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 <x86/isa/isa.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 void cpu_reset_real(void); 110 #ifdef SMP 111 static void cpu_reset_proxy(void); 112 static u_int cpu_reset_proxyid; 113 static volatile u_int cpu_reset_proxy_active; 114 #endif 115 static void sf_buf_init(void *arg); 116 SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL); 117 118 LIST_HEAD(sf_head, sf_buf); 119 120 /* 121 * A hash table of active sendfile(2) buffers 122 */ 123 static struct sf_head *sf_buf_active; 124 static u_long sf_buf_hashmask; 125 126 #define SF_BUF_HASH(m) (((m) - vm_page_array) & sf_buf_hashmask) 127 128 static TAILQ_HEAD(, sf_buf) sf_buf_freelist; 129 static u_int sf_buf_alloc_want; 130 131 /* 132 * A lock used to synchronize access to the hash table and free list 133 */ 134 static struct mtx sf_buf_lock; 135 136 extern int _ucodesel, _udatasel; 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 */ 143 void 144 cpu_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 *mdp2; 153 #ifdef DEV_NPX 154 register_t savecrit; 155 #endif 156 157 p1 = td1->td_proc; 158 if ((flags & RFPROC) == 0) { 159 if ((flags & RFMEM) == 0) { 160 /* unshare user LDT */ 161 struct mdproc *mdp1 = &p1->p_md; 162 struct proc_ldt *pldt, *pldt1; 163 164 mtx_lock_spin(&dt_lock); 165 if ((pldt1 = mdp1->md_ldt) != NULL && 166 pldt1->ldt_refcnt > 1) { 167 pldt = user_ldt_alloc(mdp1, pldt1->ldt_len); 168 if (pldt == NULL) 169 panic("could not copy LDT"); 170 mdp1->md_ldt = pldt; 171 set_user_ldt(mdp1); 172 user_ldt_deref(pldt1); 173 } else 174 mtx_unlock_spin(&dt_lock); 175 } 176 return; 177 } 178 179 /* Ensure that p1's pcb is up to date. */ 180 if (td1 == curthread) 181 td1->td_pcb->pcb_gs = rgs(); 182 #ifdef DEV_NPX 183 savecrit = intr_disable(); 184 if (PCPU_GET(fpcurthread) == td1) 185 npxsave(&td1->td_pcb->pcb_save); 186 intr_restore(savecrit); 187 #endif 188 189 /* Point the pcb to the top of the stack */ 190 pcb2 = (struct pcb *)(td2->td_kstack + 191 td2->td_kstack_pages * PAGE_SIZE) - 1; 192 td2->td_pcb = pcb2; 193 194 /* Copy p1's pcb */ 195 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 196 197 /* Point mdproc and then copy over td1's contents */ 198 mdp2 = &p2->p_md; 199 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 200 201 /* 202 * Create a new fresh stack for the new process. 203 * Copy the trap frame for the return to user mode as if from a 204 * syscall. This copies most of the user mode register values. 205 * The -16 is so we can expand the trapframe if we go to vm86. 206 */ 207 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1; 208 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 209 210 td2->td_frame->tf_eax = 0; /* Child returns zero */ 211 td2->td_frame->tf_eflags &= ~PSL_C; /* success */ 212 td2->td_frame->tf_edx = 1; 213 214 /* 215 * If the parent process has the trap bit set (i.e. a debugger had 216 * single stepped the process to the system call), we need to clear 217 * the trap flag from the new frame unless the debugger had set PF_FORK 218 * on the parent. Otherwise, the child will receive a (likely 219 * unexpected) SIGTRAP when it executes the first instruction after 220 * returning to userland. 221 */ 222 if ((p1->p_pfsflags & PF_FORK) == 0) 223 td2->td_frame->tf_eflags &= ~PSL_T; 224 225 /* 226 * Set registers for trampoline to user mode. Leave space for the 227 * return address on stack. These are the kernel mode register values. 228 */ 229 #ifdef PAE 230 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt); 231 #else 232 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); 233 #endif 234 pcb2->pcb_edi = 0; 235 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */ 236 pcb2->pcb_ebp = 0; 237 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *); 238 pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */ 239 pcb2->pcb_eip = (int)fork_trampoline; 240 pcb2->pcb_psl = PSL_KERNEL; /* ints disabled */ 241 /*- 242 * pcb2->pcb_dr*: cloned above. 243 * pcb2->pcb_savefpu: cloned above. 244 * pcb2->pcb_flags: cloned above. 245 * pcb2->pcb_onfault: cloned above (always NULL here?). 246 * pcb2->pcb_gs: cloned above. 247 * pcb2->pcb_ext: cleared below. 248 */ 249 250 /* 251 * XXX don't copy the i/o pages. this should probably be fixed. 252 */ 253 pcb2->pcb_ext = 0; 254 255 /* Copy the LDT, if necessary. */ 256 mtx_lock_spin(&dt_lock); 257 if (mdp2->md_ldt != NULL) { 258 if (flags & RFMEM) { 259 mdp2->md_ldt->ldt_refcnt++; 260 } else { 261 mdp2->md_ldt = user_ldt_alloc(mdp2, 262 mdp2->md_ldt->ldt_len); 263 if (mdp2->md_ldt == NULL) 264 panic("could not copy LDT"); 265 } 266 } 267 mtx_unlock_spin(&dt_lock); 268 269 /* Setup to release spin count in fork_exit(). */ 270 td2->td_md.md_spinlock_count = 1; 271 /* 272 * XXX XEN need to check on PSL_USER is handled 273 */ 274 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 275 /* 276 * Now, cpu_switch() can schedule the new process. 277 * pcb_esp is loaded pointing to the cpu_switch() stack frame 278 * containing the return address when exiting cpu_switch. 279 * This will normally be to fork_trampoline(), which will have 280 * %ebx loaded with the new proc's pointer. fork_trampoline() 281 * will set up a stack to call fork_return(p, frame); to complete 282 * the return to user-mode. 283 */ 284 } 285 286 /* 287 * Intercept the return address from a freshly forked process that has NOT 288 * been scheduled yet. 289 * 290 * This is needed to make kernel threads stay in kernel mode. 291 */ 292 void 293 cpu_set_fork_handler(td, func, arg) 294 struct thread *td; 295 void (*func)(void *); 296 void *arg; 297 { 298 /* 299 * Note that the trap frame follows the args, so the function 300 * is really called like this: func(arg, frame); 301 */ 302 td->td_pcb->pcb_esi = (int) func; /* function */ 303 td->td_pcb->pcb_ebx = (int) arg; /* first arg */ 304 } 305 306 void 307 cpu_exit(struct thread *td) 308 { 309 310 /* 311 * If this process has a custom LDT, release it. Reset pc->pcb_gs 312 * and %gs before we free it in case they refer to an LDT entry. 313 */ 314 mtx_lock_spin(&dt_lock); 315 if (td->td_proc->p_md.md_ldt) { 316 td->td_pcb->pcb_gs = _udatasel; 317 load_gs(_udatasel); 318 user_ldt_free(td); 319 } else 320 mtx_unlock_spin(&dt_lock); 321 } 322 323 void 324 cpu_thread_exit(struct thread *td) 325 { 326 327 #ifdef DEV_NPX 328 if (td == PCPU_GET(fpcurthread)) 329 npxdrop(); 330 #endif 331 332 /* Disable any hardware breakpoints. */ 333 if (td->td_pcb->pcb_flags & PCB_DBREGS) { 334 reset_dbregs(); 335 td->td_pcb->pcb_flags &= ~PCB_DBREGS; 336 } 337 } 338 339 void 340 cpu_thread_clean(struct thread *td) 341 { 342 struct pcb *pcb; 343 344 pcb = td->td_pcb; 345 if (pcb->pcb_ext != NULL) { 346 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */ 347 /* 348 * XXX do we need to move the TSS off the allocated pages 349 * before freeing them? (not done here) 350 */ 351 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext, 352 ctob(IOPAGES + 1)); 353 pcb->pcb_ext = NULL; 354 } 355 } 356 357 void 358 cpu_thread_swapin(struct thread *td) 359 { 360 } 361 362 void 363 cpu_thread_swapout(struct thread *td) 364 { 365 } 366 367 void 368 cpu_thread_alloc(struct thread *td) 369 { 370 371 td->td_pcb = (struct pcb *)(td->td_kstack + 372 td->td_kstack_pages * PAGE_SIZE) - 1; 373 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1; 374 td->td_pcb->pcb_ext = NULL; 375 } 376 377 void 378 cpu_thread_free(struct thread *td) 379 { 380 381 cpu_thread_clean(td); 382 } 383 384 void 385 cpu_set_syscall_retval(struct thread *td, int error) 386 { 387 388 switch (error) { 389 case 0: 390 td->td_frame->tf_eax = td->td_retval[0]; 391 td->td_frame->tf_edx = td->td_retval[1]; 392 td->td_frame->tf_eflags &= ~PSL_C; 393 break; 394 395 case ERESTART: 396 /* 397 * Reconstruct pc, assuming lcall $X,y is 7 bytes, int 398 * 0x80 is 2 bytes. We saved this in tf_err. 399 */ 400 td->td_frame->tf_eip -= td->td_frame->tf_err; 401 break; 402 403 case EJUSTRETURN: 404 break; 405 406 default: 407 if (td->td_proc->p_sysent->sv_errsize) { 408 if (error >= td->td_proc->p_sysent->sv_errsize) 409 error = -1; /* XXX */ 410 else 411 error = td->td_proc->p_sysent->sv_errtbl[error]; 412 } 413 td->td_frame->tf_eax = error; 414 td->td_frame->tf_eflags |= PSL_C; 415 break; 416 } 417 } 418 419 /* 420 * Initialize machine state (pcb and trap frame) for a new thread about to 421 * upcall. Put enough state in the new thread's PCB to get it to go back 422 * userret(), where we can intercept it again to set the return (upcall) 423 * Address and stack, along with those from upcals that are from other sources 424 * such as those generated in thread_userret() itself. 425 */ 426 void 427 cpu_set_upcall(struct thread *td, struct thread *td0) 428 { 429 struct pcb *pcb2; 430 431 /* Point the pcb to the top of the stack. */ 432 pcb2 = td->td_pcb; 433 434 /* 435 * Copy the upcall pcb. This loads kernel regs. 436 * Those not loaded individually below get their default 437 * values here. 438 */ 439 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); 440 pcb2->pcb_flags &= ~(PCB_NPXTRAP|PCB_NPXINITDONE); 441 442 /* 443 * Create a new fresh stack for the new thread. 444 */ 445 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 446 447 /* If the current thread has the trap bit set (i.e. a debugger had 448 * single stepped the process to the system call), we need to clear 449 * the trap flag from the new frame. Otherwise, the new thread will 450 * receive a (likely unexpected) SIGTRAP when it executes the first 451 * instruction after returning to userland. 452 */ 453 td->td_frame->tf_eflags &= ~PSL_T; 454 455 /* 456 * Set registers for trampoline to user mode. Leave space for the 457 * return address on stack. These are the kernel mode register values. 458 */ 459 pcb2->pcb_edi = 0; 460 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */ 461 pcb2->pcb_ebp = 0; 462 pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */ 463 pcb2->pcb_ebx = (int)td; /* trampoline arg */ 464 pcb2->pcb_eip = (int)fork_trampoline; 465 pcb2->pcb_psl &= ~(PSL_I); /* interrupts must be disabled */ 466 pcb2->pcb_gs = rgs(); 467 /* 468 * If we didn't copy the pcb, we'd need to do the following registers: 469 * pcb2->pcb_cr3: cloned above. 470 * pcb2->pcb_dr*: cloned above. 471 * pcb2->pcb_savefpu: cloned above. 472 * pcb2->pcb_flags: cloned above. 473 * pcb2->pcb_onfault: cloned above (always NULL here?). 474 * pcb2->pcb_gs: cloned above. 475 * pcb2->pcb_ext: cleared below. 476 */ 477 pcb2->pcb_ext = NULL; 478 479 /* Setup to release spin count in fork_exit(). */ 480 td->td_md.md_spinlock_count = 1; 481 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 482 } 483 484 /* 485 * Set that machine state for performing an upcall that has to 486 * be done in thread_userret() so that those upcalls generated 487 * in thread_userret() itself can be done as well. 488 */ 489 void 490 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg, 491 stack_t *stack) 492 { 493 494 /* 495 * Do any extra cleaning that needs to be done. 496 * The thread may have optional components 497 * that are not present in a fresh thread. 498 * This may be a recycled thread so make it look 499 * as though it's newly allocated. 500 */ 501 cpu_thread_clean(td); 502 503 /* 504 * Set the trap frame to point at the beginning of the uts 505 * function. 506 */ 507 td->td_frame->tf_ebp = 0; 508 td->td_frame->tf_esp = 509 (((int)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; 510 td->td_frame->tf_eip = (int)entry; 511 512 /* 513 * Pass the address of the mailbox for this kse to the uts 514 * function as a parameter on the stack. 515 */ 516 suword((void *)(td->td_frame->tf_esp + sizeof(void *)), 517 (int)arg); 518 } 519 520 int 521 cpu_set_user_tls(struct thread *td, void *tls_base) 522 { 523 struct segment_descriptor sd; 524 uint32_t base; 525 526 /* 527 * Construct a descriptor and store it in the pcb for 528 * the next context switch. Also store it in the gdt 529 * so that the load of tf_fs into %fs will activate it 530 * at return to userland. 531 */ 532 base = (uint32_t)tls_base; 533 sd.sd_lobase = base & 0xffffff; 534 sd.sd_hibase = (base >> 24) & 0xff; 535 sd.sd_lolimit = 0xffff; /* 4GB limit, wraps around */ 536 sd.sd_hilimit = 0xf; 537 sd.sd_type = SDT_MEMRWA; 538 sd.sd_dpl = SEL_UPL; 539 sd.sd_p = 1; 540 sd.sd_xx = 0; 541 sd.sd_def32 = 1; 542 sd.sd_gran = 1; 543 critical_enter(); 544 /* set %gs */ 545 td->td_pcb->pcb_gsd = sd; 546 if (td == curthread) { 547 PCPU_GET(fsgs_gdt)[1] = sd; 548 load_gs(GSEL(GUGS_SEL, SEL_UPL)); 549 } 550 critical_exit(); 551 return (0); 552 } 553 554 /* 555 * Convert kernel VA to physical address 556 */ 557 vm_paddr_t 558 kvtop(void *addr) 559 { 560 vm_paddr_t pa; 561 562 pa = pmap_kextract((vm_offset_t)addr); 563 if (pa == 0) 564 panic("kvtop: zero page frame"); 565 return (pa); 566 } 567 568 #ifdef SMP 569 static void 570 cpu_reset_proxy() 571 { 572 573 cpu_reset_proxy_active = 1; 574 while (cpu_reset_proxy_active == 1) 575 ; /* Wait for other cpu to see that we've started */ 576 stop_cpus((1<<cpu_reset_proxyid)); 577 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 578 DELAY(1000000); 579 cpu_reset_real(); 580 } 581 #endif 582 583 void 584 cpu_reset() 585 { 586 #ifdef XBOX 587 if (arch_i386_is_xbox) { 588 /* Kick the PIC16L, it can reboot the box */ 589 pic16l_reboot(); 590 for (;;); 591 } 592 #endif 593 594 #ifdef SMP 595 u_int cnt, map; 596 597 if (smp_active) { 598 map = PCPU_GET(other_cpus) & ~stopped_cpus; 599 if (map != 0) { 600 printf("cpu_reset: Stopping other CPUs\n"); 601 stop_cpus(map); 602 } 603 604 if (PCPU_GET(cpuid) != 0) { 605 cpu_reset_proxyid = PCPU_GET(cpuid); 606 cpustop_restartfunc = cpu_reset_proxy; 607 cpu_reset_proxy_active = 0; 608 printf("cpu_reset: Restarting BSP\n"); 609 610 /* Restart CPU #0. */ 611 /* XXX: restart_cpus(1 << 0); */ 612 atomic_store_rel_int(&started_cpus, (1 << 0)); 613 614 cnt = 0; 615 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 616 cnt++; /* Wait for BSP to announce restart */ 617 if (cpu_reset_proxy_active == 0) 618 printf("cpu_reset: Failed to restart BSP\n"); 619 enable_intr(); 620 cpu_reset_proxy_active = 2; 621 622 while (1); 623 /* NOTREACHED */ 624 } 625 626 DELAY(1000000); 627 } 628 #endif 629 cpu_reset_real(); 630 /* NOTREACHED */ 631 } 632 633 static void 634 cpu_reset_real() 635 { 636 struct region_descriptor null_idt; 637 #ifndef PC98 638 int b; 639 #endif 640 641 disable_intr(); 642 #ifdef XEN 643 if (smp_processor_id() == 0) 644 HYPERVISOR_shutdown(SHUTDOWN_reboot); 645 else 646 HYPERVISOR_shutdown(SHUTDOWN_poweroff); 647 #endif 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 #ifdef PC98 660 /* 661 * Attempt to do a CPU reset via CPU reset port. 662 */ 663 if ((inb(0x35) & 0xa0) != 0xa0) { 664 outb(0x37, 0x0f); /* SHUT0 = 0. */ 665 outb(0x37, 0x0b); /* SHUT1 = 0. */ 666 } 667 outb(0xf0, 0x00); /* Reset. */ 668 #else 669 #if !defined(BROKEN_KEYBOARD_RESET) 670 /* 671 * Attempt to do a CPU reset via the keyboard controller, 672 * do not turn off GateA20, as any machine that fails 673 * to do the reset here would then end up in no man's land. 674 */ 675 outb(IO_KBD + 4, 0xFE); 676 DELAY(500000); /* wait 0.5 sec to see if that did it */ 677 #endif 678 679 /* 680 * Attempt to force a reset via the Reset Control register at 681 * I/O port 0xcf9. Bit 2 forces a system reset when it 682 * transitions from 0 to 1. Bit 1 selects the type of reset 683 * to attempt: 0 selects a "soft" reset, and 1 selects a 684 * "hard" reset. We try a "hard" reset. The first write sets 685 * bit 1 to select a "hard" reset and clears bit 2. The 686 * second write forces a 0 -> 1 transition in bit 2 to trigger 687 * a reset. 688 */ 689 outb(0xcf9, 0x2); 690 outb(0xcf9, 0x6); 691 DELAY(500000); /* wait 0.5 sec to see if that did it */ 692 693 /* 694 * Attempt to force a reset via the Fast A20 and Init register 695 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate. 696 * Bit 0 asserts INIT# when set to 1. We are careful to only 697 * preserve bit 1 while setting bit 0. We also must clear bit 698 * 0 before setting it if it isn't already clear. 699 */ 700 b = inb(0x92); 701 if (b != 0xff) { 702 if ((b & 0x1) != 0) 703 outb(0x92, b & 0xfe); 704 outb(0x92, b | 0x1); 705 DELAY(500000); /* wait 0.5 sec to see if that did it */ 706 } 707 #endif /* PC98 */ 708 709 printf("No known reset method worked, attempting CPU shutdown\n"); 710 DELAY(1000000); /* wait 1 sec for printf to complete */ 711 712 /* Wipe the IDT. */ 713 null_idt.rd_limit = 0; 714 null_idt.rd_base = 0; 715 lidt(&null_idt); 716 717 /* "good night, sweet prince .... <THUNK!>" */ 718 breakpoint(); 719 720 /* NOTREACHED */ 721 while(1); 722 } 723 724 /* 725 * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-)) 726 */ 727 static void 728 sf_buf_init(void *arg) 729 { 730 struct sf_buf *sf_bufs; 731 vm_offset_t sf_base; 732 int i; 733 734 nsfbufs = NSFBUFS; 735 TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs); 736 737 sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask); 738 TAILQ_INIT(&sf_buf_freelist); 739 sf_base = kmem_alloc_nofault(kernel_map, nsfbufs * PAGE_SIZE); 740 sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP, 741 M_NOWAIT | M_ZERO); 742 for (i = 0; i < nsfbufs; i++) { 743 sf_bufs[i].kva = sf_base + i * PAGE_SIZE; 744 TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry); 745 } 746 sf_buf_alloc_want = 0; 747 mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF); 748 } 749 750 /* 751 * Invalidate the cache lines that may belong to the page, if 752 * (possibly old) mapping of the page by sf buffer exists. Returns 753 * TRUE when mapping was found and cache invalidated. 754 */ 755 boolean_t 756 sf_buf_invalidate_cache(vm_page_t m) 757 { 758 struct sf_head *hash_list; 759 struct sf_buf *sf; 760 boolean_t ret; 761 762 hash_list = &sf_buf_active[SF_BUF_HASH(m)]; 763 ret = FALSE; 764 mtx_lock(&sf_buf_lock); 765 LIST_FOREACH(sf, hash_list, list_entry) { 766 if (sf->m == m) { 767 /* 768 * Use pmap_qenter to update the pte for 769 * existing mapping, in particular, the PAT 770 * settings are recalculated. 771 */ 772 pmap_qenter(sf->kva, &m, 1); 773 pmap_invalidate_cache_range(sf->kva, sf->kva + 774 PAGE_SIZE); 775 ret = TRUE; 776 break; 777 } 778 } 779 mtx_unlock(&sf_buf_lock); 780 return (ret); 781 } 782 783 /* 784 * Get an sf_buf from the freelist. May block if none are available. 785 */ 786 struct sf_buf * 787 sf_buf_alloc(struct vm_page *m, int flags) 788 { 789 pt_entry_t opte, *ptep; 790 struct sf_head *hash_list; 791 struct sf_buf *sf; 792 #ifdef SMP 793 cpumask_t cpumask, other_cpus; 794 #endif 795 int error; 796 797 KASSERT(curthread->td_pinned > 0 || (flags & SFB_CPUPRIVATE) == 0, 798 ("sf_buf_alloc(SFB_CPUPRIVATE): curthread not pinned")); 799 hash_list = &sf_buf_active[SF_BUF_HASH(m)]; 800 mtx_lock(&sf_buf_lock); 801 LIST_FOREACH(sf, hash_list, list_entry) { 802 if (sf->m == m) { 803 sf->ref_count++; 804 if (sf->ref_count == 1) { 805 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); 806 nsfbufsused++; 807 nsfbufspeak = imax(nsfbufspeak, nsfbufsused); 808 } 809 #ifdef SMP 810 goto shootdown; 811 #else 812 goto done; 813 #endif 814 } 815 } 816 while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) { 817 if (flags & SFB_NOWAIT) 818 goto done; 819 sf_buf_alloc_want++; 820 mbstat.sf_allocwait++; 821 error = msleep(&sf_buf_freelist, &sf_buf_lock, 822 (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0); 823 sf_buf_alloc_want--; 824 825 /* 826 * If we got a signal, don't risk going back to sleep. 827 */ 828 if (error) 829 goto done; 830 } 831 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); 832 if (sf->m != NULL) 833 LIST_REMOVE(sf, list_entry); 834 LIST_INSERT_HEAD(hash_list, sf, list_entry); 835 sf->ref_count = 1; 836 sf->m = m; 837 nsfbufsused++; 838 nsfbufspeak = imax(nsfbufspeak, nsfbufsused); 839 840 /* 841 * Update the sf_buf's virtual-to-physical mapping, flushing the 842 * virtual address from the TLB. Since the reference count for 843 * the sf_buf's old mapping was zero, that mapping is not 844 * currently in use. Consequently, there is no need to exchange 845 * the old and new PTEs atomically, even under PAE. 846 */ 847 ptep = vtopte(sf->kva); 848 opte = *ptep; 849 #ifdef XEN 850 PT_SET_MA(sf->kva, xpmap_ptom(VM_PAGE_TO_PHYS(m)) | pgeflag 851 | PG_RW | PG_V | pmap_cache_bits(m->md.pat_mode, 0)); 852 #else 853 *ptep = VM_PAGE_TO_PHYS(m) | pgeflag | PG_RW | PG_V | 854 pmap_cache_bits(m->md.pat_mode, 0); 855 #endif 856 857 /* 858 * Avoid unnecessary TLB invalidations: If the sf_buf's old 859 * virtual-to-physical mapping was not used, then any processor 860 * that has invalidated the sf_buf's virtual address from its TLB 861 * since the last used mapping need not invalidate again. 862 */ 863 #ifdef SMP 864 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A)) 865 sf->cpumask = 0; 866 shootdown: 867 sched_pin(); 868 cpumask = PCPU_GET(cpumask); 869 if ((sf->cpumask & cpumask) == 0) { 870 sf->cpumask |= cpumask; 871 invlpg(sf->kva); 872 } 873 if ((flags & SFB_CPUPRIVATE) == 0) { 874 other_cpus = PCPU_GET(other_cpus) & ~sf->cpumask; 875 if (other_cpus != 0) { 876 sf->cpumask |= other_cpus; 877 smp_masked_invlpg(other_cpus, sf->kva); 878 } 879 } 880 sched_unpin(); 881 #else 882 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A)) 883 pmap_invalidate_page(kernel_pmap, sf->kva); 884 #endif 885 done: 886 mtx_unlock(&sf_buf_lock); 887 return (sf); 888 } 889 890 /* 891 * Remove a reference from the given sf_buf, adding it to the free 892 * list when its reference count reaches zero. A freed sf_buf still, 893 * however, retains its virtual-to-physical mapping until it is 894 * recycled or reactivated by sf_buf_alloc(9). 895 */ 896 void 897 sf_buf_free(struct sf_buf *sf) 898 { 899 900 mtx_lock(&sf_buf_lock); 901 sf->ref_count--; 902 if (sf->ref_count == 0) { 903 TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry); 904 nsfbufsused--; 905 #ifdef XEN 906 /* 907 * Xen doesn't like having dangling R/W mappings 908 */ 909 pmap_qremove(sf->kva, 1); 910 sf->m = NULL; 911 LIST_REMOVE(sf, list_entry); 912 #endif 913 if (sf_buf_alloc_want > 0) 914 wakeup_one(&sf_buf_freelist); 915 } 916 mtx_unlock(&sf_buf_lock); 917 } 918 919 /* 920 * Software interrupt handler for queued VM system processing. 921 */ 922 void 923 swi_vm(void *dummy) 924 { 925 if (busdma_swi_pending != 0) 926 busdma_swi(); 927 } 928 929 /* 930 * Tell whether this address is in some physical memory region. 931 * Currently used by the kernel coredump code in order to avoid 932 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 933 * or other unpredictable behaviour. 934 */ 935 936 int 937 is_physical_memory(vm_paddr_t addr) 938 { 939 940 #ifdef DEV_ISA 941 /* The ISA ``memory hole''. */ 942 if (addr >= 0xa0000 && addr < 0x100000) 943 return 0; 944 #endif 945 946 /* 947 * stuff other tests for known memory-mapped devices (PCI?) 948 * here 949 */ 950 951 return 1; 952 } 953