entire address space! 400 */ 401 402 #ifdef SMP 403 static void 404 cpu_reset_proxy() 405 { 406 u_int saved_mp_lock; 407 408 cpu_reset_proxy_active = 1; 409 while (cpu_reset_proxy_active == 1) 410 ; /* Wait for other cpu to disable interupts */ 411 saved_mp_lock = mp_lock; 412 mp_lock = 1; 413 printf("cpu_reset_proxy: Grabbed mp lock for BSP\n"); 414 cpu_reset_proxy_active = 3; 415 while (cpu_reset_proxy_active == 3) 416 ; /* Wait for other cpu to enable interrupts */ 417 stop_cpus((1<<cpu_reset_proxyid)); 418 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 419 DELAY(1000000); 420 cpu_reset_real(); 421 } 422 #endif 423 424 void 425 cpu_reset() 426 { 427 #ifdef SMP 428 if (smp_active == 0) { 429 cpu_reset_real(); 430 /* NOTREACHED */ 431 } else { 432 433 u_int map; 434 int cnt; 435 printf("cpu_reset called on cpu#%d\n",cpuid); 436 437 map = other_cpus & ~ stopped_cpus; 438 439 if (map != 0) { 440 printf("cpu_reset: Stopping other CPUs\n"); 441 stop_cpus(map); /* Stop all other CPUs */ 442 } 443 444 if (cpuid == 0) { 445 DELAY(1000000); 446 cpu_reset_real(); 447 /* NOTREACHED */ 448 } else { 449 /* We are not BSP (CPU #0) */ 450 451 cpu_reset_proxyid = cpuid; 452 cpustop_restartfunc = cpu_reset_proxy; 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 __asm __volatile("cli" : : : "memory"); 462 cpu_reset_proxy_active = 2; 463 cnt = 0; 464 while (cpu_reset_proxy_active == 2 && cnt < 10000000) 465 cnt++; /* Do nothing */ 466 if (cpu_reset_proxy_active == 2) { 467 printf("cpu_reset: BSP did not grab mp lock\n"); 468 cpu_reset_real(); /* XXX: Bogus ? */ 469 } 470 cpu_reset_proxy_active = 4; 471 __asm __volatile("sti" : : : "memory"); 472 while (1); 473 /* NOTREACHED */ 474 } 475 } 476 #else 477 cpu_reset_real(); 478 #endif 479 } 480 481 static void 482 cpu_reset_real() 483 { 484 485 #ifdef PC98 486 /* 487 * Attempt to do a CPU reset via CPU reset port. 488 */ 489 disable_intr(); 490 if ((inb(0x35) & 0xa0) != 0xa0) { 491 outb(0x37, 0x0f); /* SHUT0 = 0. */ 492 outb(0x37, 0x0b); /* SHUT1 = 0. */ 493 } 494 outb(0xf0, 0x00); /* Reset. */ 495 #else 496 /* 497 * Attempt to do a CPU reset via the keyboard controller, 498 * do not turn of the GateA20, as any machine that fails 499 * to do the reset here would then end up in no man's land. 500 */ 501 502 #if !defined(BROKEN_KEYBOARD_RESET) 503 outb(IO_KBD + 4, 0xFE); 504 DELAY(500000); /* wait 0.5 sec to see if that did it */ 505 printf("Keyboard reset did not work, attempting CPU shutdown\n"); 506 DELAY(1000000); /* wait 1 sec for printf to complete */ 507 #endif 508 #endif /* PC98 */ 509 /* force a shutdown by unmapping entire address space ! */ 510 bzero((caddr_t) PTD, PAGE_SIZE); 511 512 /* "good night, sweet prince .... <THUNK!>" */ 513 invltlb(); 514 /* NOTREACHED */ 515 while(1); 516 } 517 518 int 519 grow_stack(p, sp) 520 struct proc *p; 521 u_int sp; 522 { 523 int rv; 524 525 rv = vm_map_growstack (p, sp); 526 if (rv != KERN_SUCCESS) 527 return (0); 528 529 return (1); 530 } 531 532 SYSCTL_DECL(_vm_stats_misc); 533 534 static int cnt_prezero; 535 536 SYSCTL_INT(_vm_stats_misc, OID_AUTO, 537 cnt_prezero, CTLFLAG_RD, &cnt_prezero, 0, ""); 538 539 /* 540 * Implement the pre-zeroed page mechanism. 541 * This routine is called from the idle loop. 542 */ 543 544 #define ZIDLE_LO(v) ((v) * 2 / 3) 545 #define ZIDLE_HI(v) ((v) * 4 / 5) 546 547 int 548 vm_page_zero_idle() 549 { 550 static int free_rover; 551 static int zero_state; 552 vm_page_t m; 553 int s; 554 555 /* 556 * Attempt to maintain approximately 1/2 of our free pages in a 557 * PG_ZERO'd state. Add some hysteresis to (attempt to) avoid 558 * generally zeroing a page when the system is near steady-state. 559 * Otherwise we might get 'flutter' during disk I/O / IPC or 560 * fast sleeps. We also do not want to be continuously zeroing 561 * pages because doing so may flush our L1 and L2 caches too much. 562 */ 563 564 if (zero_state && vm_page_zero_count >= ZIDLE_LO(cnt.v_free_count)) 565 return(0); 566 if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count)) 567 return(0); 568 569 #ifdef SMP 570 if (try_mplock()) { 571 #endif 572 s = splvm(); 573 __asm __volatile("sti" : : : "memory"); 574 zero_state = 0; 575 m = vm_page_list_find(PQ_FREE, free_rover, FALSE); 576 if (m != NULL && (m->flags & PG_ZERO) == 0) { 577 vm_page_queues[m->queue].lcnt--; 578 TAILQ_REMOVE(&vm_page_queues[m->queue].pl, m, pageq); 579 m->queue = PQ_NONE; 580 splx(s); 581 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 582 (void)splvm(); 583 vm_page_flag_set(m, PG_ZERO); 584 m->queue = PQ_FREE + m->pc; 585 vm_page_queues[m->queue].lcnt++; 586 TAILQ_INSERT_TAIL(&vm_page_queues[m->queue].pl, m, 587 pageq); 588 ++vm_page_zero_count; 589 ++cnt_prezero; 590 if (vm_page_zero_count >= ZIDLE_HI(cnt.v_free_count)) 591 zero_state = 1; 592 } 593 free_rover = (free_rover + PQ_PRIME2) & PQ_L2_MASK; 594 splx(s); 595 __asm __volatile("cli" : : : "memory"); 596 #ifdef SMP 597 rel_mplock(); 598 #endif 599 return (1); 600 #ifdef SMP 601 } 602 #endif 603 /* 604 * We have to enable interrupts for a moment if the try_mplock fails 605 * in order to potentially take an IPI. XXX this should be in 606 * swtch.s 607 */ 608 __asm __volatile("sti; nop; cli" : : : "memory"); 609 return (0); 610 } 611 612 /* 613 * Software interrupt handler for queued VM system processing. 614 */ 615 void 616 swi_vm() 617 { 618 if (busdma_swi_pending != 0) 619 busdma_swi(); 620 } 621 622 /* 623 * Tell whether this address is in some physical memory region. 624 * Currently used by the kernel coredump code in order to avoid 625 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 626 * or other unpredictable behaviour. 627 */ 628 629 #include "isa.h" 630 631 int 632 is_physical_memory(addr) 633 vm_offset_t addr; 634 { 635 636 #if NISA > 0 637 /* The ISA ``memory hole''. */ 638 if (addr >= 0xa0000 && addr < 0x100000) 639 return 0; 640 #endif 641 642 /* 643 * stuff other tests for known memory-mapped devices (PCI?) 644 * here 645 */ 646 647 return 1; 648 } 649