npx.c revision 45100
1/*-
2 * Copyright (c) 1990 William Jolitz.
3 * Copyright (c) 1991 The Regents of the University of California.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by the University of
17 *	California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 *	from: @(#)npx.c	7.2 (Berkeley) 5/12/91
35 *	$Id: npx.c,v 1.65 1999/01/08 16:29:59 bde Exp $
36 */
37
38#include "npx.h"
39#if NNPX > 0
40
41#include "opt_debug_npx.h"
42#include "opt_math_emulate.h"
43
44#include <sys/param.h>
45#include <sys/systm.h>
46#include <sys/kernel.h>
47#include <sys/malloc.h>
48#include <sys/sysctl.h>
49#include <sys/proc.h>
50#ifdef NPX_DEBUG
51#include <sys/syslog.h>
52#endif
53#include <sys/signalvar.h>
54
55#ifndef SMP
56#include <machine/asmacros.h>
57#endif
58#include <machine/cputypes.h>
59#include <machine/frame.h>
60#include <machine/ipl.h>
61#include <machine/md_var.h>
62#include <machine/pcb.h>
63#include <machine/psl.h>
64#ifndef SMP
65#include <machine/clock.h>
66#endif
67#include <machine/specialreg.h>
68#include <machine/segments.h>
69
70#ifndef SMP
71#include <i386/isa/icu.h>
72#include <i386/isa/intr_machdep.h>
73#include <i386/isa/isa.h>
74#endif
75#include <i386/isa/isa_device.h>
76
77/*
78 * 387 and 287 Numeric Coprocessor Extension (NPX) Driver.
79 */
80
81/* Configuration flags. */
82#define	NPX_DISABLE_I586_OPTIMIZED_BCOPY	(1 << 0)
83#define	NPX_DISABLE_I586_OPTIMIZED_BZERO	(1 << 1)
84#define	NPX_DISABLE_I586_OPTIMIZED_COPYIO	(1 << 2)
85
86/* XXX - should be in header file. */
87ointhand2_t	npxintr;
88
89#ifdef	__GNUC__
90
91#define	fldcw(addr)		__asm("fldcw %0" : : "m" (*(addr)))
92#define	fnclex()		__asm("fnclex")
93#define	fninit()		__asm("fninit")
94#define	fnop()			__asm("fnop")
95#define	fnsave(addr)		__asm __volatile("fnsave %0" : "=m" (*(addr)))
96#define	fnstcw(addr)		__asm __volatile("fnstcw %0" : "=m" (*(addr)))
97#define	fnstsw(addr)		__asm __volatile("fnstsw %0" : "=m" (*(addr)))
98#define	fp_divide_by_0()	__asm("fldz; fld1; fdiv %st,%st(1); fnop")
99#define	frstor(addr)		__asm("frstor %0" : : "m" (*(addr)))
100#define	start_emulating()	__asm("smsw %%ax; orb %0,%%al; lmsw %%ax" \
101				      : : "n" (CR0_TS) : "ax")
102#define	stop_emulating()	__asm("clts")
103
104#else	/* not __GNUC__ */
105
106void	fldcw		__P((caddr_t addr));
107void	fnclex		__P((void));
108void	fninit		__P((void));
109void	fnop		__P((void));
110void	fnsave		__P((caddr_t addr));
111void	fnstcw		__P((caddr_t addr));
112void	fnstsw		__P((caddr_t addr));
113void	fp_divide_by_0	__P((void));
114void	frstor		__P((caddr_t addr));
115void	start_emulating	__P((void));
116void	stop_emulating	__P((void));
117
118#endif	/* __GNUC__ */
119
120typedef u_char bool_t;
121
122static	int	npxattach	__P((struct isa_device *dvp));
123static	int	npxprobe	__P((struct isa_device *dvp));
124static	int	npxprobe1	__P((struct isa_device *dvp));
125#ifdef I586_CPU
126static	long	timezero	__P((const char *funcname,
127				     void (*func)(void *buf, size_t len)));
128#endif /* I586_CPU */
129
130struct	isa_driver npxdriver = {
131	npxprobe, npxattach, "npx",
132};
133
134int	hw_float;		/* XXX currently just alias for npx_exists */
135
136SYSCTL_INT(_hw,HW_FLOATINGPT, floatingpoint,
137	CTLFLAG_RD, &hw_float, 0,
138	"Floatingpoint instructions executed in hardware");
139
140#ifndef SMP
141static	u_int			npx0_imask = SWI_CLOCK_MASK;
142static	struct gate_descriptor	npx_idt_probeintr;
143static	int			npx_intrno;
144static	volatile u_int		npx_intrs_while_probing;
145static	volatile u_int		npx_traps_while_probing;
146#endif
147
148static	bool_t			npx_ex16;
149static	bool_t			npx_exists;
150static	bool_t			npx_irq13;
151
152#ifndef SMP
153/*
154 * Special interrupt handlers.  Someday intr0-intr15 will be used to count
155 * interrupts.  We'll still need a special exception 16 handler.  The busy
156 * latch stuff in probeintr() can be moved to npxprobe().
157 */
158inthand_t probeintr;
159__asm("								\n\
160	.text							\n\
161	.p2align 2,0x90						\n\
162" __XSTRING(CNAME(probeintr)) ":				\n\
163	ss							\n\
164	incl	" __XSTRING(CNAME(npx_intrs_while_probing)) "	\n\
165	pushl	%eax						\n\
166	movb	$0x20,%al	# EOI (asm in strings loses cpp features) \n\
167	outb	%al,$0xa0	# IO_ICU2			\n\
168	outb	%al,$0x20	# IO_ICU1			\n\
169	movb	$0,%al						\n\
170	outb	%al,$0xf0	# clear BUSY# latch		\n\
171	popl	%eax						\n\
172	iret							\n\
173");
174
175inthand_t probetrap;
176__asm("								\n\
177	.text							\n\
178	.p2align 2,0x90						\n\
179" __XSTRING(CNAME(probetrap)) ":				\n\
180	ss							\n\
181	incl	" __XSTRING(CNAME(npx_traps_while_probing)) "	\n\
182	fnclex							\n\
183	iret							\n\
184");
185#endif /* SMP */
186
187/*
188 * Probe routine.  Initialize cr0 to give correct behaviour for [f]wait
189 * whether the device exists or not (XXX should be elsewhere).  Set flags
190 * to tell npxattach() what to do.  Modify device struct if npx doesn't
191 * need to use interrupts.  Return 1 if device exists.
192 */
193static int
194npxprobe(dvp)
195	struct isa_device *dvp;
196{
197#ifdef SMP
198
199	return npxprobe1(dvp);
200
201#else /* SMP */
202
203	int	result;
204	u_long	save_eflags;
205	u_char	save_icu1_mask;
206	u_char	save_icu2_mask;
207	struct	gate_descriptor save_idt_npxintr;
208	struct	gate_descriptor save_idt_npxtrap;
209	/*
210	 * This routine is now just a wrapper for npxprobe1(), to install
211	 * special npx interrupt and trap handlers, to enable npx interrupts
212	 * and to disable other interrupts.  Someday isa_configure() will
213	 * install suitable handlers and run with interrupts enabled so we
214	 * won't need to do so much here.
215	 */
216	npx_intrno = NRSVIDT + ffs(dvp->id_irq) - 1;
217	save_eflags = read_eflags();
218	disable_intr();
219	save_icu1_mask = inb(IO_ICU1 + 1);
220	save_icu2_mask = inb(IO_ICU2 + 1);
221	save_idt_npxintr = idt[npx_intrno];
222	save_idt_npxtrap = idt[16];
223	outb(IO_ICU1 + 1, ~(IRQ_SLAVE | dvp->id_irq));
224	outb(IO_ICU2 + 1, ~(dvp->id_irq >> 8));
225	setidt(16, probetrap, SDT_SYS386TGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
226	setidt(npx_intrno, probeintr, SDT_SYS386IGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
227	npx_idt_probeintr = idt[npx_intrno];
228	enable_intr();
229	result = npxprobe1(dvp);
230	disable_intr();
231	outb(IO_ICU1 + 1, save_icu1_mask);
232	outb(IO_ICU2 + 1, save_icu2_mask);
233	idt[npx_intrno] = save_idt_npxintr;
234	idt[16] = save_idt_npxtrap;
235	write_eflags(save_eflags);
236	return (result);
237
238#endif /* SMP */
239}
240
241static int
242npxprobe1(dvp)
243	struct isa_device *dvp;
244{
245#ifndef SMP
246	u_short control;
247	u_short status;
248#endif
249
250	/*
251	 * Partially reset the coprocessor, if any.  Some BIOS's don't reset
252	 * it after a warm boot.
253	 */
254	outb(0xf1, 0);		/* full reset on some systems, NOP on others */
255	outb(0xf0, 0);		/* clear BUSY# latch */
256	/*
257	 * Prepare to trap all ESC (i.e., NPX) instructions and all WAIT
258	 * instructions.  We must set the CR0_MP bit and use the CR0_TS
259	 * bit to control the trap, because setting the CR0_EM bit does
260	 * not cause WAIT instructions to trap.  It's important to trap
261	 * WAIT instructions - otherwise the "wait" variants of no-wait
262	 * control instructions would degenerate to the "no-wait" variants
263	 * after FP context switches but work correctly otherwise.  It's
264	 * particularly important to trap WAITs when there is no NPX -
265	 * otherwise the "wait" variants would always degenerate.
266	 *
267	 * Try setting CR0_NE to get correct error reporting on 486DX's.
268	 * Setting it should fail or do nothing on lesser processors.
269	 */
270	load_cr0(rcr0() | CR0_MP | CR0_NE);
271	/*
272	 * But don't trap while we're probing.
273	 */
274	stop_emulating();
275	/*
276	 * Finish resetting the coprocessor, if any.  If there is an error
277	 * pending, then we may get a bogus IRQ13, but probeintr() will handle
278	 * it OK.  Bogus halts have never been observed, but we enabled
279	 * IRQ13 and cleared the BUSY# latch early to handle them anyway.
280	 */
281	fninit();
282
283#ifdef SMP
284
285	/*
286	 * Exception 16 MUST work for SMP.
287	 */
288	npx_irq13 = 0;
289	npx_ex16 = hw_float = npx_exists = 1;
290	dvp->id_irq = 0;	/* zap the interrupt */
291	/*
292	 * special return value to flag that we do not
293	 * actually use any I/O registers
294	 */
295	return (-1);
296
297#else /* SMP */
298
299	/*
300	 * Don't use fwait here because it might hang.
301	 * Don't use fnop here because it usually hangs if there is no FPU.
302	 */
303	DELAY(1000);		/* wait for any IRQ13 */
304#ifdef DIAGNOSTIC
305	if (npx_intrs_while_probing != 0)
306		printf("fninit caused %u bogus npx interrupt(s)\n",
307		       npx_intrs_while_probing);
308	if (npx_traps_while_probing != 0)
309		printf("fninit caused %u bogus npx trap(s)\n",
310		       npx_traps_while_probing);
311#endif
312	/*
313	 * Check for a status of mostly zero.
314	 */
315	status = 0x5a5a;
316	fnstsw(&status);
317	if ((status & 0xb8ff) == 0) {
318		/*
319		 * Good, now check for a proper control word.
320		 */
321		control = 0x5a5a;
322		fnstcw(&control);
323		if ((control & 0x1f3f) == 0x033f) {
324			hw_float = npx_exists = 1;
325			/*
326			 * We have an npx, now divide by 0 to see if exception
327			 * 16 works.
328			 */
329			control &= ~(1 << 2);	/* enable divide by 0 trap */
330			fldcw(&control);
331			npx_traps_while_probing = npx_intrs_while_probing = 0;
332			fp_divide_by_0();
333			if (npx_traps_while_probing != 0) {
334				/*
335				 * Good, exception 16 works.
336				 */
337				npx_ex16 = 1;
338				dvp->id_irq = 0;	/* zap the interrupt */
339				/*
340				 * special return value to flag that we do not
341				 * actually use any I/O registers
342				 */
343				return (-1);
344			}
345			if (npx_intrs_while_probing != 0) {
346				/*
347				 * Bad, we are stuck with IRQ13.
348				 */
349				npx_irq13 = 1;
350				/*
351				 * npxattach would be too late to set npx0_imask.
352				 */
353				npx0_imask |= dvp->id_irq;
354				return (IO_NPXSIZE);
355			}
356			/*
357			 * Worse, even IRQ13 is broken.  Use emulator.
358			 */
359		}
360	}
361	/*
362	 * Probe failed, but we want to get to npxattach to initialize the
363	 * emulator and say that it has been installed.  XXX handle devices
364	 * that aren't really devices better.
365	 */
366	dvp->id_irq = 0;
367	/*
368	 * special return value to flag that we do not
369	 * actually use any I/O registers
370	 */
371	return (-1);
372
373#endif /* SMP */
374}
375
376/*
377 * Attach routine - announce which it is, and wire into system
378 */
379int
380npxattach(dvp)
381	struct isa_device *dvp;
382{
383	dvp->id_ointr = npxintr;
384
385	/* The caller has printed "irq 13" for the npx_irq13 case. */
386	if (!npx_irq13) {
387		printf("npx%d: ", dvp->id_unit);
388		if (npx_ex16)
389			printf("INT 16 interface\n");
390#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
391		else if (npx_exists) {
392			printf("error reporting broken; using 387 emulator\n");
393			hw_float = npx_exists = 0;
394		} else
395			printf("387 emulator\n");
396#else
397		else
398			printf("no 387 emulator in kernel!\n");
399#endif
400	}
401	npxinit(__INITIAL_NPXCW__);
402
403#ifdef I586_CPU
404	if (cpu_class == CPUCLASS_586 && npx_ex16 &&
405	    timezero("i586_bzero()", i586_bzero) <
406	    timezero("bzero()", bzero) * 4 / 5) {
407		if (!(dvp->id_flags & NPX_DISABLE_I586_OPTIMIZED_BCOPY)) {
408			bcopy_vector = i586_bcopy;
409			ovbcopy_vector = i586_bcopy;
410		}
411		if (!(dvp->id_flags & NPX_DISABLE_I586_OPTIMIZED_BZERO))
412			bzero = i586_bzero;
413		if (!(dvp->id_flags & NPX_DISABLE_I586_OPTIMIZED_COPYIO)) {
414			copyin_vector = i586_copyin;
415			copyout_vector = i586_copyout;
416		}
417	}
418#endif
419
420	return (1);		/* XXX unused */
421}
422
423/*
424 * Initialize floating point unit.
425 */
426void
427npxinit(control)
428	u_short control;
429{
430	struct save87 dummy;
431
432	if (!npx_exists)
433		return;
434	/*
435	 * fninit has the same h/w bugs as fnsave.  Use the detoxified
436	 * fnsave to throw away any junk in the fpu.  npxsave() initializes
437	 * the fpu and sets npxproc = NULL as important side effects.
438	 */
439	npxsave(&dummy);
440	stop_emulating();
441	fldcw(&control);
442	if (curpcb != NULL)
443		fnsave(&curpcb->pcb_savefpu);
444	start_emulating();
445}
446
447/*
448 * Free coprocessor (if we have it).
449 */
450void
451npxexit(p)
452	struct proc *p;
453{
454
455	if (p == npxproc)
456		npxsave(&curpcb->pcb_savefpu);
457#ifdef NPX_DEBUG
458	if (npx_exists) {
459		u_int	masked_exceptions;
460
461		masked_exceptions = curpcb->pcb_savefpu.sv_env.en_cw
462				    & curpcb->pcb_savefpu.sv_env.en_sw & 0x7f;
463		/*
464		 * Log exceptions that would have trapped with the old
465		 * control word (overflow, divide by 0, and invalid operand).
466		 */
467		if (masked_exceptions & 0x0d)
468			log(LOG_ERR,
469	"pid %d (%s) exited with masked floating point exceptions 0x%02x\n",
470			    p->p_pid, p->p_comm, masked_exceptions);
471	}
472#endif
473}
474
475/*
476 * Preserve the FP status word, clear FP exceptions, then generate a SIGFPE.
477 *
478 * Clearing exceptions is necessary mainly to avoid IRQ13 bugs.  We now
479 * depend on longjmp() restoring a usable state.  Restoring the state
480 * or examining it might fail if we didn't clear exceptions.
481 *
482 * XXX there is no standard way to tell SIGFPE handlers about the error
483 * state.  The old interface:
484 *
485 *	void handler(int sig, int code, struct sigcontext *scp);
486 *
487 * is broken because it is non-ANSI and because the FP state is not in
488 * struct sigcontext.
489 *
490 * XXX the FP state is not preserved across signal handlers.  So signal
491 * handlers cannot afford to do FP unless they preserve the state or
492 * longjmp() out.  Both preserving the state and longjmp()ing may be
493 * destroyed by IRQ13 bugs.  Clearing FP exceptions is not an acceptable
494 * solution for signals other than SIGFPE.
495 */
496void
497npxintr(unit)
498	int unit;
499{
500	int code;
501	struct intrframe *frame;
502
503	if (npxproc == NULL || !npx_exists) {
504		printf("npxintr: npxproc = %p, curproc = %p, npx_exists = %d\n",
505		       npxproc, curproc, npx_exists);
506		panic("npxintr from nowhere");
507	}
508	if (npxproc != curproc) {
509		printf("npxintr: npxproc = %p, curproc = %p, npx_exists = %d\n",
510		       npxproc, curproc, npx_exists);
511		panic("npxintr from non-current process");
512	}
513
514	outb(0xf0, 0);
515	fnstsw(&curpcb->pcb_savefpu.sv_ex_sw);
516	fnclex();
517
518	/*
519	 * Pass exception to process.
520	 */
521	frame = (struct intrframe *)&unit;	/* XXX */
522	if ((ISPL(frame->if_cs) == SEL_UPL) || (frame->if_eflags & PSL_VM)) {
523		/*
524		 * Interrupt is essentially a trap, so we can afford to call
525		 * the SIGFPE handler (if any) as soon as the interrupt
526		 * returns.
527		 *
528		 * XXX little or nothing is gained from this, and plenty is
529		 * lost - the interrupt frame has to contain the trap frame
530		 * (this is otherwise only necessary for the rescheduling trap
531		 * in doreti, and the frame for that could easily be set up
532		 * just before it is used).
533		 */
534		curproc->p_md.md_regs = (struct trapframe *)&frame->if_es;
535#ifdef notyet
536		/*
537		 * Encode the appropriate code for detailed information on
538		 * this exception.
539		 */
540		code = XXX_ENCODE(curpcb->pcb_savefpu.sv_ex_sw);
541#else
542		code = 0;	/* XXX */
543#endif
544		trapsignal(curproc, SIGFPE, code);
545	} else {
546		/*
547		 * Nested interrupt.  These losers occur when:
548		 *	o an IRQ13 is bogusly generated at a bogus time, e.g.:
549		 *		o immediately after an fnsave or frstor of an
550		 *		  error state.
551		 *		o a couple of 386 instructions after
552		 *		  "fstpl _memvar" causes a stack overflow.
553		 *	  These are especially nasty when combined with a
554		 *	  trace trap.
555		 *	o an IRQ13 occurs at the same time as another higher-
556		 *	  priority interrupt.
557		 *
558		 * Treat them like a true async interrupt.
559		 */
560		psignal(curproc, SIGFPE);
561	}
562}
563
564/*
565 * Implement device not available (DNA) exception
566 *
567 * It would be better to switch FP context here (if curproc != npxproc)
568 * and not necessarily for every context switch, but it is too hard to
569 * access foreign pcb's.
570 */
571int
572npxdna()
573{
574	if (!npx_exists)
575		return (0);
576	if (npxproc != NULL) {
577		printf("npxdna: npxproc = %p, curproc = %p\n",
578		       npxproc, curproc);
579		panic("npxdna");
580	}
581	stop_emulating();
582	/*
583	 * Record new context early in case frstor causes an IRQ13.
584	 */
585	npxproc = curproc;
586	curpcb->pcb_savefpu.sv_ex_sw = 0;
587	/*
588	 * The following frstor may cause an IRQ13 when the state being
589	 * restored has a pending error.  The error will appear to have been
590	 * triggered by the current (npx) user instruction even when that
591	 * instruction is a no-wait instruction that should not trigger an
592	 * error (e.g., fnclex).  On at least one 486 system all of the
593	 * no-wait instructions are broken the same as frstor, so our
594	 * treatment does not amplify the breakage.  On at least one
595	 * 386/Cyrix 387 system, fnclex works correctly while frstor and
596	 * fnsave are broken, so our treatment breaks fnclex if it is the
597	 * first FPU instruction after a context switch.
598	 */
599	frstor(&curpcb->pcb_savefpu);
600
601	return (1);
602}
603
604/*
605 * Wrapper for fnsave instruction to handle h/w bugs.  If there is an error
606 * pending, then fnsave generates a bogus IRQ13 on some systems.  Force
607 * any IRQ13 to be handled immediately, and then ignore it.  This routine is
608 * often called at splhigh so it must not use many system services.  In
609 * particular, it's much easier to install a special handler than to
610 * guarantee that it's safe to use npxintr() and its supporting code.
611 */
612void
613npxsave(addr)
614	struct save87 *addr;
615{
616#ifdef SMP
617
618	stop_emulating();
619	fnsave(addr);
620	/* fnop(); */
621	start_emulating();
622	npxproc = NULL;
623
624#else /* SMP */
625
626	u_char	icu1_mask;
627	u_char	icu2_mask;
628	u_char	old_icu1_mask;
629	u_char	old_icu2_mask;
630	struct gate_descriptor	save_idt_npxintr;
631
632	disable_intr();
633	old_icu1_mask = inb(IO_ICU1 + 1);
634	old_icu2_mask = inb(IO_ICU2 + 1);
635	save_idt_npxintr = idt[npx_intrno];
636	outb(IO_ICU1 + 1, old_icu1_mask & ~(IRQ_SLAVE | npx0_imask));
637	outb(IO_ICU2 + 1, old_icu2_mask & ~(npx0_imask >> 8));
638	idt[npx_intrno] = npx_idt_probeintr;
639	enable_intr();
640	stop_emulating();
641	fnsave(addr);
642	fnop();
643	start_emulating();
644	npxproc = NULL;
645	disable_intr();
646	icu1_mask = inb(IO_ICU1 + 1);	/* masks may have changed */
647	icu2_mask = inb(IO_ICU2 + 1);
648	outb(IO_ICU1 + 1,
649	     (icu1_mask & ~npx0_imask) | (old_icu1_mask & npx0_imask));
650	outb(IO_ICU2 + 1,
651	     (icu2_mask & ~(npx0_imask >> 8))
652	     | (old_icu2_mask & (npx0_imask >> 8)));
653	idt[npx_intrno] = save_idt_npxintr;
654	enable_intr();		/* back to usual state */
655
656#endif /* SMP */
657}
658
659#ifdef I586_CPU
660static long
661timezero(funcname, func)
662	const char *funcname;
663	void (*func) __P((void *buf, size_t len));
664
665{
666	void *buf;
667#define	BUFSIZE		1000000
668	long usec;
669	struct timeval finish, start;
670
671	buf = malloc(BUFSIZE, M_TEMP, M_NOWAIT);
672	if (buf == NULL)
673		return (BUFSIZE);
674	microtime(&start);
675	(*func)(buf, BUFSIZE);
676	microtime(&finish);
677	usec = 1000000 * (finish.tv_sec - start.tv_sec) +
678	    finish.tv_usec - start.tv_usec;
679	if (usec <= 0)
680		usec = 1;
681	if (bootverbose)
682		printf("%s bandwidth = %ld bytes/sec\n",
683		    funcname, (long)(BUFSIZE * (int64_t)1000000 / usec));
684	free(buf, M_TEMP);
685	return (usec);
686}
687#endif /* I586_CPU */
688
689#endif /* NNPX > 0 */
690