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/kse.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/lock.h> 60 #include <sys/malloc.h> 61 #include <sys/mbuf.h> 62 #include <sys/mutex.h> 63 #include <sys/pioctl.h> 64 #include <sys/proc.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 PC98 93 #include <pc98/cbus/cbus.h> 94 #else 95 #include <i386/isa/isa.h> 96 #endif 97 98 #ifdef XBOX 99 #include <machine/xbox.h> 100 #endif 101 102 #ifndef NSFBUFS 103 #define NSFBUFS (512 + maxusers * 16) 104 #endif 105 106 static void cpu_reset_real(void); 107 #ifdef SMP 108 static void cpu_reset_proxy(void); 109 static u_int cpu_reset_proxyid; 110 static volatile u_int cpu_reset_proxy_active; 111 #endif 112 static void sf_buf_init(void *arg); 113 SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL) 114 115 LIST_HEAD(sf_head, sf_buf); 116 117 /* 118 * A hash table of active sendfile(2) buffers 119 */ 120 static struct sf_head *sf_buf_active; 121 static u_long sf_buf_hashmask; 122 123 #define SF_BUF_HASH(m) (((m) - vm_page_array) & sf_buf_hashmask) 124 125 static TAILQ_HEAD(, sf_buf) sf_buf_freelist; 126 static u_int sf_buf_alloc_want; 127 128 /* 129 * A lock used to synchronize access to the hash table and free list 130 */ 131 static struct mtx sf_buf_lock; 132 133 extern int _ucodesel, _udatasel; 134 135 /* 136 * Finish a fork operation, with process p2 nearly set up. 137 * Copy and update the pcb, set up the stack so that the child 138 * ready to run and return to user mode. 139 */ 140 void 141 cpu_fork(td1, p2, td2, flags) 142 register struct thread *td1; 143 register struct proc *p2; 144 struct thread *td2; 145 int flags; 146 { 147 register struct proc *p1; 148 struct pcb *pcb2; 149 struct mdproc *mdp2; 150 #ifdef DEV_NPX 151 register_t savecrit; 152 #endif 153 154 p1 = td1->td_proc; 155 if ((flags & RFPROC) == 0) { 156 if ((flags & RFMEM) == 0) { 157 /* unshare user LDT */ 158 struct mdproc *mdp1 = &p1->p_md; 159 struct proc_ldt *pldt; 160 161 pldt = mdp1->md_ldt; 162 if (pldt && pldt->ldt_refcnt > 1) { 163 pldt = user_ldt_alloc(mdp1, pldt->ldt_len); 164 if (pldt == NULL) 165 panic("could not copy LDT"); 166 mdp1->md_ldt = pldt; 167 set_user_ldt(mdp1); 168 user_ldt_free(td1); 169 } 170 } 171 return; 172 } 173 174 /* Ensure that p1's pcb is up to date. */ 175 #ifdef DEV_NPX 176 if (td1 == curthread) 177 td1->td_pcb->pcb_gs = rgs(); 178 savecrit = intr_disable(); 179 if (PCPU_GET(fpcurthread) == td1) 180 npxsave(&td1->td_pcb->pcb_save); 181 intr_restore(savecrit); 182 #endif 183 184 /* Point the pcb to the top of the stack */ 185 pcb2 = (struct pcb *)(td2->td_kstack + 186 td2->td_kstack_pages * PAGE_SIZE) - 1; 187 td2->td_pcb = pcb2; 188 189 /* Copy p1's pcb */ 190 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 191 192 /* Point mdproc and then copy over td1's contents */ 193 mdp2 = &p2->p_md; 194 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 195 196 /* 197 * Create a new fresh stack for the new process. 198 * Copy the trap frame for the return to user mode as if from a 199 * syscall. This copies most of the user mode register values. 200 * The -16 is so we can expand the trapframe if we go to vm86. 201 */ 202 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1; 203 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 204 205 td2->td_frame->tf_eax = 0; /* Child returns zero */ 206 td2->td_frame->tf_eflags &= ~PSL_C; /* success */ 207 td2->td_frame->tf_edx = 1; 208 209 /* 210 * If the parent process has the trap bit set (i.e. a debugger had 211 * single stepped the process to the system call), we need to clear 212 * the trap flag from the new frame unless the debugger had set PF_FORK 213 * on the parent. Otherwise, the child will receive a (likely 214 * unexpected) SIGTRAP when it executes the first instruction after 215 * returning to userland. 216 */ 217 if ((p1->p_pfsflags & PF_FORK) == 0) 218 td2->td_frame->tf_eflags &= ~PSL_T; 219 220 /* 221 * Set registers for trampoline to user mode. Leave space for the 222 * return address on stack. These are the kernel mode register values. 223 */ 224 #ifdef PAE 225 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt); 226 #else 227 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); 228 #endif 229 pcb2->pcb_edi = 0; 230 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */ 231 pcb2->pcb_ebp = 0; 232 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *); 233 pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */ 234 pcb2->pcb_eip = (int)fork_trampoline; 235 pcb2->pcb_psl = PSL_KERNEL; /* ints disabled */ 236 pcb2->pcb_gs = rgs(); 237 /*- 238 * pcb2->pcb_dr*: cloned above. 239 * pcb2->pcb_savefpu: cloned above. 240 * pcb2->pcb_flags: cloned above. 241 * pcb2->pcb_onfault: cloned above (always NULL here?). 242 * pcb2->pcb_gs: cloned above. 243 * pcb2->pcb_ext: cleared below. 244 */ 245 246 /* 247 * XXX don't copy the i/o pages. this should probably be fixed. 248 */ 249 pcb2->pcb_ext = 0; 250 251 /* Copy the LDT, if necessary. */ 252 mtx_lock_spin(&sched_lock); 253 if (mdp2->md_ldt != NULL) { 254 if (flags & RFMEM) { 255 mdp2->md_ldt->ldt_refcnt++; 256 } else { 257 mdp2->md_ldt = user_ldt_alloc(mdp2, 258 mdp2->md_ldt->ldt_len); 259 if (mdp2->md_ldt == NULL) 260 panic("could not copy LDT"); 261 } 262 } 263 mtx_unlock_spin(&sched_lock); 264 265 /* Setup to release sched_lock in fork_exit(). */ 266 td2->td_md.md_spinlock_count = 1; 267 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 268 269 /* 270 * Now, cpu_switch() can schedule the new process. 271 * pcb_esp is loaded pointing to the cpu_switch() stack frame 272 * containing the return address when exiting cpu_switch. 273 * This will normally be to fork_trampoline(), which will have 274 * %ebx loaded with the new proc's pointer. fork_trampoline() 275 * will set up a stack to call fork_return(p, frame); to complete 276 * the return to user-mode. 277 */ 278 } 279 280 /* 281 * Intercept the return address from a freshly forked process that has NOT 282 * been scheduled yet. 283 * 284 * This is needed to make kernel threads stay in kernel mode. 285 */ 286 void 287 cpu_set_fork_handler(td, func, arg) 288 struct thread *td; 289 void (*func)(void *); 290 void *arg; 291 { 292 /* 293 * Note that the trap frame follows the args, so the function 294 * is really called like this: func(arg, frame); 295 */ 296 td->td_pcb->pcb_esi = (int) func; /* function */ 297 td->td_pcb->pcb_ebx = (int) arg; /* first arg */ 298 } 299 300 void 301 cpu_exit(struct thread *td) 302 { 303 304 /* 305 * If this process has a custom LDT, release it. Reset pc->pcb_gs 306 * and %gs before we free it in case they refer to an LDT entry. 307 */ 308 if (td->td_proc->p_md.md_ldt) { 309 td->td_pcb->pcb_gs = _udatasel; 310 load_gs(_udatasel); 311 user_ldt_free(td); 312 } 313 } 314 315 void 316 cpu_thread_exit(struct thread *td) 317 { 318 319 #ifdef DEV_NPX 320 if (td == PCPU_GET(fpcurthread)) 321 npxdrop(); 322 #endif 323 324 /* Disable any hardware breakpoints. */ 325 if (td->td_pcb->pcb_flags & PCB_DBREGS) { 326 reset_dbregs(); 327 td->td_pcb->pcb_flags &= ~PCB_DBREGS; 328 } 329 } 330 331 void 332 cpu_thread_clean(struct thread *td) 333 { 334 struct pcb *pcb; 335 336 pcb = td->td_pcb; 337 if (pcb->pcb_ext != NULL) { 338 /* XXXKSE XXXSMP not SMP SAFE.. what locks do we have? */ 339 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */ 340 /* 341 * XXX do we need to move the TSS off the allocated pages 342 * before freeing them? (not done here) 343 */ 344 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext, 345 ctob(IOPAGES + 1)); 346 pcb->pcb_ext = NULL; 347 } 348 } 349 350 void 351 cpu_thread_swapin(struct thread *td) 352 { 353 } 354 355 void 356 cpu_thread_swapout(struct thread *td) 357 { 358 } 359 360 void 361 cpu_thread_setup(struct thread *td) 362 { 363 364 td->td_pcb = (struct pcb *)(td->td_kstack + 365 td->td_kstack_pages * PAGE_SIZE) - 1; 366 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1; 367 td->td_pcb->pcb_ext = NULL; 368 } 369 370 /* 371 * Initialize machine state (pcb and trap frame) for a new thread about to 372 * upcall. Put enough state in the new thread's PCB to get it to go back 373 * userret(), where we can intercept it again to set the return (upcall) 374 * Address and stack, along with those from upcals that are from other sources 375 * such as those generated in thread_userret() itself. 376 */ 377 void 378 cpu_set_upcall(struct thread *td, struct thread *td0) 379 { 380 struct pcb *pcb2; 381 382 /* Point the pcb to the top of the stack. */ 383 pcb2 = td->td_pcb; 384 385 /* 386 * Copy the upcall pcb. This loads kernel regs. 387 * Those not loaded individually below get their default 388 * values here. 389 * 390 * XXXKSE It might be a good idea to simply skip this as 391 * the values of the other registers may be unimportant. 392 * This would remove any requirement for knowing the KSE 393 * at this time (see the matching comment below for 394 * more analysis) (need a good safe default). 395 */ 396 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); 397 pcb2->pcb_flags &= ~(PCB_NPXTRAP|PCB_NPXINITDONE); 398 399 /* 400 * Create a new fresh stack for the new thread. 401 * The -16 is so we can expand the trapframe if we go to vm86. 402 * Don't forget to set this stack value into whatever supplies 403 * the address for the fault handlers. 404 * The contexts are filled in at the time we actually DO the 405 * upcall as only then do we know which KSE we got. 406 */ 407 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 408 409 /* 410 * Set registers for trampoline to user mode. Leave space for the 411 * return address on stack. These are the kernel mode register values. 412 */ 413 #ifdef PAE 414 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdpt); 415 #else 416 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdir); 417 #endif 418 pcb2->pcb_edi = 0; 419 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */ 420 pcb2->pcb_ebp = 0; 421 pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */ 422 pcb2->pcb_ebx = (int)td; /* trampoline arg */ 423 pcb2->pcb_eip = (int)fork_trampoline; 424 pcb2->pcb_psl &= ~(PSL_I); /* interrupts must be disabled */ 425 pcb2->pcb_gs = rgs(); 426 /* 427 * If we didn't copy the pcb, we'd need to do the following registers: 428 * pcb2->pcb_dr*: cloned above. 429 * pcb2->pcb_savefpu: cloned above. 430 * pcb2->pcb_flags: cloned above. 431 * pcb2->pcb_onfault: cloned above (always NULL here?). 432 * pcb2->pcb_gs: cloned above. XXXKSE ??? 433 * pcb2->pcb_ext: cleared below. 434 */ 435 pcb2->pcb_ext = NULL; 436 437 /* Setup to release sched_lock in fork_exit(). */ 438 td->td_md.md_spinlock_count = 1; 439 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 440 } 441 442 /* 443 * Set that machine state for performing an upcall that has to 444 * be done in thread_userret() so that those upcalls generated 445 * in thread_userret() itself can be done as well. 446 */ 447 void 448 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg, 449 stack_t *stack) 450 { 451 452 /* 453 * Do any extra cleaning that needs to be done. 454 * The thread may have optional components 455 * that are not present in a fresh thread. 456 * This may be a recycled thread so make it look 457 * as though it's newly allocated. 458 */ 459 cpu_thread_clean(td); 460 461 /* 462 * Set the trap frame to point at the beginning of the uts 463 * function. 464 */ 465 td->td_frame->tf_ebp = 0; 466 td->td_frame->tf_esp = 467 (int)stack->ss_sp + stack->ss_size - 16; 468 td->td_frame->tf_eip = (int)entry; 469 470 /* 471 * Pass the address of the mailbox for this kse to the uts 472 * function as a parameter on the stack. 473 */ 474 suword((void *)(td->td_frame->tf_esp + sizeof(void *)), 475 (int)arg); 476 } 477 478 int 479 cpu_set_user_tls(struct thread *td, void *tls_base) 480 { 481 struct segment_descriptor sd; 482 uint32_t base; 483 484 /* 485 * Construct a descriptor and store it in the pcb for 486 * the next context switch. Also store it in the gdt 487 * so that the load of tf_fs into %fs will activate it 488 * at return to userland. 489 */ 490 base = (uint32_t)tls_base; 491 sd.sd_lobase = base & 0xffffff; 492 sd.sd_hibase = (base >> 24) & 0xff; 493 sd.sd_lolimit = 0xffff; /* 4GB limit, wraps around */ 494 sd.sd_hilimit = 0xf; 495 sd.sd_type = SDT_MEMRWA; 496 sd.sd_dpl = SEL_UPL; 497 sd.sd_p = 1; 498 sd.sd_xx = 0; 499 sd.sd_def32 = 1; 500 sd.sd_gran = 1; 501 critical_enter(); 502 /* set %gs */ 503 td->td_pcb->pcb_gsd = sd; 504 if (td == curthread) { 505 PCPU_GET(fsgs_gdt)[1] = sd; 506 load_gs(GSEL(GUGS_SEL, SEL_UPL)); 507 } 508 critical_exit(); 509 return (0); 510 } 511 512 /* 513 * Convert kernel VA to physical address 514 */ 515 vm_paddr_t 516 kvtop(void *addr) 517 { 518 vm_paddr_t pa; 519 520 pa = pmap_kextract((vm_offset_t)addr); 521 if (pa == 0) 522 panic("kvtop: zero page frame"); 523 return (pa); 524 } 525 526 #ifdef SMP 527 static void 528 cpu_reset_proxy() 529 { 530 531 cpu_reset_proxy_active = 1; 532 while (cpu_reset_proxy_active == 1) 533 ; /* Wait for other cpu to see that we've started */ 534 stop_cpus((1<<cpu_reset_proxyid)); 535 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 536 DELAY(1000000); 537 cpu_reset_real(); 538 } 539 #endif 540 541 void 542 cpu_reset() 543 { 544 #ifdef XBOX 545 if (arch_i386_is_xbox) { 546 /* Kick the PIC16L, it can reboot the box */ 547 pic16l_reboot(); 548 for (;;); 549 } 550 #endif 551 552 #ifdef SMP 553 u_int cnt, map; 554 555 if (smp_active) { 556 map = PCPU_GET(other_cpus) & ~stopped_cpus; 557 if (map != 0) { 558 printf("cpu_reset: Stopping other CPUs\n"); 559 stop_cpus(map); 560 } 561 562 if (PCPU_GET(cpuid) != 0) { 563 cpu_reset_proxyid = PCPU_GET(cpuid); 564 cpustop_restartfunc = cpu_reset_proxy; 565 cpu_reset_proxy_active = 0; 566 printf("cpu_reset: Restarting BSP\n"); 567 568 /* Restart CPU #0. */ 569 /* XXX: restart_cpus(1 << 0); */ 570 atomic_store_rel_int(&started_cpus, (1 << 0)); 571 572 cnt = 0; 573 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 574 cnt++; /* Wait for BSP to announce restart */ 575 if (cpu_reset_proxy_active == 0) 576 printf("cpu_reset: Failed to restart BSP\n"); 577 enable_intr(); 578 cpu_reset_proxy_active = 2; 579 580 while (1); 581 /* NOTREACHED */ 582 } 583 584 DELAY(1000000); 585 } 586 #endif 587 cpu_reset_real(); 588 /* NOTREACHED */ 589 } 590 591 static void 592 cpu_reset_real() 593 { 594 595 #ifdef CPU_ELAN 596 if (elan_mmcr != NULL) 597 elan_mmcr->RESCFG = 1; 598 #endif 599 600 if (cpu == CPU_GEODE1100) { 601 /* Attempt Geode's own reset */ 602 outl(0xcf8, 0x80009044ul); 603 outl(0xcfc, 0xf); 604 } 605 606 #ifdef PC98 607 /* 608 * Attempt to do a CPU reset via CPU reset port. 609 */ 610 disable_intr(); 611 if ((inb(0x35) & 0xa0) != 0xa0) { 612 outb(0x37, 0x0f); /* SHUT0 = 0. */ 613 outb(0x37, 0x0b); /* SHUT1 = 0. */ 614 } 615 outb(0xf0, 0x00); /* Reset. */ 616 #else 617 #if !defined(BROKEN_KEYBOARD_RESET) 618 /* 619 * Attempt to do a CPU reset via the keyboard controller, 620 * do not turn off GateA20, as any machine that fails 621 * to do the reset here would then end up in no man's land. 622 */ 623 outb(IO_KBD + 4, 0xFE); 624 DELAY(500000); /* wait 0.5 sec to see if that did it */ 625 printf("Keyboard reset did not work, attempting CPU shutdown\n"); 626 DELAY(1000000); /* wait 1 sec for printf to complete */ 627 #endif 628 #endif /* PC98 */ 629 630 /* Force a shutdown by unmapping entire address space. */ 631 bzero((caddr_t)PTD, NBPTD); 632 633 /* "good night, sweet prince .... <THUNK!>" */ 634 invltlb(); 635 /* NOTREACHED */ 636 while(1); 637 } 638 639 /* 640 * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-)) 641 */ 642 static void 643 sf_buf_init(void *arg) 644 { 645 struct sf_buf *sf_bufs; 646 vm_offset_t sf_base; 647 int i; 648 649 nsfbufs = NSFBUFS; 650 TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs); 651 652 sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask); 653 TAILQ_INIT(&sf_buf_freelist); 654 sf_base = kmem_alloc_nofault(kernel_map, nsfbufs * PAGE_SIZE); 655 sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP, 656 M_NOWAIT | M_ZERO); 657 for (i = 0; i < nsfbufs; i++) { 658 sf_bufs[i].kva = sf_base + i * PAGE_SIZE; 659 TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry); 660 } 661 sf_buf_alloc_want = 0; 662 mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF); 663 } 664 665 /* 666 * Get an sf_buf from the freelist. Will block if none are available. 667 */ 668 struct sf_buf * 669 sf_buf_alloc(struct vm_page *m, int flags) 670 { 671 pt_entry_t opte, *ptep; 672 struct sf_head *hash_list; 673 struct sf_buf *sf; 674 #ifdef SMP 675 cpumask_t cpumask, other_cpus; 676 #endif 677 int error; 678 679 KASSERT(curthread->td_pinned > 0 || (flags & SFB_CPUPRIVATE) == 0, 680 ("sf_buf_alloc(SFB_CPUPRIVATE): curthread not pinned")); 681 hash_list = &sf_buf_active[SF_BUF_HASH(m)]; 682 mtx_lock(&sf_buf_lock); 683 LIST_FOREACH(sf, hash_list, list_entry) { 684 if (sf->m == m) { 685 sf->ref_count++; 686 if (sf->ref_count == 1) { 687 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); 688 nsfbufsused++; 689 nsfbufspeak = imax(nsfbufspeak, nsfbufsused); 690 } 691 #ifdef SMP 692 goto shootdown; 693 #else 694 goto done; 695 #endif 696 } 697 } 698 while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) { 699 if (flags & SFB_NOWAIT) 700 goto done; 701 sf_buf_alloc_want++; 702 mbstat.sf_allocwait++; 703 error = msleep(&sf_buf_freelist, &sf_buf_lock, 704 (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0); 705 sf_buf_alloc_want--; 706 707 /* 708 * If we got a signal, don't risk going back to sleep. 709 */ 710 if (error) 711 goto done; 712 } 713 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); 714 if (sf->m != NULL) 715 LIST_REMOVE(sf, list_entry); 716 LIST_INSERT_HEAD(hash_list, sf, list_entry); 717 sf->ref_count = 1; 718 sf->m = m; 719 nsfbufsused++; 720 nsfbufspeak = imax(nsfbufspeak, nsfbufsused); 721 722 /* 723 * Update the sf_buf's virtual-to-physical mapping, flushing the 724 * virtual address from the TLB. Since the reference count for 725 * the sf_buf's old mapping was zero, that mapping is not 726 * currently in use. Consequently, there is no need to exchange 727 * the old and new PTEs atomically, even under PAE. 728 */ 729 ptep = vtopte(sf->kva); 730 opte = *ptep; 731 *ptep = VM_PAGE_TO_PHYS(m) | pgeflag | PG_RW | PG_V; 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 sf->cpumask = 0; 742 shootdown: 743 sched_pin(); 744 cpumask = PCPU_GET(cpumask); 745 if ((sf->cpumask & cpumask) == 0) { 746 sf->cpumask |= cpumask; 747 invlpg(sf->kva); 748 } 749 if ((flags & SFB_CPUPRIVATE) == 0) { 750 other_cpus = PCPU_GET(other_cpus) & ~sf->cpumask; 751 if (other_cpus != 0) { 752 sf->cpumask |= other_cpus; 753 mtx_lock_spin(&smp_ipi_mtx); 754 smp_masked_invlpg(other_cpus, sf->kva); 755 mtx_unlock_spin(&smp_ipi_mtx); 756 } 757 } 758 sched_unpin(); 759 #else 760 if ((opte & (PG_V | PG_A)) == (PG_V | PG_A)) 761 pmap_invalidate_page(kernel_pmap, sf->kva); 762 #endif 763 done: 764 mtx_unlock(&sf_buf_lock); 765 return (sf); 766 } 767 768 /* 769 * Remove a reference from the given sf_buf, adding it to the free 770 * list when its reference count reaches zero. A freed sf_buf still, 771 * however, retains its virtual-to-physical mapping until it is 772 * recycled or reactivated by sf_buf_alloc(9). 773 */ 774 void 775 sf_buf_free(struct sf_buf *sf) 776 { 777 778 mtx_lock(&sf_buf_lock); 779 sf->ref_count--; 780 if (sf->ref_count == 0) { 781 TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry); 782 nsfbufsused--; 783 if (sf_buf_alloc_want > 0) 784 wakeup_one(&sf_buf_freelist); 785 } 786 mtx_unlock(&sf_buf_lock); 787 } 788 789 /* 790 * Software interrupt handler for queued VM system processing. 791 */ 792 void 793 swi_vm(void *dummy) 794 { 795 if (busdma_swi_pending != 0) 796 busdma_swi(); 797 } 798 799 /* 800 * Tell whether this address is in some physical memory region. 801 * Currently used by the kernel coredump code in order to avoid 802 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 803 * or other unpredictable behaviour. 804 */ 805 806 int 807 is_physical_memory(vm_paddr_t addr) 808 { 809 810 #ifdef DEV_ISA 811 /* The ISA ``memory hole''. */ 812 if (addr >= 0xa0000 && addr < 0x100000) 813 return 0; 814 #endif 815 816 /* 817 * stuff other tests for known memory-mapped devices (PCI?) 818 * here 819 */ 820 821 return 1; 822 } 823