vm_machdep.c revision 216255
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: head/sys/amd64/amd64/vm_machdep.c 216255 2010-12-07 12:44:33Z kib $"); 45 46#include "opt_isa.h" 47#include "opt_cpu.h" 48#include "opt_compat.h" 49 50#include <sys/param.h> 51#include <sys/systm.h> 52#include <sys/bio.h> 53#include <sys/buf.h> 54#include <sys/kernel.h> 55#include <sys/ktr.h> 56#include <sys/lock.h> 57#include <sys/malloc.h> 58#include <sys/mbuf.h> 59#include <sys/mutex.h> 60#include <sys/pioctl.h> 61#include <sys/proc.h> 62#include <sys/sf_buf.h> 63#include <sys/smp.h> 64#include <sys/sysctl.h> 65#include <sys/sysent.h> 66#include <sys/unistd.h> 67#include <sys/vnode.h> 68#include <sys/vmmeter.h> 69 70#include <machine/cpu.h> 71#include <machine/md_var.h> 72#include <machine/pcb.h> 73#include <machine/specialreg.h> 74#include <machine/tss.h> 75 76#include <vm/vm.h> 77#include <vm/vm_extern.h> 78#include <vm/vm_kern.h> 79#include <vm/vm_page.h> 80#include <vm/vm_map.h> 81#include <vm/vm_param.h> 82 83#include <x86/isa/isa.h> 84 85static void cpu_reset_real(void); 86#ifdef SMP 87static void cpu_reset_proxy(void); 88static u_int cpu_reset_proxyid; 89static volatile u_int cpu_reset_proxy_active; 90#endif 91 92/* 93 * Finish a fork operation, with process p2 nearly set up. 94 * Copy and update the pcb, set up the stack so that the child 95 * ready to run and return to user mode. 96 */ 97void 98cpu_fork(td1, p2, td2, flags) 99 register struct thread *td1; 100 register struct proc *p2; 101 struct thread *td2; 102 int flags; 103{ 104 register struct proc *p1; 105 struct pcb *pcb2; 106 struct mdproc *mdp1, *mdp2; 107 struct proc_ldt *pldt; 108 pmap_t pmap2; 109 110 p1 = td1->td_proc; 111 if ((flags & RFPROC) == 0) { 112 if ((flags & RFMEM) == 0) { 113 /* unshare user LDT */ 114 mdp1 = &p1->p_md; 115 mtx_lock(&dt_lock); 116 if ((pldt = mdp1->md_ldt) != NULL && 117 pldt->ldt_refcnt > 1 && 118 user_ldt_alloc(p1, 1) == NULL) 119 panic("could not copy LDT"); 120 mtx_unlock(&dt_lock); 121 } 122 return; 123 } 124 125 /* Ensure that td1's pcb is up to date. */ 126 fpuexit(td1); 127 128 /* Point the pcb to the top of the stack */ 129 pcb2 = (struct pcb *)(td2->td_kstack + 130 td2->td_kstack_pages * PAGE_SIZE) - 1; 131 td2->td_pcb = pcb2; 132 133 /* Copy td1's pcb */ 134 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 135 136 /* Properly initialize pcb_save */ 137 pcb2->pcb_save = &pcb2->pcb_user_save; 138 139 /* Point mdproc and then copy over td1's contents */ 140 mdp2 = &p2->p_md; 141 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 142 143 /* 144 * Create a new fresh stack for the new process. 145 * Copy the trap frame for the return to user mode as if from a 146 * syscall. This copies most of the user mode register values. 147 */ 148 td2->td_frame = (struct trapframe *)td2->td_pcb - 1; 149 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 150 151 td2->td_frame->tf_rax = 0; /* Child returns zero */ 152 td2->td_frame->tf_rflags &= ~PSL_C; /* success */ 153 td2->td_frame->tf_rdx = 1; 154 155 /* 156 * If the parent process has the trap bit set (i.e. a debugger had 157 * single stepped the process to the system call), we need to clear 158 * the trap flag from the new frame unless the debugger had set PF_FORK 159 * on the parent. Otherwise, the child will receive a (likely 160 * unexpected) SIGTRAP when it executes the first instruction after 161 * returning to userland. 162 */ 163 if ((p1->p_pfsflags & PF_FORK) == 0) 164 td2->td_frame->tf_rflags &= ~PSL_T; 165 166 /* 167 * Set registers for trampoline to user mode. Leave space for the 168 * return address on stack. These are the kernel mode register values. 169 */ 170 pmap2 = vmspace_pmap(p2->p_vmspace); 171 pcb2->pcb_cr3 = DMAP_TO_PHYS((vm_offset_t)pmap2->pm_pml4); 172 pcb2->pcb_r12 = (register_t)fork_return; /* fork_trampoline argument */ 173 pcb2->pcb_rbp = 0; 174 pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *); 175 pcb2->pcb_rbx = (register_t)td2; /* fork_trampoline argument */ 176 pcb2->pcb_rip = (register_t)fork_trampoline; 177 /*- 178 * pcb2->pcb_dr*: cloned above. 179 * pcb2->pcb_savefpu: cloned above. 180 * pcb2->pcb_flags: cloned above. 181 * pcb2->pcb_onfault: cloned above (always NULL here?). 182 * pcb2->pcb_[fg]sbase: cloned above 183 */ 184 185 /* Setup to release spin count in fork_exit(). */ 186 td2->td_md.md_spinlock_count = 1; 187 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 188 189 /* As an i386, do not copy io permission bitmap. */ 190 pcb2->pcb_tssp = NULL; 191 192 /* New segment registers. */ 193 pcb2->pcb_full_iret = 1; 194 195 /* Copy the LDT, if necessary. */ 196 mdp1 = &td1->td_proc->p_md; 197 mdp2 = &p2->p_md; 198 mtx_lock(&dt_lock); 199 if (mdp1->md_ldt != NULL) { 200 if (flags & RFMEM) { 201 mdp1->md_ldt->ldt_refcnt++; 202 mdp2->md_ldt = mdp1->md_ldt; 203 bcopy(&mdp1->md_ldt_sd, &mdp2->md_ldt_sd, sizeof(struct 204 system_segment_descriptor)); 205 } else { 206 mdp2->md_ldt = NULL; 207 mdp2->md_ldt = user_ldt_alloc(p2, 0); 208 if (mdp2->md_ldt == NULL) 209 panic("could not copy LDT"); 210 amd64_set_ldt_data(td2, 0, max_ldt_segment, 211 (struct user_segment_descriptor *) 212 mdp1->md_ldt->ldt_base); 213 } 214 } else 215 mdp2->md_ldt = NULL; 216 mtx_unlock(&dt_lock); 217 218 /* 219 * Now, cpu_switch() can schedule the new process. 220 * pcb_rsp is loaded pointing to the cpu_switch() stack frame 221 * containing the return address when exiting cpu_switch. 222 * This will normally be to fork_trampoline(), which will have 223 * %ebx loaded with the new proc's pointer. fork_trampoline() 224 * will set up a stack to call fork_return(p, frame); to complete 225 * the return to user-mode. 226 */ 227} 228 229/* 230 * Intercept the return address from a freshly forked process that has NOT 231 * been scheduled yet. 232 * 233 * This is needed to make kernel threads stay in kernel mode. 234 */ 235void 236cpu_set_fork_handler(td, func, arg) 237 struct thread *td; 238 void (*func)(void *); 239 void *arg; 240{ 241 /* 242 * Note that the trap frame follows the args, so the function 243 * is really called like this: func(arg, frame); 244 */ 245 td->td_pcb->pcb_r12 = (long) func; /* function */ 246 td->td_pcb->pcb_rbx = (long) arg; /* first arg */ 247} 248 249void 250cpu_exit(struct thread *td) 251{ 252 253 /* 254 * If this process has a custom LDT, release it. 255 */ 256 mtx_lock(&dt_lock); 257 if (td->td_proc->p_md.md_ldt != 0) 258 user_ldt_free(td); 259 else 260 mtx_unlock(&dt_lock); 261} 262 263void 264cpu_thread_exit(struct thread *td) 265{ 266 struct pcb *pcb; 267 268 critical_enter(); 269 if (td == PCPU_GET(fpcurthread)) 270 fpudrop(); 271 critical_exit(); 272 273 pcb = td->td_pcb; 274 275 /* Disable any hardware breakpoints. */ 276 if (pcb->pcb_flags & PCB_DBREGS) { 277 reset_dbregs(); 278 pcb->pcb_flags &= ~PCB_DBREGS; 279 } 280} 281 282void 283cpu_thread_clean(struct thread *td) 284{ 285 struct pcb *pcb; 286 287 pcb = td->td_pcb; 288 289 /* 290 * Clean TSS/iomap 291 */ 292 if (pcb->pcb_tssp != NULL) { 293 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_tssp, 294 ctob(IOPAGES + 1)); 295 pcb->pcb_tssp = NULL; 296 } 297} 298 299void 300cpu_thread_swapin(struct thread *td) 301{ 302} 303 304void 305cpu_thread_swapout(struct thread *td) 306{ 307} 308 309void 310cpu_thread_alloc(struct thread *td) 311{ 312 313 td->td_pcb = (struct pcb *)(td->td_kstack + 314 td->td_kstack_pages * PAGE_SIZE) - 1; 315 td->td_frame = (struct trapframe *)td->td_pcb - 1; 316 td->td_pcb->pcb_save = &td->td_pcb->pcb_user_save; 317} 318 319void 320cpu_thread_free(struct thread *td) 321{ 322 323 cpu_thread_clean(td); 324} 325 326void 327cpu_set_syscall_retval(struct thread *td, int error) 328{ 329 330 switch (error) { 331 case 0: 332 td->td_frame->tf_rax = td->td_retval[0]; 333 td->td_frame->tf_rdx = td->td_retval[1]; 334 td->td_frame->tf_rflags &= ~PSL_C; 335 break; 336 337 case ERESTART: 338 /* 339 * Reconstruct pc, we know that 'syscall' is 2 bytes, 340 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 341 * We saved this in tf_err. 342 * %r10 (which was holding the value of %rcx) is restored 343 * for the next iteration. 344 * %r10 restore is only required for freebsd/amd64 processes, 345 * but shall be innocent for any ia32 ABI. 346 */ 347 td->td_frame->tf_rip -= td->td_frame->tf_err; 348 td->td_frame->tf_r10 = td->td_frame->tf_rcx; 349 break; 350 351 case EJUSTRETURN: 352 break; 353 354 default: 355 if (td->td_proc->p_sysent->sv_errsize) { 356 if (error >= td->td_proc->p_sysent->sv_errsize) 357 error = -1; /* XXX */ 358 else 359 error = td->td_proc->p_sysent->sv_errtbl[error]; 360 } 361 td->td_frame->tf_rax = error; 362 td->td_frame->tf_rflags |= PSL_C; 363 break; 364 } 365} 366 367/* 368 * Initialize machine state (pcb and trap frame) for a new thread about to 369 * upcall. Put enough state in the new thread's PCB to get it to go back 370 * userret(), where we can intercept it again to set the return (upcall) 371 * Address and stack, along with those from upcals that are from other sources 372 * such as those generated in thread_userret() itself. 373 */ 374void 375cpu_set_upcall(struct thread *td, struct thread *td0) 376{ 377 struct pcb *pcb2; 378 379 /* Point the pcb to the top of the stack. */ 380 pcb2 = td->td_pcb; 381 382 /* 383 * Copy the upcall pcb. This loads kernel regs. 384 * Those not loaded individually below get their default 385 * values here. 386 */ 387 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); 388 pcb2->pcb_flags &= ~(PCB_FPUINITDONE | PCB_USERFPUINITDONE); 389 pcb2->pcb_save = &pcb2->pcb_user_save; 390 pcb2->pcb_full_iret = 1; 391 392 /* 393 * Create a new fresh stack for the new thread. 394 */ 395 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 396 397 /* If the current thread has the trap bit set (i.e. a debugger had 398 * single stepped the process to the system call), we need to clear 399 * the trap flag from the new frame. Otherwise, the new thread will 400 * receive a (likely unexpected) SIGTRAP when it executes the first 401 * instruction after returning to userland. 402 */ 403 td->td_frame->tf_rflags &= ~PSL_T; 404 405 /* 406 * Set registers for trampoline to user mode. Leave space for the 407 * return address on stack. These are the kernel mode register values. 408 */ 409 pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */ 410 pcb2->pcb_rbp = 0; 411 pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */ 412 pcb2->pcb_rbx = (register_t)td; /* trampoline arg */ 413 pcb2->pcb_rip = (register_t)fork_trampoline; 414 /* 415 * If we didn't copy the pcb, we'd need to do the following registers: 416 * pcb2->pcb_cr3: cloned above. 417 * pcb2->pcb_dr*: cloned above. 418 * pcb2->pcb_savefpu: cloned above. 419 * pcb2->pcb_onfault: cloned above (always NULL here?). 420 * pcb2->pcb_[fg]sbase: cloned above 421 */ 422 423 /* Setup to release spin count in fork_exit(). */ 424 td->td_md.md_spinlock_count = 1; 425 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 426} 427 428/* 429 * Set that machine state for performing an upcall that has to 430 * be done in thread_userret() so that those upcalls generated 431 * in thread_userret() itself can be done as well. 432 */ 433void 434cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg, 435 stack_t *stack) 436{ 437 438 /* 439 * Do any extra cleaning that needs to be done. 440 * The thread may have optional components 441 * that are not present in a fresh thread. 442 * This may be a recycled thread so make it look 443 * as though it's newly allocated. 444 */ 445 cpu_thread_clean(td); 446 447#ifdef COMPAT_FREEBSD32 448 if (td->td_proc->p_sysent->sv_flags & SV_ILP32) { 449 /* 450 * Set the trap frame to point at the beginning of the uts 451 * function. 452 */ 453 td->td_frame->tf_rbp = 0; 454 td->td_frame->tf_rsp = 455 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; 456 td->td_frame->tf_rip = (uintptr_t)entry; 457 458 /* 459 * Pass the address of the mailbox for this kse to the uts 460 * function as a parameter on the stack. 461 */ 462 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)), 463 (uint32_t)(uintptr_t)arg); 464 465 return; 466 } 467#endif 468 469 /* 470 * Set the trap frame to point at the beginning of the uts 471 * function. 472 */ 473 td->td_frame->tf_rbp = 0; 474 td->td_frame->tf_rsp = 475 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f; 476 td->td_frame->tf_rsp -= 8; 477 td->td_frame->tf_rip = (register_t)entry; 478 td->td_frame->tf_ds = _udatasel; 479 td->td_frame->tf_es = _udatasel; 480 td->td_frame->tf_fs = _ufssel; 481 td->td_frame->tf_gs = _ugssel; 482 td->td_frame->tf_flags = TF_HASSEGS; 483 484 /* 485 * Pass the address of the mailbox for this kse to the uts 486 * function as a parameter on the stack. 487 */ 488 td->td_frame->tf_rdi = (register_t)arg; 489} 490 491int 492cpu_set_user_tls(struct thread *td, void *tls_base) 493{ 494 495 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS) 496 return (EINVAL); 497 498#ifdef COMPAT_FREEBSD32 499 if (td->td_proc->p_sysent->sv_flags & SV_ILP32) { 500 td->td_pcb->pcb_gsbase = (register_t)tls_base; 501 return (0); 502 } 503#endif 504 td->td_pcb->pcb_fsbase = (register_t)tls_base; 505 td->td_pcb->pcb_full_iret = 1; 506 return (0); 507} 508 509#ifdef SMP 510static void 511cpu_reset_proxy() 512{ 513 514 cpu_reset_proxy_active = 1; 515 while (cpu_reset_proxy_active == 1) 516 ; /* Wait for other cpu to see that we've started */ 517 stop_cpus((1<<cpu_reset_proxyid)); 518 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 519 DELAY(1000000); 520 cpu_reset_real(); 521} 522#endif 523 524void 525cpu_reset() 526{ 527#ifdef SMP 528 cpumask_t map; 529 u_int cnt; 530 531 if (smp_active) { 532 map = PCPU_GET(other_cpus) & ~stopped_cpus; 533 if (map != 0) { 534 printf("cpu_reset: Stopping other CPUs\n"); 535 stop_cpus(map); 536 } 537 538 if (PCPU_GET(cpuid) != 0) { 539 cpu_reset_proxyid = PCPU_GET(cpuid); 540 cpustop_restartfunc = cpu_reset_proxy; 541 cpu_reset_proxy_active = 0; 542 printf("cpu_reset: Restarting BSP\n"); 543 544 /* Restart CPU #0. */ 545 atomic_store_rel_int(&started_cpus, 1 << 0); 546 547 cnt = 0; 548 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 549 cnt++; /* Wait for BSP to announce restart */ 550 if (cpu_reset_proxy_active == 0) 551 printf("cpu_reset: Failed to restart BSP\n"); 552 enable_intr(); 553 cpu_reset_proxy_active = 2; 554 555 while (1); 556 /* NOTREACHED */ 557 } 558 559 DELAY(1000000); 560 } 561#endif 562 cpu_reset_real(); 563 /* NOTREACHED */ 564} 565 566static void 567cpu_reset_real() 568{ 569 struct region_descriptor null_idt; 570 int b; 571 572 disable_intr(); 573 574 /* 575 * Attempt to do a CPU reset via the keyboard controller, 576 * do not turn off GateA20, as any machine that fails 577 * to do the reset here would then end up in no man's land. 578 */ 579 outb(IO_KBD + 4, 0xFE); 580 DELAY(500000); /* wait 0.5 sec to see if that did it */ 581 582 /* 583 * Attempt to force a reset via the Reset Control register at 584 * I/O port 0xcf9. Bit 2 forces a system reset when it 585 * transitions from 0 to 1. Bit 1 selects the type of reset 586 * to attempt: 0 selects a "soft" reset, and 1 selects a 587 * "hard" reset. We try a "hard" reset. The first write sets 588 * bit 1 to select a "hard" reset and clears bit 2. The 589 * second write forces a 0 -> 1 transition in bit 2 to trigger 590 * a reset. 591 */ 592 outb(0xcf9, 0x2); 593 outb(0xcf9, 0x6); 594 DELAY(500000); /* wait 0.5 sec to see if that did it */ 595 596 /* 597 * Attempt to force a reset via the Fast A20 and Init register 598 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate. 599 * Bit 0 asserts INIT# when set to 1. We are careful to only 600 * preserve bit 1 while setting bit 0. We also must clear bit 601 * 0 before setting it if it isn't already clear. 602 */ 603 b = inb(0x92); 604 if (b != 0xff) { 605 if ((b & 0x1) != 0) 606 outb(0x92, b & 0xfe); 607 outb(0x92, b | 0x1); 608 DELAY(500000); /* wait 0.5 sec to see if that did it */ 609 } 610 611 printf("No known reset method worked, attempting CPU shutdown\n"); 612 DELAY(1000000); /* wait 1 sec for printf to complete */ 613 614 /* Wipe the IDT. */ 615 null_idt.rd_limit = 0; 616 null_idt.rd_base = 0; 617 lidt(&null_idt); 618 619 /* "good night, sweet prince .... <THUNK!>" */ 620 breakpoint(); 621 622 /* NOTREACHED */ 623 while(1); 624} 625 626/* 627 * Allocate an sf_buf for the given vm_page. On this machine, however, there 628 * is no sf_buf object. Instead, an opaque pointer to the given vm_page is 629 * returned. 630 */ 631struct sf_buf * 632sf_buf_alloc(struct vm_page *m, int pri) 633{ 634 635 return ((struct sf_buf *)m); 636} 637 638/* 639 * Free the sf_buf. In fact, do nothing because there are no resources 640 * associated with the sf_buf. 641 */ 642void 643sf_buf_free(struct sf_buf *sf) 644{ 645} 646 647/* 648 * Software interrupt handler for queued VM system processing. 649 */ 650void 651swi_vm(void *dummy) 652{ 653 if (busdma_swi_pending != 0) 654 busdma_swi(); 655} 656 657/* 658 * Tell whether this address is in some physical memory region. 659 * Currently used by the kernel coredump code in order to avoid 660 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 661 * or other unpredictable behaviour. 662 */ 663 664int 665is_physical_memory(vm_paddr_t addr) 666{ 667 668#ifdef DEV_ISA 669 /* The ISA ``memory hole''. */ 670 if (addr >= 0xa0000 && addr < 0x100000) 671 return 0; 672#endif 673 674 /* 675 * stuff other tests for known memory-mapped devices (PCI?) 676 * here 677 */ 678 679 return 1; 680} 681