machdep.c revision 164936
1/*-
2 * Copyright (c) 2003 Peter Wemm.
3 * Copyright (c) 1992 Terrence R. Lambert.
4 * Copyright (c) 1982, 1987, 1990 The Regents of the University of California.
5 * 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 */
40
41#include <sys/cdefs.h>
42__FBSDID("$FreeBSD: head/sys/amd64/amd64/machdep.c 164936 2006-12-06 06:34:57Z julian $");
43
44#include "opt_atalk.h"
45#include "opt_atpic.h"
46#include "opt_compat.h"
47#include "opt_cpu.h"
48#include "opt_ddb.h"
49#include "opt_inet.h"
50#include "opt_ipx.h"
51#include "opt_isa.h"
52#include "opt_kstack_pages.h"
53#include "opt_maxmem.h"
54#include "opt_msgbuf.h"
55#include "opt_perfmon.h"
56
57#include <sys/param.h>
58#include <sys/proc.h>
59#include <sys/systm.h>
60#include <sys/bio.h>
61#include <sys/buf.h>
62#include <sys/bus.h>
63#include <sys/callout.h>
64#include <sys/clock.h>
65#include <sys/cons.h>
66#include <sys/cpu.h>
67#include <sys/eventhandler.h>
68#include <sys/exec.h>
69#include <sys/imgact.h>
70#include <sys/kdb.h>
71#include <sys/kernel.h>
72#include <sys/ktr.h>
73#include <sys/linker.h>
74#include <sys/lock.h>
75#include <sys/malloc.h>
76#include <sys/memrange.h>
77#include <sys/msgbuf.h>
78#include <sys/mutex.h>
79#include <sys/pcpu.h>
80#include <sys/ptrace.h>
81#include <sys/reboot.h>
82#include <sys/sched.h>
83#include <sys/signalvar.h>
84#include <sys/sysctl.h>
85#include <sys/sysent.h>
86#include <sys/sysproto.h>
87#include <sys/ucontext.h>
88#include <sys/vmmeter.h>
89
90#include <vm/vm.h>
91#include <vm/vm_extern.h>
92#include <vm/vm_kern.h>
93#include <vm/vm_page.h>
94#include <vm/vm_map.h>
95#include <vm/vm_object.h>
96#include <vm/vm_pager.h>
97#include <vm/vm_param.h>
98
99#ifdef DDB
100#ifndef KDB
101#error KDB must be enabled in order for DDB to work!
102#endif
103#endif
104#include <ddb/ddb.h>
105
106#include <net/netisr.h>
107
108#include <machine/clock.h>
109#include <machine/cpu.h>
110#include <machine/cputypes.h>
111#include <machine/intr_machdep.h>
112#include <machine/md_var.h>
113#include <machine/metadata.h>
114#include <machine/pc/bios.h>
115#include <machine/pcb.h>
116#include <machine/proc.h>
117#include <machine/reg.h>
118#include <machine/sigframe.h>
119#include <machine/specialreg.h>
120#ifdef PERFMON
121#include <machine/perfmon.h>
122#endif
123#include <machine/tss.h>
124#ifdef SMP
125#include <machine/smp.h>
126#endif
127
128#ifdef DEV_ATPIC
129#include <amd64/isa/icu.h>
130#else
131#include <machine/apicvar.h>
132#endif
133
134#include <isa/isareg.h>
135#include <isa/rtc.h>
136
137/* Sanity check for __curthread() */
138CTASSERT(offsetof(struct pcpu, pc_curthread) == 0);
139
140extern u_int64_t hammer_time(u_int64_t, u_int64_t);
141extern void dblfault_handler(void);
142
143extern void printcpuinfo(void);	/* XXX header file */
144extern void identify_cpu(void);
145extern void panicifcpuunsupported(void);
146
147#define	CS_SECURE(cs)		(ISPL(cs) == SEL_UPL)
148#define	EFL_SECURE(ef, oef)	((((ef) ^ (oef)) & ~PSL_USERCHANGE) == 0)
149
150static void cpu_startup(void *);
151static void get_fpcontext(struct thread *td, mcontext_t *mcp);
152static int  set_fpcontext(struct thread *td, const mcontext_t *mcp);
153SYSINIT(cpu, SI_SUB_CPU, SI_ORDER_FIRST, cpu_startup, NULL)
154
155#ifdef DDB
156extern vm_offset_t ksym_start, ksym_end;
157#endif
158
159int	_udatasel, _ucodesel, _ucode32sel;
160
161int cold = 1;
162
163long Maxmem = 0;
164long realmem = 0;
165
166#define PHYSMAP_SIZE	(2 * 30)
167
168vm_paddr_t phys_avail[PHYSMAP_SIZE + 2];
169vm_paddr_t dump_avail[PHYSMAP_SIZE + 2];
170
171/* must be 2 less so 0 0 can signal end of chunks */
172#define PHYS_AVAIL_ARRAY_END ((sizeof(phys_avail) / sizeof(phys_avail[0])) - 2)
173#define DUMP_AVAIL_ARRAY_END ((sizeof(dump_avail) / sizeof(dump_avail[0])) - 2)
174
175struct kva_md_info kmi;
176
177static struct trapframe proc0_tf;
178struct region_descriptor r_gdt, r_idt;
179
180struct pcpu __pcpu[MAXCPU];
181
182struct mtx icu_lock;
183
184struct mem_range_softc mem_range_softc;
185
186static void
187cpu_startup(dummy)
188	void *dummy;
189{
190	/*
191	 * Good {morning,afternoon,evening,night}.
192	 */
193	startrtclock();
194	printcpuinfo();
195	panicifcpuunsupported();
196#ifdef PERFMON
197	perfmon_init();
198#endif
199	printf("usable memory = %ju (%ju MB)\n", ptoa((uintmax_t)physmem),
200	    ptoa((uintmax_t)physmem) / 1048576);
201	realmem = Maxmem;
202	/*
203	 * Display any holes after the first chunk of extended memory.
204	 */
205	if (bootverbose) {
206		int indx;
207
208		printf("Physical memory chunk(s):\n");
209		for (indx = 0; phys_avail[indx + 1] != 0; indx += 2) {
210			vm_paddr_t size;
211
212			size = phys_avail[indx + 1] - phys_avail[indx];
213			printf(
214			    "0x%016jx - 0x%016jx, %ju bytes (%ju pages)\n",
215			    (uintmax_t)phys_avail[indx],
216			    (uintmax_t)phys_avail[indx + 1] - 1,
217			    (uintmax_t)size, (uintmax_t)size / PAGE_SIZE);
218		}
219	}
220
221	vm_ksubmap_init(&kmi);
222
223	printf("avail memory  = %ju (%ju MB)\n",
224	    ptoa((uintmax_t)cnt.v_free_count),
225	    ptoa((uintmax_t)cnt.v_free_count) / 1048576);
226
227	/*
228	 * Set up buffers, so they can be used to read disk labels.
229	 */
230	bufinit();
231	vm_pager_bufferinit();
232
233	cpu_setregs();
234}
235
236/*
237 * Send an interrupt to process.
238 *
239 * Stack is set up to allow sigcode stored
240 * at top to call routine, followed by kcall
241 * to sigreturn routine below.  After sigreturn
242 * resets the signal mask, the stack, and the
243 * frame pointer, it returns to the user
244 * specified pc, psl.
245 */
246void
247sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
248{
249	struct sigframe sf, *sfp;
250	struct proc *p;
251	struct thread *td;
252	struct sigacts *psp;
253	char *sp;
254	struct trapframe *regs;
255	int sig;
256	int oonstack;
257
258	td = curthread;
259	p = td->td_proc;
260	PROC_LOCK_ASSERT(p, MA_OWNED);
261	sig = ksi->ksi_signo;
262	psp = p->p_sigacts;
263	mtx_assert(&psp->ps_mtx, MA_OWNED);
264	regs = td->td_frame;
265	oonstack = sigonstack(regs->tf_rsp);
266
267	/* Save user context. */
268	bzero(&sf, sizeof(sf));
269	sf.sf_uc.uc_sigmask = *mask;
270	sf.sf_uc.uc_stack = td->td_sigstk;
271	sf.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK)
272	    ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE;
273	sf.sf_uc.uc_mcontext.mc_onstack = (oonstack) ? 1 : 0;
274	bcopy(regs, &sf.sf_uc.uc_mcontext.mc_rdi, sizeof(*regs));
275	sf.sf_uc.uc_mcontext.mc_len = sizeof(sf.sf_uc.uc_mcontext); /* magic */
276	get_fpcontext(td, &sf.sf_uc.uc_mcontext);
277	fpstate_drop(td);
278
279	/* Allocate space for the signal handler context. */
280	if ((td->td_pflags & TDP_ALTSTACK) != 0 && !oonstack &&
281	    SIGISMEMBER(psp->ps_sigonstack, sig)) {
282		sp = td->td_sigstk.ss_sp +
283		    td->td_sigstk.ss_size - sizeof(struct sigframe);
284#if defined(COMPAT_43)
285		td->td_sigstk.ss_flags |= SS_ONSTACK;
286#endif
287	} else
288		sp = (char *)regs->tf_rsp - sizeof(struct sigframe) - 128;
289	/* Align to 16 bytes. */
290	sfp = (struct sigframe *)((unsigned long)sp & ~0xFul);
291
292	/* Translate the signal if appropriate. */
293	if (p->p_sysent->sv_sigtbl && sig <= p->p_sysent->sv_sigsize)
294		sig = p->p_sysent->sv_sigtbl[_SIG_IDX(sig)];
295
296	/* Build the argument list for the signal handler. */
297	regs->tf_rdi = sig;			/* arg 1 in %rdi */
298	regs->tf_rdx = (register_t)&sfp->sf_uc;	/* arg 3 in %rdx */
299	if (SIGISMEMBER(psp->ps_siginfo, sig)) {
300		/* Signal handler installed with SA_SIGINFO. */
301		regs->tf_rsi = (register_t)&sfp->sf_si;	/* arg 2 in %rsi */
302		sf.sf_ahu.sf_action = (__siginfohandler_t *)catcher;
303
304		/* Fill in POSIX parts */
305		sf.sf_si = ksi->ksi_info;
306		sf.sf_si.si_signo = sig; /* maybe a translated signal */
307		regs->tf_rcx = (register_t)ksi->ksi_addr; /* arg 4 in %rcx */
308	} else {
309		/* Old FreeBSD-style arguments. */
310		regs->tf_rsi = ksi->ksi_code;	/* arg 2 in %rsi */
311		regs->tf_rcx = (register_t)ksi->ksi_addr; /* arg 4 in %rcx */
312		sf.sf_ahu.sf_handler = catcher;
313	}
314	mtx_unlock(&psp->ps_mtx);
315	PROC_UNLOCK(p);
316
317	/*
318	 * Copy the sigframe out to the user's stack.
319	 */
320	if (copyout(&sf, sfp, sizeof(*sfp)) != 0) {
321#ifdef DEBUG
322		printf("process %ld has trashed its stack\n", (long)p->p_pid);
323#endif
324		PROC_LOCK(p);
325		sigexit(td, SIGILL);
326	}
327
328	regs->tf_rsp = (long)sfp;
329	regs->tf_rip = PS_STRINGS - *(p->p_sysent->sv_szsigcode);
330	regs->tf_rflags &= ~PSL_T;
331	regs->tf_cs = _ucodesel;
332	PROC_LOCK(p);
333	mtx_lock(&psp->ps_mtx);
334}
335
336/*
337 * System call to cleanup state after a signal
338 * has been taken.  Reset signal mask and
339 * stack state from context left by sendsig (above).
340 * Return to previous pc and psl as specified by
341 * context left by sendsig. Check carefully to
342 * make sure that the user has not modified the
343 * state to gain improper privileges.
344 *
345 * MPSAFE
346 */
347int
348sigreturn(td, uap)
349	struct thread *td;
350	struct sigreturn_args /* {
351		const struct __ucontext *sigcntxp;
352	} */ *uap;
353{
354	ucontext_t uc;
355	struct proc *p = td->td_proc;
356	struct trapframe *regs;
357	const ucontext_t *ucp;
358	long rflags;
359	int cs, error, ret;
360	ksiginfo_t ksi;
361
362	error = copyin(uap->sigcntxp, &uc, sizeof(uc));
363	if (error != 0)
364		return (error);
365	ucp = &uc;
366	regs = td->td_frame;
367	rflags = ucp->uc_mcontext.mc_rflags;
368	/*
369	 * Don't allow users to change privileged or reserved flags.
370	 */
371	/*
372	 * XXX do allow users to change the privileged flag PSL_RF.
373	 * The cpu sets PSL_RF in tf_rflags for faults.  Debuggers
374	 * should sometimes set it there too.  tf_rflags is kept in
375	 * the signal context during signal handling and there is no
376	 * other place to remember it, so the PSL_RF bit may be
377	 * corrupted by the signal handler without us knowing.
378	 * Corruption of the PSL_RF bit at worst causes one more or
379	 * one less debugger trap, so allowing it is fairly harmless.
380	 */
381	if (!EFL_SECURE(rflags & ~PSL_RF, regs->tf_rflags & ~PSL_RF)) {
382		printf("sigreturn: rflags = 0x%lx\n", rflags);
383		return (EINVAL);
384	}
385
386	/*
387	 * Don't allow users to load a valid privileged %cs.  Let the
388	 * hardware check for invalid selectors, excess privilege in
389	 * other selectors, invalid %eip's and invalid %esp's.
390	 */
391	cs = ucp->uc_mcontext.mc_cs;
392	if (!CS_SECURE(cs)) {
393		printf("sigreturn: cs = 0x%x\n", cs);
394		ksiginfo_init_trap(&ksi);
395		ksi.ksi_signo = SIGBUS;
396		ksi.ksi_code = BUS_OBJERR;
397		ksi.ksi_trapno = T_PROTFLT;
398		ksi.ksi_addr = (void *)regs->tf_rip;
399		trapsignal(td, &ksi);
400		return (EINVAL);
401	}
402
403	ret = set_fpcontext(td, &ucp->uc_mcontext);
404	if (ret != 0)
405		return (ret);
406	bcopy(&ucp->uc_mcontext.mc_rdi, regs, sizeof(*regs));
407
408	PROC_LOCK(p);
409#if defined(COMPAT_43)
410	if (ucp->uc_mcontext.mc_onstack & 1)
411		td->td_sigstk.ss_flags |= SS_ONSTACK;
412	else
413		td->td_sigstk.ss_flags &= ~SS_ONSTACK;
414#endif
415
416	td->td_sigmask = ucp->uc_sigmask;
417	SIG_CANTMASK(td->td_sigmask);
418	signotify(td);
419	PROC_UNLOCK(p);
420	td->td_pcb->pcb_flags |= PCB_FULLCTX;
421	return (EJUSTRETURN);
422}
423
424#ifdef COMPAT_FREEBSD4
425int
426freebsd4_sigreturn(struct thread *td, struct freebsd4_sigreturn_args *uap)
427{
428
429	return sigreturn(td, (struct sigreturn_args *)uap);
430}
431#endif
432
433
434/*
435 * Machine dependent boot() routine
436 *
437 * I haven't seen anything to put here yet
438 * Possibly some stuff might be grafted back here from boot()
439 */
440void
441cpu_boot(int howto)
442{
443}
444
445/* Get current clock frequency for the given cpu id. */
446int
447cpu_est_clockrate(int cpu_id, uint64_t *rate)
448{
449	register_t reg;
450	uint64_t tsc1, tsc2;
451
452	if (pcpu_find(cpu_id) == NULL || rate == NULL)
453		return (EINVAL);
454
455	/* If we're booting, trust the rate calibrated moments ago. */
456	if (cold) {
457		*rate = tsc_freq;
458		return (0);
459	}
460
461#ifdef SMP
462	/* Schedule ourselves on the indicated cpu. */
463	mtx_lock_spin(&sched_lock);
464	sched_bind(curthread, cpu_id);
465	mtx_unlock_spin(&sched_lock);
466#endif
467
468	/* Calibrate by measuring a short delay. */
469	reg = intr_disable();
470	tsc1 = rdtsc();
471	DELAY(1000);
472	tsc2 = rdtsc();
473	intr_restore(reg);
474
475#ifdef SMP
476	mtx_lock_spin(&sched_lock);
477	sched_unbind(curthread);
478	mtx_unlock_spin(&sched_lock);
479#endif
480
481	/*
482	 * Calculate the difference in readings, convert to Mhz, and
483	 * subtract 0.5% of the total.  Empirical testing has shown that
484	 * overhead in DELAY() works out to approximately this value.
485	 */
486	tsc2 -= tsc1;
487	*rate = tsc2 * 1000 - tsc2 * 5;
488	return (0);
489}
490
491/*
492 * Shutdown the CPU as much as possible
493 */
494void
495cpu_halt(void)
496{
497	for (;;)
498		__asm__ ("hlt");
499}
500
501/*
502 * Hook to idle the CPU when possible.  In the SMP case we default to
503 * off because a halted cpu will not currently pick up a new thread in the
504 * run queue until the next timer tick.  If turned on this will result in
505 * approximately a 4.2% loss in real time performance in buildworld tests
506 * (but improves user and sys times oddly enough), and saves approximately
507 * 5% in power consumption on an idle machine (tests w/2xCPU 1.1GHz P3).
508 *
509 * XXX we need to have a cpu mask of idle cpus and generate an IPI or
510 * otherwise generate some sort of interrupt to wake up cpus sitting in HLT.
511 * Then we can have our cake and eat it too.
512 *
513 * XXX I'm turning it on for SMP as well by default for now.  It seems to
514 * help lock contention somewhat, and this is critical for HTT. -Peter
515 */
516static int	cpu_idle_hlt = 1;
517SYSCTL_INT(_machdep, OID_AUTO, cpu_idle_hlt, CTLFLAG_RW,
518    &cpu_idle_hlt, 0, "Idle loop HLT enable");
519
520static void
521cpu_idle_default(void)
522{
523	/*
524	 * we must absolutely guarentee that hlt is the
525	 * absolute next instruction after sti or we
526	 * introduce a timing window.
527	 */
528	__asm __volatile("sti; hlt");
529}
530
531/*
532 * Note that we have to be careful here to avoid a race between checking
533 * sched_runnable() and actually halting.  If we don't do this, we may waste
534 * the time between calling hlt and the next interrupt even though there
535 * is a runnable process.
536 */
537void
538cpu_idle(void)
539{
540
541#ifdef SMP
542	if (mp_grab_cpu_hlt())
543		return;
544#endif
545	if (cpu_idle_hlt) {
546		disable_intr();
547  		if (sched_runnable())
548			enable_intr();
549		else
550			(*cpu_idle_hook)();
551	}
552}
553
554/* Other subsystems (e.g., ACPI) can hook this later. */
555void (*cpu_idle_hook)(void) = cpu_idle_default;
556
557/*
558 * Clear registers on exec
559 */
560void
561exec_setregs(td, entry, stack, ps_strings)
562	struct thread *td;
563	u_long entry;
564	u_long stack;
565	u_long ps_strings;
566{
567	struct trapframe *regs = td->td_frame;
568	struct pcb *pcb = td->td_pcb;
569
570	critical_enter();
571	wrmsr(MSR_FSBASE, 0);
572	wrmsr(MSR_KGSBASE, 0);	/* User value while we're in the kernel */
573	pcb->pcb_fsbase = 0;
574	pcb->pcb_gsbase = 0;
575	critical_exit();
576	load_ds(_udatasel);
577	load_es(_udatasel);
578	load_fs(_udatasel);
579	load_gs(_udatasel);
580	pcb->pcb_ds = _udatasel;
581	pcb->pcb_es = _udatasel;
582	pcb->pcb_fs = _udatasel;
583	pcb->pcb_gs = _udatasel;
584
585	bzero((char *)regs, sizeof(struct trapframe));
586	regs->tf_rip = entry;
587	regs->tf_rsp = ((stack - 8) & ~0xFul) + 8;
588	regs->tf_rdi = stack;		/* argv */
589	regs->tf_rflags = PSL_USER | (regs->tf_rflags & PSL_T);
590	regs->tf_ss = _udatasel;
591	regs->tf_cs = _ucodesel;
592
593	/*
594	 * Reset the hardware debug registers if they were in use.
595	 * They won't have any meaning for the newly exec'd process.
596	 */
597	if (pcb->pcb_flags & PCB_DBREGS) {
598		pcb->pcb_dr0 = 0;
599		pcb->pcb_dr1 = 0;
600		pcb->pcb_dr2 = 0;
601		pcb->pcb_dr3 = 0;
602		pcb->pcb_dr6 = 0;
603		pcb->pcb_dr7 = 0;
604		if (pcb == PCPU_GET(curpcb)) {
605			/*
606			 * Clear the debug registers on the running
607			 * CPU, otherwise they will end up affecting
608			 * the next process we switch to.
609			 */
610			reset_dbregs();
611		}
612		pcb->pcb_flags &= ~PCB_DBREGS;
613	}
614
615	/*
616	 * Drop the FP state if we hold it, so that the process gets a
617	 * clean FP state if it uses the FPU again.
618	 */
619	fpstate_drop(td);
620}
621
622void
623cpu_setregs(void)
624{
625	register_t cr0;
626
627	cr0 = rcr0();
628	/*
629	 * CR0_MP, CR0_NE and CR0_TS are also set by npx_probe() for the
630	 * BSP.  See the comments there about why we set them.
631	 */
632	cr0 |= CR0_MP | CR0_NE | CR0_TS | CR0_WP | CR0_AM;
633	load_cr0(cr0);
634}
635
636/*
637 * Initialize amd64 and configure to run kernel
638 */
639
640/*
641 * Initialize segments & interrupt table
642 */
643
644struct user_segment_descriptor gdt[NGDT * MAXCPU];/* global descriptor table */
645static struct gate_descriptor idt0[NIDT];
646struct gate_descriptor *idt = &idt0[0];	/* interrupt descriptor table */
647
648static char dblfault_stack[PAGE_SIZE] __aligned(16);
649
650struct amd64tss common_tss[MAXCPU];
651
652/* software prototypes -- in more palatable form */
653struct soft_segment_descriptor gdt_segs[] = {
654/* GNULL_SEL	0 Null Descriptor */
655{	0x0,			/* segment base address  */
656	0x0,			/* length */
657	0,			/* segment type */
658	0,			/* segment descriptor priority level */
659	0,			/* segment descriptor present */
660	0,			/* long */
661	0,			/* default 32 vs 16 bit size */
662	0  			/* limit granularity (byte/page units)*/ },
663/* GCODE_SEL	1 Code Descriptor for kernel */
664{	0x0,			/* segment base address  */
665	0xfffff,		/* length - all address space */
666	SDT_MEMERA,		/* segment type */
667	SEL_KPL,		/* segment descriptor priority level */
668	1,			/* segment descriptor present */
669	1,			/* long */
670	0,			/* default 32 vs 16 bit size */
671	1  			/* limit granularity (byte/page units)*/ },
672/* GDATA_SEL	2 Data Descriptor for kernel */
673{	0x0,			/* segment base address  */
674	0xfffff,		/* length - all address space */
675	SDT_MEMRWA,		/* segment type */
676	SEL_KPL,		/* segment descriptor priority level */
677	1,			/* segment descriptor present */
678	1,			/* long */
679	0,			/* default 32 vs 16 bit size */
680	1  			/* limit granularity (byte/page units)*/ },
681/* GUCODE32_SEL	3 32 bit Code Descriptor for user */
682{	0x0,			/* segment base address  */
683	0xfffff,		/* length - all address space */
684	SDT_MEMERA,		/* segment type */
685	SEL_UPL,		/* segment descriptor priority level */
686	1,			/* segment descriptor present */
687	0,			/* long */
688	1,			/* default 32 vs 16 bit size */
689	1  			/* limit granularity (byte/page units)*/ },
690/* GUDATA_SEL	4 32/64 bit Data Descriptor for user */
691{	0x0,			/* segment base address  */
692	0xfffff,		/* length - all address space */
693	SDT_MEMRWA,		/* segment type */
694	SEL_UPL,		/* segment descriptor priority level */
695	1,			/* segment descriptor present */
696	0,			/* long */
697	1,			/* default 32 vs 16 bit size */
698	1  			/* limit granularity (byte/page units)*/ },
699/* GUCODE_SEL	5 64 bit Code Descriptor for user */
700{	0x0,			/* segment base address  */
701	0xfffff,		/* length - all address space */
702	SDT_MEMERA,		/* segment type */
703	SEL_UPL,		/* segment descriptor priority level */
704	1,			/* segment descriptor present */
705	1,			/* long */
706	0,			/* default 32 vs 16 bit size */
707	1  			/* limit granularity (byte/page units)*/ },
708/* GPROC0_SEL	6 Proc 0 Tss Descriptor */
709{
710	0x0,			/* segment base address */
711	sizeof(struct amd64tss)-1,/* length - all address space */
712	SDT_SYSTSS,		/* segment type */
713	SEL_KPL,		/* segment descriptor priority level */
714	1,			/* segment descriptor present */
715	0,			/* long */
716	0,			/* unused - default 32 vs 16 bit size */
717	0  			/* limit granularity (byte/page units)*/ },
718/* Actually, the TSS is a system descriptor which is double size */
719{	0x0,			/* segment base address  */
720	0x0,			/* length */
721	0,			/* segment type */
722	0,			/* segment descriptor priority level */
723	0,			/* segment descriptor present */
724	0,			/* long */
725	0,			/* default 32 vs 16 bit size */
726	0  			/* limit granularity (byte/page units)*/ },
727};
728
729void
730setidt(idx, func, typ, dpl, ist)
731	int idx;
732	inthand_t *func;
733	int typ;
734	int dpl;
735	int ist;
736{
737	struct gate_descriptor *ip;
738
739	ip = idt + idx;
740	ip->gd_looffset = (uintptr_t)func;
741	ip->gd_selector = GSEL(GCODE_SEL, SEL_KPL);
742	ip->gd_ist = ist;
743	ip->gd_xx = 0;
744	ip->gd_type = typ;
745	ip->gd_dpl = dpl;
746	ip->gd_p = 1;
747	ip->gd_hioffset = ((uintptr_t)func)>>16 ;
748}
749
750extern inthand_t
751	IDTVEC(div), IDTVEC(dbg), IDTVEC(nmi), IDTVEC(bpt), IDTVEC(ofl),
752	IDTVEC(bnd), IDTVEC(ill), IDTVEC(dna), IDTVEC(fpusegm),
753	IDTVEC(tss), IDTVEC(missing), IDTVEC(stk), IDTVEC(prot),
754	IDTVEC(page), IDTVEC(mchk), IDTVEC(rsvd), IDTVEC(fpu), IDTVEC(align),
755	IDTVEC(xmm), IDTVEC(dblfault),
756	IDTVEC(fast_syscall), IDTVEC(fast_syscall32);
757
758void
759sdtossd(sd, ssd)
760	struct user_segment_descriptor *sd;
761	struct soft_segment_descriptor *ssd;
762{
763
764	ssd->ssd_base  = (sd->sd_hibase << 24) | sd->sd_lobase;
765	ssd->ssd_limit = (sd->sd_hilimit << 16) | sd->sd_lolimit;
766	ssd->ssd_type  = sd->sd_type;
767	ssd->ssd_dpl   = sd->sd_dpl;
768	ssd->ssd_p     = sd->sd_p;
769	ssd->ssd_long  = sd->sd_long;
770	ssd->ssd_def32 = sd->sd_def32;
771	ssd->ssd_gran  = sd->sd_gran;
772}
773
774void
775ssdtosd(ssd, sd)
776	struct soft_segment_descriptor *ssd;
777	struct user_segment_descriptor *sd;
778{
779
780	sd->sd_lobase = (ssd->ssd_base) & 0xffffff;
781	sd->sd_hibase = (ssd->ssd_base >> 24) & 0xff;
782	sd->sd_lolimit = (ssd->ssd_limit) & 0xffff;
783	sd->sd_hilimit = (ssd->ssd_limit >> 16) & 0xf;
784	sd->sd_type  = ssd->ssd_type;
785	sd->sd_dpl   = ssd->ssd_dpl;
786	sd->sd_p     = ssd->ssd_p;
787	sd->sd_long  = ssd->ssd_long;
788	sd->sd_def32 = ssd->ssd_def32;
789	sd->sd_gran  = ssd->ssd_gran;
790}
791
792void
793ssdtosyssd(ssd, sd)
794	struct soft_segment_descriptor *ssd;
795	struct system_segment_descriptor *sd;
796{
797
798	sd->sd_lobase = (ssd->ssd_base) & 0xffffff;
799	sd->sd_hibase = (ssd->ssd_base >> 24) & 0xfffffffffful;
800	sd->sd_lolimit = (ssd->ssd_limit) & 0xffff;
801	sd->sd_hilimit = (ssd->ssd_limit >> 16) & 0xf;
802	sd->sd_type  = ssd->ssd_type;
803	sd->sd_dpl   = ssd->ssd_dpl;
804	sd->sd_p     = ssd->ssd_p;
805	sd->sd_gran  = ssd->ssd_gran;
806}
807
808#if !defined(DEV_ATPIC) && defined(DEV_ISA)
809#include <isa/isavar.h>
810u_int
811isa_irq_pending(void)
812{
813
814	return (0);
815}
816#endif
817
818u_int basemem;
819
820/*
821 * Populate the (physmap) array with base/bound pairs describing the
822 * available physical memory in the system, then test this memory and
823 * build the phys_avail array describing the actually-available memory.
824 *
825 * If we cannot accurately determine the physical memory map, then use
826 * value from the 0xE801 call, and failing that, the RTC.
827 *
828 * Total memory size may be set by the kernel environment variable
829 * hw.physmem or the compile-time define MAXMEM.
830 *
831 * XXX first should be vm_paddr_t.
832 */
833static void
834getmemsize(caddr_t kmdp, u_int64_t first)
835{
836	int i, off, physmap_idx, pa_indx, da_indx;
837	vm_paddr_t pa, physmap[PHYSMAP_SIZE];
838	u_long physmem_tunable;
839	pt_entry_t *pte;
840	struct bios_smap *smapbase, *smap, *smapend;
841	u_int32_t smapsize;
842	quad_t dcons_addr, dcons_size;
843
844	bzero(physmap, sizeof(physmap));
845	basemem = 0;
846	physmap_idx = 0;
847
848	/*
849	 * get memory map from INT 15:E820, kindly supplied by the loader.
850	 *
851	 * subr_module.c says:
852	 * "Consumer may safely assume that size value precedes data."
853	 * ie: an int32_t immediately precedes smap.
854	 */
855	smapbase = (struct bios_smap *)preload_search_info(kmdp,
856	    MODINFO_METADATA | MODINFOMD_SMAP);
857	if (smapbase == NULL)
858		panic("No BIOS smap info from loader!");
859
860	smapsize = *((u_int32_t *)smapbase - 1);
861	smapend = (struct bios_smap *)((uintptr_t)smapbase + smapsize);
862
863	for (smap = smapbase; smap < smapend; smap++) {
864		if (boothowto & RB_VERBOSE)
865			printf("SMAP type=%02x base=%016lx len=%016lx\n",
866			    smap->type, smap->base, smap->length);
867
868		if (smap->type != 0x01)
869			continue;
870
871		if (smap->length == 0)
872			continue;
873
874		for (i = 0; i <= physmap_idx; i += 2) {
875			if (smap->base < physmap[i + 1]) {
876				if (boothowto & RB_VERBOSE)
877					printf(
878	"Overlapping or non-monotonic memory region, ignoring second region\n");
879				continue;
880			}
881		}
882
883		if (smap->base == physmap[physmap_idx + 1]) {
884			physmap[physmap_idx + 1] += smap->length;
885			continue;
886		}
887
888		physmap_idx += 2;
889		if (physmap_idx == PHYSMAP_SIZE) {
890			printf(
891		"Too many segments in the physical address map, giving up\n");
892			break;
893		}
894		physmap[physmap_idx] = smap->base;
895		physmap[physmap_idx + 1] = smap->base + smap->length;
896	}
897
898	/*
899	 * Find the 'base memory' segment for SMP
900	 */
901	basemem = 0;
902	for (i = 0; i <= physmap_idx; i += 2) {
903		if (physmap[i] == 0x00000000) {
904			basemem = physmap[i + 1] / 1024;
905			break;
906		}
907	}
908	if (basemem == 0)
909		panic("BIOS smap did not include a basemem segment!");
910
911#ifdef SMP
912	/* make hole for AP bootstrap code */
913	physmap[1] = mp_bootaddress(physmap[1] / 1024);
914#endif
915
916	/*
917	 * Maxmem isn't the "maximum memory", it's one larger than the
918	 * highest page of the physical address space.  It should be
919	 * called something like "Maxphyspage".  We may adjust this
920	 * based on ``hw.physmem'' and the results of the memory test.
921	 */
922	Maxmem = atop(physmap[physmap_idx + 1]);
923
924#ifdef MAXMEM
925	Maxmem = MAXMEM / 4;
926#endif
927
928	if (TUNABLE_ULONG_FETCH("hw.physmem", &physmem_tunable))
929		Maxmem = atop(physmem_tunable);
930
931	/*
932	 * Don't allow MAXMEM or hw.physmem to extend the amount of memory
933	 * in the system.
934	 */
935	if (Maxmem > atop(physmap[physmap_idx + 1]))
936		Maxmem = atop(physmap[physmap_idx + 1]);
937
938	if (atop(physmap[physmap_idx + 1]) != Maxmem &&
939	    (boothowto & RB_VERBOSE))
940		printf("Physical memory use set to %ldK\n", Maxmem * 4);
941
942	/* call pmap initialization to make new kernel address space */
943	pmap_bootstrap(&first);
944
945	/*
946	 * Size up each available chunk of physical memory.
947	 */
948	physmap[0] = PAGE_SIZE;		/* mask off page 0 */
949	pa_indx = 0;
950	da_indx = 1;
951	phys_avail[pa_indx++] = physmap[0];
952	phys_avail[pa_indx] = physmap[0];
953	dump_avail[da_indx] = physmap[0];
954	pte = CMAP1;
955
956	/*
957	 * Get dcons buffer address
958	 */
959	if (getenv_quad("dcons.addr", &dcons_addr) == 0 ||
960	    getenv_quad("dcons.size", &dcons_size) == 0)
961		dcons_addr = 0;
962
963	/*
964	 * physmap is in bytes, so when converting to page boundaries,
965	 * round up the start address and round down the end address.
966	 */
967	for (i = 0; i <= physmap_idx; i += 2) {
968		vm_paddr_t end;
969
970		end = ptoa((vm_paddr_t)Maxmem);
971		if (physmap[i + 1] < end)
972			end = trunc_page(physmap[i + 1]);
973		for (pa = round_page(physmap[i]); pa < end; pa += PAGE_SIZE) {
974			int tmp, page_bad, full;
975			int *ptr = (int *)CADDR1;
976
977			full = FALSE;
978			/*
979			 * block out kernel memory as not available.
980			 */
981			if (pa >= 0x100000 && pa < first)
982				goto do_dump_avail;
983
984			/*
985			 * block out dcons buffer
986			 */
987			if (dcons_addr > 0
988			    && pa >= trunc_page(dcons_addr)
989			    && pa < dcons_addr + dcons_size)
990				goto do_dump_avail;
991
992			page_bad = FALSE;
993
994			/*
995			 * map page into kernel: valid, read/write,non-cacheable
996			 */
997			*pte = pa | PG_V | PG_RW | PG_N;
998			invltlb();
999
1000			tmp = *(int *)ptr;
1001			/*
1002			 * Test for alternating 1's and 0's
1003			 */
1004			*(volatile int *)ptr = 0xaaaaaaaa;
1005			if (*(volatile int *)ptr != 0xaaaaaaaa)
1006				page_bad = TRUE;
1007			/*
1008			 * Test for alternating 0's and 1's
1009			 */
1010			*(volatile int *)ptr = 0x55555555;
1011			if (*(volatile int *)ptr != 0x55555555)
1012				page_bad = TRUE;
1013			/*
1014			 * Test for all 1's
1015			 */
1016			*(volatile int *)ptr = 0xffffffff;
1017			if (*(volatile int *)ptr != 0xffffffff)
1018				page_bad = TRUE;
1019			/*
1020			 * Test for all 0's
1021			 */
1022			*(volatile int *)ptr = 0x0;
1023			if (*(volatile int *)ptr != 0x0)
1024				page_bad = TRUE;
1025			/*
1026			 * Restore original value.
1027			 */
1028			*(int *)ptr = tmp;
1029
1030			/*
1031			 * Adjust array of valid/good pages.
1032			 */
1033			if (page_bad == TRUE)
1034				continue;
1035			/*
1036			 * If this good page is a continuation of the
1037			 * previous set of good pages, then just increase
1038			 * the end pointer. Otherwise start a new chunk.
1039			 * Note that "end" points one higher than end,
1040			 * making the range >= start and < end.
1041			 * If we're also doing a speculative memory
1042			 * test and we at or past the end, bump up Maxmem
1043			 * so that we keep going. The first bad page
1044			 * will terminate the loop.
1045			 */
1046			if (phys_avail[pa_indx] == pa) {
1047				phys_avail[pa_indx] += PAGE_SIZE;
1048			} else {
1049				pa_indx++;
1050				if (pa_indx == PHYS_AVAIL_ARRAY_END) {
1051					printf(
1052		"Too many holes in the physical address space, giving up\n");
1053					pa_indx--;
1054					full = TRUE;
1055					goto do_dump_avail;
1056				}
1057				phys_avail[pa_indx++] = pa;	/* start */
1058				phys_avail[pa_indx] = pa + PAGE_SIZE; /* end */
1059			}
1060			physmem++;
1061do_dump_avail:
1062			if (dump_avail[da_indx] == pa) {
1063				dump_avail[da_indx] += PAGE_SIZE;
1064			} else {
1065				da_indx++;
1066				if (da_indx == DUMP_AVAIL_ARRAY_END) {
1067					da_indx--;
1068					goto do_next;
1069				}
1070				dump_avail[da_indx++] = pa; /* start */
1071				dump_avail[da_indx] = pa + PAGE_SIZE; /* end */
1072			}
1073do_next:
1074			if (full)
1075				break;
1076		}
1077	}
1078	*pte = 0;
1079	invltlb();
1080
1081	/*
1082	 * XXX
1083	 * The last chunk must contain at least one page plus the message
1084	 * buffer to avoid complicating other code (message buffer address
1085	 * calculation, etc.).
1086	 */
1087	while (phys_avail[pa_indx - 1] + PAGE_SIZE +
1088	    round_page(MSGBUF_SIZE) >= phys_avail[pa_indx]) {
1089		physmem -= atop(phys_avail[pa_indx] - phys_avail[pa_indx - 1]);
1090		phys_avail[pa_indx--] = 0;
1091		phys_avail[pa_indx--] = 0;
1092	}
1093
1094	Maxmem = atop(phys_avail[pa_indx]);
1095
1096	/* Trim off space for the message buffer. */
1097	phys_avail[pa_indx] -= round_page(MSGBUF_SIZE);
1098
1099	/* Map the message buffer. */
1100	for (off = 0; off < round_page(MSGBUF_SIZE); off += PAGE_SIZE)
1101		pmap_kenter((vm_offset_t)msgbufp + off, phys_avail[pa_indx] +
1102		    off);
1103}
1104
1105u_int64_t
1106hammer_time(u_int64_t modulep, u_int64_t physfree)
1107{
1108	caddr_t kmdp;
1109	int gsel_tss, x;
1110	struct pcpu *pc;
1111	u_int64_t msr;
1112	char *env;
1113
1114	thread0.td_kstack = physfree + KERNBASE;
1115	bzero((void *)thread0.td_kstack, KSTACK_PAGES * PAGE_SIZE);
1116	physfree += KSTACK_PAGES * PAGE_SIZE;
1117	thread0.td_pcb = (struct pcb *)
1118	   (thread0.td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
1119
1120	/*
1121 	 * This may be done better later if it gets more high level
1122 	 * components in it. If so just link td->td_proc here.
1123	 */
1124	proc_linkup(&proc0, &thread0);
1125
1126	preload_metadata = (caddr_t)(uintptr_t)(modulep + KERNBASE);
1127	preload_bootstrap_relocate(KERNBASE);
1128	kmdp = preload_search_by_type("elf kernel");
1129	if (kmdp == NULL)
1130		kmdp = preload_search_by_type("elf64 kernel");
1131	boothowto = MD_FETCH(kmdp, MODINFOMD_HOWTO, int);
1132	kern_envp = MD_FETCH(kmdp, MODINFOMD_ENVP, char *) + KERNBASE;
1133#ifdef DDB
1134	ksym_start = MD_FETCH(kmdp, MODINFOMD_SSYM, uintptr_t);
1135	ksym_end = MD_FETCH(kmdp, MODINFOMD_ESYM, uintptr_t);
1136#endif
1137
1138	/* Init basic tunables, hz etc */
1139	init_param1();
1140
1141	/*
1142	 * make gdt memory segments
1143	 */
1144	gdt_segs[GPROC0_SEL].ssd_base = (uintptr_t)&common_tss[0];
1145
1146	for (x = 0; x < NGDT; x++) {
1147		if (x != GPROC0_SEL && x != (GPROC0_SEL + 1))
1148			ssdtosd(&gdt_segs[x], &gdt[x]);
1149	}
1150	ssdtosyssd(&gdt_segs[GPROC0_SEL],
1151	    (struct system_segment_descriptor *)&gdt[GPROC0_SEL]);
1152
1153	r_gdt.rd_limit = NGDT * sizeof(gdt[0]) - 1;
1154	r_gdt.rd_base =  (long) gdt;
1155	lgdt(&r_gdt);
1156	pc = &__pcpu[0];
1157
1158	wrmsr(MSR_FSBASE, 0);		/* User value */
1159	wrmsr(MSR_GSBASE, (u_int64_t)pc);
1160	wrmsr(MSR_KGSBASE, 0);		/* User value while in the kernel */
1161
1162	pcpu_init(pc, 0, sizeof(struct pcpu));
1163	PCPU_SET(prvspace, pc);
1164	PCPU_SET(curthread, &thread0);
1165	PCPU_SET(curpcb, thread0.td_pcb);
1166	PCPU_SET(tssp, &common_tss[0]);
1167
1168	/*
1169	 * Initialize mutexes.
1170	 *
1171	 * icu_lock: in order to allow an interrupt to occur in a critical
1172	 * 	     section, to set pcpu->ipending (etc...) properly, we
1173	 *	     must be able to get the icu lock, so it can't be
1174	 *	     under witness.
1175	 */
1176	mutex_init();
1177	mtx_init(&clock_lock, "clk", NULL, MTX_SPIN);
1178	mtx_init(&icu_lock, "icu", NULL, MTX_SPIN | MTX_NOWITNESS);
1179
1180	/* exceptions */
1181	for (x = 0; x < NIDT; x++)
1182		setidt(x, &IDTVEC(rsvd), SDT_SYSIGT, SEL_KPL, 0);
1183	setidt(IDT_DE, &IDTVEC(div),  SDT_SYSIGT, SEL_KPL, 0);
1184	setidt(IDT_DB, &IDTVEC(dbg),  SDT_SYSIGT, SEL_KPL, 0);
1185	setidt(IDT_NMI, &IDTVEC(nmi),  SDT_SYSIGT, SEL_KPL, 0);
1186 	setidt(IDT_BP, &IDTVEC(bpt),  SDT_SYSIGT, SEL_UPL, 0);
1187	setidt(IDT_OF, &IDTVEC(ofl),  SDT_SYSIGT, SEL_KPL, 0);
1188	setidt(IDT_BR, &IDTVEC(bnd),  SDT_SYSIGT, SEL_KPL, 0);
1189	setidt(IDT_UD, &IDTVEC(ill),  SDT_SYSIGT, SEL_KPL, 0);
1190	setidt(IDT_NM, &IDTVEC(dna),  SDT_SYSIGT, SEL_KPL, 0);
1191	setidt(IDT_DF, &IDTVEC(dblfault), SDT_SYSIGT, SEL_KPL, 1);
1192	setidt(IDT_FPUGP, &IDTVEC(fpusegm),  SDT_SYSIGT, SEL_KPL, 0);
1193	setidt(IDT_TS, &IDTVEC(tss),  SDT_SYSIGT, SEL_KPL, 0);
1194	setidt(IDT_NP, &IDTVEC(missing),  SDT_SYSIGT, SEL_KPL, 0);
1195	setidt(IDT_SS, &IDTVEC(stk),  SDT_SYSIGT, SEL_KPL, 0);
1196	setidt(IDT_GP, &IDTVEC(prot),  SDT_SYSIGT, SEL_KPL, 0);
1197	setidt(IDT_PF, &IDTVEC(page),  SDT_SYSIGT, SEL_KPL, 0);
1198	setidt(IDT_MF, &IDTVEC(fpu),  SDT_SYSIGT, SEL_KPL, 0);
1199	setidt(IDT_AC, &IDTVEC(align), SDT_SYSIGT, SEL_KPL, 0);
1200	setidt(IDT_MC, &IDTVEC(mchk),  SDT_SYSIGT, SEL_KPL, 0);
1201	setidt(IDT_XF, &IDTVEC(xmm), SDT_SYSIGT, SEL_KPL, 0);
1202
1203	r_idt.rd_limit = sizeof(idt0) - 1;
1204	r_idt.rd_base = (long) idt;
1205	lidt(&r_idt);
1206
1207	/*
1208	 * Initialize the console before we print anything out.
1209	 */
1210	cninit();
1211
1212#ifdef DEV_ISA
1213#ifdef DEV_ATPIC
1214	elcr_probe();
1215	atpic_startup();
1216#else
1217	/* Reset and mask the atpics and leave them shut down. */
1218	atpic_reset();
1219
1220	/*
1221	 * Point the ICU spurious interrupt vectors at the APIC spurious
1222	 * interrupt handler.
1223	 */
1224	setidt(IDT_IO_INTS + 7, IDTVEC(spuriousint), SDT_SYSIGT, SEL_KPL, 0);
1225	setidt(IDT_IO_INTS + 15, IDTVEC(spuriousint), SDT_SYSIGT, SEL_KPL, 0);
1226#endif
1227#else
1228#error "have you forgotten the isa device?";
1229#endif
1230
1231	kdb_init();
1232
1233#ifdef KDB
1234	if (boothowto & RB_KDB)
1235		kdb_enter("Boot flags requested debugger");
1236#endif
1237
1238	identify_cpu();		/* Final stage of CPU initialization */
1239	initializecpu();	/* Initialize CPU registers */
1240
1241	/* make an initial tss so cpu can get interrupt stack on syscall! */
1242	common_tss[0].tss_rsp0 = thread0.td_kstack + \
1243	    KSTACK_PAGES * PAGE_SIZE - sizeof(struct pcb);
1244	/* Ensure the stack is aligned to 16 bytes */
1245	common_tss[0].tss_rsp0 &= ~0xFul;
1246	PCPU_SET(rsp0, common_tss[0].tss_rsp0);
1247
1248	/* doublefault stack space, runs on ist1 */
1249	common_tss[0].tss_ist1 = (long)&dblfault_stack[sizeof(dblfault_stack)];
1250
1251	/* Set the IO permission bitmap (empty due to tss seg limit) */
1252	common_tss[0].tss_iobase = sizeof(struct amd64tss);
1253
1254	gsel_tss = GSEL(GPROC0_SEL, SEL_KPL);
1255	ltr(gsel_tss);
1256
1257	/* Set up the fast syscall stuff */
1258	msr = rdmsr(MSR_EFER) | EFER_SCE;
1259	wrmsr(MSR_EFER, msr);
1260	wrmsr(MSR_LSTAR, (u_int64_t)IDTVEC(fast_syscall));
1261	wrmsr(MSR_CSTAR, (u_int64_t)IDTVEC(fast_syscall32));
1262	msr = ((u_int64_t)GSEL(GCODE_SEL, SEL_KPL) << 32) |
1263	      ((u_int64_t)GSEL(GUCODE32_SEL, SEL_UPL) << 48);
1264	wrmsr(MSR_STAR, msr);
1265	wrmsr(MSR_SF_MASK, PSL_NT|PSL_T|PSL_I|PSL_C|PSL_D);
1266
1267	getmemsize(kmdp, physfree);
1268	init_param2(physmem);
1269
1270	/* now running on new page tables, configured,and u/iom is accessible */
1271
1272	msgbufinit(msgbufp, MSGBUF_SIZE);
1273	fpuinit();
1274
1275	/* transfer to user mode */
1276
1277	_ucodesel = GSEL(GUCODE_SEL, SEL_UPL);
1278	_udatasel = GSEL(GUDATA_SEL, SEL_UPL);
1279	_ucode32sel = GSEL(GUCODE32_SEL, SEL_UPL);
1280
1281	/* setup proc 0's pcb */
1282	thread0.td_pcb->pcb_flags = 0; /* XXXKSE */
1283	thread0.td_pcb->pcb_cr3 = KPML4phys;
1284	thread0.td_frame = &proc0_tf;
1285
1286        env = getenv("kernelname");
1287	if (env != NULL)
1288		strlcpy(kernelname, env, sizeof(kernelname));
1289
1290	/* Location of kernel stack for locore */
1291	return ((u_int64_t)thread0.td_pcb);
1292}
1293
1294void
1295cpu_pcpu_init(struct pcpu *pcpu, int cpuid, size_t size)
1296{
1297
1298	pcpu->pc_acpi_id = 0xffffffff;
1299}
1300
1301void
1302spinlock_enter(void)
1303{
1304	struct thread *td;
1305
1306	td = curthread;
1307	if (td->td_md.md_spinlock_count == 0)
1308		td->td_md.md_saved_flags = intr_disable();
1309	td->td_md.md_spinlock_count++;
1310	critical_enter();
1311}
1312
1313void
1314spinlock_exit(void)
1315{
1316	struct thread *td;
1317
1318	td = curthread;
1319	critical_exit();
1320	td->td_md.md_spinlock_count--;
1321	if (td->td_md.md_spinlock_count == 0)
1322		intr_restore(td->td_md.md_saved_flags);
1323}
1324
1325/*
1326 * Construct a PCB from a trapframe. This is called from kdb_trap() where
1327 * we want to start a backtrace from the function that caused us to enter
1328 * the debugger. We have the context in the trapframe, but base the trace
1329 * on the PCB. The PCB doesn't have to be perfect, as long as it contains
1330 * enough for a backtrace.
1331 */
1332void
1333makectx(struct trapframe *tf, struct pcb *pcb)
1334{
1335
1336	pcb->pcb_r12 = tf->tf_r12;
1337	pcb->pcb_r13 = tf->tf_r13;
1338	pcb->pcb_r14 = tf->tf_r14;
1339	pcb->pcb_r15 = tf->tf_r15;
1340	pcb->pcb_rbp = tf->tf_rbp;
1341	pcb->pcb_rbx = tf->tf_rbx;
1342	pcb->pcb_rip = tf->tf_rip;
1343	pcb->pcb_rsp = (ISPL(tf->tf_cs)) ? tf->tf_rsp : (long)(tf + 1) - 8;
1344}
1345
1346int
1347ptrace_set_pc(struct thread *td, unsigned long addr)
1348{
1349	td->td_frame->tf_rip = addr;
1350	return (0);
1351}
1352
1353int
1354ptrace_single_step(struct thread *td)
1355{
1356	td->td_frame->tf_rflags |= PSL_T;
1357	return (0);
1358}
1359
1360int
1361ptrace_clear_single_step(struct thread *td)
1362{
1363	td->td_frame->tf_rflags &= ~PSL_T;
1364	return (0);
1365}
1366
1367int
1368fill_regs(struct thread *td, struct reg *regs)
1369{
1370	struct trapframe *tp;
1371
1372	tp = td->td_frame;
1373	regs->r_r15 = tp->tf_r15;
1374	regs->r_r14 = tp->tf_r14;
1375	regs->r_r13 = tp->tf_r13;
1376	regs->r_r12 = tp->tf_r12;
1377	regs->r_r11 = tp->tf_r11;
1378	regs->r_r10 = tp->tf_r10;
1379	regs->r_r9  = tp->tf_r9;
1380	regs->r_r8  = tp->tf_r8;
1381	regs->r_rdi = tp->tf_rdi;
1382	regs->r_rsi = tp->tf_rsi;
1383	regs->r_rbp = tp->tf_rbp;
1384	regs->r_rbx = tp->tf_rbx;
1385	regs->r_rdx = tp->tf_rdx;
1386	regs->r_rcx = tp->tf_rcx;
1387	regs->r_rax = tp->tf_rax;
1388	regs->r_rip = tp->tf_rip;
1389	regs->r_cs = tp->tf_cs;
1390	regs->r_rflags = tp->tf_rflags;
1391	regs->r_rsp = tp->tf_rsp;
1392	regs->r_ss = tp->tf_ss;
1393	return (0);
1394}
1395
1396int
1397set_regs(struct thread *td, struct reg *regs)
1398{
1399	struct trapframe *tp;
1400	register_t rflags;
1401
1402	tp = td->td_frame;
1403	rflags = regs->r_rflags & 0xffffffff;
1404	if (!EFL_SECURE(rflags, tp->tf_rflags) || !CS_SECURE(regs->r_cs))
1405		return (EINVAL);
1406	tp->tf_r15 = regs->r_r15;
1407	tp->tf_r14 = regs->r_r14;
1408	tp->tf_r13 = regs->r_r13;
1409	tp->tf_r12 = regs->r_r12;
1410	tp->tf_r11 = regs->r_r11;
1411	tp->tf_r10 = regs->r_r10;
1412	tp->tf_r9  = regs->r_r9;
1413	tp->tf_r8  = regs->r_r8;
1414	tp->tf_rdi = regs->r_rdi;
1415	tp->tf_rsi = regs->r_rsi;
1416	tp->tf_rbp = regs->r_rbp;
1417	tp->tf_rbx = regs->r_rbx;
1418	tp->tf_rdx = regs->r_rdx;
1419	tp->tf_rcx = regs->r_rcx;
1420	tp->tf_rax = regs->r_rax;
1421	tp->tf_rip = regs->r_rip;
1422	tp->tf_cs = regs->r_cs;
1423	tp->tf_rflags = rflags;
1424	tp->tf_rsp = regs->r_rsp;
1425	tp->tf_ss = regs->r_ss;
1426	td->td_pcb->pcb_flags |= PCB_FULLCTX;
1427	return (0);
1428}
1429
1430/* XXX check all this stuff! */
1431/* externalize from sv_xmm */
1432static void
1433fill_fpregs_xmm(struct savefpu *sv_xmm, struct fpreg *fpregs)
1434{
1435	struct envxmm *penv_fpreg = (struct envxmm *)&fpregs->fpr_env;
1436	struct envxmm *penv_xmm = &sv_xmm->sv_env;
1437	int i;
1438
1439	/* pcb -> fpregs */
1440	bzero(fpregs, sizeof(*fpregs));
1441
1442	/* FPU control/status */
1443	penv_fpreg->en_cw = penv_xmm->en_cw;
1444	penv_fpreg->en_sw = penv_xmm->en_sw;
1445	penv_fpreg->en_tw = penv_xmm->en_tw;
1446	penv_fpreg->en_opcode = penv_xmm->en_opcode;
1447	penv_fpreg->en_rip = penv_xmm->en_rip;
1448	penv_fpreg->en_rdp = penv_xmm->en_rdp;
1449	penv_fpreg->en_mxcsr = penv_xmm->en_mxcsr;
1450	penv_fpreg->en_mxcsr_mask = penv_xmm->en_mxcsr_mask;
1451
1452	/* FPU registers */
1453	for (i = 0; i < 8; ++i)
1454		bcopy(sv_xmm->sv_fp[i].fp_acc.fp_bytes, fpregs->fpr_acc[i], 10);
1455
1456	/* SSE registers */
1457	for (i = 0; i < 16; ++i)
1458		bcopy(sv_xmm->sv_xmm[i].xmm_bytes, fpregs->fpr_xacc[i], 16);
1459}
1460
1461/* internalize from fpregs into sv_xmm */
1462static void
1463set_fpregs_xmm(struct fpreg *fpregs, struct savefpu *sv_xmm)
1464{
1465	struct envxmm *penv_xmm = &sv_xmm->sv_env;
1466	struct envxmm *penv_fpreg = (struct envxmm *)&fpregs->fpr_env;
1467	int i;
1468
1469	/* fpregs -> pcb */
1470	/* FPU control/status */
1471	penv_xmm->en_cw = penv_fpreg->en_cw;
1472	penv_xmm->en_sw = penv_fpreg->en_sw;
1473	penv_xmm->en_tw = penv_fpreg->en_tw;
1474	penv_xmm->en_opcode = penv_fpreg->en_opcode;
1475	penv_xmm->en_rip = penv_fpreg->en_rip;
1476	penv_xmm->en_rdp = penv_fpreg->en_rdp;
1477	penv_xmm->en_mxcsr = penv_fpreg->en_mxcsr;
1478	penv_xmm->en_mxcsr_mask = penv_fpreg->en_mxcsr_mask & cpu_mxcsr_mask;
1479
1480	/* FPU registers */
1481	for (i = 0; i < 8; ++i)
1482		bcopy(fpregs->fpr_acc[i], sv_xmm->sv_fp[i].fp_acc.fp_bytes, 10);
1483
1484	/* SSE registers */
1485	for (i = 0; i < 16; ++i)
1486		bcopy(fpregs->fpr_xacc[i], sv_xmm->sv_xmm[i].xmm_bytes, 16);
1487}
1488
1489/* externalize from td->pcb */
1490int
1491fill_fpregs(struct thread *td, struct fpreg *fpregs)
1492{
1493
1494	fill_fpregs_xmm(&td->td_pcb->pcb_save, fpregs);
1495	return (0);
1496}
1497
1498/* internalize to td->pcb */
1499int
1500set_fpregs(struct thread *td, struct fpreg *fpregs)
1501{
1502
1503	set_fpregs_xmm(fpregs, &td->td_pcb->pcb_save);
1504	return (0);
1505}
1506
1507/*
1508 * Get machine context.
1509 */
1510int
1511get_mcontext(struct thread *td, mcontext_t *mcp, int flags)
1512{
1513	struct trapframe *tp;
1514
1515	tp = td->td_frame;
1516	PROC_LOCK(curthread->td_proc);
1517	mcp->mc_onstack = sigonstack(tp->tf_rsp);
1518	PROC_UNLOCK(curthread->td_proc);
1519	mcp->mc_r15 = tp->tf_r15;
1520	mcp->mc_r14 = tp->tf_r14;
1521	mcp->mc_r13 = tp->tf_r13;
1522	mcp->mc_r12 = tp->tf_r12;
1523	mcp->mc_r11 = tp->tf_r11;
1524	mcp->mc_r10 = tp->tf_r10;
1525	mcp->mc_r9  = tp->tf_r9;
1526	mcp->mc_r8  = tp->tf_r8;
1527	mcp->mc_rdi = tp->tf_rdi;
1528	mcp->mc_rsi = tp->tf_rsi;
1529	mcp->mc_rbp = tp->tf_rbp;
1530	mcp->mc_rbx = tp->tf_rbx;
1531	mcp->mc_rcx = tp->tf_rcx;
1532	mcp->mc_rflags = tp->tf_rflags;
1533	if (flags & GET_MC_CLEAR_RET) {
1534		mcp->mc_rax = 0;
1535		mcp->mc_rdx = 0;
1536		mcp->mc_rflags &= ~PSL_C;
1537	} else {
1538		mcp->mc_rax = tp->tf_rax;
1539		mcp->mc_rdx = tp->tf_rdx;
1540	}
1541	mcp->mc_rip = tp->tf_rip;
1542	mcp->mc_cs = tp->tf_cs;
1543	mcp->mc_rsp = tp->tf_rsp;
1544	mcp->mc_ss = tp->tf_ss;
1545	mcp->mc_len = sizeof(*mcp);
1546	get_fpcontext(td, mcp);
1547	return (0);
1548}
1549
1550/*
1551 * Set machine context.
1552 *
1553 * However, we don't set any but the user modifiable flags, and we won't
1554 * touch the cs selector.
1555 */
1556int
1557set_mcontext(struct thread *td, const mcontext_t *mcp)
1558{
1559	struct trapframe *tp;
1560	long rflags;
1561	int ret;
1562
1563	tp = td->td_frame;
1564	if (mcp->mc_len != sizeof(*mcp))
1565		return (EINVAL);
1566	rflags = (mcp->mc_rflags & PSL_USERCHANGE) |
1567	    (tp->tf_rflags & ~PSL_USERCHANGE);
1568	ret = set_fpcontext(td, mcp);
1569	if (ret != 0)
1570		return (ret);
1571	tp->tf_r15 = mcp->mc_r15;
1572	tp->tf_r14 = mcp->mc_r14;
1573	tp->tf_r13 = mcp->mc_r13;
1574	tp->tf_r12 = mcp->mc_r12;
1575	tp->tf_r11 = mcp->mc_r11;
1576	tp->tf_r10 = mcp->mc_r10;
1577	tp->tf_r9  = mcp->mc_r9;
1578	tp->tf_r8  = mcp->mc_r8;
1579	tp->tf_rdi = mcp->mc_rdi;
1580	tp->tf_rsi = mcp->mc_rsi;
1581	tp->tf_rbp = mcp->mc_rbp;
1582	tp->tf_rbx = mcp->mc_rbx;
1583	tp->tf_rdx = mcp->mc_rdx;
1584	tp->tf_rcx = mcp->mc_rcx;
1585	tp->tf_rax = mcp->mc_rax;
1586	tp->tf_rip = mcp->mc_rip;
1587	tp->tf_rflags = rflags;
1588	tp->tf_rsp = mcp->mc_rsp;
1589	tp->tf_ss = mcp->mc_ss;
1590	td->td_pcb->pcb_flags |= PCB_FULLCTX;
1591	return (0);
1592}
1593
1594static void
1595get_fpcontext(struct thread *td, mcontext_t *mcp)
1596{
1597
1598	mcp->mc_ownedfp = fpugetregs(td, (struct savefpu *)&mcp->mc_fpstate);
1599	mcp->mc_fpformat = fpuformat();
1600}
1601
1602static int
1603set_fpcontext(struct thread *td, const mcontext_t *mcp)
1604{
1605	struct savefpu *fpstate;
1606
1607	if (mcp->mc_fpformat == _MC_FPFMT_NODEV)
1608		return (0);
1609	else if (mcp->mc_fpformat != _MC_FPFMT_XMM)
1610		return (EINVAL);
1611	else if (mcp->mc_ownedfp == _MC_FPOWNED_NONE)
1612		/* We don't care what state is left in the FPU or PCB. */
1613		fpstate_drop(td);
1614	else if (mcp->mc_ownedfp == _MC_FPOWNED_FPU ||
1615	    mcp->mc_ownedfp == _MC_FPOWNED_PCB) {
1616		/*
1617		 * XXX we violate the dubious requirement that fpusetregs()
1618		 * be called with interrupts disabled.
1619		 * XXX obsolete on trap-16 systems?
1620		 */
1621		fpstate = (struct savefpu *)&mcp->mc_fpstate;
1622		fpstate->sv_env.en_mxcsr &= cpu_mxcsr_mask;
1623		fpusetregs(td, fpstate);
1624	} else
1625		return (EINVAL);
1626	return (0);
1627}
1628
1629void
1630fpstate_drop(struct thread *td)
1631{
1632	register_t s;
1633
1634	s = intr_disable();
1635	if (PCPU_GET(fpcurthread) == td)
1636		fpudrop();
1637	/*
1638	 * XXX force a full drop of the fpu.  The above only drops it if we
1639	 * owned it.
1640	 *
1641	 * XXX I don't much like fpugetregs()'s semantics of doing a full
1642	 * drop.  Dropping only to the pcb matches fnsave's behaviour.
1643	 * We only need to drop to !PCB_INITDONE in sendsig().  But
1644	 * sendsig() is the only caller of fpugetregs()... perhaps we just
1645	 * have too many layers.
1646	 */
1647	curthread->td_pcb->pcb_flags &= ~PCB_FPUINITDONE;
1648	intr_restore(s);
1649}
1650
1651int
1652fill_dbregs(struct thread *td, struct dbreg *dbregs)
1653{
1654	struct pcb *pcb;
1655
1656	if (td == NULL) {
1657		dbregs->dr[0] = rdr0();
1658		dbregs->dr[1] = rdr1();
1659		dbregs->dr[2] = rdr2();
1660		dbregs->dr[3] = rdr3();
1661		dbregs->dr[6] = rdr6();
1662		dbregs->dr[7] = rdr7();
1663	} else {
1664		pcb = td->td_pcb;
1665		dbregs->dr[0] = pcb->pcb_dr0;
1666		dbregs->dr[1] = pcb->pcb_dr1;
1667		dbregs->dr[2] = pcb->pcb_dr2;
1668		dbregs->dr[3] = pcb->pcb_dr3;
1669		dbregs->dr[6] = pcb->pcb_dr6;
1670		dbregs->dr[7] = pcb->pcb_dr7;
1671	}
1672	dbregs->dr[4] = 0;
1673	dbregs->dr[5] = 0;
1674	dbregs->dr[8] = 0;
1675	dbregs->dr[9] = 0;
1676	dbregs->dr[10] = 0;
1677	dbregs->dr[11] = 0;
1678	dbregs->dr[12] = 0;
1679	dbregs->dr[13] = 0;
1680	dbregs->dr[14] = 0;
1681	dbregs->dr[15] = 0;
1682	return (0);
1683}
1684
1685int
1686set_dbregs(struct thread *td, struct dbreg *dbregs)
1687{
1688	struct pcb *pcb;
1689	int i;
1690
1691	if (td == NULL) {
1692		load_dr0(dbregs->dr[0]);
1693		load_dr1(dbregs->dr[1]);
1694		load_dr2(dbregs->dr[2]);
1695		load_dr3(dbregs->dr[3]);
1696		load_dr6(dbregs->dr[6]);
1697		load_dr7(dbregs->dr[7]);
1698	} else {
1699		/*
1700		 * Don't let an illegal value for dr7 get set.  Specifically,
1701		 * check for undefined settings.  Setting these bit patterns
1702		 * result in undefined behaviour and can lead to an unexpected
1703		 * TRCTRAP or a general protection fault right here.
1704		 * Upper bits of dr6 and dr7 must not be set
1705		 */
1706		for (i = 0; i < 4; i++) {
1707			if (DBREG_DR7_ACCESS(dbregs->dr[7], i) == 0x02)
1708				return (EINVAL);
1709			if (td->td_frame->tf_cs == _ucode32sel &&
1710			    DBREG_DR7_LEN(dbregs->dr[7], i) == DBREG_DR7_LEN_8)
1711				return (EINVAL);
1712		}
1713		if ((dbregs->dr[6] & 0xffffffff00000000ul) != 0 ||
1714		    (dbregs->dr[7] & 0xffffffff00000000ul) != 0)
1715			return (EINVAL);
1716
1717		pcb = td->td_pcb;
1718
1719		/*
1720		 * Don't let a process set a breakpoint that is not within the
1721		 * process's address space.  If a process could do this, it
1722		 * could halt the system by setting a breakpoint in the kernel
1723		 * (if ddb was enabled).  Thus, we need to check to make sure
1724		 * that no breakpoints are being enabled for addresses outside
1725		 * process's address space.
1726		 *
1727		 * XXX - what about when the watched area of the user's
1728		 * address space is written into from within the kernel
1729		 * ... wouldn't that still cause a breakpoint to be generated
1730		 * from within kernel mode?
1731		 */
1732
1733		if (DBREG_DR7_ENABLED(dbregs->dr[7], 0)) {
1734			/* dr0 is enabled */
1735			if (dbregs->dr[0] >= VM_MAXUSER_ADDRESS)
1736				return (EINVAL);
1737		}
1738		if (DBREG_DR7_ENABLED(dbregs->dr[7], 1)) {
1739			/* dr1 is enabled */
1740			if (dbregs->dr[1] >= VM_MAXUSER_ADDRESS)
1741				return (EINVAL);
1742		}
1743		if (DBREG_DR7_ENABLED(dbregs->dr[7], 2)) {
1744			/* dr2 is enabled */
1745			if (dbregs->dr[2] >= VM_MAXUSER_ADDRESS)
1746				return (EINVAL);
1747		}
1748		if (DBREG_DR7_ENABLED(dbregs->dr[7], 3)) {
1749			/* dr3 is enabled */
1750			if (dbregs->dr[3] >= VM_MAXUSER_ADDRESS)
1751				return (EINVAL);
1752		}
1753
1754		pcb->pcb_dr0 = dbregs->dr[0];
1755		pcb->pcb_dr1 = dbregs->dr[1];
1756		pcb->pcb_dr2 = dbregs->dr[2];
1757		pcb->pcb_dr3 = dbregs->dr[3];
1758		pcb->pcb_dr6 = dbregs->dr[6];
1759		pcb->pcb_dr7 = dbregs->dr[7];
1760
1761		pcb->pcb_flags |= PCB_DBREGS;
1762	}
1763
1764	return (0);
1765}
1766
1767void
1768reset_dbregs(void)
1769{
1770
1771	load_dr7(0);	/* Turn off the control bits first */
1772	load_dr0(0);
1773	load_dr1(0);
1774	load_dr2(0);
1775	load_dr3(0);
1776	load_dr6(0);
1777}
1778
1779/*
1780 * Return > 0 if a hardware breakpoint has been hit, and the
1781 * breakpoint was in user space.  Return 0, otherwise.
1782 */
1783int
1784user_dbreg_trap(void)
1785{
1786        u_int64_t dr7, dr6; /* debug registers dr6 and dr7 */
1787        u_int64_t bp;       /* breakpoint bits extracted from dr6 */
1788        int nbp;            /* number of breakpoints that triggered */
1789        caddr_t addr[4];    /* breakpoint addresses */
1790        int i;
1791
1792        dr7 = rdr7();
1793        if ((dr7 & 0x000000ff) == 0) {
1794                /*
1795                 * all GE and LE bits in the dr7 register are zero,
1796                 * thus the trap couldn't have been caused by the
1797                 * hardware debug registers
1798                 */
1799                return 0;
1800        }
1801
1802        nbp = 0;
1803        dr6 = rdr6();
1804        bp = dr6 & 0x0000000f;
1805
1806        if (!bp) {
1807                /*
1808                 * None of the breakpoint bits are set meaning this
1809                 * trap was not caused by any of the debug registers
1810                 */
1811                return 0;
1812        }
1813
1814        /*
1815         * at least one of the breakpoints were hit, check to see
1816         * which ones and if any of them are user space addresses
1817         */
1818
1819        if (bp & 0x01) {
1820                addr[nbp++] = (caddr_t)rdr0();
1821        }
1822        if (bp & 0x02) {
1823                addr[nbp++] = (caddr_t)rdr1();
1824        }
1825        if (bp & 0x04) {
1826                addr[nbp++] = (caddr_t)rdr2();
1827        }
1828        if (bp & 0x08) {
1829                addr[nbp++] = (caddr_t)rdr3();
1830        }
1831
1832        for (i = 0; i < nbp; i++) {
1833                if (addr[i] < (caddr_t)VM_MAXUSER_ADDRESS) {
1834                        /*
1835                         * addr[i] is in user space
1836                         */
1837                        return nbp;
1838                }
1839        }
1840
1841        /*
1842         * None of the breakpoints are in user space.
1843         */
1844        return 0;
1845}
1846
1847#ifdef KDB
1848
1849/*
1850 * Provide inb() and outb() as functions.  They are normally only
1851 * available as macros calling inlined functions, thus cannot be
1852 * called from the debugger.
1853 *
1854 * The actual code is stolen from <machine/cpufunc.h>, and de-inlined.
1855 */
1856
1857#undef inb
1858#undef outb
1859
1860/* silence compiler warnings */
1861u_char inb(u_int);
1862void outb(u_int, u_char);
1863
1864u_char
1865inb(u_int port)
1866{
1867	u_char	data;
1868	/*
1869	 * We use %%dx and not %1 here because i/o is done at %dx and not at
1870	 * %edx, while gcc generates inferior code (movw instead of movl)
1871	 * if we tell it to load (u_short) port.
1872	 */
1873	__asm __volatile("inb %%dx,%0" : "=a" (data) : "d" (port));
1874	return (data);
1875}
1876
1877void
1878outb(u_int port, u_char data)
1879{
1880	u_char	al;
1881	/*
1882	 * Use an unnecessary assignment to help gcc's register allocator.
1883	 * This make a large difference for gcc-1.40 and a tiny difference
1884	 * for gcc-2.6.0.  For gcc-1.40, al had to be ``asm("ax")'' for
1885	 * best results.  gcc-2.6.0 can't handle this.
1886	 */
1887	al = data;
1888	__asm __volatile("outb %0,%%dx" : : "a" (al), "d" (port));
1889}
1890
1891#endif /* KDB */
1892