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 51 #include <sys/param.h> 52 #include <sys/systm.h> 53 #include <sys/bio.h> 54 #include <sys/buf.h> 55 #include <sys/kernel.h> 56 #include <sys/ktr.h> 57 #include <sys/lock.h> 58 #include <sys/malloc.h> 59 #include <sys/mbuf.h> 60 #include <sys/mutex.h> 61 #include <sys/pioctl.h> 62 #include <sys/proc.h> 63 #include <sys/sysent.h> 64 #include <sys/sf_buf.h> 65 #include <sys/smp.h> 66 #include <sys/sched.h> 67 #include <sys/sysctl.h> 68 #include <sys/unistd.h> 69 #include <sys/vnode.h> 70 #include <sys/vmmeter.h> 71 72 #include <machine/cpu.h> 73 #include <machine/cputypes.h> 74 #include <machine/md_var.h> 75 #include <machine/pcb.h> 76 #include <machine/pcb_ext.h> 77 #include <machine/smp.h> 78 #include <machine/vm86.h> 79 80 #ifdef CPU_ELAN 81 #include <machine/elan_mmcr.h> 82 #endif 83 84 #include <vm/vm.h> 85 #include <vm/vm_extern.h> 86 #include <vm/vm_kern.h> 87 #include <vm/vm_page.h> 88 #include <vm/vm_map.h> 89 #include <vm/vm_param.h> 90 91 #include <isa/isareg.h> 92 93 #ifndef NSFBUFS 94 #define NSFBUFS (512 + maxusers * 16) 95 #endif 96 97 _Static_assert(OFFSETOF_CURTHREAD == offsetof(struct pcpu, pc_curthread), 98 "OFFSETOF_CURTHREAD does not correspond with offset of pc_curthread."); 99 _Static_assert(OFFSETOF_CURPCB == offsetof(struct pcpu, pc_curpcb), 100 "OFFSETOF_CURPCB does not correspond with offset of pc_curpcb."); 101 _Static_assert(__OFFSETOF_MONITORBUF == offsetof(struct pcpu, pc_monitorbuf), 102 "__OFFSETOF_MONINORBUF does not correspond with offset of pc_monitorbuf."); 103 104 static void cpu_reset_real(void); 105 #ifdef SMP 106 static void cpu_reset_proxy(void); 107 static u_int cpu_reset_proxyid; 108 static volatile u_int cpu_reset_proxy_active; 109 #endif 110 111 union savefpu * 112 get_pcb_user_save_td(struct thread *td) 113 { 114 vm_offset_t p; 115 116 p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE - 117 roundup2(cpu_max_ext_state_size, XSAVE_AREA_ALIGN); 118 KASSERT((p % XSAVE_AREA_ALIGN) == 0, ("Unaligned pcb_user_save area")); 119 return ((union savefpu *)p); 120 } 121 122 union savefpu * 123 get_pcb_user_save_pcb(struct pcb *pcb) 124 { 125 vm_offset_t p; 126 127 p = (vm_offset_t)(pcb + 1); 128 return ((union savefpu *)p); 129 } 130 131 struct pcb * 132 get_pcb_td(struct thread *td) 133 { 134 vm_offset_t p; 135 136 p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE - 137 roundup2(cpu_max_ext_state_size, XSAVE_AREA_ALIGN) - 138 sizeof(struct pcb); 139 return ((struct pcb *)p); 140 } 141 142 void * 143 alloc_fpusave(int flags) 144 { 145 void *res; 146 struct savefpu_ymm *sf; 147 148 res = malloc(cpu_max_ext_state_size, M_DEVBUF, flags); 149 if (use_xsave) { 150 sf = (struct savefpu_ymm *)res; 151 bzero(&sf->sv_xstate.sx_hd, sizeof(sf->sv_xstate.sx_hd)); 152 sf->sv_xstate.sx_hd.xstate_bv = xsave_mask; 153 } 154 return (res); 155 } 156 /* 157 * Finish a fork operation, with process p2 nearly set up. 158 * Copy and update the pcb, set up the stack so that the child 159 * ready to run and return to user mode. 160 */ 161 void 162 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 163 { 164 struct proc *p1; 165 struct pcb *pcb2; 166 struct mdproc *mdp2; 167 168 p1 = td1->td_proc; 169 if ((flags & RFPROC) == 0) { 170 if ((flags & RFMEM) == 0) { 171 /* unshare user LDT */ 172 struct mdproc *mdp1 = &p1->p_md; 173 struct proc_ldt *pldt, *pldt1; 174 175 mtx_lock_spin(&dt_lock); 176 if ((pldt1 = mdp1->md_ldt) != NULL && 177 pldt1->ldt_refcnt > 1) { 178 pldt = user_ldt_alloc(mdp1, pldt1->ldt_len); 179 if (pldt == NULL) 180 panic("could not copy LDT"); 181 mdp1->md_ldt = pldt; 182 set_user_ldt(mdp1); 183 user_ldt_deref(pldt1); 184 } else 185 mtx_unlock_spin(&dt_lock); 186 } 187 return; 188 } 189 190 /* Ensure that td1's pcb is up to date. */ 191 if (td1 == curthread) 192 td1->td_pcb->pcb_gs = rgs(); 193 critical_enter(); 194 if (PCPU_GET(fpcurthread) == td1) 195 npxsave(td1->td_pcb->pcb_save); 196 critical_exit(); 197 198 /* Point the pcb to the top of the stack */ 199 pcb2 = get_pcb_td(td2); 200 td2->td_pcb = pcb2; 201 202 /* Copy td1's pcb */ 203 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 204 205 /* Properly initialize pcb_save */ 206 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2); 207 bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2), 208 cpu_max_ext_state_size); 209 210 /* Point mdproc and then copy over td1's contents */ 211 mdp2 = &p2->p_md; 212 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 213 214 /* 215 * Create a new fresh stack for the new process. 216 * Copy the trap frame for the return to user mode as if from a 217 * syscall. This copies most of the user mode register values. 218 * The -16 is so we can expand the trapframe if we go to vm86. 219 */ 220 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1; 221 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 222 223 td2->td_frame->tf_eax = 0; /* Child returns zero */ 224 td2->td_frame->tf_eflags &= ~PSL_C; /* success */ 225 td2->td_frame->tf_edx = 1; 226 227 /* 228 * If the parent process has the trap bit set (i.e. a debugger had 229 * single stepped the process to the system call), we need to clear 230 * the trap flag from the new frame unless the debugger had set PF_FORK 231 * on the parent. Otherwise, the child will receive a (likely 232 * unexpected) SIGTRAP when it executes the first instruction after 233 * returning to userland. 234 */ 235 if ((p1->p_pfsflags & PF_FORK) == 0) 236 td2->td_frame->tf_eflags &= ~PSL_T; 237 238 /* 239 * Set registers for trampoline to user mode. Leave space for the 240 * return address on stack. These are the kernel mode register values. 241 */ 242 #if defined(PAE) || defined(PAE_TABLES) 243 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt); 244 #else 245 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); 246 #endif 247 pcb2->pcb_edi = 0; 248 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */ 249 pcb2->pcb_ebp = 0; 250 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *); 251 pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */ 252 pcb2->pcb_eip = (int)fork_trampoline; 253 /*- 254 * pcb2->pcb_dr*: cloned above. 255 * pcb2->pcb_savefpu: cloned above. 256 * pcb2->pcb_flags: cloned above. 257 * pcb2->pcb_onfault: cloned above (always NULL here?). 258 * pcb2->pcb_gs: cloned above. 259 * pcb2->pcb_ext: cleared below. 260 */ 261 262 /* 263 * XXX don't copy the i/o pages. this should probably be fixed. 264 */ 265 pcb2->pcb_ext = 0; 266 267 /* Copy the LDT, if necessary. */ 268 mtx_lock_spin(&dt_lock); 269 if (mdp2->md_ldt != NULL) { 270 if (flags & RFMEM) { 271 mdp2->md_ldt->ldt_refcnt++; 272 } else { 273 mdp2->md_ldt = user_ldt_alloc(mdp2, 274 mdp2->md_ldt->ldt_len); 275 if (mdp2->md_ldt == NULL) 276 panic("could not copy LDT"); 277 } 278 } 279 mtx_unlock_spin(&dt_lock); 280 281 /* Setup to release spin count in fork_exit(). */ 282 td2->td_md.md_spinlock_count = 1; 283 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 284 285 /* 286 * Now, cpu_switch() can schedule the new process. 287 * pcb_esp is loaded pointing to the cpu_switch() stack frame 288 * containing the return address when exiting cpu_switch. 289 * This will normally be to fork_trampoline(), which will have 290 * %ebx loaded with the new proc's pointer. fork_trampoline() 291 * will set up a stack to call fork_return(p, frame); to complete 292 * the return to user-mode. 293 */ 294 } 295 296 /* 297 * Intercept the return address from a freshly forked process that has NOT 298 * been scheduled yet. 299 * 300 * This is needed to make kernel threads stay in kernel mode. 301 */ 302 void 303 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 304 { 305 /* 306 * Note that the trap frame follows the args, so the function 307 * is really called like this: func(arg, frame); 308 */ 309 td->td_pcb->pcb_esi = (int) func; /* function */ 310 td->td_pcb->pcb_ebx = (int) arg; /* first arg */ 311 } 312 313 void 314 cpu_exit(struct thread *td) 315 { 316 317 /* 318 * If this process has a custom LDT, release it. Reset pc->pcb_gs 319 * and %gs before we free it in case they refer to an LDT entry. 320 */ 321 mtx_lock_spin(&dt_lock); 322 if (td->td_proc->p_md.md_ldt) { 323 td->td_pcb->pcb_gs = _udatasel; 324 load_gs(_udatasel); 325 user_ldt_free(td); 326 } else 327 mtx_unlock_spin(&dt_lock); 328 } 329 330 void 331 cpu_thread_exit(struct thread *td) 332 { 333 334 critical_enter(); 335 if (td == PCPU_GET(fpcurthread)) 336 npxdrop(); 337 critical_exit(); 338 339 /* Disable any hardware breakpoints. */ 340 if (td->td_pcb->pcb_flags & PCB_DBREGS) { 341 reset_dbregs(); 342 td->td_pcb->pcb_flags &= ~PCB_DBREGS; 343 } 344 } 345 346 void 347 cpu_thread_clean(struct thread *td) 348 { 349 struct pcb *pcb; 350 351 pcb = td->td_pcb; 352 if (pcb->pcb_ext != NULL) { 353 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */ 354 /* 355 * XXX do we need to move the TSS off the allocated pages 356 * before freeing them? (not done here) 357 */ 358 kmem_free(kernel_arena, (vm_offset_t)pcb->pcb_ext, 359 ctob(IOPAGES + 1)); 360 pcb->pcb_ext = NULL; 361 } 362 } 363 364 void 365 cpu_thread_swapin(struct thread *td) 366 { 367 } 368 369 void 370 cpu_thread_swapout(struct thread *td) 371 { 372 } 373 374 void 375 cpu_thread_alloc(struct thread *td) 376 { 377 struct pcb *pcb; 378 struct xstate_hdr *xhdr; 379 380 td->td_pcb = pcb = get_pcb_td(td); 381 td->td_frame = (struct trapframe *)((caddr_t)pcb - 16) - 1; 382 pcb->pcb_ext = NULL; 383 pcb->pcb_save = get_pcb_user_save_pcb(pcb); 384 if (use_xsave) { 385 xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1); 386 bzero(xhdr, sizeof(*xhdr)); 387 xhdr->xstate_bv = xsave_mask; 388 } 389 } 390 391 void 392 cpu_thread_free(struct thread *td) 393 { 394 395 cpu_thread_clean(td); 396 } 397 398 void 399 cpu_set_syscall_retval(struct thread *td, int error) 400 { 401 402 switch (error) { 403 case 0: 404 td->td_frame->tf_eax = td->td_retval[0]; 405 td->td_frame->tf_edx = td->td_retval[1]; 406 td->td_frame->tf_eflags &= ~PSL_C; 407 break; 408 409 case ERESTART: 410 /* 411 * Reconstruct pc, assuming lcall $X,y is 7 bytes, int 412 * 0x80 is 2 bytes. We saved this in tf_err. 413 */ 414 td->td_frame->tf_eip -= td->td_frame->tf_err; 415 break; 416 417 case EJUSTRETURN: 418 break; 419 420 default: 421 td->td_frame->tf_eax = SV_ABI_ERRNO(td->td_proc, error); 422 td->td_frame->tf_eflags |= PSL_C; 423 break; 424 } 425 } 426 427 /* 428 * Initialize machine state, mostly pcb and trap frame for a new 429 * thread, about to return to userspace. Put enough state in the new 430 * thread's PCB to get it to go back to the fork_return(), which 431 * finalizes the thread state and handles peculiarities of the first 432 * return to userspace for the new thread. 433 */ 434 void 435 cpu_copy_thread(struct thread *td, struct thread *td0) 436 { 437 struct pcb *pcb2; 438 439 /* Point the pcb to the top of the stack. */ 440 pcb2 = td->td_pcb; 441 442 /* 443 * Copy the upcall pcb. This loads kernel regs. 444 * Those not loaded individually below get their default 445 * values here. 446 */ 447 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); 448 pcb2->pcb_flags &= ~(PCB_NPXINITDONE | PCB_NPXUSERINITDONE | 449 PCB_KERNNPX); 450 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2); 451 bcopy(get_pcb_user_save_td(td0), pcb2->pcb_save, 452 cpu_max_ext_state_size); 453 454 /* 455 * Create a new fresh stack for the new thread. 456 */ 457 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 458 459 /* If the current thread has the trap bit set (i.e. a debugger had 460 * single stepped the process to the system call), we need to clear 461 * the trap flag from the new frame. Otherwise, the new thread will 462 * receive a (likely unexpected) SIGTRAP when it executes the first 463 * instruction after returning to userland. 464 */ 465 td->td_frame->tf_eflags &= ~PSL_T; 466 467 /* 468 * Set registers for trampoline to user mode. Leave space for the 469 * return address on stack. These are the kernel mode register values. 470 */ 471 pcb2->pcb_edi = 0; 472 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */ 473 pcb2->pcb_ebp = 0; 474 pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */ 475 pcb2->pcb_ebx = (int)td; /* trampoline arg */ 476 pcb2->pcb_eip = (int)fork_trampoline; 477 pcb2->pcb_gs = rgs(); 478 /* 479 * If we didn't copy the pcb, we'd need to do the following registers: 480 * pcb2->pcb_cr3: cloned above. 481 * pcb2->pcb_dr*: cloned above. 482 * pcb2->pcb_savefpu: cloned above. 483 * pcb2->pcb_flags: cloned above. 484 * pcb2->pcb_onfault: cloned above (always NULL here?). 485 * pcb2->pcb_gs: cloned above. 486 * pcb2->pcb_ext: cleared below. 487 */ 488 pcb2->pcb_ext = NULL; 489 490 /* Setup to release spin count in fork_exit(). */ 491 td->td_md.md_spinlock_count = 1; 492 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 493 } 494 495 /* 496 * Set that machine state for performing an upcall that starts 497 * the entry function with the given argument. 498 */ 499 void 500 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 501 stack_t *stack) 502 { 503 504 /* 505 * Do any extra cleaning that needs to be done. 506 * The thread may have optional components 507 * that are not present in a fresh thread. 508 * This may be a recycled thread so make it look 509 * as though it's newly allocated. 510 */ 511 cpu_thread_clean(td); 512 513 /* 514 * Set the trap frame to point at the beginning of the entry 515 * function. 516 */ 517 td->td_frame->tf_ebp = 0; 518 td->td_frame->tf_esp = 519 (((int)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; 520 td->td_frame->tf_eip = (int)entry; 521 522 /* Return address sentinel value to stop stack unwinding. */ 523 suword((void *)td->td_frame->tf_esp, 0); 524 525 /* Pass the argument to the entry point. */ 526 suword((void *)(td->td_frame->tf_esp + sizeof(void *)), 527 (int)arg); 528 } 529 530 int 531 cpu_set_user_tls(struct thread *td, void *tls_base) 532 { 533 struct segment_descriptor sd; 534 uint32_t base; 535 536 /* 537 * Construct a descriptor and store it in the pcb for 538 * the next context switch. Also store it in the gdt 539 * so that the load of tf_fs into %fs will activate it 540 * at return to userland. 541 */ 542 base = (uint32_t)tls_base; 543 sd.sd_lobase = base & 0xffffff; 544 sd.sd_hibase = (base >> 24) & 0xff; 545 sd.sd_lolimit = 0xffff; /* 4GB limit, wraps around */ 546 sd.sd_hilimit = 0xf; 547 sd.sd_type = SDT_MEMRWA; 548 sd.sd_dpl = SEL_UPL; 549 sd.sd_p = 1; 550 sd.sd_xx = 0; 551 sd.sd_def32 = 1; 552 sd.sd_gran = 1; 553 critical_enter(); 554 /* set %gs */ 555 td->td_pcb->pcb_gsd = sd; 556 if (td == curthread) { 557 PCPU_GET(fsgs_gdt)[1] = sd; 558 load_gs(GSEL(GUGS_SEL, SEL_UPL)); 559 } 560 critical_exit(); 561 return (0); 562 } 563 564 /* 565 * Convert kernel VA to physical address 566 */ 567 vm_paddr_t 568 kvtop(void *addr) 569 { 570 vm_paddr_t pa; 571 572 pa = pmap_kextract((vm_offset_t)addr); 573 if (pa == 0) 574 panic("kvtop: zero page frame"); 575 return (pa); 576 } 577 578 #ifdef SMP 579 static void 580 cpu_reset_proxy() 581 { 582 cpuset_t tcrp; 583 584 cpu_reset_proxy_active = 1; 585 while (cpu_reset_proxy_active == 1) 586 ; /* Wait for other cpu to see that we've started */ 587 CPU_SETOF(cpu_reset_proxyid, &tcrp); 588 stop_cpus(tcrp); 589 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 590 DELAY(1000000); 591 cpu_reset_real(); 592 } 593 #endif 594 595 void 596 cpu_reset() 597 { 598 #ifdef SMP 599 cpuset_t map; 600 u_int cnt; 601 602 if (smp_started) { 603 map = all_cpus; 604 CPU_CLR(PCPU_GET(cpuid), &map); 605 CPU_NAND(&map, &stopped_cpus); 606 if (!CPU_EMPTY(&map)) { 607 printf("cpu_reset: Stopping other CPUs\n"); 608 stop_cpus(map); 609 } 610 611 if (PCPU_GET(cpuid) != 0) { 612 cpu_reset_proxyid = PCPU_GET(cpuid); 613 cpustop_restartfunc = cpu_reset_proxy; 614 cpu_reset_proxy_active = 0; 615 printf("cpu_reset: Restarting BSP\n"); 616 617 /* Restart CPU #0. */ 618 /* XXX: restart_cpus(1 << 0); */ 619 CPU_SETOF(0, &started_cpus); 620 wmb(); 621 622 cnt = 0; 623 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 624 cnt++; /* Wait for BSP to announce restart */ 625 if (cpu_reset_proxy_active == 0) 626 printf("cpu_reset: Failed to restart BSP\n"); 627 enable_intr(); 628 cpu_reset_proxy_active = 2; 629 630 while (1); 631 /* NOTREACHED */ 632 } 633 634 DELAY(1000000); 635 } 636 #endif 637 cpu_reset_real(); 638 /* NOTREACHED */ 639 } 640 641 static void 642 cpu_reset_real() 643 { 644 struct region_descriptor null_idt; 645 int b; 646 647 disable_intr(); 648 #ifdef CPU_ELAN 649 if (elan_mmcr != NULL) 650 elan_mmcr->RESCFG = 1; 651 #endif 652 653 if (cpu == CPU_GEODE1100) { 654 /* Attempt Geode's own reset */ 655 outl(0xcf8, 0x80009044ul); 656 outl(0xcfc, 0xf); 657 } 658 659 #if !defined(BROKEN_KEYBOARD_RESET) 660 /* 661 * Attempt to do a CPU reset via the keyboard controller, 662 * do not turn off GateA20, as any machine that fails 663 * to do the reset here would then end up in no man's land. 664 */ 665 outb(IO_KBD + 4, 0xFE); 666 DELAY(500000); /* wait 0.5 sec to see if that did it */ 667 #endif 668 669 /* 670 * Attempt to force a reset via the Reset Control register at 671 * I/O port 0xcf9. Bit 2 forces a system reset when it 672 * transitions from 0 to 1. Bit 1 selects the type of reset 673 * to attempt: 0 selects a "soft" reset, and 1 selects a 674 * "hard" reset. We try a "hard" reset. The first write sets 675 * bit 1 to select a "hard" reset and clears bit 2. The 676 * second write forces a 0 -> 1 transition in bit 2 to trigger 677 * a reset. 678 */ 679 outb(0xcf9, 0x2); 680 outb(0xcf9, 0x6); 681 DELAY(500000); /* wait 0.5 sec to see if that did it */ 682 683 /* 684 * Attempt to force a reset via the Fast A20 and Init register 685 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate. 686 * Bit 0 asserts INIT# when set to 1. We are careful to only 687 * preserve bit 1 while setting bit 0. We also must clear bit 688 * 0 before setting it if it isn't already clear. 689 */ 690 b = inb(0x92); 691 if (b != 0xff) { 692 if ((b & 0x1) != 0) 693 outb(0x92, b & 0xfe); 694 outb(0x92, b | 0x1); 695 DELAY(500000); /* wait 0.5 sec to see if that did it */ 696 } 697 698 printf("No known reset method worked, attempting CPU shutdown\n"); 699 DELAY(1000000); /* wait 1 sec for printf to complete */ 700 701 /* Wipe the IDT. */ 702 null_idt.rd_limit = 0; 703 null_idt.rd_base = 0; 704 lidt(&null_idt); 705 706 /* "good night, sweet prince .... <THUNK!>" */ 707 breakpoint(); 708 709 /* NOTREACHED */ 710 while(1); 711 } 712 713 /* 714 * Get an sf_buf from the freelist. May block if none are available. 715 */ 716 void 717 sf_buf_map(struct sf_buf *sf, int flags) 718 { 719 pt_entry_t opte, *ptep; 720 721 /* 722 * Update the sf_buf's virtual-to-physical mapping, flushing the 723 * virtual address from the TLB. Since the reference count for 724 * the sf_buf's old mapping was zero, that mapping is not 725 * currently in use. Consequently, there is no need to exchange 726 * the old and new PTEs atomically, even under PAE. 727 */ 728 ptep = vtopte(sf->kva); 729 opte = *ptep; 730 *ptep = VM_PAGE_TO_PHYS(sf->m) | pgeflag | PG_RW | PG_V | 731 pmap_cache_bits(sf->m->md.pat_mode, 0); 732 733 /* 734 * Avoid unnecessary TLB invalidations: If the sf_buf's old 735 * virtual-to-physical mapping was not used, then any processor 736 * that has invalidated the sf_buf's virtual address from its TLB 737 * since the last used mapping need not invalidate again. 738 */ 739 #ifdef SMP 740 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A)) 741 CPU_ZERO(&sf->cpumask); 742 743 sf_buf_shootdown(sf, flags); 744 #else 745 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A)) 746 pmap_invalidate_page(kernel_pmap, sf->kva); 747 #endif 748 } 749 750 #ifdef SMP 751 void 752 sf_buf_shootdown(struct sf_buf *sf, int flags) 753 { 754 cpuset_t other_cpus; 755 u_int cpuid; 756 757 sched_pin(); 758 cpuid = PCPU_GET(cpuid); 759 if (!CPU_ISSET(cpuid, &sf->cpumask)) { 760 CPU_SET(cpuid, &sf->cpumask); 761 invlpg(sf->kva); 762 } 763 if ((flags & SFB_CPUPRIVATE) == 0) { 764 other_cpus = all_cpus; 765 CPU_CLR(cpuid, &other_cpus); 766 CPU_NAND(&other_cpus, &sf->cpumask); 767 if (!CPU_EMPTY(&other_cpus)) { 768 CPU_OR(&sf->cpumask, &other_cpus); 769 smp_masked_invlpg(other_cpus, sf->kva); 770 } 771 } 772 sched_unpin(); 773 } 774 #endif 775 776 /* 777 * MD part of sf_buf_free(). 778 */ 779 int 780 sf_buf_unmap(struct sf_buf *sf) 781 { 782 783 return (0); 784 } 785 786 static void 787 sf_buf_invalidate(struct sf_buf *sf) 788 { 789 vm_page_t m = sf->m; 790 791 /* 792 * Use pmap_qenter to update the pte for 793 * existing mapping, in particular, the PAT 794 * settings are recalculated. 795 */ 796 pmap_qenter(sf->kva, &m, 1); 797 pmap_invalidate_cache_range(sf->kva, sf->kva + PAGE_SIZE, FALSE); 798 } 799 800 /* 801 * Invalidate the cache lines that may belong to the page, if 802 * (possibly old) mapping of the page by sf buffer exists. Returns 803 * TRUE when mapping was found and cache invalidated. 804 */ 805 boolean_t 806 sf_buf_invalidate_cache(vm_page_t m) 807 { 808 809 return (sf_buf_process_page(m, sf_buf_invalidate)); 810 } 811 812 /* 813 * Software interrupt handler for queued VM system processing. 814 */ 815 void 816 swi_vm(void *dummy) 817 { 818 if (busdma_swi_pending != 0) 819 busdma_swi(); 820 } 821 822 /* 823 * Tell whether this address is in some physical memory region. 824 * Currently used by the kernel coredump code in order to avoid 825 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 826 * or other unpredictable behaviour. 827 */ 828 829 int 830 is_physical_memory(vm_paddr_t addr) 831 { 832 833 #ifdef DEV_ISA 834 /* The ISA ``memory hole''. */ 835 if (addr >= 0xa0000 && addr < 0x100000) 836 return 0; 837 #endif 838 839 /* 840 * stuff other tests for known memory-mapped devices (PCI?) 841 * here 842 */ 843 844 return 1; 845 } 846