1 /*-
2  * Copyright (c) 1992 Terrence R. Lambert.
3  * Copyright (C) 1994, David Greenman
4  * Copyright (c) 1982, 1987, 1990, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * William Jolitz.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	from: @(#)machdep.c	7.4 (Berkeley) 6/3/91
39  * $FreeBSD: src/sys/i386/i386/machdep.c,v 1.385.2.30 2003/05/31 08:48:05 alc Exp $
40  */
41 
42 #include "opt_ddb.h"
43 #include "opt_directio.h"
44 #include "opt_inet.h"
45 #include "opt_msgbuf.h"
46 #include "opt_swap.h"
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/sysproto.h>
51 #include <sys/signalvar.h>
52 #include <sys/kernel.h>
53 #include <sys/linker.h>
54 #include <sys/malloc.h>
55 #include <sys/proc.h>
56 #include <sys/buf.h>
57 #include <sys/reboot.h>
58 #include <sys/mbuf.h>
59 #include <sys/msgbuf.h>
60 #include <sys/sysent.h>
61 #include <sys/sysctl.h>
62 #include <sys/vmmeter.h>
63 #include <sys/bus.h>
64 #include <sys/usched.h>
65 #include <sys/reg.h>
66 
67 #include <vm/vm.h>
68 #include <vm/vm_param.h>
69 #include <sys/lock.h>
70 #include <vm/vm_kern.h>
71 #include <vm/vm_object.h>
72 #include <vm/vm_page.h>
73 #include <vm/vm_map.h>
74 #include <vm/vm_pager.h>
75 #include <vm/vm_extern.h>
76 
77 #include <sys/thread2.h>
78 #include <sys/mplock2.h>
79 
80 #include <sys/user.h>
81 #include <sys/exec.h>
82 #include <sys/cons.h>
83 
84 #include <ddb/ddb.h>
85 
86 #include <machine/cpu.h>
87 #include <machine/clock.h>
88 #include <machine/specialreg.h>
89 #include <machine/md_var.h>
90 #include <machine/pcb_ext.h>		/* pcb.h included via sys/user.h */
91 #include <machine/globaldata.h>		/* CPU_prvspace */
92 #include <machine/smp.h>
93 #include <machine/cputypes.h>
94 
95 #include <bus/isa/rtc.h>
96 #include <sys/random.h>
97 #include <sys/ptrace.h>
98 #include <machine/sigframe.h>
99 #include <unistd.h>		/* umtx_* functions */
100 #include <pthread.h>		/* pthread_yield() */
101 
102 extern void dblfault_handler (void);
103 
104 static void set_fpregs_xmm (struct save87 *, struct savexmm *);
105 static void fill_fpregs_xmm (struct savexmm *, struct save87 *);
106 #ifdef DIRECTIO
107 extern void ffs_rawread_setup(void);
108 #endif /* DIRECTIO */
109 
110 int64_t tsc_offsets[MAXCPU];
111 
112 #if defined(SWTCH_OPTIM_STATS)
113 extern int swtch_optim_stats;
114 SYSCTL_INT(_debug, OID_AUTO, swtch_optim_stats,
115 	CTLFLAG_RD, &swtch_optim_stats, 0, "");
116 SYSCTL_INT(_debug, OID_AUTO, tlb_flush_count,
117 	CTLFLAG_RD, &tlb_flush_count, 0, "");
118 #endif
119 
120 static int
121 sysctl_hw_physmem(SYSCTL_HANDLER_ARGS)
122 {
123 	u_long pmem = ctob(physmem);
124 
125 	int error = sysctl_handle_long(oidp, &pmem, 0, req);
126 	return (error);
127 }
128 
129 SYSCTL_PROC(_hw, HW_PHYSMEM, physmem, CTLTYPE_ULONG|CTLFLAG_RD,
130 	0, 0, sysctl_hw_physmem, "LU", "Total system memory in bytes (number of pages * page size)");
131 
132 static int
133 sysctl_hw_usermem(SYSCTL_HANDLER_ARGS)
134 {
135 	/* JG */
136 	int error = sysctl_handle_int(oidp, 0,
137 		ctob((int)Maxmem - vmstats.v_wire_count), req);
138 	return (error);
139 }
140 
141 SYSCTL_PROC(_hw, HW_USERMEM, usermem, CTLTYPE_INT|CTLFLAG_RD,
142 	0, 0, sysctl_hw_usermem, "IU", "");
143 
144 SYSCTL_ULONG(_hw, OID_AUTO, availpages, CTLFLAG_RD, &Maxmem, 0, "");
145 
146 /*
147  * Send an interrupt to process.
148  *
149  * Stack is set up to allow sigcode stored
150  * at top to call routine, followed by kcall
151  * to sigreturn routine below.  After sigreturn
152  * resets the signal mask, the stack, and the
153  * frame pointer, it returns to the user
154  * specified pc, psl.
155  */
156 void
157 sendsig(sig_t catcher, int sig, sigset_t *mask, u_long code)
158 {
159 	struct lwp *lp = curthread->td_lwp;
160 	struct proc *p = lp->lwp_proc;
161 	struct trapframe *regs;
162 	struct sigacts *psp = p->p_sigacts;
163 	struct sigframe sf, *sfp;
164 	int oonstack;
165 	char *sp;
166 
167 	regs = lp->lwp_md.md_regs;
168 	oonstack = (lp->lwp_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
169 
170 	/* Save user context */
171 	bzero(&sf, sizeof(struct sigframe));
172 	sf.sf_uc.uc_sigmask = *mask;
173 	sf.sf_uc.uc_stack = lp->lwp_sigstk;
174 	sf.sf_uc.uc_mcontext.mc_onstack = oonstack;
175 	KKASSERT(__offsetof(struct trapframe, tf_rdi) == 0);
176 	bcopy(regs, &sf.sf_uc.uc_mcontext.mc_rdi, sizeof(struct trapframe));
177 
178 	/* Make the size of the saved context visible to userland */
179 	sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext);
180 
181 	/* Allocate and validate space for the signal handler context. */
182         if ((lp->lwp_flags & LWP_ALTSTACK) != 0 && !oonstack &&
183 	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
184 		sp = (char *)(lp->lwp_sigstk.ss_sp + lp->lwp_sigstk.ss_size -
185 			      sizeof(struct sigframe));
186 		lp->lwp_sigstk.ss_flags |= SS_ONSTACK;
187 	} else {
188 		/* We take red zone into account */
189 		sp = (char *)regs->tf_rsp - sizeof(struct sigframe) - 128;
190 	}
191 
192 	/* Align to 16 bytes */
193 	sfp = (struct sigframe *)((intptr_t)sp & ~0xFUL);
194 
195 	/* Translate the signal is appropriate */
196 	if (p->p_sysent->sv_sigtbl) {
197 		if (sig <= p->p_sysent->sv_sigsize)
198 			sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)];
199 	}
200 
201 	/*
202 	 * Build the argument list for the signal handler.
203 	 *
204 	 * Arguments are in registers (%rdi, %rsi, %rdx, %rcx)
205 	 */
206 	regs->tf_rdi = sig;				/* argument 1 */
207 	regs->tf_rdx = (register_t)&sfp->sf_uc;		/* argument 3 */
208 
209 	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
210 		/*
211 		 * Signal handler installed with SA_SIGINFO.
212 		 *
213 		 * action(signo, siginfo, ucontext)
214 		 */
215 		regs->tf_rsi = (register_t)&sfp->sf_si;	/* argument 2 */
216 		regs->tf_rcx = (register_t)regs->tf_err; /* argument 4 */
217 		sf.sf_ahu.sf_action = (__siginfohandler_t *)catcher;
218 
219 		/* fill siginfo structure */
220 		sf.sf_si.si_signo = sig;
221 		sf.sf_si.si_code = code;
222 		sf.sf_si.si_addr = (void *)regs->tf_addr;
223 	} else {
224 		/*
225 		 * Old FreeBSD-style arguments.
226 		 *
227 		 * handler (signo, code, [uc], addr)
228 		 */
229 		regs->tf_rsi = (register_t)code;	/* argument 2 */
230 		regs->tf_rcx = (register_t)regs->tf_addr; /* argument 4 */
231 		sf.sf_ahu.sf_handler = catcher;
232 	}
233 
234 #if 0
235 	/*
236 	 * If we're a vm86 process, we want to save the segment registers.
237 	 * We also change eflags to be our emulated eflags, not the actual
238 	 * eflags.
239 	 */
240 	if (regs->tf_eflags & PSL_VM) {
241 		struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs;
242 		struct vm86_kernel *vm86 = &lp->lwp_thread->td_pcb->pcb_ext->ext_vm86;
243 
244 		sf.sf_uc.uc_mcontext.mc_gs = tf->tf_vm86_gs;
245 		sf.sf_uc.uc_mcontext.mc_fs = tf->tf_vm86_fs;
246 		sf.sf_uc.uc_mcontext.mc_es = tf->tf_vm86_es;
247 		sf.sf_uc.uc_mcontext.mc_ds = tf->tf_vm86_ds;
248 
249 		if (vm86->vm86_has_vme == 0)
250 			sf.sf_uc.uc_mcontext.mc_eflags =
251 			    (tf->tf_eflags & ~(PSL_VIF | PSL_VIP)) |
252 			    (vm86->vm86_eflags & (PSL_VIF | PSL_VIP));
253 
254 		/*
255 		 * Clear PSL_NT to inhibit T_TSSFLT faults on return from
256 		 * syscalls made by the signal handler.  This just avoids
257 		 * wasting time for our lazy fixup of such faults.  PSL_NT
258 		 * does nothing in vm86 mode, but vm86 programs can set it
259 		 * almost legitimately in probes for old cpu types.
260 		 */
261 		tf->tf_eflags &= ~(PSL_VM | PSL_NT | PSL_VIF | PSL_VIP);
262 	}
263 #endif
264 
265 	/*
266 	 * Save the FPU state and reinit the FP unit
267 	 */
268 	npxpush(&sf.sf_uc.uc_mcontext);
269 
270 	/*
271 	 * Copy the sigframe out to the user's stack.
272 	 */
273 	if (copyout(&sf, sfp, sizeof(struct sigframe)) != 0) {
274 		/*
275 		 * Something is wrong with the stack pointer.
276 		 * ...Kill the process.
277 		 */
278 		sigexit(lp, SIGILL);
279 	}
280 
281 	regs->tf_rsp = (register_t)sfp;
282 	regs->tf_rip = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
283 
284 	/*
285 	 * i386 abi specifies that the direction flag must be cleared
286 	 * on function entry
287 	 */
288 	regs->tf_rflags &= ~(PSL_T|PSL_D);
289 
290 	/*
291 	 * 64 bit mode has a code and stack selector but
292 	 * no data or extra selector.  %fs and %gs are not
293 	 * stored in-context.
294 	 */
295 	regs->tf_cs = _ucodesel;
296 	regs->tf_ss = _udatasel;
297 }
298 
299 /*
300  * Sanitize the trapframe for a virtual kernel passing control to a custom
301  * VM context.  Remove any items that would otherwise create a privilage
302  * issue.
303  *
304  * XXX at the moment we allow userland to set the resume flag.  Is this a
305  * bad idea?
306  */
307 int
308 cpu_sanitize_frame(struct trapframe *frame)
309 {
310 	frame->tf_cs = _ucodesel;
311 	frame->tf_ss = _udatasel;
312 	/* XXX VM (8086) mode not supported? */
313 	frame->tf_rflags &= (PSL_RF | PSL_USERCHANGE | PSL_VM_UNSUPP);
314 	frame->tf_rflags |= PSL_RESERVED_DEFAULT | PSL_I;
315 
316 	return(0);
317 }
318 
319 /*
320  * Sanitize the tls so loading the descriptor does not blow up
321  * on us.  For x86_64 we don't have to do anything.
322  */
323 int
324 cpu_sanitize_tls(struct savetls *tls)
325 {
326 	return(0);
327 }
328 
329 /*
330  * sigreturn(ucontext_t *sigcntxp)
331  *
332  * System call to cleanup state after a signal
333  * has been taken.  Reset signal mask and
334  * stack state from context left by sendsig (above).
335  * Return to previous pc and psl as specified by
336  * context left by sendsig. Check carefully to
337  * make sure that the user has not modified the
338  * state to gain improper privileges.
339  */
340 #define	EFL_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
341 #define	CS_SECURE(cs)		(ISPL(cs) == SEL_UPL)
342 
343 int
344 sys_sigreturn(struct sigreturn_args *uap)
345 {
346 	struct lwp *lp = curthread->td_lwp;
347 	struct trapframe *regs;
348 	ucontext_t uc;
349 	ucontext_t *ucp;
350 	register_t rflags;
351 	int cs;
352 	int error;
353 
354 	/*
355 	 * We have to copy the information into kernel space so userland
356 	 * can't modify it while we are sniffing it.
357 	 */
358 	regs = lp->lwp_md.md_regs;
359 	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
360 	if (error)
361 		return (error);
362 	ucp = &uc;
363 	rflags = ucp->uc_mcontext.mc_rflags;
364 
365 	/* VM (8086) mode not supported */
366 	rflags &= ~PSL_VM_UNSUPP;
367 
368 #if 0
369 	if (eflags & PSL_VM) {
370 		struct trapframe_vm86 *tf = (struct trapframe_vm86 *)regs;
371 		struct vm86_kernel *vm86;
372 
373 		/*
374 		 * if pcb_ext == 0 or vm86_inited == 0, the user hasn't
375 		 * set up the vm86 area, and we can't enter vm86 mode.
376 		 */
377 		if (lp->lwp_thread->td_pcb->pcb_ext == 0)
378 			return (EINVAL);
379 		vm86 = &lp->lwp_thread->td_pcb->pcb_ext->ext_vm86;
380 		if (vm86->vm86_inited == 0)
381 			return (EINVAL);
382 
383 		/* go back to user mode if both flags are set */
384 		if ((eflags & PSL_VIP) && (eflags & PSL_VIF))
385 			trapsignal(lp->lwp_proc, SIGBUS, 0);
386 
387 		if (vm86->vm86_has_vme) {
388 			eflags = (tf->tf_eflags & ~VME_USERCHANGE) |
389 			    (eflags & VME_USERCHANGE) | PSL_VM;
390 		} else {
391 			vm86->vm86_eflags = eflags;	/* save VIF, VIP */
392 			eflags = (tf->tf_eflags & ~VM_USERCHANGE) |					    (eflags & VM_USERCHANGE) | PSL_VM;
393 		}
394 		bcopy(&ucp.uc_mcontext.mc_gs, tf, sizeof(struct trapframe));
395 		tf->tf_eflags = eflags;
396 		tf->tf_vm86_ds = tf->tf_ds;
397 		tf->tf_vm86_es = tf->tf_es;
398 		tf->tf_vm86_fs = tf->tf_fs;
399 		tf->tf_vm86_gs = tf->tf_gs;
400 		tf->tf_ds = _udatasel;
401 		tf->tf_es = _udatasel;
402 #if 0
403 		tf->tf_fs = _udatasel;
404 		tf->tf_gs = _udatasel;
405 #endif
406 	} else
407 #endif
408 	{
409 		/*
410 		 * Don't allow users to change privileged or reserved flags.
411 		 */
412 		/*
413 		 * XXX do allow users to change the privileged flag PSL_RF.
414 		 * The cpu sets PSL_RF in tf_eflags for faults.  Debuggers
415 		 * should sometimes set it there too.  tf_eflags is kept in
416 		 * the signal context during signal handling and there is no
417 		 * other place to remember it, so the PSL_RF bit may be
418 		 * corrupted by the signal handler without us knowing.
419 		 * Corruption of the PSL_RF bit at worst causes one more or
420 		 * one less debugger trap, so allowing it is fairly harmless.
421 		 */
422 		if (!EFL_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) {
423 			kprintf("sigreturn: rflags = 0x%lx\n", (long)rflags);
424 			return(EINVAL);
425 		}
426 
427 		/*
428 		 * Don't allow users to load a valid privileged %cs.  Let the
429 		 * hardware check for invalid selectors, excess privilege in
430 		 * other selectors, invalid %eip's and invalid %esp's.
431 		 */
432 		cs = ucp->uc_mcontext.mc_cs;
433 		if (!CS_SECURE(cs)) {
434 			kprintf("sigreturn: cs = 0x%x\n", cs);
435 			trapsignal(lp, SIGBUS, T_PROTFLT);
436 			return(EINVAL);
437 		}
438 		bcopy(&ucp->uc_mcontext.mc_rdi, regs, sizeof(struct trapframe));
439 	}
440 
441 	/*
442 	 * Restore the FPU state from the frame
443 	 */
444 	npxpop(&ucp->uc_mcontext);
445 
446 	if (ucp->uc_mcontext.mc_onstack & 1)
447 		lp->lwp_sigstk.ss_flags |= SS_ONSTACK;
448 	else
449 		lp->lwp_sigstk.ss_flags &= ~SS_ONSTACK;
450 
451 	lp->lwp_sigmask = ucp->uc_sigmask;
452 	SIG_CANTMASK(lp->lwp_sigmask);
453 	return(EJUSTRETURN);
454 }
455 
456 /*
457  * cpu_idle() represents the idle LWKT.  You cannot return from this function
458  * (unless you want to blow things up!).  Instead we look for runnable threads
459  * and loop or halt as appropriate.  Giant is not held on entry to the thread.
460  *
461  * The main loop is entered with a critical section held, we must release
462  * the critical section before doing anything else.  lwkt_switch() will
463  * check for pending interrupts due to entering and exiting its own
464  * critical section.
465  *
466  * Note on cpu_idle_hlt:  On an SMP system we rely on a scheduler IPI
467  * to wake a HLTed cpu up.
468  */
469 static int	cpu_idle_hlt = 1;
470 static int	cpu_idle_hltcnt;
471 static int	cpu_idle_spincnt;
472 SYSCTL_INT(_machdep, OID_AUTO, cpu_idle_hlt, CTLFLAG_RW,
473     &cpu_idle_hlt, 0, "Idle loop HLT enable");
474 SYSCTL_INT(_machdep, OID_AUTO, cpu_idle_hltcnt, CTLFLAG_RW,
475     &cpu_idle_hltcnt, 0, "Idle loop entry halts");
476 SYSCTL_INT(_machdep, OID_AUTO, cpu_idle_spincnt, CTLFLAG_RW,
477     &cpu_idle_spincnt, 0, "Idle loop entry spins");
478 
479 void
480 cpu_idle(void)
481 {
482 	struct thread *td = curthread;
483 	struct mdglobaldata *gd = mdcpu;
484 	int reqflags;
485 
486 	crit_exit();
487 	KKASSERT(td->td_critcount == 0);
488 	cpu_enable_intr();
489 
490 	for (;;) {
491 		/*
492 		 * See if there are any LWKTs ready to go.
493 		 */
494 		lwkt_switch();
495 
496 		/*
497 		 * The idle loop halts only if no threads are scheduleable
498 		 * and no signals have occured.
499 		 */
500 		if (cpu_idle_hlt &&
501 		    (td->td_gd->gd_reqflags & RQF_IDLECHECK_WK_MASK) == 0) {
502 			splz();
503 			if ((td->td_gd->gd_reqflags & RQF_IDLECHECK_WK_MASK) == 0) {
504 #ifdef DEBUGIDLE
505 				struct timeval tv1, tv2;
506 				gettimeofday(&tv1, NULL);
507 #endif
508 				reqflags = gd->mi.gd_reqflags &
509 					   ~RQF_IDLECHECK_WK_MASK;
510 				KKASSERT(gd->mi.gd_processing_ipiq == 0);
511 				umtx_sleep(&gd->mi.gd_reqflags, reqflags,
512 					   1000000);
513 #ifdef DEBUGIDLE
514 				gettimeofday(&tv2, NULL);
515 				if (tv2.tv_usec - tv1.tv_usec +
516 				    (tv2.tv_sec - tv1.tv_sec) * 1000000
517 				    > 500000) {
518 					kprintf("cpu %d idlelock %08x %08x\n",
519 						gd->mi.gd_cpuid,
520 						gd->mi.gd_reqflags,
521 						gd->gd_fpending);
522 				}
523 #endif
524 			}
525 			++cpu_idle_hltcnt;
526 		} else {
527 			splz();
528 			__asm __volatile("pause");
529 			++cpu_idle_spincnt;
530 		}
531 	}
532 }
533 
534 /*
535  * Called by the spinlock code with or without a critical section held
536  * when a spinlock is found to be seriously constested.
537  *
538  * We need to enter a critical section to prevent signals from recursing
539  * into pthreads.
540  */
541 void
542 cpu_spinlock_contested(void)
543 {
544 	cpu_pause();
545 }
546 
547 /*
548  * Clear registers on exec
549  */
550 void
551 exec_setregs(u_long entry, u_long stack, u_long ps_strings)
552 {
553 	struct thread *td = curthread;
554 	struct lwp *lp = td->td_lwp;
555 	struct pcb *pcb = td->td_pcb;
556 	struct trapframe *regs = lp->lwp_md.md_regs;
557 
558 	/* was i386_user_cleanup() in NetBSD */
559 	user_ldt_free(pcb);
560 
561 	bzero((char *)regs, sizeof(struct trapframe));
562 	regs->tf_rip = entry;
563 	regs->tf_rsp = ((stack - 8) & ~0xFul) + 8; /* align the stack */
564 	regs->tf_rdi = stack;		/* argv */
565 	regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T);
566 	regs->tf_ss = _udatasel;
567 	regs->tf_cs = _ucodesel;
568 	regs->tf_rbx = ps_strings;
569 
570 	/*
571 	 * Reset the hardware debug registers if they were in use.
572 	 * They won't have any meaning for the newly exec'd process.
573 	 */
574 	if (pcb->pcb_flags & PCB_DBREGS) {
575 		pcb->pcb_dr0 = 0;
576 		pcb->pcb_dr1 = 0;
577 		pcb->pcb_dr2 = 0;
578 		pcb->pcb_dr3 = 0;
579 		pcb->pcb_dr6 = 0;
580 		pcb->pcb_dr7 = 0; /* JG set bit 10? */
581 		if (pcb == td->td_pcb) {
582 			/*
583 			 * Clear the debug registers on the running
584 			 * CPU, otherwise they will end up affecting
585 			 * the next process we switch to.
586 			 */
587 			reset_dbregs();
588 		}
589 		pcb->pcb_flags &= ~PCB_DBREGS;
590 	}
591 
592 	/*
593 	 * Initialize the math emulator (if any) for the current process.
594 	 * Actually, just clear the bit that says that the emulator has
595 	 * been initialized.  Initialization is delayed until the process
596 	 * traps to the emulator (if it is done at all) mainly because
597 	 * emulators don't provide an entry point for initialization.
598 	 */
599 	pcb->pcb_flags &= ~FP_SOFTFP;
600 
601 	/*
602 	 * NOTE: do not set CR0_TS here.  npxinit() must do it after clearing
603 	 *	 gd_npxthread.  Otherwise a preemptive interrupt thread
604 	 *	 may panic in npxdna().
605 	 */
606 	crit_enter();
607 #if 0
608 	load_cr0(rcr0() | CR0_MP);
609 #endif
610 
611 	/*
612 	 * NOTE: The MSR values must be correct so we can return to
613 	 * 	 userland.  gd_user_fs/gs must be correct so the switch
614 	 *	 code knows what the current MSR values are.
615 	 */
616 	pcb->pcb_fsbase = 0;	/* Values loaded from PCB on switch */
617 	pcb->pcb_gsbase = 0;
618 	/* Initialize the npx (if any) for the current process. */
619 	npxinit();
620 	crit_exit();
621 
622 	/*
623 	 * note: linux emulator needs edx to be 0x0 on entry, which is
624 	 * handled in execve simply by setting the 64 bit syscall
625 	 * return value to 0.
626 	 */
627 }
628 
629 void
630 cpu_setregs(void)
631 {
632 #if 0
633 	unsigned int cr0;
634 
635 	cr0 = rcr0();
636 	cr0 |= CR0_NE;			/* Done by npxinit() */
637 	cr0 |= CR0_MP | CR0_TS;		/* Done at every execve() too. */
638 	cr0 |= CR0_WP | CR0_AM;
639 	load_cr0(cr0);
640 	load_gs(_udatasel);
641 #endif
642 }
643 
644 static int
645 sysctl_machdep_adjkerntz(SYSCTL_HANDLER_ARGS)
646 {
647 	int error;
648 	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2,
649 		req);
650 	if (!error && req->newptr)
651 		resettodr();
652 	return (error);
653 }
654 
655 SYSCTL_PROC(_machdep, CPU_ADJKERNTZ, adjkerntz, CTLTYPE_INT|CTLFLAG_RW,
656 	&adjkerntz, 0, sysctl_machdep_adjkerntz, "I", "");
657 
658 extern u_long bootdev;		/* not a cdev_t - encoding is different */
659 SYSCTL_ULONG(_machdep, OID_AUTO, guessed_bootdev,
660 	CTLFLAG_RD, &bootdev, 0, "Boot device (not in cdev_t format)");
661 
662 /*
663  * Initialize 386 and configure to run kernel
664  */
665 
666 /*
667  * Initialize segments & interrupt table
668  */
669 
670 extern  struct user *proc0paddr;
671 
672 #if 0
673 
674 extern inthand_t
675 	IDTVEC(div), IDTVEC(dbg), IDTVEC(nmi), IDTVEC(bpt), IDTVEC(ofl),
676 	IDTVEC(bnd), IDTVEC(ill), IDTVEC(dna), IDTVEC(fpusegm),
677 	IDTVEC(tss), IDTVEC(missing), IDTVEC(stk), IDTVEC(prot),
678 	IDTVEC(page), IDTVEC(mchk), IDTVEC(rsvd), IDTVEC(fpu), IDTVEC(align),
679 	IDTVEC(xmm), IDTVEC(dblfault),
680 	IDTVEC(fast_syscall), IDTVEC(fast_syscall32);
681 #endif
682 
683 int
684 ptrace_set_pc(struct lwp *lp, unsigned long addr)
685 {
686 	lp->lwp_md.md_regs->tf_rip = addr;
687 	return (0);
688 }
689 
690 int
691 ptrace_single_step(struct lwp *lp)
692 {
693 	lp->lwp_md.md_regs->tf_rflags |= PSL_T;
694 	return (0);
695 }
696 
697 int
698 fill_regs(struct lwp *lp, struct reg *regs)
699 {
700 	struct trapframe *tp;
701 
702 	if ((tp = lp->lwp_md.md_regs) == NULL)
703 		return EINVAL;
704 	bcopy(&tp->tf_rdi, &regs->r_rdi, sizeof(*regs));
705 	return (0);
706 }
707 
708 int
709 set_regs(struct lwp *lp, struct reg *regs)
710 {
711 	struct trapframe *tp;
712 
713 	tp = lp->lwp_md.md_regs;
714 	if (!EFL_SECURE(regs->r_rflags, tp->tf_rflags) ||
715 	    !CS_SECURE(regs->r_cs))
716 		return (EINVAL);
717 	bcopy(&regs->r_rdi, &tp->tf_rdi, sizeof(*regs));
718 	return (0);
719 }
720 
721 static void
722 fill_fpregs_xmm(struct savexmm *sv_xmm, struct save87 *sv_87)
723 {
724 	struct env87 *penv_87 = &sv_87->sv_env;
725 	struct envxmm *penv_xmm = &sv_xmm->sv_env;
726 	int i;
727 
728 	/* FPU control/status */
729 	penv_87->en_cw = penv_xmm->en_cw;
730 	penv_87->en_sw = penv_xmm->en_sw;
731 	penv_87->en_tw = penv_xmm->en_tw;
732 	penv_87->en_fip = penv_xmm->en_fip;
733 	penv_87->en_fcs = penv_xmm->en_fcs;
734 	penv_87->en_opcode = penv_xmm->en_opcode;
735 	penv_87->en_foo = penv_xmm->en_foo;
736 	penv_87->en_fos = penv_xmm->en_fos;
737 
738 	/* FPU registers */
739 	for (i = 0; i < 8; ++i)
740 		sv_87->sv_ac[i] = sv_xmm->sv_fp[i].fp_acc;
741 }
742 
743 static void
744 set_fpregs_xmm(struct save87 *sv_87, struct savexmm *sv_xmm)
745 {
746 	struct env87 *penv_87 = &sv_87->sv_env;
747 	struct envxmm *penv_xmm = &sv_xmm->sv_env;
748 	int i;
749 
750 	/* FPU control/status */
751 	penv_xmm->en_cw = penv_87->en_cw;
752 	penv_xmm->en_sw = penv_87->en_sw;
753 	penv_xmm->en_tw = penv_87->en_tw;
754 	penv_xmm->en_fip = penv_87->en_fip;
755 	penv_xmm->en_fcs = penv_87->en_fcs;
756 	penv_xmm->en_opcode = penv_87->en_opcode;
757 	penv_xmm->en_foo = penv_87->en_foo;
758 	penv_xmm->en_fos = penv_87->en_fos;
759 
760 	/* FPU registers */
761 	for (i = 0; i < 8; ++i)
762 		sv_xmm->sv_fp[i].fp_acc = sv_87->sv_ac[i];
763 }
764 
765 int
766 fill_fpregs(struct lwp *lp, struct fpreg *fpregs)
767 {
768 	if (lp->lwp_thread == NULL || lp->lwp_thread->td_pcb == NULL)
769 		return EINVAL;
770 	if (cpu_fxsr) {
771 		fill_fpregs_xmm(&lp->lwp_thread->td_pcb->pcb_save.sv_xmm,
772 				(struct save87 *)fpregs);
773 		return (0);
774 	}
775 	bcopy(&lp->lwp_thread->td_pcb->pcb_save.sv_87, fpregs, sizeof *fpregs);
776 	return (0);
777 }
778 
779 int
780 set_fpregs(struct lwp *lp, struct fpreg *fpregs)
781 {
782 	if (cpu_fxsr) {
783 		set_fpregs_xmm((struct save87 *)fpregs,
784 			       &lp->lwp_thread->td_pcb->pcb_save.sv_xmm);
785 		return (0);
786 	}
787 	bcopy(fpregs, &lp->lwp_thread->td_pcb->pcb_save.sv_87, sizeof *fpregs);
788 	return (0);
789 }
790 
791 int
792 fill_dbregs(struct lwp *lp, struct dbreg *dbregs)
793 {
794 	return (ENOSYS);
795 }
796 
797 int
798 set_dbregs(struct lwp *lp, struct dbreg *dbregs)
799 {
800 	return (ENOSYS);
801 }
802 
803 #if 0
804 /*
805  * Return > 0 if a hardware breakpoint has been hit, and the
806  * breakpoint was in user space.  Return 0, otherwise.
807  */
808 int
809 user_dbreg_trap(void)
810 {
811         u_int32_t dr7, dr6; /* debug registers dr6 and dr7 */
812         u_int32_t bp;       /* breakpoint bits extracted from dr6 */
813         int nbp;            /* number of breakpoints that triggered */
814         caddr_t addr[4];    /* breakpoint addresses */
815         int i;
816 
817         dr7 = rdr7();
818         if ((dr7 & 0x000000ff) == 0) {
819                 /*
820                  * all GE and LE bits in the dr7 register are zero,
821                  * thus the trap couldn't have been caused by the
822                  * hardware debug registers
823                  */
824                 return 0;
825         }
826 
827         nbp = 0;
828         dr6 = rdr6();
829         bp = dr6 & 0x0000000f;
830 
831         if (!bp) {
832                 /*
833                  * None of the breakpoint bits are set meaning this
834                  * trap was not caused by any of the debug registers
835                  */
836                 return 0;
837         }
838 
839         /*
840          * at least one of the breakpoints were hit, check to see
841          * which ones and if any of them are user space addresses
842          */
843 
844         if (bp & 0x01) {
845                 addr[nbp++] = (caddr_t)rdr0();
846         }
847         if (bp & 0x02) {
848                 addr[nbp++] = (caddr_t)rdr1();
849         }
850         if (bp & 0x04) {
851                 addr[nbp++] = (caddr_t)rdr2();
852         }
853         if (bp & 0x08) {
854                 addr[nbp++] = (caddr_t)rdr3();
855         }
856 
857         for (i=0; i<nbp; i++) {
858                 if (addr[i] <
859                     (caddr_t)VM_MAX_USER_ADDRESS) {
860                         /*
861                          * addr[i] is in user space
862                          */
863                         return nbp;
864                 }
865         }
866 
867         /*
868          * None of the breakpoints are in user space.
869          */
870         return 0;
871 }
872 
873 #endif
874 
875 void
876 identcpu(void)
877 {
878 	int regs[4];
879 
880 	do_cpuid(1, regs);
881 	cpu_feature = regs[3];
882 }
883 
884 
885 #ifndef DDB
886 void
887 Debugger(const char *msg)
888 {
889 	kprintf("Debugger(\"%s\") called.\n", msg);
890 }
891 #endif /* no DDB */
892