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:
--- 18 unchanged lines hidden (view full) ---
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 1.17 1994/11/14 14:59:06 bde Exp $
36 */
37
38#include "npx.h"
39#if NNPX > 0
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/conf.h>
--- 15 unchanged lines hidden (view full) ---
59#include <i386/isa/isa.h>
60
61/*
62 * 387 and 287 Numeric Coprocessor Extension (NPX) Driver.
63 */
64
65#ifdef __GNUC__
66
67#define fldcw(addr) __asm("fldcw %0" : : "m" (*(addr)))
68#define fnclex() __asm("fnclex")
69#define fninit() __asm("fninit")
70#define fnop() __asm("fnop")
71#define fnsave(addr) __asm("fnsave %0" : "=m" (*(addr)))
72#define fnstcw(addr) __asm("fnstcw %0" : "=m" (*(addr)))
73#define fnstsw(addr) __asm("fnstsw %0" : "=m" (*(addr)))
74#define fp_divide_by_0() __asm("fldz; fld1; fdiv %st,%st(1); fnop")
75#define frstor(addr) __asm("frstor %0" : : "m" (*(addr)))
76#define start_emulating() __asm("smsw %%ax; orb %0,%%al; lmsw %%ax" \
77 : : "n" (CR0_TS) : "ax")
78#define stop_emulating() __asm("clts")
79
80#else /* not __GNUC__ */
81
82void fldcw __P((caddr_t addr));
83void fnclex __P((void));
84void fninit __P((void));
85void fnop __P((void));
86void fnsave __P((caddr_t addr));
87void fnstcw __P((caddr_t addr));
88void fnstsw __P((caddr_t addr));
89void fp_divide_by_0 __P((void));
90void frstor __P((caddr_t addr));
91void start_emulating __P((void));
92void stop_emulating __P((void));
93
94#endif /* __GNUC__ */
95
96typedef u_char bool_t;
97
98static int npxattach __P((struct isa_device *dvp));
99static int npxprobe __P((struct isa_device *dvp));
100static int npxprobe1 __P((struct isa_device *dvp));
101
102struct isa_driver npxdriver = {
103 npxprobe, npxattach, "npx",
104};
105
106int hw_float; /* XXX currently just alias for npx_exists */
107u_int npx0_imask = SWI_CLOCK_MASK;
108struct proc *npxproc;
109
110static bool_t npx_ex16;
111static bool_t npx_exists;
112static struct gate_descriptor npx_idt_probeintr;
113static int npx_intrno;
114static volatile u_int npx_intrs_while_probing;
115static bool_t npx_irq13;
116static volatile u_int npx_traps_while_probing;
117
118/*
119 * Special interrupt handlers. Someday intr0-intr15 will be used to count
120 * interrupts. We'll still need a special exception 16 handler. The busy
121 * latch stuff in probeintr() can be moved to npxprobe().
122 */
123inthand_t probeintr;
124asm
125("
126 .text
127_probeintr:
128 ss
129 incl _npx_intrs_while_probing
130 pushl %eax
131 movb $0x20,%al # EOI (asm in strings loses cpp features)
132 outb %al,$0xa0 # IO_ICU2
133 outb %al,$0x20 # IO_ICU1
134 movb $0,%al
135 outb %al,$0xf0 # clear BUSY# latch
136 popl %eax
137 iret
138");
139
140inthand_t probetrap;
141asm
--- 51 unchanged lines hidden (view full) ---
193 write_eflags(save_eflags);
194 return (result);
195}
196
197static int
198npxprobe1(dvp)
199 struct isa_device *dvp;
200{
201 u_short control;
202 u_short status;
203
204 /*
205 * Partially reset the coprocessor, if any. Some BIOS's don't reset
206 * it after a warm boot.
207 */
208 outb(0xf1, 0); /* full reset on some systems, NOP on others */
209 outb(0xf0, 0); /* clear BUSY# latch */
210 /*
211 * Prepare to trap all ESC (i.e., NPX) instructions and all WAIT
--- 16 unchanged lines hidden (view full) ---
228 stop_emulating();
229 /*
230 * Finish resetting the coprocessor, if any. If there is an error
231 * pending, then we may get a bogus IRQ13, but probeintr() will handle
232 * it OK. Bogus halts have never been observed, but we enabled
233 * IRQ13 and cleared the BUSY# latch early to handle them anyway.
234 */
235 fninit();
236 fnop(); /* wait for fninit (fwait might hang) */
237 DELAY(1000); /* wait for any IRQ13 */
238#ifdef DIAGNOSTIC
239 if (npx_intrs_while_probing != 0)
240 printf("fninit caused %u bogus npx interrupt(s)\n",
241 npx_intrs_while_probing);
242 if (npx_traps_while_probing != 0)
243 printf("fninit caused %u bogus npx trap(s)\n",
244 npx_traps_while_probing);
245#endif
--- 30 unchanged lines hidden (view full) ---
276 */
277 return (-1);
278 }
279 if (npx_intrs_while_probing != 0) {
280 /*
281 * Bad, we are stuck with IRQ13.
282 */
283 npx_irq13 = 1;
284 /*
285 * npxattach would be too late to set npx0_imask.
286 */
287 npx0_imask |= dvp->id_irq;
288 return (IO_NPXSIZE);
289 }
290 /*
291 * Worse, even IRQ13 is broken. Use emulator.
292 */
293 }
294 }
295 /*
--- 10 unchanged lines hidden (view full) ---
306}
307
308static struct kern_devconf kdc_npx[NNPX] = { {
309 0, 0, 0, /* filled in by dev_attach */
310 "npx", 0, { MDDT_ISA, 0 },
311 isa_generic_externalize, 0, 0, ISA_EXTERNALLEN,
312 &kdc_isa0, /* parent */
313 0, /* parentdata */
314 DC_BUSY,
315 "Floating-point unit"
316} };
317
318static inline void
319npx_registerdev(struct isa_device *id)
320{
321 int unit;
322
323 unit = id->id_unit;
324 if (unit != 0)
325 kdc_npx[unit] = kdc_npx[0];
326 kdc_npx[unit].kdc_unit = unit;
327 kdc_npx[unit].kdc_isa = id;
328 dev_attach(&kdc_npx[unit]);
329}
330
331/*
332 * Attach routine - announce which it is, and wire into system
333 */
334int
335npxattach(dvp)
336 struct isa_device *dvp;
337{
338 printf("npx%d: ", dvp->id_unit);
339 if (npx_ex16)
340 printf("INT 16 interface\n");
341 else if (npx_irq13)
342 printf("IRQ 13 interface\n");
343#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
344 else if (npx_exists) {
345 printf("error reporting broken; using 387 emulator\n");
346 npx_exists = 0;
347 } else
348 printf("387 emulator\n");
349#else
350 else
351 printf("no 387 emulator in kernel!\n");
352#endif
353 npxinit(__INITIAL_NPXCW__);
354 if (npx_exists)
355 npx_registerdev(dvp);
356 return (1); /* XXX unused */
357}
358
359/*
360 * Initialize floating point unit.
361 */
362void
363npxinit(control)
364 u_short control;
365{
366 struct save87 dummy;
367
368 if (!npx_exists)
369 return;
370 /*
371 * fninit has the same h/w bugs as fnsave. Use the detoxified
372 * fnsave to throw away any junk in the fpu. npxsave() initializes
373 * the fpu and sets npxproc = NULL as important side effects.
374 */
375 npxsave(&dummy);
376 stop_emulating();
377 fldcw(&control);
378 if (curpcb != NULL)
379 fnsave(&curpcb->pcb_savefpu);
380 start_emulating();
--- 21 unchanged lines hidden (view full) ---
402 if (masked_exceptions & 0x0d)
403 log(LOG_ERR,
404 "pid %d (%s) exited with masked floating point exceptions 0x%02x\n",
405 p->p_pid, p->p_comm, masked_exceptions);
406 }
407}
408
409/*
410 * Preserve the FP status word, clear FP exceptions, then generate a SIGFPE.
411 *
412 * Clearing exceptions is necessary mainly to avoid IRQ13 bugs. We now
413 * depend on longjmp() restoring a usable state. Restoring the state
414 * or examining it might fail if we didn't clear exceptions.
415 *
416 * XXX there is no standard way to tell SIGFPE handlers about the error
417 * state. The old interface:
418 *
419 * void handler(int sig, int code, struct sigcontext *scp);
420 *
421 * is broken because it is non-ANSI and because the FP state is not in
422 * struct sigcontext.
423 *
424 * XXX the FP state is not preserved across signal handlers. So signal
425 * handlers cannot afford to do FP unless they preserve the state or
426 * longjmp() out. Both preserving the state and longjmp()ing may be
427 * destroyed by IRQ13 bugs. Clearing FP exceptions is not an acceptable
428 * solution for signals other than SIGFPE.
429 */
430void
431npxintr(frame)
432 struct intrframe frame;
433{
434 int code;
435
436 if (npxproc == NULL || !npx_exists) {
437 printf("npxintr: npxproc = %p, curproc = %p, npx_exists = %d\n",
438 npxproc, curproc, npx_exists);
439 panic("npxintr from nowhere");
440 }
441 if (npxproc != curproc) {
442 printf("npxintr: npxproc = %p, curproc = %p, npx_exists = %d\n",
443 npxproc, curproc, npx_exists);
444 panic("npxintr from non-current process");
445 }
446
447 fnstsw(&curpcb->pcb_savefpu.sv_ex_sw);
448 fnclex();
449 outb(0xf0, 0);
450
451 /*
452 * Pass exception to process.
453 */
454 if (ISPL(frame.if_cs) == SEL_UPL) {
455 /*
456 * Interrupt is essentially a trap, so we can afford to call
457 * the SIGFPE handler (if any) as soon as the interrupt
--- 26 unchanged lines hidden (view full) ---
484 * "fstpl _memvar" causes a stack overflow.
485 * These are especially nasty when combined with a
486 * trace trap.
487 * o an IRQ13 occurs at the same time as another higher-
488 * priority interrupt.
489 *
490 * Treat them like a true async interrupt.
491 */
492 psignal(curproc, SIGFPE);
493 }
494}
495
496/*
497 * Implement device not available (DNA) exception
498 *
499 * It would be better to switch FP context here (if curproc != npxproc)
500 * and not necessarily for every context switch, but it is too hard to
501 * access foreign pcb's.
502 */
503int
504npxdna()
505{
506 if (!npx_exists)
507 return (0);
508 if (npxproc != NULL) {
509 printf("npxdna: npxproc = %p, curproc = %p\n",
510 npxproc, curproc);
511 panic("npxdna");
512 }
513 stop_emulating();
514 /*
515 * Record new context early in case frstor causes an IRQ13.
516 */
517 npxproc = curproc;
518 curpcb->pcb_savefpu.sv_ex_sw = 0;
519 /*
520 * The following frstor may cause an IRQ13 when the state being
521 * restored has a pending error. The error will appear to have been
522 * triggered by the current (npx) user instruction even when that
523 * instruction is a no-wait instruction that should not trigger an
524 * error (e.g., fnclex). On at least one 486 system all of the
525 * no-wait instructions are broken the same as frstor, so our
526 * treatment does not amplify the breakage. On at least one
--- 29 unchanged lines hidden (view full) ---
556 old_icu2_mask = inb(IO_ICU2 + 1);
557 save_idt_npxintr = idt[npx_intrno];
558 outb(IO_ICU1 + 1, old_icu1_mask & ~(IRQ_SLAVE | npx0_imask));
559 outb(IO_ICU2 + 1, old_icu2_mask & ~(npx0_imask >> 8));
560 idt[npx_intrno] = npx_idt_probeintr;
561 enable_intr();
562 stop_emulating();
563 fnsave(addr);
564 fnop();
565 outb(0xf0, 0);
566 start_emulating();
567 npxproc = NULL;
568 disable_intr();
569 icu1_mask = inb(IO_ICU1 + 1); /* masks may have changed */
570 icu2_mask = inb(IO_ICU2 + 1);
571 outb(IO_ICU1 + 1,
572 (icu1_mask & ~npx0_imask) | (old_icu1_mask & npx0_imask));
573 outb(IO_ICU2 + 1,
574 (icu2_mask & ~(npx0_imask >> 8))
575 | (old_icu2_mask & (npx0_imask >> 8)));
576 idt[npx_intrno] = save_idt_npxintr;
577 enable_intr(); /* back to usual state */
578}
579
580#endif /* NNPX > 0 */
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:
--- 18 unchanged lines hidden (view full) ---
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 1.17 1994/11/14 14:59:06 bde Exp $
36 */
37
38#include "npx.h"
39#if NNPX > 0
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/conf.h>
--- 15 unchanged lines hidden (view full) ---
59#include <i386/isa/isa.h>
60
61/*
62 * 387 and 287 Numeric Coprocessor Extension (NPX) Driver.
63 */
64
65#ifdef __GNUC__
66
67#define fldcw(addr) __asm("fldcw %0" : : "m" (*(addr)))
68#define fnclex() __asm("fnclex")
69#define fninit() __asm("fninit")
70#define fnop() __asm("fnop")
71#define fnsave(addr) __asm("fnsave %0" : "=m" (*(addr)))
72#define fnstcw(addr) __asm("fnstcw %0" : "=m" (*(addr)))
73#define fnstsw(addr) __asm("fnstsw %0" : "=m" (*(addr)))
74#define fp_divide_by_0() __asm("fldz; fld1; fdiv %st,%st(1); fnop")
75#define frstor(addr) __asm("frstor %0" : : "m" (*(addr)))
76#define start_emulating() __asm("smsw %%ax; orb %0,%%al; lmsw %%ax" \
77 : : "n" (CR0_TS) : "ax")
78#define stop_emulating() __asm("clts")
79
80#else /* not __GNUC__ */
81
82void fldcw __P((caddr_t addr));
83void fnclex __P((void));
84void fninit __P((void));
85void fnop __P((void));
86void fnsave __P((caddr_t addr));
87void fnstcw __P((caddr_t addr));
88void fnstsw __P((caddr_t addr));
89void fp_divide_by_0 __P((void));
90void frstor __P((caddr_t addr));
91void start_emulating __P((void));
92void stop_emulating __P((void));
93
94#endif /* __GNUC__ */
95
96typedef u_char bool_t;
97
98static int npxattach __P((struct isa_device *dvp));
99static int npxprobe __P((struct isa_device *dvp));
100static int npxprobe1 __P((struct isa_device *dvp));
101
102struct isa_driver npxdriver = {
103 npxprobe, npxattach, "npx",
104};
105
106int hw_float; /* XXX currently just alias for npx_exists */
107u_int npx0_imask = SWI_CLOCK_MASK;
108struct proc *npxproc;
109
110static bool_t npx_ex16;
111static bool_t npx_exists;
112static struct gate_descriptor npx_idt_probeintr;
113static int npx_intrno;
114static volatile u_int npx_intrs_while_probing;
115static bool_t npx_irq13;
116static volatile u_int npx_traps_while_probing;
117
118/*
119 * Special interrupt handlers. Someday intr0-intr15 will be used to count
120 * interrupts. We'll still need a special exception 16 handler. The busy
121 * latch stuff in probeintr() can be moved to npxprobe().
122 */
123inthand_t probeintr;
124asm
125("
126 .text
127_probeintr:
128 ss
129 incl _npx_intrs_while_probing
130 pushl %eax
131 movb $0x20,%al # EOI (asm in strings loses cpp features)
132 outb %al,$0xa0 # IO_ICU2
133 outb %al,$0x20 # IO_ICU1
134 movb $0,%al
135 outb %al,$0xf0 # clear BUSY# latch
136 popl %eax
137 iret
138");
139
140inthand_t probetrap;
141asm
--- 51 unchanged lines hidden (view full) ---
193 write_eflags(save_eflags);
194 return (result);
195}
196
197static int
198npxprobe1(dvp)
199 struct isa_device *dvp;
200{
201 u_short control;
202 u_short status;
203
204 /*
205 * Partially reset the coprocessor, if any. Some BIOS's don't reset
206 * it after a warm boot.
207 */
208 outb(0xf1, 0); /* full reset on some systems, NOP on others */
209 outb(0xf0, 0); /* clear BUSY# latch */
210 /*
211 * Prepare to trap all ESC (i.e., NPX) instructions and all WAIT
--- 16 unchanged lines hidden (view full) ---
228 stop_emulating();
229 /*
230 * Finish resetting the coprocessor, if any. If there is an error
231 * pending, then we may get a bogus IRQ13, but probeintr() will handle
232 * it OK. Bogus halts have never been observed, but we enabled
233 * IRQ13 and cleared the BUSY# latch early to handle them anyway.
234 */
235 fninit();
236 fnop(); /* wait for fninit (fwait might hang) */
237 DELAY(1000); /* wait for any IRQ13 */
238#ifdef DIAGNOSTIC
239 if (npx_intrs_while_probing != 0)
240 printf("fninit caused %u bogus npx interrupt(s)\n",
241 npx_intrs_while_probing);
242 if (npx_traps_while_probing != 0)
243 printf("fninit caused %u bogus npx trap(s)\n",
244 npx_traps_while_probing);
245#endif
--- 30 unchanged lines hidden (view full) ---
276 */
277 return (-1);
278 }
279 if (npx_intrs_while_probing != 0) {
280 /*
281 * Bad, we are stuck with IRQ13.
282 */
283 npx_irq13 = 1;
284 /*
285 * npxattach would be too late to set npx0_imask.
286 */
287 npx0_imask |= dvp->id_irq;
288 return (IO_NPXSIZE);
289 }
290 /*
291 * Worse, even IRQ13 is broken. Use emulator.
292 */
293 }
294 }
295 /*
--- 10 unchanged lines hidden (view full) ---
306}
307
308static struct kern_devconf kdc_npx[NNPX] = { {
309 0, 0, 0, /* filled in by dev_attach */
310 "npx", 0, { MDDT_ISA, 0 },
311 isa_generic_externalize, 0, 0, ISA_EXTERNALLEN,
312 &kdc_isa0, /* parent */
313 0, /* parentdata */
314 DC_BUSY,
315 "Floating-point unit"
316} };
317
318static inline void
319npx_registerdev(struct isa_device *id)
320{
321 int unit;
322
323 unit = id->id_unit;
324 if (unit != 0)
325 kdc_npx[unit] = kdc_npx[0];
326 kdc_npx[unit].kdc_unit = unit;
327 kdc_npx[unit].kdc_isa = id;
328 dev_attach(&kdc_npx[unit]);
329}
330
331/*
332 * Attach routine - announce which it is, and wire into system
333 */
334int
335npxattach(dvp)
336 struct isa_device *dvp;
337{
338 printf("npx%d: ", dvp->id_unit);
339 if (npx_ex16)
340 printf("INT 16 interface\n");
341 else if (npx_irq13)
342 printf("IRQ 13 interface\n");
343#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
344 else if (npx_exists) {
345 printf("error reporting broken; using 387 emulator\n");
346 npx_exists = 0;
347 } else
348 printf("387 emulator\n");
349#else
350 else
351 printf("no 387 emulator in kernel!\n");
352#endif
353 npxinit(__INITIAL_NPXCW__);
354 if (npx_exists)
355 npx_registerdev(dvp);
356 return (1); /* XXX unused */
357}
358
359/*
360 * Initialize floating point unit.
361 */
362void
363npxinit(control)
364 u_short control;
365{
366 struct save87 dummy;
367
368 if (!npx_exists)
369 return;
370 /*
371 * fninit has the same h/w bugs as fnsave. Use the detoxified
372 * fnsave to throw away any junk in the fpu. npxsave() initializes
373 * the fpu and sets npxproc = NULL as important side effects.
374 */
375 npxsave(&dummy);
376 stop_emulating();
377 fldcw(&control);
378 if (curpcb != NULL)
379 fnsave(&curpcb->pcb_savefpu);
380 start_emulating();
--- 21 unchanged lines hidden (view full) ---
402 if (masked_exceptions & 0x0d)
403 log(LOG_ERR,
404 "pid %d (%s) exited with masked floating point exceptions 0x%02x\n",
405 p->p_pid, p->p_comm, masked_exceptions);
406 }
407}
408
409/*
410 * Preserve the FP status word, clear FP exceptions, then generate a SIGFPE.
411 *
412 * Clearing exceptions is necessary mainly to avoid IRQ13 bugs. We now
413 * depend on longjmp() restoring a usable state. Restoring the state
414 * or examining it might fail if we didn't clear exceptions.
415 *
416 * XXX there is no standard way to tell SIGFPE handlers about the error
417 * state. The old interface:
418 *
419 * void handler(int sig, int code, struct sigcontext *scp);
420 *
421 * is broken because it is non-ANSI and because the FP state is not in
422 * struct sigcontext.
423 *
424 * XXX the FP state is not preserved across signal handlers. So signal
425 * handlers cannot afford to do FP unless they preserve the state or
426 * longjmp() out. Both preserving the state and longjmp()ing may be
427 * destroyed by IRQ13 bugs. Clearing FP exceptions is not an acceptable
428 * solution for signals other than SIGFPE.
429 */
430void
431npxintr(frame)
432 struct intrframe frame;
433{
434 int code;
435
436 if (npxproc == NULL || !npx_exists) {
437 printf("npxintr: npxproc = %p, curproc = %p, npx_exists = %d\n",
438 npxproc, curproc, npx_exists);
439 panic("npxintr from nowhere");
440 }
441 if (npxproc != curproc) {
442 printf("npxintr: npxproc = %p, curproc = %p, npx_exists = %d\n",
443 npxproc, curproc, npx_exists);
444 panic("npxintr from non-current process");
445 }
446
447 fnstsw(&curpcb->pcb_savefpu.sv_ex_sw);
448 fnclex();
449 outb(0xf0, 0);
450
451 /*
452 * Pass exception to process.
453 */
454 if (ISPL(frame.if_cs) == SEL_UPL) {
455 /*
456 * Interrupt is essentially a trap, so we can afford to call
457 * the SIGFPE handler (if any) as soon as the interrupt
--- 26 unchanged lines hidden (view full) ---
484 * "fstpl _memvar" causes a stack overflow.
485 * These are especially nasty when combined with a
486 * trace trap.
487 * o an IRQ13 occurs at the same time as another higher-
488 * priority interrupt.
489 *
490 * Treat them like a true async interrupt.
491 */
492 psignal(curproc, SIGFPE);
493 }
494}
495
496/*
497 * Implement device not available (DNA) exception
498 *
499 * It would be better to switch FP context here (if curproc != npxproc)
500 * and not necessarily for every context switch, but it is too hard to
501 * access foreign pcb's.
502 */
503int
504npxdna()
505{
506 if (!npx_exists)
507 return (0);
508 if (npxproc != NULL) {
509 printf("npxdna: npxproc = %p, curproc = %p\n",
510 npxproc, curproc);
511 panic("npxdna");
512 }
513 stop_emulating();
514 /*
515 * Record new context early in case frstor causes an IRQ13.
516 */
517 npxproc = curproc;
518 curpcb->pcb_savefpu.sv_ex_sw = 0;
519 /*
520 * The following frstor may cause an IRQ13 when the state being
521 * restored has a pending error. The error will appear to have been
522 * triggered by the current (npx) user instruction even when that
523 * instruction is a no-wait instruction that should not trigger an
524 * error (e.g., fnclex). On at least one 486 system all of the
525 * no-wait instructions are broken the same as frstor, so our
526 * treatment does not amplify the breakage. On at least one
--- 29 unchanged lines hidden (view full) ---
556 old_icu2_mask = inb(IO_ICU2 + 1);
557 save_idt_npxintr = idt[npx_intrno];
558 outb(IO_ICU1 + 1, old_icu1_mask & ~(IRQ_SLAVE | npx0_imask));
559 outb(IO_ICU2 + 1, old_icu2_mask & ~(npx0_imask >> 8));
560 idt[npx_intrno] = npx_idt_probeintr;
561 enable_intr();
562 stop_emulating();
563 fnsave(addr);
564 fnop();
565 outb(0xf0, 0);
566 start_emulating();
567 npxproc = NULL;
568 disable_intr();
569 icu1_mask = inb(IO_ICU1 + 1); /* masks may have changed */
570 icu2_mask = inb(IO_ICU2 + 1);
571 outb(IO_ICU1 + 1,
572 (icu1_mask & ~npx0_imask) | (old_icu1_mask & npx0_imask));
573 outb(IO_ICU2 + 1,
574 (icu2_mask & ~(npx0_imask >> 8))
575 | (old_icu2_mask & (npx0_imask >> 8)));
576 idt[npx_intrno] = save_idt_npxintr;
577 enable_intr(); /* back to usual state */
578}
579
580#endif /* NNPX > 0 */