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/6.4/sys/amd64/amd64/vm_machdep.c 183158 2008-09-18 20:20:28Z jhb $");
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/kse.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/proc.h>
63 #include <sys/sf_buf.h>
64 #include <sys/smp.h>
65 #include <sys/sysctl.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
75 #include <vm/vm.h>
76 #include <vm/vm_extern.h>
77 #include <vm/vm_kern.h>
78 #include <vm/vm_page.h>
79 #include <vm/vm_map.h>
80 #include <vm/vm_param.h>
81
82 #include <amd64/isa/isa.h>
83
84 #ifdef COMPAT_IA32
85
86 extern struct sysentvec ia32_freebsd_sysvec;
87
88 #endif
89
90 static void cpu_reset_real(void);
91 #ifdef SMP
92 static void cpu_reset_proxy(void);
93 static u_int cpu_reset_proxyid;
94 static volatile u_int cpu_reset_proxy_active;
95 #endif
96
97 /*
98 * Finish a fork operation, with process p2 nearly set up.
99 * Copy and update the pcb, set up the stack so that the child
100 * ready to run and return to user mode.
101 */
102 void
103 cpu_fork(td1, p2, td2, flags)
104 register struct thread *td1;
105 register struct proc *p2;
106 struct thread *td2;
107 int flags;
108 {
109 register struct proc *p1;
110 struct pcb *pcb2;
111 struct mdproc *mdp2;
112
113 p1 = td1->td_proc;
114 if ((flags & RFPROC) == 0)
115 return;
116
117 /* Ensure that p1's pcb is up to date. */
118 fpuexit(td1);
119
120 /* Point the pcb to the top of the stack */
121 pcb2 = (struct pcb *)(td2->td_kstack +
122 td2->td_kstack_pages * PAGE_SIZE) - 1;
123 td2->td_pcb = pcb2;
124
125 /* Copy p1's pcb */
126 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
127
128 /* Point mdproc and then copy over td1's contents */
129 mdp2 = &p2->p_md;
130 bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
131
132 /*
133 * Create a new fresh stack for the new process.
134 * Copy the trap frame for the return to user mode as if from a
135 * syscall. This copies most of the user mode register values.
136 */
137 td2->td_frame = (struct trapframe *)td2->td_pcb - 1;
138 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
139
140 td2->td_frame->tf_rax = 0; /* Child returns zero */
141 td2->td_frame->tf_rflags &= ~PSL_C; /* success */
142 td2->td_frame->tf_rdx = 1;
143
144 /*
145 * If the parent process has the trap bit set (i.e. a debugger had
146 * single stepped the process to the system call), we need to clear
147 * the trap flag from the new frame unless the debugger had set PF_FORK
148 * on the parent. Otherwise, the child will receive a (likely
149 * unexpected) SIGTRAP when it executes the first instruction after
150 * returning to userland.
151 */
152 if ((p1->p_pfsflags & PF_FORK) == 0)
153 td2->td_frame->tf_rflags &= ~PSL_T;
154
155 /*
156 * Set registers for trampoline to user mode. Leave space for the
157 * return address on stack. These are the kernel mode register values.
158 */
159 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pml4);
160 pcb2->pcb_r12 = (register_t)fork_return; /* fork_trampoline argument */
161 pcb2->pcb_rbp = 0;
162 pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *);
163 pcb2->pcb_rbx = (register_t)td2; /* fork_trampoline argument */
164 pcb2->pcb_rip = (register_t)fork_trampoline;
165 /*-
166 * pcb2->pcb_dr*: cloned above.
167 * pcb2->pcb_savefpu: cloned above.
168 * pcb2->pcb_flags: cloned above.
169 * pcb2->pcb_onfault: cloned above (always NULL here?).
170 * pcb2->pcb_[fg]sbase: cloned above
171 */
172
173 /* Setup to release sched_lock in fork_exit(). */
174 td2->td_md.md_spinlock_count = 1;
175 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
176
177 /*
178 * Now, cpu_switch() can schedule the new process.
179 * pcb_rsp is loaded pointing to the cpu_switch() stack frame
180 * containing the return address when exiting cpu_switch.
181 * This will normally be to fork_trampoline(), which will have
182 * %ebx loaded with the new proc's pointer. fork_trampoline()
183 * will set up a stack to call fork_return(p, frame); to complete
184 * the return to user-mode.
185 */
186 }
187
188 /*
189 * Intercept the return address from a freshly forked process that has NOT
190 * been scheduled yet.
191 *
192 * This is needed to make kernel threads stay in kernel mode.
193 */
194 void
195 cpu_set_fork_handler(td, func, arg)
196 struct thread *td;
197 void (*func)(void *);
198 void *arg;
199 {
200 /*
201 * Note that the trap frame follows the args, so the function
202 * is really called like this: func(arg, frame);
203 */
204 td->td_pcb->pcb_r12 = (long) func; /* function */
205 td->td_pcb->pcb_rbx = (long) arg; /* first arg */
206 }
207
208 void
209 cpu_exit(struct thread *td)
210 {
211 }
212
213 void
214 cpu_thread_exit(struct thread *td)
215 {
216
217 if (td == PCPU_GET(fpcurthread))
218 fpudrop();
219
220 /* Disable any hardware breakpoints. */
221 if (td->td_pcb->pcb_flags & PCB_DBREGS) {
222 reset_dbregs();
223 td->td_pcb->pcb_flags &= ~PCB_DBREGS;
224 }
225 }
226
227 void
228 cpu_thread_clean(struct thread *td)
229 {
230 }
231
232 void
233 cpu_thread_swapin(struct thread *td)
234 {
235 }
236
237 void
238 cpu_thread_swapout(struct thread *td)
239 {
240 }
241
242 void
243 cpu_thread_setup(struct thread *td)
244 {
245
246 td->td_pcb = (struct pcb *)(td->td_kstack +
247 td->td_kstack_pages * PAGE_SIZE) - 1;
248 td->td_frame = (struct trapframe *)td->td_pcb - 1;
249 }
250
251 /*
252 * Initialize machine state (pcb and trap frame) for a new thread about to
253 * upcall. Put enough state in the new thread's PCB to get it to go back
254 * userret(), where we can intercept it again to set the return (upcall)
255 * Address and stack, along with those from upcals that are from other sources
256 * such as those generated in thread_userret() itself.
257 */
258 void
259 cpu_set_upcall(struct thread *td, struct thread *td0)
260 {
261 struct pcb *pcb2;
262
263 /* Point the pcb to the top of the stack. */
264 pcb2 = td->td_pcb;
265
266 /*
267 * Copy the upcall pcb. This loads kernel regs.
268 * Those not loaded individually below get their default
269 * values here.
270 *
271 * XXXKSE It might be a good idea to simply skip this as
272 * the values of the other registers may be unimportant.
273 * This would remove any requirement for knowing the KSE
274 * at this time (see the matching comment below for
275 * more analysis) (need a good safe default).
276 */
277 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
278 pcb2->pcb_flags &= ~PCB_FPUINITDONE;
279
280 /*
281 * Create a new fresh stack for the new thread.
282 * Don't forget to set this stack value into whatever supplies
283 * the address for the fault handlers.
284 * The contexts are filled in at the time we actually DO the
285 * upcall as only then do we know which KSE we got.
286 */
287 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
288
289 /*
290 * Set registers for trampoline to user mode. Leave space for the
291 * return address on stack. These are the kernel mode register values.
292 */
293 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pml4);
294 pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */
295 pcb2->pcb_rbp = 0;
296 pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */
297 pcb2->pcb_rbx = (register_t)td; /* trampoline arg */
298 pcb2->pcb_rip = (register_t)fork_trampoline;
299 /*
300 * If we didn't copy the pcb, we'd need to do the following registers:
301 * pcb2->pcb_dr*: cloned above.
302 * pcb2->pcb_savefpu: cloned above.
303 * pcb2->pcb_onfault: cloned above (always NULL here?).
304 * pcb2->pcb_[fg]sbase: cloned above
305 */
306
307 /* Setup to release sched_lock in fork_exit(). */
308 td->td_md.md_spinlock_count = 1;
309 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
310 }
311
312 /*
313 * Set that machine state for performing an upcall that has to
314 * be done in thread_userret() so that those upcalls generated
315 * in thread_userret() itself can be done as well.
316 */
317 void
318 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
319 stack_t *stack)
320 {
321
322 /*
323 * Do any extra cleaning that needs to be done.
324 * The thread may have optional components
325 * that are not present in a fresh thread.
326 * This may be a recycled thread so make it look
327 * as though it's newly allocated.
328 */
329 cpu_thread_clean(td);
330
331 #ifdef COMPAT_IA32
332 if (td->td_proc->p_sysent == &ia32_freebsd_sysvec) {
333 /*
334 * Set the trap frame to point at the beginning of the uts
335 * function.
336 */
337 td->td_frame->tf_rbp = 0;
338 td->td_frame->tf_rsp =
339 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
340 td->td_frame->tf_rip = (uintptr_t)entry;
341
342 /*
343 * Pass the address of the mailbox for this kse to the uts
344 * function as a parameter on the stack.
345 */
346 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)),
347 (uint32_t)(uintptr_t)arg);
348
349 return;
350 }
351 #endif
352
353 /*
354 * Set the trap frame to point at the beginning of the uts
355 * function.
356 */
357 td->td_frame->tf_rbp = 0;
358 td->td_frame->tf_rsp =
359 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f;
360 td->td_frame->tf_rsp -= 8;
361 td->td_frame->tf_rip = (register_t)entry;
362
363 /*
364 * Pass the address of the mailbox for this kse to the uts
365 * function as a parameter on the stack.
366 */
367 td->td_frame->tf_rdi = (register_t)arg;
368 }
369
370 int
371 cpu_set_user_tls(struct thread *td, void *tls_base)
372 {
373
374 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS)
375 return (EINVAL);
376
377 #ifdef COMPAT_IA32
378 if (td->td_proc->p_sysent == &ia32_freebsd_sysvec) {
379 if (td == curthread) {
380 critical_enter();
381 td->td_pcb->pcb_gsbase = (register_t)tls_base;
382 wrmsr(MSR_KGSBASE, td->td_pcb->pcb_gsbase);
383 critical_exit();
384 } else {
385 td->td_pcb->pcb_gsbase = (register_t)tls_base;
386 }
387 return (0);
388 }
389 #endif
390 if (td == curthread) {
391 critical_enter();
392 td->td_pcb->pcb_fsbase = (register_t)tls_base;
393 wrmsr(MSR_FSBASE, td->td_pcb->pcb_fsbase);
394 critical_exit();
395 } else {
396 td->td_pcb->pcb_fsbase = (register_t)tls_base;
397 }
398 return (0);
399 }
400
401 #ifdef SMP
402 static void
403 cpu_reset_proxy()
404 {
405
406 cpu_reset_proxy_active = 1;
407 while (cpu_reset_proxy_active == 1)
408 ; /* Wait for other cpu to see that we've started */
409 stop_cpus((1<<cpu_reset_proxyid));
410 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
411 DELAY(1000000);
412 cpu_reset_real();
413 }
414 #endif
415
416 void
417 cpu_reset()
418 {
419 #ifdef SMP
420 u_int cnt, map;
421
422 if (smp_active) {
423 map = PCPU_GET(other_cpus) & ~stopped_cpus;
424 if (map != 0) {
425 printf("cpu_reset: Stopping other CPUs\n");
426 stop_cpus(map);
427 }
428
429 if (PCPU_GET(cpuid) != 0) {
430 cpu_reset_proxyid = PCPU_GET(cpuid);
431 cpustop_restartfunc = cpu_reset_proxy;
432 cpu_reset_proxy_active = 0;
433 printf("cpu_reset: Restarting BSP\n");
434 started_cpus = (1<<0); /* Restart CPU #0 */
435
436 cnt = 0;
437 while (cpu_reset_proxy_active == 0 && cnt < 10000000)
438 cnt++; /* Wait for BSP to announce restart */
439 if (cpu_reset_proxy_active == 0)
440 printf("cpu_reset: Failed to restart BSP\n");
441 enable_intr();
442 cpu_reset_proxy_active = 2;
443
444 while (1);
445 /* NOTREACHED */
446 }
447
448 DELAY(1000000);
449 }
450 #endif
451 cpu_reset_real();
452 /* NOTREACHED */
453 }
454
455 static void
456 cpu_reset_real()
457 {
458 struct region_descriptor null_idt;
459 int b;
460
461 disable_intr();
462
463 /*
464 * Attempt to do a CPU reset via the keyboard controller,
465 * do not turn off GateA20, as any machine that fails
466 * to do the reset here would then end up in no man's land.
467 */
468 outb(IO_KBD + 4, 0xFE);
469 DELAY(500000); /* wait 0.5 sec to see if that did it */
470
471 /*
472 * Attempt to force a reset via the Reset Control register at
473 * I/O port 0xcf9. Bit 2 forces a system reset when it
474 * transitions from 0 to 1. Bit 1 selects the type of reset
475 * to attempt: 0 selects a "soft" reset, and 1 selects a
476 * "hard" reset. We try a "hard" reset. The first write sets
477 * bit 1 to select a "hard" reset and clears bit 2. The
478 * second write forces a 0 -> 1 transition in bit 2 to trigger
479 * a reset.
480 */
481 outb(0xcf9, 0x2);
482 outb(0xcf9, 0x6);
483 DELAY(500000); /* wait 0.5 sec to see if that did it */
484
485 /*
486 * Attempt to force a reset via the Fast A20 and Init register
487 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate.
488 * Bit 0 asserts INIT# when set to 1. We are careful to only
489 * preserve bit 1 while setting bit 0. We also must clear bit
490 * 0 before setting it if it isn't already clear.
491 */
492 b = inb(0x92);
493 if (b != 0xff) {
494 if ((b & 0x1) != 0)
495 outb(0x92, b & 0xfe);
496 outb(0x92, b | 0x1);
497 DELAY(500000); /* wait 0.5 sec to see if that did it */
498 }
499
500 printf("No known reset method worked, attempting CPU shutdown\n");
501 DELAY(1000000); /* wait 1 sec for printf to complete */
502
503 /* Wipe the IDT. */
504 null_idt.rd_limit = 0;
505 null_idt.rd_base = 0;
506 lidt(&null_idt);
507
508 /* "good night, sweet prince .... <THUNK!>" */
509 breakpoint();
510
511 /* NOTREACHED */
512 while(1);
513 }
514
515 /*
516 * Allocate an sf_buf for the given vm_page. On this machine, however, there
517 * is no sf_buf object. Instead, an opaque pointer to the given vm_page is
518 * returned.
519 */
520 struct sf_buf *
521 sf_buf_alloc(struct vm_page *m, int pri)
522 {
523
524 return ((struct sf_buf *)m);
525 }
526
527 /*
528 * Free the sf_buf. In fact, do nothing because there are no resources
529 * associated with the sf_buf.
530 */
531 void
532 sf_buf_free(struct sf_buf *sf)
533 {
534 }
535
536 /*
537 * Software interrupt handler for queued VM system processing.
538 */
539 void
540 swi_vm(void *dummy)
541 {
542 if (busdma_swi_pending != 0)
543 busdma_swi();
544 }
545
546 /*
547 * Tell whether this address is in some physical memory region.
548 * Currently used by the kernel coredump code in order to avoid
549 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
550 * or other unpredictable behaviour.
551 */
552
553 int
554 is_physical_memory(vm_paddr_t addr)
555 {
556
557 #ifdef DEV_ISA
558 /* The ISA ``memory hole''. */
559 if (addr >= 0xa0000 && addr < 0x100000)
560 return 0;
561 #endif
562
563 /*
564 * stuff other tests for known memory-mapped devices (PCI?)
565 * here
566 */
567
568 return 1;
569 }
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