vm_machdep.c revision 200444
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 200444 2009-12-12 20:11:31Z 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 <amd64/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 p1'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 p1's pcb */ 134 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 135 136 /* Point mdproc and then copy over td1's contents */ 137 mdp2 = &p2->p_md; 138 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 139 140 /* 141 * Create a new fresh stack for the new process. 142 * Copy the trap frame for the return to user mode as if from a 143 * syscall. This copies most of the user mode register values. 144 */ 145 td2->td_frame = (struct trapframe *)td2->td_pcb - 1; 146 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 147 148 td2->td_frame->tf_rax = 0; /* Child returns zero */ 149 td2->td_frame->tf_rflags &= ~PSL_C; /* success */ 150 td2->td_frame->tf_rdx = 1; 151 152 /* 153 * If the parent process has the trap bit set (i.e. a debugger had 154 * single stepped the process to the system call), we need to clear 155 * the trap flag from the new frame unless the debugger had set PF_FORK 156 * on the parent. Otherwise, the child will receive a (likely 157 * unexpected) SIGTRAP when it executes the first instruction after 158 * returning to userland. 159 */ 160 if ((p1->p_pfsflags & PF_FORK) == 0) 161 td2->td_frame->tf_rflags &= ~PSL_T; 162 163 /* 164 * Set registers for trampoline to user mode. Leave space for the 165 * return address on stack. These are the kernel mode register values. 166 */ 167 pmap2 = vmspace_pmap(p2->p_vmspace); 168 pcb2->pcb_cr3 = DMAP_TO_PHYS((vm_offset_t)pmap2->pm_pml4); 169 pcb2->pcb_r12 = (register_t)fork_return; /* fork_trampoline argument */ 170 pcb2->pcb_rbp = 0; 171 pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *); 172 pcb2->pcb_rbx = (register_t)td2; /* fork_trampoline argument */ 173 pcb2->pcb_rip = (register_t)fork_trampoline; 174 /*- 175 * pcb2->pcb_dr*: cloned above. 176 * pcb2->pcb_savefpu: cloned above. 177 * pcb2->pcb_flags: cloned above. 178 * pcb2->pcb_onfault: cloned above (always NULL here?). 179 * pcb2->pcb_[fg]sbase: cloned above 180 */ 181 182 /* Setup to release spin count in fork_exit(). */ 183 td2->td_md.md_spinlock_count = 1; 184 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 185 186 /* As an i386, do not copy io permission bitmap. */ 187 pcb2->pcb_tssp = NULL; 188 189 /* New segment registers. */ 190 pcb2->pcb_full_iret = 1; 191 192 /* Copy the LDT, if necessary. */ 193 mdp1 = &td1->td_proc->p_md; 194 mdp2 = &p2->p_md; 195 mtx_lock(&dt_lock); 196 if (mdp1->md_ldt != NULL) { 197 if (flags & RFMEM) { 198 mdp1->md_ldt->ldt_refcnt++; 199 mdp2->md_ldt = mdp1->md_ldt; 200 bcopy(&mdp1->md_ldt_sd, &mdp2->md_ldt_sd, sizeof(struct 201 system_segment_descriptor)); 202 } else { 203 mdp2->md_ldt = NULL; 204 mdp2->md_ldt = user_ldt_alloc(p2, 0); 205 if (mdp2->md_ldt == NULL) 206 panic("could not copy LDT"); 207 amd64_set_ldt_data(td2, 0, max_ldt_segment, 208 (struct user_segment_descriptor *) 209 mdp1->md_ldt->ldt_base); 210 } 211 } else 212 mdp2->md_ldt = NULL; 213 mtx_unlock(&dt_lock); 214 215 /* 216 * Now, cpu_switch() can schedule the new process. 217 * pcb_rsp is loaded pointing to the cpu_switch() stack frame 218 * containing the return address when exiting cpu_switch. 219 * This will normally be to fork_trampoline(), which will have 220 * %ebx loaded with the new proc's pointer. fork_trampoline() 221 * will set up a stack to call fork_return(p, frame); to complete 222 * the return to user-mode. 223 */ 224} 225 226/* 227 * Intercept the return address from a freshly forked process that has NOT 228 * been scheduled yet. 229 * 230 * This is needed to make kernel threads stay in kernel mode. 231 */ 232void 233cpu_set_fork_handler(td, func, arg) 234 struct thread *td; 235 void (*func)(void *); 236 void *arg; 237{ 238 /* 239 * Note that the trap frame follows the args, so the function 240 * is really called like this: func(arg, frame); 241 */ 242 td->td_pcb->pcb_r12 = (long) func; /* function */ 243 td->td_pcb->pcb_rbx = (long) arg; /* first arg */ 244} 245 246void 247cpu_exit(struct thread *td) 248{ 249 250 /* 251 * If this process has a custom LDT, release it. 252 */ 253 mtx_lock(&dt_lock); 254 if (td->td_proc->p_md.md_ldt != 0) 255 user_ldt_free(td); 256 else 257 mtx_unlock(&dt_lock); 258} 259 260void 261cpu_thread_exit(struct thread *td) 262{ 263 struct pcb *pcb; 264 265 if (td == PCPU_GET(fpcurthread)) 266 fpudrop(); 267 268 pcb = td->td_pcb; 269 270 /* Disable any hardware breakpoints. */ 271 if (pcb->pcb_flags & PCB_DBREGS) { 272 reset_dbregs(); 273 pcb->pcb_flags &= ~PCB_DBREGS; 274 } 275} 276 277void 278cpu_thread_clean(struct thread *td) 279{ 280 struct pcb *pcb; 281 282 pcb = td->td_pcb; 283 284 /* 285 * Clean TSS/iomap 286 */ 287 if (pcb->pcb_tssp != NULL) { 288 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_tssp, 289 ctob(IOPAGES + 1)); 290 pcb->pcb_tssp = NULL; 291 } 292} 293 294void 295cpu_thread_swapin(struct thread *td) 296{ 297} 298 299void 300cpu_thread_swapout(struct thread *td) 301{ 302} 303 304void 305cpu_thread_alloc(struct thread *td) 306{ 307 308 td->td_pcb = (struct pcb *)(td->td_kstack + 309 td->td_kstack_pages * PAGE_SIZE) - 1; 310 td->td_frame = (struct trapframe *)td->td_pcb - 1; 311} 312 313void 314cpu_thread_free(struct thread *td) 315{ 316 317 cpu_thread_clean(td); 318} 319 320void 321cpu_set_syscall_retval(struct thread *td, int error) 322{ 323 324 switch (error) { 325 case 0: 326 td->td_frame->tf_rax = td->td_retval[0]; 327 td->td_frame->tf_rdx = td->td_retval[1]; 328 td->td_frame->tf_rflags &= ~PSL_C; 329 break; 330 331 case ERESTART: 332 /* 333 * Reconstruct pc, we know that 'syscall' is 2 bytes, 334 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes. 335 * We saved this in tf_err. 336 * We have to do a full context restore so that %r10 337 * (which was holding the value of %rcx) is restored 338 * for the next iteration. 339 * r10 restore is only required for freebsd/amd64 processes, 340 * but shall be innocent for any ia32 ABI. 341 */ 342 td->td_frame->tf_rip -= td->td_frame->tf_err; 343 td->td_frame->tf_r10 = td->td_frame->tf_rcx; 344 td->td_pcb->pcb_flags |= PCB_FULLCTX; 345 break; 346 347 case EJUSTRETURN: 348 break; 349 350 default: 351 if (td->td_proc->p_sysent->sv_errsize) { 352 if (error >= td->td_proc->p_sysent->sv_errsize) 353 error = -1; /* XXX */ 354 else 355 error = td->td_proc->p_sysent->sv_errtbl[error]; 356 } 357 td->td_frame->tf_rax = error; 358 td->td_frame->tf_rflags |= PSL_C; 359 break; 360 } 361} 362 363/* 364 * Initialize machine state (pcb and trap frame) for a new thread about to 365 * upcall. Put enough state in the new thread's PCB to get it to go back 366 * userret(), where we can intercept it again to set the return (upcall) 367 * Address and stack, along with those from upcals that are from other sources 368 * such as those generated in thread_userret() itself. 369 */ 370void 371cpu_set_upcall(struct thread *td, struct thread *td0) 372{ 373 struct pcb *pcb2; 374 375 /* Point the pcb to the top of the stack. */ 376 pcb2 = td->td_pcb; 377 378 /* 379 * Copy the upcall pcb. This loads kernel regs. 380 * Those not loaded individually below get their default 381 * values here. 382 */ 383 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); 384 pcb2->pcb_flags &= ~PCB_FPUINITDONE; 385 pcb2->pcb_full_iret = 1; 386 387 /* 388 * Create a new fresh stack for the new thread. 389 */ 390 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 391 392 /* If the current thread has the trap bit set (i.e. a debugger had 393 * single stepped the process to the system call), we need to clear 394 * the trap flag from the new frame. Otherwise, the new thread will 395 * receive a (likely unexpected) SIGTRAP when it executes the first 396 * instruction after returning to userland. 397 */ 398 td->td_frame->tf_rflags &= ~PSL_T; 399 400 /* 401 * Set registers for trampoline to user mode. Leave space for the 402 * return address on stack. These are the kernel mode register values. 403 */ 404 pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */ 405 pcb2->pcb_rbp = 0; 406 pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */ 407 pcb2->pcb_rbx = (register_t)td; /* trampoline arg */ 408 pcb2->pcb_rip = (register_t)fork_trampoline; 409 /* 410 * If we didn't copy the pcb, we'd need to do the following registers: 411 * pcb2->pcb_cr3: cloned above. 412 * pcb2->pcb_dr*: cloned above. 413 * pcb2->pcb_savefpu: cloned above. 414 * pcb2->pcb_onfault: cloned above (always NULL here?). 415 * pcb2->pcb_[fg]sbase: cloned above 416 */ 417 418 /* Setup to release spin count in fork_exit(). */ 419 td->td_md.md_spinlock_count = 1; 420 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I; 421} 422 423/* 424 * Set that machine state for performing an upcall that has to 425 * be done in thread_userret() so that those upcalls generated 426 * in thread_userret() itself can be done as well. 427 */ 428void 429cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg, 430 stack_t *stack) 431{ 432 433 /* 434 * Do any extra cleaning that needs to be done. 435 * The thread may have optional components 436 * that are not present in a fresh thread. 437 * This may be a recycled thread so make it look 438 * as though it's newly allocated. 439 */ 440 cpu_thread_clean(td); 441 442#ifdef COMPAT_IA32 443 if (td->td_proc->p_sysent->sv_flags & SV_ILP32) { 444 /* 445 * Set the trap frame to point at the beginning of the uts 446 * function. 447 */ 448 td->td_frame->tf_rbp = 0; 449 td->td_frame->tf_rsp = 450 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4; 451 td->td_frame->tf_rip = (uintptr_t)entry; 452 453 /* 454 * Pass the address of the mailbox for this kse to the uts 455 * function as a parameter on the stack. 456 */ 457 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)), 458 (uint32_t)(uintptr_t)arg); 459 460 return; 461 } 462#endif 463 464 /* 465 * Set the trap frame to point at the beginning of the uts 466 * function. 467 */ 468 td->td_frame->tf_rbp = 0; 469 td->td_frame->tf_rsp = 470 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f; 471 td->td_frame->tf_rsp -= 8; 472 td->td_frame->tf_rip = (register_t)entry; 473 td->td_frame->tf_ds = _udatasel; 474 td->td_frame->tf_es = _udatasel; 475 td->td_frame->tf_fs = _ufssel; 476 td->td_frame->tf_gs = _ugssel; 477 td->td_frame->tf_flags = TF_HASSEGS; 478 479 /* 480 * Pass the address of the mailbox for this kse to the uts 481 * function as a parameter on the stack. 482 */ 483 td->td_frame->tf_rdi = (register_t)arg; 484} 485 486int 487cpu_set_user_tls(struct thread *td, void *tls_base) 488{ 489 490 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS) 491 return (EINVAL); 492 493#ifdef COMPAT_IA32 494 if (td->td_proc->p_sysent->sv_flags & SV_ILP32) { 495 td->td_pcb->pcb_gsbase = (register_t)tls_base; 496 return (0); 497 } 498#endif 499 td->td_pcb->pcb_fsbase = (register_t)tls_base; 500 td->td_pcb->pcb_full_iret = 1; 501 return (0); 502} 503 504#ifdef SMP 505static void 506cpu_reset_proxy() 507{ 508 509 cpu_reset_proxy_active = 1; 510 while (cpu_reset_proxy_active == 1) 511 ; /* Wait for other cpu to see that we've started */ 512 stop_cpus((1<<cpu_reset_proxyid)); 513 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid); 514 DELAY(1000000); 515 cpu_reset_real(); 516} 517#endif 518 519void 520cpu_reset() 521{ 522#ifdef SMP 523 u_int cnt, map; 524 525 if (smp_active) { 526 map = PCPU_GET(other_cpus) & ~stopped_cpus; 527 if (map != 0) { 528 printf("cpu_reset: Stopping other CPUs\n"); 529 stop_cpus(map); 530 } 531 532 if (PCPU_GET(cpuid) != 0) { 533 cpu_reset_proxyid = PCPU_GET(cpuid); 534 cpustop_restartfunc = cpu_reset_proxy; 535 cpu_reset_proxy_active = 0; 536 printf("cpu_reset: Restarting BSP\n"); 537 538 /* Restart CPU #0. */ 539 atomic_store_rel_int(&started_cpus, 1 << 0); 540 541 cnt = 0; 542 while (cpu_reset_proxy_active == 0 && cnt < 10000000) 543 cnt++; /* Wait for BSP to announce restart */ 544 if (cpu_reset_proxy_active == 0) 545 printf("cpu_reset: Failed to restart BSP\n"); 546 enable_intr(); 547 cpu_reset_proxy_active = 2; 548 549 while (1); 550 /* NOTREACHED */ 551 } 552 553 DELAY(1000000); 554 } 555#endif 556 cpu_reset_real(); 557 /* NOTREACHED */ 558} 559 560static void 561cpu_reset_real() 562{ 563 struct region_descriptor null_idt; 564 int b; 565 566 disable_intr(); 567 568 /* 569 * Attempt to do a CPU reset via the keyboard controller, 570 * do not turn off GateA20, as any machine that fails 571 * to do the reset here would then end up in no man's land. 572 */ 573 outb(IO_KBD + 4, 0xFE); 574 DELAY(500000); /* wait 0.5 sec to see if that did it */ 575 576 /* 577 * Attempt to force a reset via the Reset Control register at 578 * I/O port 0xcf9. Bit 2 forces a system reset when it 579 * transitions from 0 to 1. Bit 1 selects the type of reset 580 * to attempt: 0 selects a "soft" reset, and 1 selects a 581 * "hard" reset. We try a "hard" reset. The first write sets 582 * bit 1 to select a "hard" reset and clears bit 2. The 583 * second write forces a 0 -> 1 transition in bit 2 to trigger 584 * a reset. 585 */ 586 outb(0xcf9, 0x2); 587 outb(0xcf9, 0x6); 588 DELAY(500000); /* wait 0.5 sec to see if that did it */ 589 590 /* 591 * Attempt to force a reset via the Fast A20 and Init register 592 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate. 593 * Bit 0 asserts INIT# when set to 1. We are careful to only 594 * preserve bit 1 while setting bit 0. We also must clear bit 595 * 0 before setting it if it isn't already clear. 596 */ 597 b = inb(0x92); 598 if (b != 0xff) { 599 if ((b & 0x1) != 0) 600 outb(0x92, b & 0xfe); 601 outb(0x92, b | 0x1); 602 DELAY(500000); /* wait 0.5 sec to see if that did it */ 603 } 604 605 printf("No known reset method worked, attempting CPU shutdown\n"); 606 DELAY(1000000); /* wait 1 sec for printf to complete */ 607 608 /* Wipe the IDT. */ 609 null_idt.rd_limit = 0; 610 null_idt.rd_base = 0; 611 lidt(&null_idt); 612 613 /* "good night, sweet prince .... <THUNK!>" */ 614 breakpoint(); 615 616 /* NOTREACHED */ 617 while(1); 618} 619 620/* 621 * Allocate an sf_buf for the given vm_page. On this machine, however, there 622 * is no sf_buf object. Instead, an opaque pointer to the given vm_page is 623 * returned. 624 */ 625struct sf_buf * 626sf_buf_alloc(struct vm_page *m, int pri) 627{ 628 629 return ((struct sf_buf *)m); 630} 631 632/* 633 * Free the sf_buf. In fact, do nothing because there are no resources 634 * associated with the sf_buf. 635 */ 636void 637sf_buf_free(struct sf_buf *sf) 638{ 639} 640 641/* 642 * Software interrupt handler for queued VM system processing. 643 */ 644void 645swi_vm(void *dummy) 646{ 647 if (busdma_swi_pending != 0) 648 busdma_swi(); 649} 650 651/* 652 * Tell whether this address is in some physical memory region. 653 * Currently used by the kernel coredump code in order to avoid 654 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 655 * or other unpredictable behaviour. 656 */ 657 658int 659is_physical_memory(vm_paddr_t addr) 660{ 661 662#ifdef DEV_ISA 663 /* The ISA ``memory hole''. */ 664 if (addr >= 0xa0000 && addr < 0x100000) 665 return 0; 666#endif 667 668 /* 669 * stuff other tests for known memory-mapped devices (PCI?) 670 * here 671 */ 672 673 return 1; 674} 675