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("$FreeBSD$"); 45 46 #include "opt_isa.h" 47 #include "opt_npx.h" 48 #include "opt_reset.h" 49 #include "opt_cpu.h" 50 #include "opt_xbox.h" 51 52 #include <sys/param.h> 53 #include <sys/systm.h> 54 #include <sys/bio.h> 55 #include <sys/buf.h> 56 #include <sys/kernel.h> 57 #include <sys/ktr.h> 58 #include <sys/lock.h> 59 #include <sys/malloc.h> 60 #include <sys/mbuf.h> 61 #include <sys/mutex.h> 62 #include <sys/pioctl.h> 63 #include <sys/proc.h> 64 #include <sys/sysent.h> 65 #include <sys/sf_buf.h> 66 #include <sys/smp.h> 67 #include <sys/sched.h> 68 #include <sys/sysctl.h> 69 #include <sys/unistd.h> 70 #include <sys/vnode.h> 71 #include <sys/vmmeter.h> 72 73 #include <machine/cpu.h> 74 #include <machine/cputypes.h> 75 #include <machine/md_var.h> 76 #include <machine/pcb.h> 77 #include <machine/pcb_ext.h> 78 #include <machine/smp.h> 79 #include <machine/vm86.h> 80 81 #ifdef CPU_ELAN 82 #include <machine/elan_mmcr.h> 83 #endif 84 85 #include <vm/vm.h> 86 #include <vm/vm_extern.h> 87 #include <vm/vm_kern.h> 88 #include <vm/vm_page.h> 89 #include <vm/vm_map.h> 90 #include <vm/vm_param.h> 91 92 #ifdef XEN 93 #include <xen/hypervisor.h> 94 #endif 95 #ifdef PC98 96 #include <pc98/cbus/cbus.h> 97 #else 98 #include <isa/isareg.h> 99 #endif 100 101 #ifdef XBOX 102 #include <machine/xbox.h> 103 #endif 104 105 #ifndef NSFBUFS 106 #define NSFBUFS (512 + maxusers * 16) 107 #endif 108 109 _Static_assert(OFFSETOF_CURTHREAD == offsetof(struct pcpu, pc_curthread), 110 "OFFSETOF_CURTHREAD does not correspond with offset of pc_curthread."); 111 _Static_assert(OFFSETOF_CURPCB == offsetof(struct pcpu, pc_curpcb), 112 "OFFSETOF_CURPCB does not correspond with offset of pc_curpcb."); 113 114 static void cpu_reset_real(void); 115 #ifdef SMP 116 static void cpu_reset_proxy(void); 117 static u_int cpu_reset_proxyid; 118 static volatile u_int cpu_reset_proxy_active; 119 #endif 120 121 extern int _ucodesel, _udatasel; 122 123 /* 124 * Finish a fork operation, with process p2 nearly set up. 125 * Copy and update the pcb, set up the stack so that the child 126 * ready to run and return to user mode. 127 */ 128 void 129 cpu_fork(td1, p2, td2, flags) 130 register struct thread *td1; 131 register struct proc *p2; 132 struct thread *td2; 133 int flags; 134 { 135 register struct proc *p1; 136 struct pcb *pcb2; 137 struct mdproc *mdp2; 138 139 p1 = td1->td_proc; 140 if ((flags & RFPROC) == 0) { 141 if ((flags & RFMEM) == 0) { 142 /* unshare user LDT */ 143 struct mdproc *mdp1 = &p1->p_md; 144 struct proc_ldt *pldt, *pldt1; 145 146 mtx_lock_spin(&dt_lock); 147 if ((pldt1 = mdp1->md_ldt) != NULL && 148 pldt1->ldt_refcnt > 1) { 149 pldt = user_ldt_alloc(mdp1, pldt1->ldt_len); 150 if (pldt == NULL) 151 panic("could not copy LDT"); 152 mdp1->md_ldt = pldt; 153 set_user_ldt(mdp1); 154 user_ldt_deref(pldt1); 155 } else 156 mtx_unlock_spin(&dt_lock); 157 } 158 return; 159 } 160 161 /* Ensure that td1's pcb is up to date. */ 162 if (td1 == curthread) 163 td1->td_pcb->pcb_gs = rgs(); 164 #ifdef DEV_NPX 165 critical_enter(); 166 if (PCPU_GET(fpcurthread) == td1) 167 npxsave(td1->td_pcb->pcb_save); 168 critical_exit(); 169 #endif 170 171 /* Point the pcb to the top of the stack */ 172 pcb2 = (struct pcb *)(td2->td_kstack + 173 td2->td_kstack_pages * PAGE_SIZE) - 1; 174 td2->td_pcb = pcb2; 175 176 /* Copy td1's pcb */ 177 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 178 179 /* Properly initialize pcb_save */ 180 pcb2->pcb_save = &pcb2->pcb_user_save; 181 182 /* Point mdproc and then copy over td1's contents */ 183 mdp2 = &p2->p_md; 184 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 185 186 /* 187 * Create a new fresh stack for the new process. 188 * Copy the trap frame for the return to user mode as if from a 189 * syscall. This copies most of the user mode register values. 190 * The -16 is so we can expand the trapframe if we go to vm86. 191 */ 192 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1; 193 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 194 195 td2->td_frame->tf_eax = 0; /* Child returns zero */ 196 td2->td_frame->tf_eflags &= ~PSL_C; /* success */ 197 td2->td_frame->tf_edx = 1; 198 199 /* 200 * If the parent process has the trap bit set (i.e. a debugger had 201 * single stepped the process to the system call), we need to clear 202 * the trap flag from the new frame unless the debugger had set PF_FORK 203 * on the parent. Otherwise, the child will receive a (likely 204 * unexpected) SIGTRAP when it executes the first instruction after 205 * returning to userland. 206 */ 207 if ((p1->p_pfsflags & PF_FORK) == 0) 208 td2->td_frame->tf_eflags &= ~PSL_T; 209 210 /* 211 * Set registers for trampoline to user mode. Leave space for the 212 * return address on stack. These are the kernel mode register values. 213 */ 214 #ifdef PAE 215 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt); 216 #else 217 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); 218 #endif 219 pcb2->pcb_edi = 0; 220 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */ 221 pcb2->pcb_ebp = 0; 222 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *); 223 pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */ 224 pcb2->pcb_eip = (int)fork_trampoline; 225 pcb2->pcb_psl = PSL_KERNEL; /* ints disabled */ 226 /*- 227 * pcb2->pcb_dr*: cloned above. 228 * pcb2->pcb_savefpu: cloned above. 229 * pcb2->pcb_flags: cloned above. 230 * pcb2->pcb_onfault: cloned above (always NULL here?). 231 * pcb2->pcb_gs: cloned above. 232 * pcb2->pcb_ext: cleared below. 233 */ 234 235 /* 236 * XXX don't copy the i/o pages. this should probably be fixed. 237 */ 238 pcb2->pcb_ext = 0; 239 240 /* Copy the LDT, if necessary. */ 241 mtx_lock_spin(&dt_lock); 242 if (mdp2->md_ldt != NULL) { 243 if (flags & RFMEM) { 244 mdp2->md_ldt->ldt_refcnt++; 245 } else { 246 mdp2->md_ldt = user_ldt_alloc(mdp2, 247 mdp2->md_ldt->ldt_len); 248 if (mdp2->md_ldt == NULL) 249 panic("could not copy LDT"); 250 } 251 } 252 mtx_unlock_spin(&dt_lock); 253 254 /* Setup to release spin count in fork_exit(). */ 255 td2->td_md.md_spinlock_count = 1; 256 /* 257 * XXX XEN need to check on PSL_USER is handled 258 */ 259 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 260 /* 261 * Now, cpu_switch() can schedule the new process. 262 * pcb_esp is loaded pointing to the cpu_switch() stack frame 263 * containing the return address when exiting cpu_switch. 264 * This will normally be to fork_trampoline(), which will have 265 * %ebx loaded with the new proc's pointer. fork_trampoline() 266 * will set up a stack to call fork_return(p, frame); to complete 267 * the return to user-mode. 268 */ 269 } 270 271 /* 272 * Intercept the return address from a freshly forked process that has NOT 273 * been scheduled yet. 274 * 275 * This is needed to make kernel threads stay in kernel mode. 276 */ 277 void 278 cpu_set_fork_handler(td, func, arg) 279 struct thread *td; 280 void (*func)(void *); 281 void *arg; 282 { 283 /* 284 * Note that the trap frame follows the args, so the function 285 * is really called like this: func(arg, frame); 286 */ 287 td->td_pcb->pcb_esi = (int) func; /* function */ 288 td->td_pcb->pcb_ebx = (int) arg; /* first arg */ 289 } 290 291 void 292 cpu_exit(struct thread *td) 293 { 294 295 /* 296 * If this process has a custom LDT, release it. Reset pc->pcb_gs 297 * and %gs before we free it in case they refer to an LDT entry. 298 */ 299 mtx_lock_spin(&dt_lock); 300 if (td->td_proc->p_md.md_ldt) { 301 td->td_pcb->pcb_gs = _udatasel; 302 load_gs(_udatasel); 303 user_ldt_free(td); 304 } else 305 mtx_unlock_spin(&dt_lock); 306 } 307 308 void 309 cpu_thread_exit(struct thread *td) 310 { 311 312 #ifdef DEV_NPX 313 critical_enter(); 314 if (td == PCPU_GET(fpcurthread)) 315 npxdrop(); 316 critical_exit(); 317 #endif 318 319 /* Disable any hardware breakpoints. */ 320 if (td->td_pcb->pcb_flags & PCB_DBREGS) { 321 reset_dbregs(); 322 td->td_pcb->pcb_flags &= ~PCB_DBREGS; 323 } 324 } 325 326 void 327 cpu_thread_clean(struct thread *td) 328 { 329 struct pcb *pcb; 330 331 pcb = td->td_pcb; 332 if (pcb->pcb_ext != NULL) { 333 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */ 334 /* 335 * XXX do we need to move the TSS off the allocated pages 336 * before freeing them? (not done here) 337 */ 338 kmem_free(kernel_arena, (vm_offset_t)pcb->pcb_ext, 339 ctob(IOPAGES + 1)); 340 pcb->pcb_ext = NULL; 341 } 342 } 343 344 void 345 cpu_thread_swapin(struct thread *td) 346 { 347 } 348 349 void 350 cpu_thread_swapout(struct thread *td) 351 { 352 } 353 354 void 355 cpu_thread_alloc(struct thread *td) 356 { 357 358 td->td_pcb = (struct pcb *)(td->td_kstack + 359 td->td_kstack_pages * PAGE_SIZE) - 1; 360 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1; 361 td->td_pcb->pcb_ext = NULL; 362 td->td_pcb->pcb_save = &td->td_pcb->pcb_user_save; 363 } 364 365 void 366 cpu_thread_free(struct thread *td) 367 { 368 369 cpu_thread_clean(td); 370 } 371 372 void 373 cpu_set_syscall_retval(struct thread *td, int error) 374 { 375 376 switch (error) { 377 case 0: 378 td->td_frame->tf_eax = td->td_retval[0]; 379 td->td_frame->tf_edx = td->td_retval[1]; 380 td->td_frame->tf_eflags &= ~PSL_C; 381 break; 382 383 case ERESTART: 384 /* 385 * Reconstruct pc, assuming lcall $X,y is 7 bytes, int 386 * 0x80 is 2 bytes. We saved this in tf_err. 387 */ 388 td->td_frame->tf_eip -= td->td_frame->tf_err; 389 break; 390 391 case EJUSTRETURN: 392 break; 393 394 default: 395 if (td->td_proc->p_sysent->sv_errsize) { 396 if (error >= td->td_proc->p_sysent->sv_errsize) 397 error = -1; /* XXX */ 398 else 399 error = td->td_proc->p_sysent->sv_errtbl[error]; 400 } 401 td->td_frame->tf_eax = error; 402 td->td_frame->tf_eflags |= PSL_C; 403 break; 404 } 405 } 406 407 /* 408 * Initialize machine state (pcb and trap frame) for a new thread about to 409 * upcall. Put enough state in the new thread's PCB to get it to go back 410 * userret(), where we can intercept it again to set the return (upcall) 411 * Address and stack, along with those from upcals that are from other sources 412 * such as those generated in thread_userret() itself. 413 */ 414 void 415 cpu_set_upcall(struct thread *td, struct thread *td0) 416 { 417 struct pcb *pcb2; 418 419 /* Point the pcb to the top of the stack. */ 420 pcb2 = td->td_pcb; 421 422 /* 423 * Copy the upcall pcb. This loads kernel regs. 424 * Those not loaded individually below get their default 425 * values here. 426 */ 427 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); 428 pcb2->pcb_flags &= ~(PCB_NPXINITDONE | PCB_NPXUSERINITDONE | 429 PCB_KERNNPX); 430 pcb2->pcb_save = &pcb2->pcb_user_save; 431 432 /* 433 * Create a new fresh stack for the new thread. 434 */ 435 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 436 437 /* If the current thread has the trap bit set (i.e. a debugger had 438 * single stepped the process to the system call), we need to clear 439 * the trap flag from the new frame. Otherwise, the new thread will 440 * receive a (likely unexpected) SIGTRAP when it executes the first 441 * instruction after returning to userland. 442 */ 443 td->td_frame->tf_eflags &= ~PSL_T; 444 445 /* 446 * Set registers for trampoline to user mode. Leave space for the 447 * return address on stack. These are the kernel mode register values. 448 */ 449 pcb2->pcb_edi = 0; 450 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */ 451 pcb2->pcb_ebp = 0; 452 pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */ 453 pcb2->pcb_ebx = (int)td; /* trampoline arg */ 454 pcb2->pcb_eip = (int)fork_trampoline; 455 pcb2->pcb_psl &= ~(PSL_I); /* interrupts must be disabled */ 456 pcb2->pcb_gs = rgs(); 457 /* 458 * If we didn't copy the pcb, we'd need to do the following registers: 459 * pcb2->pcb_cr3: cloned above. 460 * pcb2->pcb_dr*: cloned above. 461 * pcb2->pcb_savefpu: cloned above. 462 * pcb2->pcb_flags: cloned above. 463 * pcb2->pcb_onfault: cloned above (always NULL here?). 464 * pcb2->pcb_gs: cloned above. 465 * pcb2->pcb_ext: cleared below. 466 */ 467 pcb2->pcb_ext = NULL; 468 469 /* Setup to release spin count in fork_exit(). */ 470 td->td_md.md_spinlock_count = 1; 471 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 472 } 473 474 /* 475 * Set that machine state for performing an upcall that has to 476 * be done in thread_userret() so that those upcalls generated 477 * in thread_userret() itself can be done as well. 478 */ 479 void 480 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg, 481 stack_t *stack) 482 { 483 484 /* 485 * Do any extra cleaning that needs to be done. 486 * The thread may have optional components 487 * that are not present in a fresh thread. 488 * This may be a recycled thread so make it look 489 * as though it's newly allocated. 490 */ 491 cpu_thread_clean(td); 492 493 /* 494 * Set the trap frame to point at the beginning of the uts 495 * function. 496 */ 497 td->td_frame->tf_ebp = 0; 498 td->td_frame->tf_esp = 499 (((int)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; 500 td->td_frame->tf_eip = (int)entry; 501 502 /* 503 * Pass the address of the mailbox for this kse to the uts 504 * function as a parameter on the stack. 505 */ 506 suword((void *)(td->td_frame->tf_esp + sizeof(void *)), 507 (int)arg); 508 } 509 510 int 511 cpu_set_user_tls(struct thread *td, void *tls_base) 512 { 513 struct segment_descriptor sd; 514 uint32_t base; 515 516 /* 517 * Construct a descriptor and store it in the pcb for 518 * the next context switch. Also store it in the gdt 519 * so that the load of tf_fs into %fs will activate it 520 * at return to userland. 521 */ 522 base = (uint32_t)tls_base; 523 sd.sd_lobase = base & 0xffffff; 524 sd.sd_hibase = (base >> 24) & 0xff; 525 sd.sd_lolimit = 0xffff; /* 4GB limit, wraps around */ 526 sd.sd_hilimit = 0xf; 527 sd.sd_type = SDT_MEMRWA; 528 sd.sd_dpl = SEL_UPL; 529 sd.sd_p = 1; 530 sd.sd_xx = 0; 531 sd.sd_def32 = 1; 532 sd.sd_gran = 1; 533 critical_enter(); 534 /* set %gs */ 535 td->td_pcb->pcb_gsd = sd; 536 if (td == curthread) { 537 PCPU_GET(fsgs_gdt)[1] = sd; 538 load_gs(GSEL(GUGS_SEL, SEL_UPL)); 539 } 540 critical_exit(); 541 return (0); 542 } 543 544 /* 545 * Convert kernel VA to physical address 546 */ 547 vm_paddr_t 548 kvtop(void *addr) 549 { 550 vm_paddr_t pa; 551 552 pa = pmap_kextract((vm_offset_t)addr); 553 if (pa == 0) 554 panic("kvtop: zero page frame"); 555 return (pa); 556 } 557 558 #ifdef SMP 559 static void 560 cpu_reset_proxy() 561 { 562 cpuset_t tcrp; 563 564 cpu_reset_proxy_active = 1; 565 while (cpu_reset_proxy_active == 1) 566 ; /* Wait for other cpu to see that we've started */ 567 CPU_SETOF(cpu_reset_proxyid, &tcrp); 568 stop_cpus(tcrp); 569 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 570 DELAY(1000000); 571 cpu_reset_real(); 572 } 573 #endif 574 575 void 576 cpu_reset() 577 { 578 #ifdef XBOX 579 if (arch_i386_is_xbox) { 580 /* Kick the PIC16L, it can reboot the box */ 581 pic16l_reboot(); 582 for (;;); 583 } 584 #endif 585 586 #ifdef SMP 587 cpuset_t map; 588 u_int cnt; 589 590 if (smp_started) { 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 /* XXX: restart_cpus(1 << 0); */ 607 CPU_SETOF(0, &started_cpus); 608 wmb(); 609 610 cnt = 0; 611 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 612 cnt++; /* Wait for BSP to announce restart */ 613 if (cpu_reset_proxy_active == 0) 614 printf("cpu_reset: Failed to restart BSP\n"); 615 enable_intr(); 616 cpu_reset_proxy_active = 2; 617 618 while (1); 619 /* NOTREACHED */ 620 } 621 622 DELAY(1000000); 623 } 624 #endif 625 cpu_reset_real(); 626 /* NOTREACHED */ 627 } 628 629 static void 630 cpu_reset_real() 631 { 632 struct region_descriptor null_idt; 633 #ifndef PC98 634 int b; 635 #endif 636 637 disable_intr(); 638 #ifdef XEN 639 if (smp_processor_id() == 0) 640 HYPERVISOR_shutdown(SHUTDOWN_reboot); 641 else 642 HYPERVISOR_shutdown(SHUTDOWN_poweroff); 643 #endif 644 #ifdef CPU_ELAN 645 if (elan_mmcr != NULL) 646 elan_mmcr->RESCFG = 1; 647 #endif 648 649 if (cpu == CPU_GEODE1100) { 650 /* Attempt Geode's own reset */ 651 outl(0xcf8, 0x80009044ul); 652 outl(0xcfc, 0xf); 653 } 654 655 #ifdef PC98 656 /* 657 * Attempt to do a CPU reset via CPU reset port. 658 */ 659 if ((inb(0x35) & 0xa0) != 0xa0) { 660 outb(0x37, 0x0f); /* SHUT0 = 0. */ 661 outb(0x37, 0x0b); /* SHUT1 = 0. */ 662 } 663 outb(0xf0, 0x00); /* Reset. */ 664 #else 665 #if !defined(BROKEN_KEYBOARD_RESET) 666 /* 667 * Attempt to do a CPU reset via the keyboard controller, 668 * do not turn off GateA20, as any machine that fails 669 * to do the reset here would then end up in no man's land. 670 */ 671 outb(IO_KBD + 4, 0xFE); 672 DELAY(500000); /* wait 0.5 sec to see if that did it */ 673 #endif 674 675 /* 676 * Attempt to force a reset via the Reset Control register at 677 * I/O port 0xcf9. Bit 2 forces a system reset when it 678 * transitions from 0 to 1. Bit 1 selects the type of reset 679 * to attempt: 0 selects a "soft" reset, and 1 selects a 680 * "hard" reset. We try a "hard" reset. The first write sets 681 * bit 1 to select a "hard" reset and clears bit 2. The 682 * second write forces a 0 -> 1 transition in bit 2 to trigger 683 * a reset. 684 */ 685 outb(0xcf9, 0x2); 686 outb(0xcf9, 0x6); 687 DELAY(500000); /* wait 0.5 sec to see if that did it */ 688 689 /* 690 * Attempt to force a reset via the Fast A20 and Init register 691 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate. 692 * Bit 0 asserts INIT# when set to 1. We are careful to only 693 * preserve bit 1 while setting bit 0. We also must clear bit 694 * 0 before setting it if it isn't already clear. 695 */ 696 b = inb(0x92); 697 if (b != 0xff) { 698 if ((b & 0x1) != 0) 699 outb(0x92, b & 0xfe); 700 outb(0x92, b | 0x1); 701 DELAY(500000); /* wait 0.5 sec to see if that did it */ 702 } 703 #endif /* PC98 */ 704 705 printf("No known reset method worked, attempting CPU shutdown\n"); 706 DELAY(1000000); /* wait 1 sec for printf to complete */ 707 708 /* Wipe the IDT. */ 709 null_idt.rd_limit = 0; 710 null_idt.rd_base = 0; 711 lidt(&null_idt); 712 713 /* "good night, sweet prince .... <THUNK!>" */ 714 breakpoint(); 715 716 /* NOTREACHED */ 717 while(1); 718 } 719 720 /* 721 * Get an sf_buf from the freelist. May block if none are available. 722 */ 723 void 724 sf_buf_map(struct sf_buf *sf, int flags) 725 { 726 pt_entry_t opte, *ptep; 727 728 /* 729 * Update the sf_buf's virtual-to-physical mapping, flushing the 730 * virtual address from the TLB. Since the reference count for 731 * the sf_buf's old mapping was zero, that mapping is not 732 * currently in use. Consequently, there is no need to exchange 733 * the old and new PTEs atomically, even under PAE. 734 */ 735 ptep = vtopte(sf->kva); 736 opte = *ptep; 737 #ifdef XEN 738 PT_SET_MA(sf->kva, xpmap_ptom(VM_PAGE_TO_PHYS(sf->m)) | pgeflag 739 | PG_RW | PG_V | pmap_cache_bits(sf->m->md.pat_mode, 0)); 740 #else 741 *ptep = VM_PAGE_TO_PHYS(sf->m) | pgeflag | PG_RW | PG_V | 742 pmap_cache_bits(sf->m->md.pat_mode, 0); 743 #endif 744 745 /* 746 * Avoid unnecessary TLB invalidations: If the sf_buf's old 747 * virtual-to-physical mapping was not used, then any processor 748 * that has invalidated the sf_buf's virtual address from its TLB 749 * since the last used mapping need not invalidate again. 750 */ 751 #ifdef SMP 752 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A)) 753 CPU_ZERO(&sf->cpumask); 754 755 sf_buf_shootdown(sf, flags); 756 #else 757 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A)) 758 pmap_invalidate_page(kernel_pmap, sf->kva); 759 #endif 760 } 761 762 #ifdef SMP 763 void 764 sf_buf_shootdown(struct sf_buf *sf, int flags) 765 { 766 cpuset_t other_cpus; 767 u_int cpuid; 768 769 sched_pin(); 770 cpuid = PCPU_GET(cpuid); 771 if (!CPU_ISSET(cpuid, &sf->cpumask)) { 772 CPU_SET(cpuid, &sf->cpumask); 773 invlpg(sf->kva); 774 } 775 if ((flags & SFB_CPUPRIVATE) == 0) { 776 other_cpus = all_cpus; 777 CPU_CLR(cpuid, &other_cpus); 778 CPU_NAND(&other_cpus, &sf->cpumask); 779 if (!CPU_EMPTY(&other_cpus)) { 780 CPU_OR(&sf->cpumask, &other_cpus); 781 smp_masked_invlpg(other_cpus, sf->kva); 782 } 783 } 784 sched_unpin(); 785 } 786 #endif 787 788 /* 789 * MD part of sf_buf_free(). 790 */ 791 int 792 sf_buf_unmap(struct sf_buf *sf) 793 { 794 #ifdef XEN 795 /* 796 * Xen doesn't like having dangling R/W mappings 797 */ 798 pmap_qremove(sf->kva, 1); 799 return (1); 800 #else 801 return (0); 802 #endif 803 } 804 805 static void 806 sf_buf_invalidate(struct sf_buf *sf) 807 { 808 vm_page_t m = sf->m; 809 810 /* 811 * Use pmap_qenter to update the pte for 812 * existing mapping, in particular, the PAT 813 * settings are recalculated. 814 */ 815 pmap_qenter(sf->kva, &m, 1); 816 pmap_invalidate_cache_range(sf->kva, sf->kva + PAGE_SIZE, FALSE); 817 } 818 819 /* 820 * Invalidate the cache lines that may belong to the page, if 821 * (possibly old) mapping of the page by sf buffer exists. Returns 822 * TRUE when mapping was found and cache invalidated. 823 */ 824 boolean_t 825 sf_buf_invalidate_cache(vm_page_t m) 826 { 827 828 return (sf_buf_process_page(m, sf_buf_invalidate)); 829 } 830 831 /* 832 * Software interrupt handler for queued VM system processing. 833 */ 834 void 835 swi_vm(void *dummy) 836 { 837 if (busdma_swi_pending != 0) 838 busdma_swi(); 839 } 840 841 /* 842 * Tell whether this address is in some physical memory region. 843 * Currently used by the kernel coredump code in order to avoid 844 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 845 * or other unpredictable behaviour. 846 */ 847 848 int 849 is_physical_memory(vm_paddr_t addr) 850 { 851 852 #ifdef DEV_ISA 853 /* The ISA ``memory hole''. */ 854 if (addr >= 0xa0000 && addr < 0x100000) 855 return 0; 856 #endif 857 858 /* 859 * stuff other tests for known memory-mapped devices (PCI?) 860 * here 861 */ 862 863 return 1; 864 } 865