1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1982, 1986 The Regents of the University of California. 5 * Copyright (c) 1989, 1990 William Jolitz 6 * Copyright (c) 1994 John Dyson 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * the Systems Programming Group of the University of Utah Computer 11 * Science Department, and William Jolitz. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91 42 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ 43 */ 44 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include "opt_isa.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/priv.h> 63 #include <sys/proc.h> 64 #include <sys/procctl.h> 65 #include <sys/smp.h> 66 #include <sys/sysctl.h> 67 #include <sys/sysent.h> 68 #include <sys/unistd.h> 69 #include <sys/vnode.h> 70 #include <sys/vmmeter.h> 71 #include <sys/wait.h> 72 73 #include <machine/cpu.h> 74 #include <machine/md_var.h> 75 #include <machine/pcb.h> 76 #include <machine/smp.h> 77 #include <machine/specialreg.h> 78 #include <machine/tss.h> 79 80 #include <vm/vm.h> 81 #include <vm/vm_extern.h> 82 #include <vm/vm_kern.h> 83 #include <vm/vm_page.h> 84 #include <vm/vm_map.h> 85 #include <vm/vm_param.h> 86 87 _Static_assert(OFFSETOF_MONITORBUF == offsetof(struct pcpu, pc_monitorbuf), 88 "OFFSETOF_MONITORBUF does not correspond with offset of pc_monitorbuf."); 89 90 void 91 set_top_of_stack_td(struct thread *td) 92 { 93 td->td_md.md_stack_base = td->td_kstack + 94 td->td_kstack_pages * PAGE_SIZE - 95 roundup2(cpu_max_ext_state_size, XSAVE_AREA_ALIGN); 96 } 97 98 struct savefpu * 99 get_pcb_user_save_td(struct thread *td) 100 { 101 vm_offset_t p; 102 103 p = td->td_md.md_stack_base; 104 KASSERT((p % XSAVE_AREA_ALIGN) == 0, 105 ("Unaligned pcb_user_save area ptr %#lx td %p", p, td)); 106 return ((struct savefpu *)p); 107 } 108 109 struct pcb * 110 get_pcb_td(struct thread *td) 111 { 112 113 return (&td->td_md.md_pcb); 114 } 115 116 struct savefpu * 117 get_pcb_user_save_pcb(struct pcb *pcb) 118 { 119 struct thread *td; 120 121 td = __containerof(pcb, struct thread, td_md.md_pcb); 122 return (get_pcb_user_save_td(td)); 123 } 124 125 void * 126 alloc_fpusave(int flags) 127 { 128 void *res; 129 struct savefpu_ymm *sf; 130 131 res = malloc(cpu_max_ext_state_size, M_DEVBUF, flags); 132 if (use_xsave) { 133 sf = (struct savefpu_ymm *)res; 134 bzero(&sf->sv_xstate.sx_hd, sizeof(sf->sv_xstate.sx_hd)); 135 sf->sv_xstate.sx_hd.xstate_bv = xsave_mask; 136 } 137 return (res); 138 } 139 140 /* 141 * Finish a fork operation, with process p2 nearly set up. 142 * Copy and update the pcb, set up the stack so that the child 143 * ready to run and return to user mode. 144 */ 145 void 146 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 147 { 148 struct proc *p1; 149 struct pcb *pcb2; 150 struct mdproc *mdp1, *mdp2; 151 struct proc_ldt *pldt; 152 153 p1 = td1->td_proc; 154 if ((flags & RFPROC) == 0) { 155 if ((flags & RFMEM) == 0) { 156 /* unshare user LDT */ 157 mdp1 = &p1->p_md; 158 mtx_lock(&dt_lock); 159 if ((pldt = mdp1->md_ldt) != NULL && 160 pldt->ldt_refcnt > 1 && 161 user_ldt_alloc(p1, 1) == NULL) 162 panic("could not copy LDT"); 163 mtx_unlock(&dt_lock); 164 } 165 return; 166 } 167 168 /* Ensure that td1's pcb is up to date. */ 169 fpuexit(td1); 170 update_pcb_bases(td1->td_pcb); 171 172 /* Point the stack and pcb to the actual location */ 173 set_top_of_stack_td(td2); 174 td2->td_pcb = pcb2 = get_pcb_td(td2); 175 176 /* Copy td1's pcb */ 177 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 178 179 /* Properly initialize pcb_save */ 180 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2); 181 bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2), 182 cpu_max_ext_state_size); 183 184 /* Point mdproc and then copy over td1's contents */ 185 mdp2 = &p2->p_md; 186 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 187 188 /* 189 * Create a new fresh stack for the new process. 190 * Copy the trap frame for the return to user mode as if from a 191 * syscall. This copies most of the user mode register values. 192 */ 193 td2->td_frame = (struct trapframe *)td2->td_md.md_stack_base - 1; 194 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 195 196 td2->td_frame->tf_rax = 0; /* Child returns zero */ 197 td2->td_frame->tf_rflags &= ~PSL_C; /* success */ 198 td2->td_frame->tf_rdx = 1; 199 200 /* 201 * If the parent process has the trap bit set (i.e. a debugger had 202 * single stepped the process to the system call), we need to clear 203 * the trap flag from the new frame unless the debugger had set PF_FORK 204 * on the parent. Otherwise, the child will receive a (likely 205 * unexpected) SIGTRAP when it executes the first instruction after 206 * returning to userland. 207 */ 208 if ((p1->p_pfsflags & PF_FORK) == 0) 209 td2->td_frame->tf_rflags &= ~PSL_T; 210 211 /* 212 * Set registers for trampoline to user mode. Leave space for the 213 * return address on stack. These are the kernel mode register values. 214 */ 215 pcb2->pcb_r12 = (register_t)fork_return; /* fork_trampoline argument */ 216 pcb2->pcb_rbp = 0; 217 pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *); 218 pcb2->pcb_rbx = (register_t)td2; /* fork_trampoline argument */ 219 pcb2->pcb_rip = (register_t)fork_trampoline; 220 /*- 221 * pcb2->pcb_dr*: cloned above. 222 * pcb2->pcb_savefpu: cloned above. 223 * pcb2->pcb_flags: cloned above. 224 * pcb2->pcb_onfault: cloned above (always NULL here?). 225 * pcb2->pcb_[fg]sbase: cloned above 226 */ 227 228 /* Setup to release spin count in fork_exit(). */ 229 td2->td_md.md_spinlock_count = 1; 230 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 231 pmap_thread_init_invl_gen(td2); 232 233 /* As an i386, do not copy io permission bitmap. */ 234 pcb2->pcb_tssp = NULL; 235 236 /* New segment registers. */ 237 set_pcb_flags_raw(pcb2, PCB_FULL_IRET); 238 239 /* Copy the LDT, if necessary. */ 240 mdp1 = &td1->td_proc->p_md; 241 mdp2 = &p2->p_md; 242 if (mdp1->md_ldt == NULL) { 243 mdp2->md_ldt = NULL; 244 return; 245 } 246 mtx_lock(&dt_lock); 247 if (mdp1->md_ldt != NULL) { 248 if (flags & RFMEM) { 249 mdp1->md_ldt->ldt_refcnt++; 250 mdp2->md_ldt = mdp1->md_ldt; 251 bcopy(&mdp1->md_ldt_sd, &mdp2->md_ldt_sd, sizeof(struct 252 system_segment_descriptor)); 253 } else { 254 mdp2->md_ldt = NULL; 255 mdp2->md_ldt = user_ldt_alloc(p2, 0); 256 if (mdp2->md_ldt == NULL) 257 panic("could not copy LDT"); 258 amd64_set_ldt_data(td2, 0, max_ldt_segment, 259 (struct user_segment_descriptor *) 260 mdp1->md_ldt->ldt_base); 261 } 262 } else 263 mdp2->md_ldt = NULL; 264 mtx_unlock(&dt_lock); 265 266 /* 267 * Now, cpu_switch() can schedule the new process. 268 * pcb_rsp is loaded pointing to the cpu_switch() stack frame 269 * containing the return address when exiting cpu_switch. 270 * This will normally be to fork_trampoline(), which will have 271 * %ebx loaded with the new proc's pointer. fork_trampoline() 272 * will set up a stack to call fork_return(p, frame); to complete 273 * the return to user-mode. 274 */ 275 } 276 277 /* 278 * Intercept the return address from a freshly forked process that has NOT 279 * been scheduled yet. 280 * 281 * This is needed to make kernel threads stay in kernel mode. 282 */ 283 void 284 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 285 { 286 /* 287 * Note that the trap frame follows the args, so the function 288 * is really called like this: func(arg, frame); 289 */ 290 td->td_pcb->pcb_r12 = (long) func; /* function */ 291 td->td_pcb->pcb_rbx = (long) arg; /* first arg */ 292 } 293 294 void 295 cpu_exit(struct thread *td) 296 { 297 298 /* 299 * If this process has a custom LDT, release it. 300 */ 301 if (td->td_proc->p_md.md_ldt != NULL) 302 user_ldt_free(td); 303 } 304 305 void 306 cpu_thread_exit(struct thread *td) 307 { 308 struct pcb *pcb; 309 310 critical_enter(); 311 if (td == PCPU_GET(fpcurthread)) 312 fpudrop(); 313 critical_exit(); 314 315 pcb = td->td_pcb; 316 317 /* Disable any hardware breakpoints. */ 318 if (pcb->pcb_flags & PCB_DBREGS) { 319 reset_dbregs(); 320 clear_pcb_flags(pcb, PCB_DBREGS); 321 } 322 } 323 324 void 325 cpu_thread_clean(struct thread *td) 326 { 327 struct pcb *pcb; 328 329 pcb = td->td_pcb; 330 331 /* 332 * Clean TSS/iomap 333 */ 334 if (pcb->pcb_tssp != NULL) { 335 pmap_pti_remove_kva((vm_offset_t)pcb->pcb_tssp, 336 (vm_offset_t)pcb->pcb_tssp + ctob(IOPAGES + 1)); 337 kmem_free((vm_offset_t)pcb->pcb_tssp, ctob(IOPAGES + 1)); 338 pcb->pcb_tssp = NULL; 339 } 340 } 341 342 void 343 cpu_thread_swapin(struct thread *td) 344 { 345 } 346 347 void 348 cpu_thread_swapout(struct thread *td) 349 { 350 } 351 352 void 353 cpu_thread_alloc(struct thread *td) 354 { 355 struct pcb *pcb; 356 struct xstate_hdr *xhdr; 357 358 set_top_of_stack_td(td); 359 td->td_pcb = pcb = get_pcb_td(td); 360 td->td_frame = (struct trapframe *)td->td_md.md_stack_base - 1; 361 pcb->pcb_save = get_pcb_user_save_pcb(pcb); 362 if (use_xsave) { 363 xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1); 364 bzero(xhdr, sizeof(*xhdr)); 365 xhdr->xstate_bv = xsave_mask; 366 } 367 } 368 369 void 370 cpu_thread_free(struct thread *td) 371 { 372 373 cpu_thread_clean(td); 374 } 375 376 bool 377 cpu_exec_vmspace_reuse(struct proc *p, vm_map_t map) 378 { 379 380 return (((curproc->p_md.md_flags & P_MD_KPTI) != 0) == 381 (vm_map_pmap(map)->pm_ucr3 != PMAP_NO_CR3)); 382 } 383 384 static void 385 cpu_procctl_kpti(struct proc *p, int com, int *val) 386 { 387 388 if (com == PROC_KPTI_CTL) { 389 if (pti && *val == PROC_KPTI_CTL_ENABLE_ON_EXEC) 390 p->p_md.md_flags |= P_MD_KPTI; 391 if (*val == PROC_KPTI_CTL_DISABLE_ON_EXEC) 392 p->p_md.md_flags &= ~P_MD_KPTI; 393 } else /* PROC_KPTI_STATUS */ { 394 *val = (p->p_md.md_flags & P_MD_KPTI) != 0 ? 395 PROC_KPTI_CTL_ENABLE_ON_EXEC: 396 PROC_KPTI_CTL_DISABLE_ON_EXEC; 397 if (vmspace_pmap(p->p_vmspace)->pm_ucr3 != PMAP_NO_CR3) 398 *val |= PROC_KPTI_STATUS_ACTIVE; 399 } 400 } 401 402 int 403 cpu_procctl(struct thread *td, int idtype, id_t id, int com, void *data) 404 { 405 struct proc *p; 406 int error, val; 407 408 switch (com) { 409 case PROC_KPTI_CTL: 410 case PROC_KPTI_STATUS: 411 if (idtype != P_PID) { 412 error = EINVAL; 413 break; 414 } 415 if (com == PROC_KPTI_CTL) { 416 /* sad but true and not a joke */ 417 error = priv_check(td, PRIV_IO); 418 if (error != 0) 419 break; 420 error = copyin(data, &val, sizeof(val)); 421 if (error != 0) 422 break; 423 if (val != PROC_KPTI_CTL_ENABLE_ON_EXEC && 424 val != PROC_KPTI_CTL_DISABLE_ON_EXEC) { 425 error = EINVAL; 426 break; 427 } 428 } 429 error = pget(id, PGET_CANSEE | PGET_NOTWEXIT | PGET_NOTID, &p); 430 if (error == 0) { 431 cpu_procctl_kpti(p, com, &val); 432 PROC_UNLOCK(p); 433 if (com == PROC_KPTI_STATUS) 434 error = copyout(&val, data, sizeof(val)); 435 } 436 break; 437 default: 438 error = EINVAL; 439 break; 440 } 441 return (error); 442 } 443 444 void 445 cpu_set_syscall_retval(struct thread *td, int error) 446 { 447 struct trapframe *frame; 448 449 frame = td->td_frame; 450 if (__predict_true(error == 0)) { 451 frame->tf_rax = td->td_retval[0]; 452 frame->tf_rdx = td->td_retval[1]; 453 frame->tf_rflags &= ~PSL_C; 454 return; 455 } 456 457 switch (error) { 458 case ERESTART: 459 /* 460 * Reconstruct pc, we know that 'syscall' is 2 bytes, 461 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 462 * We saved this in tf_err. 463 * %r10 (which was holding the value of %rcx) is restored 464 * for the next iteration. 465 * %r10 restore is only required for freebsd/amd64 processes, 466 * but shall be innocent for any ia32 ABI. 467 * 468 * Require full context restore to get the arguments 469 * in the registers reloaded at return to usermode. 470 */ 471 frame->tf_rip -= frame->tf_err; 472 frame->tf_r10 = frame->tf_rcx; 473 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 474 break; 475 476 case EJUSTRETURN: 477 break; 478 479 default: 480 frame->tf_rax = SV_ABI_ERRNO(td->td_proc, error); 481 frame->tf_rflags |= PSL_C; 482 break; 483 } 484 } 485 486 /* 487 * Initialize machine state, mostly pcb and trap frame for a new 488 * thread, about to return to userspace. Put enough state in the new 489 * thread's PCB to get it to go back to the fork_return(), which 490 * finalizes the thread state and handles peculiarities of the first 491 * return to userspace for the new thread. 492 */ 493 void 494 cpu_copy_thread(struct thread *td, struct thread *td0) 495 { 496 struct pcb *pcb2; 497 498 pcb2 = td->td_pcb; 499 500 /* 501 * Copy the upcall pcb. This loads kernel regs. 502 * Those not loaded individually below get their default 503 * values here. 504 */ 505 update_pcb_bases(td0->td_pcb); 506 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); 507 clear_pcb_flags(pcb2, PCB_FPUINITDONE | PCB_USERFPUINITDONE | 508 PCB_KERNFPU); 509 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2); 510 bcopy(get_pcb_user_save_td(td0), pcb2->pcb_save, 511 cpu_max_ext_state_size); 512 set_pcb_flags_raw(pcb2, PCB_FULL_IRET); 513 514 /* 515 * Create a new fresh stack for the new thread. 516 */ 517 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 518 519 /* If the current thread has the trap bit set (i.e. a debugger had 520 * single stepped the process to the system call), we need to clear 521 * the trap flag from the new frame. Otherwise, the new thread will 522 * receive a (likely unexpected) SIGTRAP when it executes the first 523 * instruction after returning to userland. 524 */ 525 td->td_frame->tf_rflags &= ~PSL_T; 526 527 /* 528 * Set registers for trampoline to user mode. Leave space for the 529 * return address on stack. These are the kernel mode register values. 530 */ 531 pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */ 532 pcb2->pcb_rbp = 0; 533 pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */ 534 pcb2->pcb_rbx = (register_t)td; /* trampoline arg */ 535 pcb2->pcb_rip = (register_t)fork_trampoline; 536 /* 537 * If we didn't copy the pcb, we'd need to do the following registers: 538 * pcb2->pcb_dr*: cloned above. 539 * pcb2->pcb_savefpu: cloned above. 540 * pcb2->pcb_onfault: cloned above (always NULL here?). 541 * pcb2->pcb_[fg]sbase: cloned above 542 */ 543 544 /* Setup to release spin count in fork_exit(). */ 545 td->td_md.md_spinlock_count = 1; 546 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 547 pmap_thread_init_invl_gen(td); 548 } 549 550 /* 551 * Set that machine state for performing an upcall that starts 552 * the entry function with the given argument. 553 */ 554 void 555 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 556 stack_t *stack) 557 { 558 559 /* 560 * Do any extra cleaning that needs to be done. 561 * The thread may have optional components 562 * that are not present in a fresh thread. 563 * This may be a recycled thread so make it look 564 * as though it's newly allocated. 565 */ 566 cpu_thread_clean(td); 567 568 #ifdef COMPAT_FREEBSD32 569 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 570 /* 571 * Set the trap frame to point at the beginning of the entry 572 * function. 573 */ 574 td->td_frame->tf_rbp = 0; 575 td->td_frame->tf_rsp = 576 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; 577 td->td_frame->tf_rip = (uintptr_t)entry; 578 579 /* Return address sentinel value to stop stack unwinding. */ 580 suword32((void *)td->td_frame->tf_rsp, 0); 581 582 /* Pass the argument to the entry point. */ 583 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)), 584 (uint32_t)(uintptr_t)arg); 585 586 return; 587 } 588 #endif 589 590 /* 591 * Set the trap frame to point at the beginning of the uts 592 * function. 593 */ 594 td->td_frame->tf_rbp = 0; 595 td->td_frame->tf_rsp = 596 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f; 597 td->td_frame->tf_rsp -= 8; 598 td->td_frame->tf_rip = (register_t)entry; 599 td->td_frame->tf_ds = _udatasel; 600 td->td_frame->tf_es = _udatasel; 601 td->td_frame->tf_fs = _ufssel; 602 td->td_frame->tf_gs = _ugssel; 603 td->td_frame->tf_flags = TF_HASSEGS; 604 605 /* Return address sentinel value to stop stack unwinding. */ 606 suword((void *)td->td_frame->tf_rsp, 0); 607 608 /* Pass the argument to the entry point. */ 609 td->td_frame->tf_rdi = (register_t)arg; 610 } 611 612 int 613 cpu_set_user_tls(struct thread *td, void *tls_base) 614 { 615 struct pcb *pcb; 616 617 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS) 618 return (EINVAL); 619 620 pcb = td->td_pcb; 621 set_pcb_flags(pcb, PCB_FULL_IRET); 622 #ifdef COMPAT_FREEBSD32 623 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) { 624 pcb->pcb_gsbase = (register_t)tls_base; 625 return (0); 626 } 627 #endif 628 pcb->pcb_fsbase = (register_t)tls_base; 629 return (0); 630 } 631 632 /* 633 * Software interrupt handler for queued VM system processing. 634 */ 635 void 636 swi_vm(void *dummy) 637 { 638 if (busdma_swi_pending != 0) 639 busdma_swi(); 640 } 641 642 /* 643 * Tell whether this address is in some physical memory region. 644 * Currently used by the kernel coredump code in order to avoid 645 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 646 * or other unpredictable behaviour. 647 */ 648 649 int 650 is_physical_memory(vm_paddr_t addr) 651 { 652 653 #ifdef DEV_ISA 654 /* The ISA ``memory hole''. */ 655 if (addr >= 0xa0000 && addr < 0x100000) 656 return 0; 657 #endif 658 659 /* 660 * stuff other tests for known memory-mapped devices (PCI?) 661 * here 662 */ 663 664 return 1; 665 } 666