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 */ |