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("$FreeBSD$");
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 spin count 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_alloc(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 void
252 cpu_thread_free(struct thread *td)
253 {
254 }
255
256 /*
257 * Initialize machine state (pcb and trap frame) for a new thread about to
258 * upcall. Put enough state in the new thread's PCB to get it to go back
259 * userret(), where we can intercept it again to set the return (upcall)
260 * Address and stack, along with those from upcals that are from other sources
261 * such as those generated in thread_userret() itself.
262 */
263 void
264 cpu_set_upcall(struct thread *td, struct thread *td0)
265 {
266 struct pcb *pcb2;
267
268 /* Point the pcb to the top of the stack. */
269 pcb2 = td->td_pcb;
270
271 /*
272 * Copy the upcall pcb. This loads kernel regs.
273 * Those not loaded individually below get their default
274 * values here.
275 *
276 * XXXKSE It might be a good idea to simply skip this as
277 * the values of the other registers may be unimportant.
278 * This would remove any requirement for knowing the KSE
279 * at this time (see the matching comment below for
280 * more analysis) (need a good safe default).
281 */
282 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
283 pcb2->pcb_flags &= ~PCB_FPUINITDONE;
284
285 /*
286 * Create a new fresh stack for the new thread.
287 * Don't forget to set this stack value into whatever supplies
288 * the address for the fault handlers.
289 * The contexts are filled in at the time we actually DO the
290 * upcall as only then do we know which KSE we got.
291 */
292 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
293
294 /*
295 * Set registers for trampoline to user mode. Leave space for the
296 * return address on stack. These are the kernel mode register values.
297 */
298 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pml4);
299 pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */
300 pcb2->pcb_rbp = 0;
301 pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */
302 pcb2->pcb_rbx = (register_t)td; /* trampoline arg */
303 pcb2->pcb_rip = (register_t)fork_trampoline;
304 /*
305 * If we didn't copy the pcb, we'd need to do the following registers:
306 * pcb2->pcb_dr*: cloned above.
307 * pcb2->pcb_savefpu: cloned above.
308 * pcb2->pcb_onfault: cloned above (always NULL here?).
309 * pcb2->pcb_[fg]sbase: cloned above
310 */
311
312 /* Setup to release spin count in fork_exit(). */
313 td->td_md.md_spinlock_count = 1;
314 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
315 }
316
317 /*
318 * Set that machine state for performing an upcall that has to
319 * be done in thread_userret() so that those upcalls generated
320 * in thread_userret() itself can be done as well.
321 */
322 void
323 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
324 stack_t *stack)
325 {
326
327 /*
328 * Do any extra cleaning that needs to be done.
329 * The thread may have optional components
330 * that are not present in a fresh thread.
331 * This may be a recycled thread so make it look
332 * as though it's newly allocated.
333 */
334 cpu_thread_clean(td);
335
336 #ifdef COMPAT_IA32
337 if (td->td_proc->p_sysent == &ia32_freebsd_sysvec) {
338 /*
339 * Set the trap frame to point at the beginning of the uts
340 * function.
341 */
342 td->td_frame->tf_rbp = 0;
343 td->td_frame->tf_rsp =
344 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
345 td->td_frame->tf_rip = (uintptr_t)entry;
346
347 /*
348 * Pass the address of the mailbox for this kse to the uts
349 * function as a parameter on the stack.
350 */
351 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)),
352 (uint32_t)(uintptr_t)arg);
353
354 return;
355 }
356 #endif
357
358 /*
359 * Set the trap frame to point at the beginning of the uts
360 * function.
361 */
362 td->td_frame->tf_rbp = 0;
363 td->td_frame->tf_rsp =
364 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f;
365 td->td_frame->tf_rsp -= 8;
366 td->td_frame->tf_rip = (register_t)entry;
367
368 /*
369 * Pass the address of the mailbox for this kse to the uts
370 * function as a parameter on the stack.
371 */
372 td->td_frame->tf_rdi = (register_t)arg;
373 }
374
375 int
376 cpu_set_user_tls(struct thread *td, void *tls_base)
377 {
378
379 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS)
380 return (EINVAL);
381
382 #ifdef COMPAT_IA32
383 if (td->td_proc->p_sysent == &ia32_freebsd_sysvec) {
384 if (td == curthread) {
385 critical_enter();
386 td->td_pcb->pcb_gsbase = (register_t)tls_base;
387 wrmsr(MSR_KGSBASE, td->td_pcb->pcb_gsbase);
388 critical_exit();
389 } else {
390 td->td_pcb->pcb_gsbase = (register_t)tls_base;
391 }
392 return (0);
393 }
394 #endif
395 if (td == curthread) {
396 critical_enter();
397 td->td_pcb->pcb_fsbase = (register_t)tls_base;
398 wrmsr(MSR_FSBASE, td->td_pcb->pcb_fsbase);
399 critical_exit();
400 } else {
401 td->td_pcb->pcb_fsbase = (register_t)tls_base;
402 }
403 return (0);
404 }
405
406 #ifdef SMP
407 static void
408 cpu_reset_proxy()
409 {
410
411 cpu_reset_proxy_active = 1;
412 while (cpu_reset_proxy_active == 1)
413 ; /* Wait for other cpu to see that we've started */
414 stop_cpus((1<<cpu_reset_proxyid));
415 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
416 DELAY(1000000);
417 cpu_reset_real();
418 }
419 #endif
420
421 void
422 cpu_reset()
423 {
424 #ifdef SMP
425 u_int cnt, map;
426
427 if (smp_active) {
428 map = PCPU_GET(other_cpus) & ~stopped_cpus;
429 if (map != 0) {
430 printf("cpu_reset: Stopping other CPUs\n");
431 stop_cpus(map);
432 }
433
434 if (PCPU_GET(cpuid) != 0) {
435 cpu_reset_proxyid = PCPU_GET(cpuid);
436 cpustop_restartfunc = cpu_reset_proxy;
437 cpu_reset_proxy_active = 0;
438 printf("cpu_reset: Restarting BSP\n");
439
440 /* Restart CPU #0. */
441 atomic_store_rel_int(&started_cpus, 1 << 0);
442
443 cnt = 0;
444 while (cpu_reset_proxy_active == 0 && cnt < 10000000)
445 cnt++; /* Wait for BSP to announce restart */
446 if (cpu_reset_proxy_active == 0)
447 printf("cpu_reset: Failed to restart BSP\n");
448 enable_intr();
449 cpu_reset_proxy_active = 2;
450
451 while (1);
452 /* NOTREACHED */
453 }
454
455 DELAY(1000000);
456 }
457 #endif
458 cpu_reset_real();
459 /* NOTREACHED */
460 }
461
462 static void
463 cpu_reset_real()
464 {
465 struct region_descriptor null_idt;
466 int b;
467
468 disable_intr();
469
470 /*
471 * Attempt to do a CPU reset via the keyboard controller,
472 * do not turn off GateA20, as any machine that fails
473 * to do the reset here would then end up in no man's land.
474 */
475 outb(IO_KBD + 4, 0xFE);
476 DELAY(500000); /* wait 0.5 sec to see if that did it */
477
478 /*
479 * Attempt to force a reset via the Reset Control register at
480 * I/O port 0xcf9. Bit 2 forces a system reset when it
481 * transitions from 0 to 1. Bit 1 selects the type of reset
482 * to attempt: 0 selects a "soft" reset, and 1 selects a
483 * "hard" reset. We try a "hard" reset. The first write sets
484 * bit 1 to select a "hard" reset and clears bit 2. The
485 * second write forces a 0 -> 1 transition in bit 2 to trigger
486 * a reset.
487 */
488 outb(0xcf9, 0x2);
489 outb(0xcf9, 0x6);
490 DELAY(500000); /* wait 0.5 sec to see if that did it */
491
492 /*
493 * Attempt to force a reset via the Fast A20 and Init register
494 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate.
495 * Bit 0 asserts INIT# when set to 1. We are careful to only
496 * preserve bit 1 while setting bit 0. We also must clear bit
497 * 0 before setting it if it isn't already clear.
498 */
499 b = inb(0x92);
500 if (b != 0xff) {
501 if ((b & 0x1) != 0)
502 outb(0x92, b & 0xfe);
503 outb(0x92, b | 0x1);
504 DELAY(500000); /* wait 0.5 sec to see if that did it */
505 }
506
507 printf("No known reset method worked, attempting CPU shutdown\n");
508 DELAY(1000000); /* wait 1 sec for printf to complete */
509
510 /* Wipe the IDT. */
511 null_idt.rd_limit = 0;
512 null_idt.rd_base = 0;
513 lidt(&null_idt);
514
515 /* "good night, sweet prince .... <THUNK!>" */
516 breakpoint();
517
518 /* NOTREACHED */
519 while(1);
520 }
521
522 /*
523 * Allocate an sf_buf for the given vm_page. On this machine, however, there
524 * is no sf_buf object. Instead, an opaque pointer to the given vm_page is
525 * returned.
526 */
527 struct sf_buf *
528 sf_buf_alloc(struct vm_page *m, int pri)
529 {
530
531 return ((struct sf_buf *)m);
532 }
533
534 /*
535 * Free the sf_buf. In fact, do nothing because there are no resources
536 * associated with the sf_buf.
537 */
538 void
539 sf_buf_free(struct sf_buf *sf)
540 {
541 }
542
543 /*
544 * Software interrupt handler for queued VM system processing.
545 */
546 void
547 swi_vm(void *dummy)
548 {
549 if (busdma_swi_pending != 0)
550 busdma_swi();
551 }
552
553 /*
554 * Tell whether this address is in some physical memory region.
555 * Currently used by the kernel coredump code in order to avoid
556 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
557 * or other unpredictable behaviour.
558 */
559
560 int
561 is_physical_memory(vm_paddr_t addr)
562 {
563
564 #ifdef DEV_ISA
565 /* The ISA ``memory hole''. */
566 if (addr >= 0xa0000 && addr < 0x100000)
567 return 0;
568 #endif
569
570 /*
571 * stuff other tests for known memory-mapped devices (PCI?)
572 * here
573 */
574
575 return 1;
576 }
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