vm_machdep.c revision 230426
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 */ 42 43#include <sys/cdefs.h> 44__FBSDID("$FreeBSD: head/sys/amd64/amd64/vm_machdep.c 230426 2012-01-21 17:45:27Z kib $"); 45 46#include "opt_isa.h" 47#include "opt_cpu.h" 48#include "opt_compat.h" 49 50#include <sys/param.h> 51#include <sys/systm.h> 52#include <sys/bio.h> 53#include <sys/buf.h> 54#include <sys/kernel.h> 55#include <sys/ktr.h> 56#include <sys/lock.h> 57#include <sys/malloc.h> 58#include <sys/mbuf.h> 59#include <sys/mutex.h> 60#include <sys/pioctl.h> 61#include <sys/proc.h> 62#include <sys/sf_buf.h> 63#include <sys/smp.h> 64#include <sys/sysctl.h> 65#include <sys/sysent.h> 66#include <sys/unistd.h> 67#include <sys/vnode.h> 68#include <sys/vmmeter.h> 69 70#include <machine/cpu.h> 71#include <machine/md_var.h> 72#include <machine/pcb.h> 73#include <machine/smp.h> 74#include <machine/specialreg.h> 75#include <machine/tss.h> 76 77#include <vm/vm.h> 78#include <vm/vm_extern.h> 79#include <vm/vm_kern.h> 80#include <vm/vm_page.h> 81#include <vm/vm_map.h> 82#include <vm/vm_param.h> 83 84#include <x86/isa/isa.h> 85 86static void cpu_reset_real(void); 87#ifdef SMP 88static void cpu_reset_proxy(void); 89static u_int cpu_reset_proxyid; 90static volatile u_int cpu_reset_proxy_active; 91#endif 92 93struct savefpu * 94get_pcb_user_save_td(struct thread *td) 95{ 96 vm_offset_t p; 97 98 p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE - 99 cpu_max_ext_state_size; 100 KASSERT((p % 64) == 0, ("Unaligned pcb_user_save area")); 101 return ((struct savefpu *)p); 102} 103 104struct savefpu * 105get_pcb_user_save_pcb(struct pcb *pcb) 106{ 107 vm_offset_t p; 108 109 p = (vm_offset_t)(pcb + 1); 110 return ((struct savefpu *)p); 111} 112 113struct pcb * 114get_pcb_td(struct thread *td) 115{ 116 vm_offset_t p; 117 118 p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE - 119 cpu_max_ext_state_size - sizeof(struct pcb); 120 return ((struct pcb *)p); 121} 122 123void * 124alloc_fpusave(int flags) 125{ 126 struct pcb *res; 127 struct savefpu_ymm *sf; 128 129 res = malloc(cpu_max_ext_state_size, M_DEVBUF, flags); 130 if (use_xsave) { 131 sf = (struct savefpu_ymm *)res; 132 bzero(&sf->sv_xstate.sx_hd, sizeof(sf->sv_xstate.sx_hd)); 133 sf->sv_xstate.sx_hd.xstate_bv = xsave_mask; 134 } 135 return (res); 136} 137 138/* 139 * Finish a fork operation, with process p2 nearly set up. 140 * Copy and update the pcb, set up the stack so that the child 141 * ready to run and return to user mode. 142 */ 143void 144cpu_fork(td1, p2, td2, flags) 145 register struct thread *td1; 146 register struct proc *p2; 147 struct thread *td2; 148 int flags; 149{ 150 register struct proc *p1; 151 struct pcb *pcb2; 152 struct mdproc *mdp1, *mdp2; 153 struct proc_ldt *pldt; 154 pmap_t pmap2; 155 156 p1 = td1->td_proc; 157 if ((flags & RFPROC) == 0) { 158 if ((flags & RFMEM) == 0) { 159 /* unshare user LDT */ 160 mdp1 = &p1->p_md; 161 mtx_lock(&dt_lock); 162 if ((pldt = mdp1->md_ldt) != NULL && 163 pldt->ldt_refcnt > 1 && 164 user_ldt_alloc(p1, 1) == NULL) 165 panic("could not copy LDT"); 166 mtx_unlock(&dt_lock); 167 } 168 return; 169 } 170 171 /* Ensure that td1's pcb is up to date. */ 172 fpuexit(td1); 173 174 /* Point the pcb to the top of the stack */ 175 pcb2 = get_pcb_td(td2); 176 td2->td_pcb = pcb2; 177 178 /* Copy td1's pcb */ 179 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 180 181 /* Properly initialize pcb_save */ 182 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2); 183 bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2), 184 cpu_max_ext_state_size); 185 186 /* Point mdproc and then copy over td1's contents */ 187 mdp2 = &p2->p_md; 188 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 189 190 /* 191 * Create a new fresh stack for the new process. 192 * Copy the trap frame for the return to user mode as if from a 193 * syscall. This copies most of the user mode register values. 194 */ 195 td2->td_frame = (struct trapframe *)td2->td_pcb - 1; 196 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 197 198 td2->td_frame->tf_rax = 0; /* Child returns zero */ 199 td2->td_frame->tf_rflags &= ~PSL_C; /* success */ 200 td2->td_frame->tf_rdx = 1; 201 202 /* 203 * If the parent process has the trap bit set (i.e. a debugger had 204 * single stepped the process to the system call), we need to clear 205 * the trap flag from the new frame unless the debugger had set PF_FORK 206 * on the parent. Otherwise, the child will receive a (likely 207 * unexpected) SIGTRAP when it executes the first instruction after 208 * returning to userland. 209 */ 210 if ((p1->p_pfsflags & PF_FORK) == 0) 211 td2->td_frame->tf_rflags &= ~PSL_T; 212 213 /* 214 * Set registers for trampoline to user mode. Leave space for the 215 * return address on stack. These are the kernel mode register values. 216 */ 217 pmap2 = vmspace_pmap(p2->p_vmspace); 218 pcb2->pcb_cr3 = DMAP_TO_PHYS((vm_offset_t)pmap2->pm_pml4); 219 pcb2->pcb_r12 = (register_t)fork_return; /* fork_trampoline argument */ 220 pcb2->pcb_rbp = 0; 221 pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *); 222 pcb2->pcb_rbx = (register_t)td2; /* fork_trampoline argument */ 223 pcb2->pcb_rip = (register_t)fork_trampoline; 224 /*- 225 * pcb2->pcb_dr*: cloned above. 226 * pcb2->pcb_savefpu: cloned above. 227 * pcb2->pcb_flags: cloned above. 228 * pcb2->pcb_onfault: cloned above (always NULL here?). 229 * pcb2->pcb_[fg]sbase: cloned above 230 */ 231 232 /* Setup to release spin count in fork_exit(). */ 233 td2->td_md.md_spinlock_count = 1; 234 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 235 236 /* As an i386, do not copy io permission bitmap. */ 237 pcb2->pcb_tssp = NULL; 238 239 /* New segment registers. */ 240 set_pcb_flags(pcb2, PCB_FULL_IRET); 241 242 /* Copy the LDT, if necessary. */ 243 mdp1 = &td1->td_proc->p_md; 244 mdp2 = &p2->p_md; 245 mtx_lock(&dt_lock); 246 if (mdp1->md_ldt != NULL) { 247 if (flags & RFMEM) { 248 mdp1->md_ldt->ldt_refcnt++; 249 mdp2->md_ldt = mdp1->md_ldt; 250 bcopy(&mdp1->md_ldt_sd, &mdp2->md_ldt_sd, sizeof(struct 251 system_segment_descriptor)); 252 } else { 253 mdp2->md_ldt = NULL; 254 mdp2->md_ldt = user_ldt_alloc(p2, 0); 255 if (mdp2->md_ldt == NULL) 256 panic("could not copy LDT"); 257 amd64_set_ldt_data(td2, 0, max_ldt_segment, 258 (struct user_segment_descriptor *) 259 mdp1->md_ldt->ldt_base); 260 } 261 } else 262 mdp2->md_ldt = NULL; 263 mtx_unlock(&dt_lock); 264 265 /* 266 * Now, cpu_switch() can schedule the new process. 267 * pcb_rsp is loaded pointing to the cpu_switch() stack frame 268 * containing the return address when exiting cpu_switch. 269 * This will normally be to fork_trampoline(), which will have 270 * %ebx loaded with the new proc's pointer. fork_trampoline() 271 * will set up a stack to call fork_return(p, frame); to complete 272 * the return to user-mode. 273 */ 274} 275 276/* 277 * Intercept the return address from a freshly forked process that has NOT 278 * been scheduled yet. 279 * 280 * This is needed to make kernel threads stay in kernel mode. 281 */ 282void 283cpu_set_fork_handler(td, func, arg) 284 struct thread *td; 285 void (*func)(void *); 286 void *arg; 287{ 288 /* 289 * Note that the trap frame follows the args, so the function 290 * is really called like this: func(arg, frame); 291 */ 292 td->td_pcb->pcb_r12 = (long) func; /* function */ 293 td->td_pcb->pcb_rbx = (long) arg; /* first arg */ 294} 295 296void 297cpu_exit(struct thread *td) 298{ 299 300 /* 301 * If this process has a custom LDT, release it. 302 */ 303 mtx_lock(&dt_lock); 304 if (td->td_proc->p_md.md_ldt != 0) 305 user_ldt_free(td); 306 else 307 mtx_unlock(&dt_lock); 308} 309 310void 311cpu_thread_exit(struct thread *td) 312{ 313 struct pcb *pcb; 314 315 critical_enter(); 316 if (td == PCPU_GET(fpcurthread)) 317 fpudrop(); 318 critical_exit(); 319 320 pcb = td->td_pcb; 321 322 /* Disable any hardware breakpoints. */ 323 if (pcb->pcb_flags & PCB_DBREGS) { 324 reset_dbregs(); 325 clear_pcb_flags(pcb, PCB_DBREGS); 326 } 327} 328 329void 330cpu_thread_clean(struct thread *td) 331{ 332 struct pcb *pcb; 333 334 pcb = td->td_pcb; 335 336 /* 337 * Clean TSS/iomap 338 */ 339 if (pcb->pcb_tssp != NULL) { 340 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_tssp, 341 ctob(IOPAGES + 1)); 342 pcb->pcb_tssp = NULL; 343 } 344} 345 346void 347cpu_thread_swapin(struct thread *td) 348{ 349} 350 351void 352cpu_thread_swapout(struct thread *td) 353{ 354} 355 356void 357cpu_thread_alloc(struct thread *td) 358{ 359 struct pcb *pcb; 360 struct xstate_hdr *xhdr; 361 362 td->td_pcb = pcb = get_pcb_td(td); 363 td->td_frame = (struct trapframe *)pcb - 1; 364 pcb->pcb_save = get_pcb_user_save_pcb(pcb); 365 if (use_xsave) { 366 xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1); 367 bzero(xhdr, sizeof(*xhdr)); 368 xhdr->xstate_bv = xsave_mask; 369 } 370} 371 372void 373cpu_thread_free(struct thread *td) 374{ 375 376 cpu_thread_clean(td); 377} 378 379void 380cpu_set_syscall_retval(struct thread *td, int error) 381{ 382 383 switch (error) { 384 case 0: 385 td->td_frame->tf_rax = td->td_retval[0]; 386 td->td_frame->tf_rdx = td->td_retval[1]; 387 td->td_frame->tf_rflags &= ~PSL_C; 388 break; 389 390 case ERESTART: 391 /* 392 * Reconstruct pc, we know that 'syscall' is 2 bytes, 393 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 394 * We saved this in tf_err. 395 * %r10 (which was holding the value of %rcx) is restored 396 * for the next iteration. 397 * %r10 restore is only required for freebsd/amd64 processes, 398 * but shall be innocent for any ia32 ABI. 399 */ 400 td->td_frame->tf_rip -= td->td_frame->tf_err; 401 td->td_frame->tf_r10 = td->td_frame->tf_rcx; 402 break; 403 404 case EJUSTRETURN: 405 break; 406 407 default: 408 if (td->td_proc->p_sysent->sv_errsize) { 409 if (error >= td->td_proc->p_sysent->sv_errsize) 410 error = -1; /* XXX */ 411 else 412 error = td->td_proc->p_sysent->sv_errtbl[error]; 413 } 414 td->td_frame->tf_rax = error; 415 td->td_frame->tf_rflags |= PSL_C; 416 break; 417 } 418} 419 420/* 421 * Initialize machine state (pcb and trap frame) for a new thread about to 422 * upcall. Put enough state in the new thread's PCB to get it to go back 423 * userret(), where we can intercept it again to set the return (upcall) 424 * Address and stack, along with those from upcals that are from other sources 425 * such as those generated in thread_userret() itself. 426 */ 427void 428cpu_set_upcall(struct thread *td, struct thread *td0) 429{ 430 struct pcb *pcb2; 431 432 /* Point the pcb to the top of the stack. */ 433 pcb2 = td->td_pcb; 434 435 /* 436 * Copy the upcall pcb. This loads kernel regs. 437 * Those not loaded individually below get their default 438 * values here. 439 */ 440 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); 441 clear_pcb_flags(pcb2, PCB_FPUINITDONE | PCB_USERFPUINITDONE); 442 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2); 443 bcopy(get_pcb_user_save_td(td0), pcb2->pcb_save, 444 cpu_max_ext_state_size); 445 set_pcb_flags(pcb2, PCB_FULL_IRET); 446 447 /* 448 * Create a new fresh stack for the new thread. 449 */ 450 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 451 452 /* If the current thread has the trap bit set (i.e. a debugger had 453 * single stepped the process to the system call), we need to clear 454 * the trap flag from the new frame. Otherwise, the new thread will 455 * receive a (likely unexpected) SIGTRAP when it executes the first 456 * instruction after returning to userland. 457 */ 458 td->td_frame->tf_rflags &= ~PSL_T; 459 460 /* 461 * Set registers for trampoline to user mode. Leave space for the 462 * return address on stack. These are the kernel mode register values. 463 */ 464 pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */ 465 pcb2->pcb_rbp = 0; 466 pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */ 467 pcb2->pcb_rbx = (register_t)td; /* trampoline arg */ 468 pcb2->pcb_rip = (register_t)fork_trampoline; 469 /* 470 * If we didn't copy the pcb, we'd need to do the following registers: 471 * pcb2->pcb_cr3: cloned above. 472 * pcb2->pcb_dr*: cloned above. 473 * pcb2->pcb_savefpu: cloned above. 474 * pcb2->pcb_onfault: cloned above (always NULL here?). 475 * pcb2->pcb_[fg]sbase: cloned above 476 */ 477 478 /* Setup to release spin count in fork_exit(). */ 479 td->td_md.md_spinlock_count = 1; 480 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 481} 482 483/* 484 * Set that machine state for performing an upcall that has to 485 * be done in thread_userret() so that those upcalls generated 486 * in thread_userret() itself can be done as well. 487 */ 488void 489cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg, 490 stack_t *stack) 491{ 492 493 /* 494 * Do any extra cleaning that needs to be done. 495 * The thread may have optional components 496 * that are not present in a fresh thread. 497 * This may be a recycled thread so make it look 498 * as though it's newly allocated. 499 */ 500 cpu_thread_clean(td); 501 502#ifdef COMPAT_FREEBSD32 503 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 504 /* 505 * Set the trap frame to point at the beginning of the uts 506 * function. 507 */ 508 td->td_frame->tf_rbp = 0; 509 td->td_frame->tf_rsp = 510 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; 511 td->td_frame->tf_rip = (uintptr_t)entry; 512 513 /* 514 * Pass the address of the mailbox for this kse to the uts 515 * function as a parameter on the stack. 516 */ 517 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)), 518 (uint32_t)(uintptr_t)arg); 519 520 return; 521 } 522#endif 523 524 /* 525 * Set the trap frame to point at the beginning of the uts 526 * function. 527 */ 528 td->td_frame->tf_rbp = 0; 529 td->td_frame->tf_rsp = 530 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f; 531 td->td_frame->tf_rsp -= 8; 532 td->td_frame->tf_rip = (register_t)entry; 533 td->td_frame->tf_ds = _udatasel; 534 td->td_frame->tf_es = _udatasel; 535 td->td_frame->tf_fs = _ufssel; 536 td->td_frame->tf_gs = _ugssel; 537 td->td_frame->tf_flags = TF_HASSEGS; 538 539 /* 540 * Pass the address of the mailbox for this kse to the uts 541 * function as a parameter on the stack. 542 */ 543 td->td_frame->tf_rdi = (register_t)arg; 544} 545 546int 547cpu_set_user_tls(struct thread *td, void *tls_base) 548{ 549 struct pcb *pcb; 550 551 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS) 552 return (EINVAL); 553 554 pcb = td->td_pcb; 555#ifdef COMPAT_FREEBSD32 556 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 557 pcb->pcb_gsbase = (register_t)tls_base; 558 return (0); 559 } 560#endif 561 pcb->pcb_fsbase = (register_t)tls_base; 562 set_pcb_flags(pcb, PCB_FULL_IRET); 563 return (0); 564} 565 566#ifdef SMP 567static void 568cpu_reset_proxy() 569{ 570 cpuset_t tcrp; 571 572 cpu_reset_proxy_active = 1; 573 while (cpu_reset_proxy_active == 1) 574 ; /* Wait for other cpu to see that we've started */ 575 CPU_SETOF(cpu_reset_proxyid, &tcrp); 576 stop_cpus(tcrp); 577 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 578 DELAY(1000000); 579 cpu_reset_real(); 580} 581#endif 582 583void 584cpu_reset() 585{ 586#ifdef SMP 587 cpuset_t map; 588 u_int cnt; 589 590 if (smp_active) { 591 map = all_cpus; 592 CPU_CLR(PCPU_GET(cpuid), &map); 593 CPU_NAND(&map, &stopped_cpus); 594 if (!CPU_EMPTY(&map)) { 595 printf("cpu_reset: Stopping other CPUs\n"); 596 stop_cpus(map); 597 } 598 599 if (PCPU_GET(cpuid) != 0) { 600 cpu_reset_proxyid = PCPU_GET(cpuid); 601 cpustop_restartfunc = cpu_reset_proxy; 602 cpu_reset_proxy_active = 0; 603 printf("cpu_reset: Restarting BSP\n"); 604 605 /* Restart CPU #0. */ 606 CPU_SETOF(0, &started_cpus); 607 wmb(); 608 609 cnt = 0; 610 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 611 cnt++; /* Wait for BSP to announce restart */ 612 if (cpu_reset_proxy_active == 0) 613 printf("cpu_reset: Failed to restart BSP\n"); 614 enable_intr(); 615 cpu_reset_proxy_active = 2; 616 617 while (1); 618 /* NOTREACHED */ 619 } 620 621 DELAY(1000000); 622 } 623#endif 624 cpu_reset_real(); 625 /* NOTREACHED */ 626} 627 628static void 629cpu_reset_real() 630{ 631 struct region_descriptor null_idt; 632 int b; 633 634 disable_intr(); 635 636 /* 637 * Attempt to do a CPU reset via the keyboard controller, 638 * do not turn off GateA20, as any machine that fails 639 * to do the reset here would then end up in no man's land. 640 */ 641 outb(IO_KBD + 4, 0xFE); 642 DELAY(500000); /* wait 0.5 sec to see if that did it */ 643 644 /* 645 * Attempt to force a reset via the Reset Control register at 646 * I/O port 0xcf9. Bit 2 forces a system reset when it 647 * transitions from 0 to 1. Bit 1 selects the type of reset 648 * to attempt: 0 selects a "soft" reset, and 1 selects a 649 * "hard" reset. We try a "hard" reset. The first write sets 650 * bit 1 to select a "hard" reset and clears bit 2. The 651 * second write forces a 0 -> 1 transition in bit 2 to trigger 652 * a reset. 653 */ 654 outb(0xcf9, 0x2); 655 outb(0xcf9, 0x6); 656 DELAY(500000); /* wait 0.5 sec to see if that did it */ 657 658 /* 659 * Attempt to force a reset via the Fast A20 and Init register 660 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate. 661 * Bit 0 asserts INIT# when set to 1. We are careful to only 662 * preserve bit 1 while setting bit 0. We also must clear bit 663 * 0 before setting it if it isn't already clear. 664 */ 665 b = inb(0x92); 666 if (b != 0xff) { 667 if ((b & 0x1) != 0) 668 outb(0x92, b & 0xfe); 669 outb(0x92, b | 0x1); 670 DELAY(500000); /* wait 0.5 sec to see if that did it */ 671 } 672 673 printf("No known reset method worked, attempting CPU shutdown\n"); 674 DELAY(1000000); /* wait 1 sec for printf to complete */ 675 676 /* Wipe the IDT. */ 677 null_idt.rd_limit = 0; 678 null_idt.rd_base = 0; 679 lidt(&null_idt); 680 681 /* "good night, sweet prince .... <THUNK!>" */ 682 breakpoint(); 683 684 /* NOTREACHED */ 685 while(1); 686} 687 688/* 689 * Allocate an sf_buf for the given vm_page. On this machine, however, there 690 * is no sf_buf object. Instead, an opaque pointer to the given vm_page is 691 * returned. 692 */ 693struct sf_buf * 694sf_buf_alloc(struct vm_page *m, int pri) 695{ 696 697 return ((struct sf_buf *)m); 698} 699 700/* 701 * Free the sf_buf. In fact, do nothing because there are no resources 702 * associated with the sf_buf. 703 */ 704void 705sf_buf_free(struct sf_buf *sf) 706{ 707} 708 709/* 710 * Software interrupt handler for queued VM system processing. 711 */ 712void 713swi_vm(void *dummy) 714{ 715 if (busdma_swi_pending != 0) 716 busdma_swi(); 717} 718 719/* 720 * Tell whether this address is in some physical memory region. 721 * Currently used by the kernel coredump code in order to avoid 722 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 723 * or other unpredictable behaviour. 724 */ 725 726int 727is_physical_memory(vm_paddr_t addr) 728{ 729 730#ifdef DEV_ISA 731 /* The ISA ``memory hole''. */ 732 if (addr >= 0xa0000 && addr < 0x100000) 733 return 0; 734#endif 735 736 /* 737 * stuff other tests for known memory-mapped devices (PCI?) 738 * here 739 */ 740 741 return 1; 742} 743