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/8.0/sys/amd64/amd64/vm_machdep.c 195486 2009-07-09 09:34:11Z 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
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 /*
321 * Initialize machine state (pcb and trap frame) for a new thread about to
322 * upcall. Put enough state in the new thread's PCB to get it to go back
323 * userret(), where we can intercept it again to set the return (upcall)
324 * Address and stack, along with those from upcals that are from other sources
325 * such as those generated in thread_userret() itself.
326 */
327 void
328 cpu_set_upcall(struct thread *td, struct thread *td0)
329 {
330 struct pcb *pcb2;
331
332 /* Point the pcb to the top of the stack. */
333 pcb2 = td->td_pcb;
334
335 /*
336 * Copy the upcall pcb. This loads kernel regs.
337 * Those not loaded individually below get their default
338 * values here.
339 */
340 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
341 pcb2->pcb_flags &= ~PCB_FPUINITDONE;
342 pcb2->pcb_full_iret = 1;
343
344 /*
345 * Create a new fresh stack for the new thread.
346 */
347 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
348
349 /* If the current thread has the trap bit set (i.e. a debugger had
350 * single stepped the process to the system call), we need to clear
351 * the trap flag from the new frame. Otherwise, the new thread will
352 * receive a (likely unexpected) SIGTRAP when it executes the first
353 * instruction after returning to userland.
354 */
355 td->td_frame->tf_rflags &= ~PSL_T;
356
357 /*
358 * Set registers for trampoline to user mode. Leave space for the
359 * return address on stack. These are the kernel mode register values.
360 */
361 pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */
362 pcb2->pcb_rbp = 0;
363 pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */
364 pcb2->pcb_rbx = (register_t)td; /* trampoline arg */
365 pcb2->pcb_rip = (register_t)fork_trampoline;
366 /*
367 * If we didn't copy the pcb, we'd need to do the following registers:
368 * pcb2->pcb_cr3: cloned above.
369 * pcb2->pcb_dr*: cloned above.
370 * pcb2->pcb_savefpu: cloned above.
371 * pcb2->pcb_onfault: cloned above (always NULL here?).
372 * pcb2->pcb_[fg]sbase: cloned above
373 */
374
375 /* Setup to release spin count in fork_exit(). */
376 td->td_md.md_spinlock_count = 1;
377 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
378 }
379
380 /*
381 * Set that machine state for performing an upcall that has to
382 * be done in thread_userret() so that those upcalls generated
383 * in thread_userret() itself can be done as well.
384 */
385 void
386 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
387 stack_t *stack)
388 {
389
390 /*
391 * Do any extra cleaning that needs to be done.
392 * The thread may have optional components
393 * that are not present in a fresh thread.
394 * This may be a recycled thread so make it look
395 * as though it's newly allocated.
396 */
397 cpu_thread_clean(td);
398
399 #ifdef COMPAT_IA32
400 if (td->td_proc->p_sysent->sv_flags & SV_ILP32) {
401 /*
402 * Set the trap frame to point at the beginning of the uts
403 * function.
404 */
405 td->td_frame->tf_rbp = 0;
406 td->td_frame->tf_rsp =
407 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
408 td->td_frame->tf_rip = (uintptr_t)entry;
409
410 /*
411 * Pass the address of the mailbox for this kse to the uts
412 * function as a parameter on the stack.
413 */
414 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)),
415 (uint32_t)(uintptr_t)arg);
416
417 return;
418 }
419 #endif
420
421 /*
422 * Set the trap frame to point at the beginning of the uts
423 * function.
424 */
425 td->td_frame->tf_rbp = 0;
426 td->td_frame->tf_rsp =
427 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f;
428 td->td_frame->tf_rsp -= 8;
429 td->td_frame->tf_rip = (register_t)entry;
430 td->td_frame->tf_ds = _udatasel;
431 td->td_frame->tf_es = _udatasel;
432 td->td_frame->tf_fs = _ufssel;
433 td->td_frame->tf_gs = _ugssel;
434 td->td_frame->tf_flags = TF_HASSEGS;
435
436 /*
437 * Pass the address of the mailbox for this kse to the uts
438 * function as a parameter on the stack.
439 */
440 td->td_frame->tf_rdi = (register_t)arg;
441 }
442
443 int
444 cpu_set_user_tls(struct thread *td, void *tls_base)
445 {
446
447 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS)
448 return (EINVAL);
449
450 #ifdef COMPAT_IA32
451 if (td->td_proc->p_sysent->sv_flags & SV_ILP32) {
452 td->td_pcb->pcb_gsbase = (register_t)tls_base;
453 return (0);
454 }
455 #endif
456 td->td_pcb->pcb_fsbase = (register_t)tls_base;
457 td->td_pcb->pcb_full_iret = 1;
458 return (0);
459 }
460
461 #ifdef SMP
462 static void
463 cpu_reset_proxy()
464 {
465
466 cpu_reset_proxy_active = 1;
467 while (cpu_reset_proxy_active == 1)
468 ; /* Wait for other cpu to see that we've started */
469 stop_cpus((1<<cpu_reset_proxyid));
470 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
471 DELAY(1000000);
472 cpu_reset_real();
473 }
474 #endif
475
476 void
477 cpu_reset()
478 {
479 #ifdef SMP
480 u_int cnt, map;
481
482 if (smp_active) {
483 map = PCPU_GET(other_cpus) & ~stopped_cpus;
484 if (map != 0) {
485 printf("cpu_reset: Stopping other CPUs\n");
486 stop_cpus(map);
487 }
488
489 if (PCPU_GET(cpuid) != 0) {
490 cpu_reset_proxyid = PCPU_GET(cpuid);
491 cpustop_restartfunc = cpu_reset_proxy;
492 cpu_reset_proxy_active = 0;
493 printf("cpu_reset: Restarting BSP\n");
494
495 /* Restart CPU #0. */
496 atomic_store_rel_int(&started_cpus, 1 << 0);
497
498 cnt = 0;
499 while (cpu_reset_proxy_active == 0 && cnt < 10000000)
500 cnt++; /* Wait for BSP to announce restart */
501 if (cpu_reset_proxy_active == 0)
502 printf("cpu_reset: Failed to restart BSP\n");
503 enable_intr();
504 cpu_reset_proxy_active = 2;
505
506 while (1);
507 /* NOTREACHED */
508 }
509
510 DELAY(1000000);
511 }
512 #endif
513 cpu_reset_real();
514 /* NOTREACHED */
515 }
516
517 static void
518 cpu_reset_real()
519 {
520 struct region_descriptor null_idt;
521 int b;
522
523 disable_intr();
524
525 /*
526 * Attempt to do a CPU reset via the keyboard controller,
527 * do not turn off GateA20, as any machine that fails
528 * to do the reset here would then end up in no man's land.
529 */
530 outb(IO_KBD + 4, 0xFE);
531 DELAY(500000); /* wait 0.5 sec to see if that did it */
532
533 /*
534 * Attempt to force a reset via the Reset Control register at
535 * I/O port 0xcf9. Bit 2 forces a system reset when it
536 * transitions from 0 to 1. Bit 1 selects the type of reset
537 * to attempt: 0 selects a "soft" reset, and 1 selects a
538 * "hard" reset. We try a "hard" reset. The first write sets
539 * bit 1 to select a "hard" reset and clears bit 2. The
540 * second write forces a 0 -> 1 transition in bit 2 to trigger
541 * a reset.
542 */
543 outb(0xcf9, 0x2);
544 outb(0xcf9, 0x6);
545 DELAY(500000); /* wait 0.5 sec to see if that did it */
546
547 /*
548 * Attempt to force a reset via the Fast A20 and Init register
549 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate.
550 * Bit 0 asserts INIT# when set to 1. We are careful to only
551 * preserve bit 1 while setting bit 0. We also must clear bit
552 * 0 before setting it if it isn't already clear.
553 */
554 b = inb(0x92);
555 if (b != 0xff) {
556 if ((b & 0x1) != 0)
557 outb(0x92, b & 0xfe);
558 outb(0x92, b | 0x1);
559 DELAY(500000); /* wait 0.5 sec to see if that did it */
560 }
561
562 printf("No known reset method worked, attempting CPU shutdown\n");
563 DELAY(1000000); /* wait 1 sec for printf to complete */
564
565 /* Wipe the IDT. */
566 null_idt.rd_limit = 0;
567 null_idt.rd_base = 0;
568 lidt(&null_idt);
569
570 /* "good night, sweet prince .... <THUNK!>" */
571 breakpoint();
572
573 /* NOTREACHED */
574 while(1);
575 }
576
577 /*
578 * Allocate an sf_buf for the given vm_page. On this machine, however, there
579 * is no sf_buf object. Instead, an opaque pointer to the given vm_page is
580 * returned.
581 */
582 struct sf_buf *
583 sf_buf_alloc(struct vm_page *m, int pri)
584 {
585
586 return ((struct sf_buf *)m);
587 }
588
589 /*
590 * Free the sf_buf. In fact, do nothing because there are no resources
591 * associated with the sf_buf.
592 */
593 void
594 sf_buf_free(struct sf_buf *sf)
595 {
596 }
597
598 /*
599 * Software interrupt handler for queued VM system processing.
600 */
601 void
602 swi_vm(void *dummy)
603 {
604 if (busdma_swi_pending != 0)
605 busdma_swi();
606 }
607
608 /*
609 * Tell whether this address is in some physical memory region.
610 * Currently used by the kernel coredump code in order to avoid
611 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
612 * or other unpredictable behaviour.
613 */
614
615 int
616 is_physical_memory(vm_paddr_t addr)
617 {
618
619 #ifdef DEV_ISA
620 /* The ISA ``memory hole''. */
621 if (addr >= 0xa0000 && addr < 0x100000)
622 return 0;
623 #endif
624
625 /*
626 * stuff other tests for known memory-mapped devices (PCI?)
627 * here
628 */
629
630 return 1;
631 }
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