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: releng/8.1/sys/amd64/amd64/vm_machdep.c 206336 2010-04-07 02:24:41Z nwhitehorn $");
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
85 static void cpu_reset_real(void);
86 #ifdef SMP
87 static void cpu_reset_proxy(void);
88 static u_int cpu_reset_proxyid;
89 static 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 */
97 void
98 cpu_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 */
232 void
233 cpu_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
246 void
247 cpu_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
260 void
261 cpu_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
277 void
278 cpu_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
294 void
295 cpu_thread_swapin(struct thread *td)
296 {
297 }
298
299 void
300 cpu_thread_swapout(struct thread *td)
301 {
302 }
303
304 void
305 cpu_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
313 void
314 cpu_thread_free(struct thread *td)
315 {
316
317 cpu_thread_clean(td);
318 }
319
320 void
321 cpu_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 */
370 void
371 cpu_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 */
428 void
429 cpu_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_FREEBSD32
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
486 int
487 cpu_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_FREEBSD32
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
505 static void
506 cpu_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
519 void
520 cpu_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
560 static void
561 cpu_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 */
625 struct sf_buf *
626 sf_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 */
636 void
637 sf_buf_free(struct sf_buf *sf)
638 {
639 }
640
641 /*
642 * Software interrupt handler for queued VM system processing.
643 */
644 void
645 swi_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
658 int
659 is_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 }
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