npx.c revision 115703
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 */ 36 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: head/sys/i386/isa/npx.c 115703 2003-06-02 16:32:55Z obrien $"); 39 40#include "opt_cpu.h" 41#include "opt_debug_npx.h" 42#include "opt_isa.h" 43#include "opt_math_emulate.h" 44#include "opt_npx.h" 45 46#include <sys/param.h> 47#include <sys/systm.h> 48#include <sys/bus.h> 49#include <sys/kernel.h> 50#include <sys/lock.h> 51#include <sys/malloc.h> 52#include <sys/module.h> 53#include <sys/mutex.h> 54#include <sys/mutex.h> 55#include <sys/proc.h> 56#include <sys/sysctl.h> 57#include <machine/bus.h> 58#include <sys/rman.h> 59#ifdef NPX_DEBUG 60#include <sys/syslog.h> 61#endif 62#include <sys/signalvar.h> 63#include <sys/user.h> 64 65#ifndef SMP 66#include <machine/asmacros.h> 67#endif 68#include <machine/cputypes.h> 69#include <machine/frame.h> 70#include <machine/md_var.h> 71#include <machine/pcb.h> 72#include <machine/psl.h> 73#ifndef SMP 74#include <machine/clock.h> 75#endif 76#include <machine/resource.h> 77#include <machine/specialreg.h> 78#include <machine/segments.h> 79#include <machine/ucontext.h> 80 81#ifndef SMP 82#include <i386/isa/icu.h> 83#ifdef PC98 84#include <pc98/pc98/pc98.h> 85#else 86#include <i386/isa/isa.h> 87#endif 88#endif 89#include <i386/isa/intr_machdep.h> 90#ifdef DEV_ISA 91#include <isa/isavar.h> 92#endif 93 94#if !defined(CPU_ENABLE_SSE) && defined(I686_CPU) 95#define CPU_ENABLE_SSE 96#endif 97#if defined(CPU_DISABLE_SSE) 98#undef CPU_ENABLE_SSE 99#endif 100 101/* 102 * 387 and 287 Numeric Coprocessor Extension (NPX) Driver. 103 */ 104 105/* Configuration flags. */ 106#define NPX_DISABLE_I586_OPTIMIZED_BCOPY (1 << 0) 107#define NPX_DISABLE_I586_OPTIMIZED_BZERO (1 << 1) 108#define NPX_DISABLE_I586_OPTIMIZED_COPYIO (1 << 2) 109#define NPX_PREFER_EMULATOR (1 << 3) 110 111#if defined(__GNUC__) && !defined(lint) 112 113#define fldcw(addr) __asm("fldcw %0" : : "m" (*(addr))) 114#define fnclex() __asm("fnclex") 115#define fninit() __asm("fninit") 116#define fnsave(addr) __asm __volatile("fnsave %0" : "=m" (*(addr))) 117#define fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) 118#define fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr))) 119#define fp_divide_by_0() __asm("fldz; fld1; fdiv %st,%st(1); fnop") 120#define frstor(addr) __asm("frstor %0" : : "m" (*(addr))) 121#ifdef CPU_ENABLE_SSE 122#define fxrstor(addr) __asm("fxrstor %0" : : "m" (*(addr))) 123#define fxsave(addr) __asm __volatile("fxsave %0" : "=m" (*(addr))) 124#endif 125#define start_emulating() __asm("smsw %%ax; orb %0,%%al; lmsw %%ax" \ 126 : : "n" (CR0_TS) : "ax") 127#define stop_emulating() __asm("clts") 128 129#else /* not __GNUC__ */ 130 131void fldcw(caddr_t addr); 132void fnclex(void); 133void fninit(void); 134void fnsave(caddr_t addr); 135void fnstcw(caddr_t addr); 136void fnstsw(caddr_t addr); 137void fp_divide_by_0(void); 138void frstor(caddr_t addr); 139#ifdef CPU_ENABLE_SSE 140void fxsave(caddr_t addr); 141void fxrstor(caddr_t addr); 142#endif 143void start_emulating(void); 144void stop_emulating(void); 145 146#endif /* __GNUC__ */ 147 148#ifdef CPU_ENABLE_SSE 149#define GET_FPU_CW(thread) \ 150 (cpu_fxsr ? \ 151 (thread)->td_pcb->pcb_save.sv_xmm.sv_env.en_cw : \ 152 (thread)->td_pcb->pcb_save.sv_87.sv_env.en_cw) 153#define GET_FPU_SW(thread) \ 154 (cpu_fxsr ? \ 155 (thread)->td_pcb->pcb_save.sv_xmm.sv_env.en_sw : \ 156 (thread)->td_pcb->pcb_save.sv_87.sv_env.en_sw) 157#else /* CPU_ENABLE_SSE */ 158#define GET_FPU_CW(thread) \ 159 (thread->td_pcb->pcb_save.sv_87.sv_env.en_cw) 160#define GET_FPU_SW(thread) \ 161 (thread->td_pcb->pcb_save.sv_87.sv_env.en_sw) 162#endif /* CPU_ENABLE_SSE */ 163 164typedef u_char bool_t; 165 166static void fpusave(union savefpu *); 167static void fpurstor(union savefpu *); 168static int npx_attach(device_t dev); 169static void npx_identify(driver_t *driver, device_t parent); 170#ifndef SMP 171static void npx_intr(void *); 172#endif 173static int npx_probe(device_t dev); 174#ifdef I586_CPU_XXX 175static long timezero(const char *funcname, 176 void (*func)(void *buf, size_t len)); 177#endif /* I586_CPU */ 178 179int hw_float; /* XXX currently just alias for npx_exists */ 180 181SYSCTL_INT(_hw,HW_FLOATINGPT, floatingpoint, 182 CTLFLAG_RD, &hw_float, 0, 183 "Floatingpoint instructions executed in hardware"); 184 185#ifndef SMP 186static volatile u_int npx_intrs_while_probing; 187static volatile u_int npx_traps_while_probing; 188#endif 189 190static union savefpu npx_cleanstate; 191static bool_t npx_cleanstate_ready; 192static bool_t npx_ex16; 193static bool_t npx_exists; 194static bool_t npx_irq13; 195 196#ifndef SMP 197alias_for_inthand_t probetrap; 198__asm(" \n\ 199 .text \n\ 200 .p2align 2,0x90 \n\ 201 .type " __XSTRING(CNAME(probetrap)) ",@function \n\ 202" __XSTRING(CNAME(probetrap)) ": \n\ 203 ss \n\ 204 incl " __XSTRING(CNAME(npx_traps_while_probing)) " \n\ 205 fnclex \n\ 206 iret \n\ 207"); 208#endif /* SMP */ 209 210/* 211 * Identify routine. Create a connection point on our parent for probing. 212 */ 213static void 214npx_identify(driver, parent) 215 driver_t *driver; 216 device_t parent; 217{ 218 device_t child; 219 220 child = BUS_ADD_CHILD(parent, 0, "npx", 0); 221 if (child == NULL) 222 panic("npx_identify"); 223} 224 225#ifndef SMP 226/* 227 * Do minimal handling of npx interrupts to convert them to traps. 228 */ 229static void 230npx_intr(dummy) 231 void *dummy; 232{ 233 struct thread *td; 234 235#ifndef SMP 236 npx_intrs_while_probing++; 237#endif 238 239 /* 240 * The BUSY# latch must be cleared in all cases so that the next 241 * unmasked npx exception causes an interrupt. 242 */ 243#ifdef PC98 244 outb(0xf8, 0); 245#else 246 outb(0xf0, 0); 247#endif 248 249 /* 250 * fpcurthread is normally non-null here. In that case, schedule an 251 * AST to finish the exception handling in the correct context 252 * (this interrupt may occur after the thread has entered the 253 * kernel via a syscall or an interrupt). Otherwise, the npx 254 * state of the thread that caused this interrupt must have been 255 * pushed to the thread's pcb, and clearing of the busy latch 256 * above has finished the (essentially null) handling of this 257 * interrupt. Control will eventually return to the instruction 258 * that caused it and it will repeat. We will eventually (usually 259 * soon) win the race to handle the interrupt properly. 260 */ 261 td = PCPU_GET(fpcurthread); 262 if (td != NULL) { 263 td->td_pcb->pcb_flags |= PCB_NPXTRAP; 264 mtx_lock_spin(&sched_lock); 265 td->td_flags |= TDF_ASTPENDING; 266 mtx_unlock_spin(&sched_lock); 267 } 268} 269#endif /* !SMP */ 270 271/* 272 * Probe routine. Initialize cr0 to give correct behaviour for [f]wait 273 * whether the device exists or not (XXX should be elsewhere). Set flags 274 * to tell npxattach() what to do. Modify device struct if npx doesn't 275 * need to use interrupts. Return 0 if device exists. 276 */ 277static int 278npx_probe(dev) 279 device_t dev; 280{ 281#ifndef SMP 282 struct gate_descriptor save_idt_npxtrap; 283 struct resource *ioport_res, *irq_res; 284 void *irq_cookie; 285 int ioport_rid, irq_num, irq_rid; 286 u_short control; 287 u_short status; 288 289 save_idt_npxtrap = idt[16]; 290 setidt(16, probetrap, SDT_SYS386TGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL)); 291 ioport_rid = 0; 292 ioport_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &ioport_rid, 293 IO_NPX, IO_NPX, IO_NPXSIZE, RF_ACTIVE); 294 if (ioport_res == NULL) 295 panic("npx: can't get ports"); 296#ifdef PC98 297 if (resource_int_value("npx", 0, "irq", &irq_num) != 0) 298 irq_num = 8; 299#else 300 if (resource_int_value("npx", 0, "irq", &irq_num) != 0) 301 irq_num = 13; 302#endif 303 irq_rid = 0; 304 irq_res = bus_alloc_resource(dev, SYS_RES_IRQ, &irq_rid, irq_num, 305 irq_num, 1, RF_ACTIVE); 306 if (irq_res == NULL) 307 panic("npx: can't get IRQ"); 308 if (bus_setup_intr(dev, irq_res, INTR_TYPE_MISC | INTR_FAST, npx_intr, 309 NULL, &irq_cookie) != 0) 310 panic("npx: can't create intr"); 311#endif /* !SMP */ 312 313 /* 314 * Partially reset the coprocessor, if any. Some BIOS's don't reset 315 * it after a warm boot. 316 */ 317#ifdef PC98 318 outb(0xf8,0); 319#else 320 outb(0xf1, 0); /* full reset on some systems, NOP on others */ 321 outb(0xf0, 0); /* clear BUSY# latch */ 322#endif 323 /* 324 * Prepare to trap all ESC (i.e., NPX) instructions and all WAIT 325 * instructions. We must set the CR0_MP bit and use the CR0_TS 326 * bit to control the trap, because setting the CR0_EM bit does 327 * not cause WAIT instructions to trap. It's important to trap 328 * WAIT instructions - otherwise the "wait" variants of no-wait 329 * control instructions would degenerate to the "no-wait" variants 330 * after FP context switches but work correctly otherwise. It's 331 * particularly important to trap WAITs when there is no NPX - 332 * otherwise the "wait" variants would always degenerate. 333 * 334 * Try setting CR0_NE to get correct error reporting on 486DX's. 335 * Setting it should fail or do nothing on lesser processors. 336 */ 337 load_cr0(rcr0() | CR0_MP | CR0_NE); 338 /* 339 * But don't trap while we're probing. 340 */ 341 stop_emulating(); 342 /* 343 * Finish resetting the coprocessor, if any. If there is an error 344 * pending, then we may get a bogus IRQ13, but npx_intr() will handle 345 * it OK. Bogus halts have never been observed, but we enabled 346 * IRQ13 and cleared the BUSY# latch early to handle them anyway. 347 */ 348 fninit(); 349 350 device_set_desc(dev, "math processor"); 351 352#ifdef SMP 353 354 /* 355 * Exception 16 MUST work for SMP. 356 */ 357 npx_ex16 = hw_float = npx_exists = 1; 358 return (0); 359 360#else /* !SMP */ 361 362 /* 363 * Don't use fwait here because it might hang. 364 * Don't use fnop here because it usually hangs if there is no FPU. 365 */ 366 DELAY(1000); /* wait for any IRQ13 */ 367#ifdef DIAGNOSTIC 368 if (npx_intrs_while_probing != 0) 369 printf("fninit caused %u bogus npx interrupt(s)\n", 370 npx_intrs_while_probing); 371 if (npx_traps_while_probing != 0) 372 printf("fninit caused %u bogus npx trap(s)\n", 373 npx_traps_while_probing); 374#endif 375 /* 376 * Check for a status of mostly zero. 377 */ 378 status = 0x5a5a; 379 fnstsw(&status); 380 if ((status & 0xb8ff) == 0) { 381 /* 382 * Good, now check for a proper control word. 383 */ 384 control = 0x5a5a; 385 fnstcw(&control); 386 if ((control & 0x1f3f) == 0x033f) { 387 hw_float = npx_exists = 1; 388 /* 389 * We have an npx, now divide by 0 to see if exception 390 * 16 works. 391 */ 392 control &= ~(1 << 2); /* enable divide by 0 trap */ 393 fldcw(&control); 394#ifdef FPU_ERROR_BROKEN 395 /* 396 * FPU error signal doesn't work on some CPU 397 * accelerator board. 398 */ 399 npx_ex16 = 1; 400 return (0); 401#endif 402 npx_traps_while_probing = npx_intrs_while_probing = 0; 403 fp_divide_by_0(); 404 if (npx_traps_while_probing != 0) { 405 /* 406 * Good, exception 16 works. 407 */ 408 npx_ex16 = 1; 409 goto no_irq13; 410 } 411 if (npx_intrs_while_probing != 0) { 412 /* 413 * Bad, we are stuck with IRQ13. 414 */ 415 npx_irq13 = 1; 416 idt[16] = save_idt_npxtrap; 417 return (0); 418 } 419 /* 420 * Worse, even IRQ13 is broken. Use emulator. 421 */ 422 } 423 } 424 /* 425 * Probe failed, but we want to get to npxattach to initialize the 426 * emulator and say that it has been installed. XXX handle devices 427 * that aren't really devices better. 428 */ 429 /* FALLTHROUGH */ 430no_irq13: 431 idt[16] = save_idt_npxtrap; 432 bus_teardown_intr(dev, irq_res, irq_cookie); 433 434 /* 435 * XXX hack around brokenness of bus_teardown_intr(). If we left the 436 * irq active then we would get it instead of exception 16. 437 */ 438 { 439 register_t crit; 440 441 crit = intr_disable(); 442 mtx_lock_spin(&icu_lock); 443 INTRDIS(1 << irq_num); 444 mtx_unlock_spin(&icu_lock); 445 intr_restore(crit); 446 } 447 448 bus_release_resource(dev, SYS_RES_IRQ, irq_rid, irq_res); 449 bus_release_resource(dev, SYS_RES_IOPORT, ioport_rid, ioport_res); 450 return (0); 451 452#endif /* SMP */ 453} 454 455/* 456 * Attach routine - announce which it is, and wire into system 457 */ 458static int 459npx_attach(dev) 460 device_t dev; 461{ 462 int flags; 463 register_t s; 464 465 if (resource_int_value("npx", 0, "flags", &flags) != 0) 466 flags = 0; 467 468 if (flags) 469 device_printf(dev, "flags 0x%x ", flags); 470 if (npx_irq13) { 471 device_printf(dev, "using IRQ 13 interface\n"); 472 } else { 473#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE) 474 if (npx_ex16) { 475 if (!(flags & NPX_PREFER_EMULATOR)) 476 device_printf(dev, "INT 16 interface\n"); 477 else { 478 device_printf(dev, "FPU exists, but flags request " 479 "emulator\n"); 480 hw_float = npx_exists = 0; 481 } 482 } else if (npx_exists) { 483 device_printf(dev, "error reporting broken; using 387 emulator\n"); 484 hw_float = npx_exists = 0; 485 } else 486 device_printf(dev, "387 emulator\n"); 487#else 488 if (npx_ex16) { 489 device_printf(dev, "INT 16 interface\n"); 490 if (flags & NPX_PREFER_EMULATOR) { 491 device_printf(dev, "emulator requested, but none compiled " 492 "into kernel, using FPU\n"); 493 } 494 } else 495 device_printf(dev, "no 387 emulator in kernel and no FPU!\n"); 496#endif 497 } 498 npxinit(__INITIAL_NPXCW__); 499 500 if (npx_cleanstate_ready == 0) { 501 s = intr_disable(); 502 stop_emulating(); 503 fpusave(&npx_cleanstate); 504 start_emulating(); 505 npx_cleanstate_ready = 1; 506 intr_restore(s); 507 } 508#ifdef I586_CPU_XXX 509 if (cpu_class == CPUCLASS_586 && npx_ex16 && npx_exists && 510 timezero("i586_bzero()", i586_bzero) < 511 timezero("bzero()", bzero) * 4 / 5) { 512 if (!(flags & NPX_DISABLE_I586_OPTIMIZED_BCOPY)) 513 bcopy_vector = i586_bcopy; 514 if (!(flags & NPX_DISABLE_I586_OPTIMIZED_BZERO)) 515 bzero_vector = i586_bzero; 516 if (!(flags & NPX_DISABLE_I586_OPTIMIZED_COPYIO)) { 517 copyin_vector = i586_copyin; 518 copyout_vector = i586_copyout; 519 } 520 } 521#endif 522 523 return (0); /* XXX unused */ 524} 525 526/* 527 * Initialize floating point unit. 528 */ 529void 530npxinit(control) 531 u_short control; 532{ 533 static union savefpu dummy; 534 register_t savecrit; 535 536 if (!npx_exists) 537 return; 538 /* 539 * fninit has the same h/w bugs as fnsave. Use the detoxified 540 * fnsave to throw away any junk in the fpu. npxsave() initializes 541 * the fpu and sets fpcurthread = NULL as important side effects. 542 */ 543 savecrit = intr_disable(); 544 npxsave(&dummy); 545 stop_emulating(); 546#ifdef CPU_ENABLE_SSE 547 /* XXX npxsave() doesn't actually initialize the fpu in the SSE case. */ 548 if (cpu_fxsr) 549 fninit(); 550#endif 551 fldcw(&control); 552 start_emulating(); 553 intr_restore(savecrit); 554} 555 556/* 557 * Free coprocessor (if we have it). 558 */ 559void 560npxexit(td) 561 struct thread *td; 562{ 563 register_t savecrit; 564 565 savecrit = intr_disable(); 566 if (curthread == PCPU_GET(fpcurthread)) 567 npxsave(&PCPU_GET(curpcb)->pcb_save); 568 intr_restore(savecrit); 569#ifdef NPX_DEBUG 570 if (npx_exists) { 571 u_int masked_exceptions; 572 573 masked_exceptions = GET_FPU_CW(td) & GET_FPU_SW(td) & 0x7f; 574 /* 575 * Log exceptions that would have trapped with the old 576 * control word (overflow, divide by 0, and invalid operand). 577 */ 578 if (masked_exceptions & 0x0d) 579 log(LOG_ERR, 580 "pid %d (%s) exited with masked floating point exceptions 0x%02x\n", 581 td->td_proc->p_pid, td->td_proc->p_comm, 582 masked_exceptions); 583 } 584#endif 585} 586 587int 588npxformat() 589{ 590 591 if (!npx_exists) 592 return (_MC_FPFMT_NODEV); 593#ifdef CPU_ENABLE_SSE 594 if (cpu_fxsr) 595 return (_MC_FPFMT_XMM); 596#endif 597 return (_MC_FPFMT_387); 598} 599 600/* 601 * The following mechanism is used to ensure that the FPE_... value 602 * that is passed as a trapcode to the signal handler of the user 603 * process does not have more than one bit set. 604 * 605 * Multiple bits may be set if the user process modifies the control 606 * word while a status word bit is already set. While this is a sign 607 * of bad coding, we have no choise than to narrow them down to one 608 * bit, since we must not send a trapcode that is not exactly one of 609 * the FPE_ macros. 610 * 611 * The mechanism has a static table with 127 entries. Each combination 612 * of the 7 FPU status word exception bits directly translates to a 613 * position in this table, where a single FPE_... value is stored. 614 * This FPE_... value stored there is considered the "most important" 615 * of the exception bits and will be sent as the signal code. The 616 * precedence of the bits is based upon Intel Document "Numerical 617 * Applications", Chapter "Special Computational Situations". 618 * 619 * The macro to choose one of these values does these steps: 1) Throw 620 * away status word bits that cannot be masked. 2) Throw away the bits 621 * currently masked in the control word, assuming the user isn't 622 * interested in them anymore. 3) Reinsert status word bit 7 (stack 623 * fault) if it is set, which cannot be masked but must be presered. 624 * 4) Use the remaining bits to point into the trapcode table. 625 * 626 * The 6 maskable bits in order of their preference, as stated in the 627 * above referenced Intel manual: 628 * 1 Invalid operation (FP_X_INV) 629 * 1a Stack underflow 630 * 1b Stack overflow 631 * 1c Operand of unsupported format 632 * 1d SNaN operand. 633 * 2 QNaN operand (not an exception, irrelavant here) 634 * 3 Any other invalid-operation not mentioned above or zero divide 635 * (FP_X_INV, FP_X_DZ) 636 * 4 Denormal operand (FP_X_DNML) 637 * 5 Numeric over/underflow (FP_X_OFL, FP_X_UFL) 638 * 6 Inexact result (FP_X_IMP) 639 */ 640static char fpetable[128] = { 641 0, 642 FPE_FLTINV, /* 1 - INV */ 643 FPE_FLTUND, /* 2 - DNML */ 644 FPE_FLTINV, /* 3 - INV | DNML */ 645 FPE_FLTDIV, /* 4 - DZ */ 646 FPE_FLTINV, /* 5 - INV | DZ */ 647 FPE_FLTDIV, /* 6 - DNML | DZ */ 648 FPE_FLTINV, /* 7 - INV | DNML | DZ */ 649 FPE_FLTOVF, /* 8 - OFL */ 650 FPE_FLTINV, /* 9 - INV | OFL */ 651 FPE_FLTUND, /* A - DNML | OFL */ 652 FPE_FLTINV, /* B - INV | DNML | OFL */ 653 FPE_FLTDIV, /* C - DZ | OFL */ 654 FPE_FLTINV, /* D - INV | DZ | OFL */ 655 FPE_FLTDIV, /* E - DNML | DZ | OFL */ 656 FPE_FLTINV, /* F - INV | DNML | DZ | OFL */ 657 FPE_FLTUND, /* 10 - UFL */ 658 FPE_FLTINV, /* 11 - INV | UFL */ 659 FPE_FLTUND, /* 12 - DNML | UFL */ 660 FPE_FLTINV, /* 13 - INV | DNML | UFL */ 661 FPE_FLTDIV, /* 14 - DZ | UFL */ 662 FPE_FLTINV, /* 15 - INV | DZ | UFL */ 663 FPE_FLTDIV, /* 16 - DNML | DZ | UFL */ 664 FPE_FLTINV, /* 17 - INV | DNML | DZ | UFL */ 665 FPE_FLTOVF, /* 18 - OFL | UFL */ 666 FPE_FLTINV, /* 19 - INV | OFL | UFL */ 667 FPE_FLTUND, /* 1A - DNML | OFL | UFL */ 668 FPE_FLTINV, /* 1B - INV | DNML | OFL | UFL */ 669 FPE_FLTDIV, /* 1C - DZ | OFL | UFL */ 670 FPE_FLTINV, /* 1D - INV | DZ | OFL | UFL */ 671 FPE_FLTDIV, /* 1E - DNML | DZ | OFL | UFL */ 672 FPE_FLTINV, /* 1F - INV | DNML | DZ | OFL | UFL */ 673 FPE_FLTRES, /* 20 - IMP */ 674 FPE_FLTINV, /* 21 - INV | IMP */ 675 FPE_FLTUND, /* 22 - DNML | IMP */ 676 FPE_FLTINV, /* 23 - INV | DNML | IMP */ 677 FPE_FLTDIV, /* 24 - DZ | IMP */ 678 FPE_FLTINV, /* 25 - INV | DZ | IMP */ 679 FPE_FLTDIV, /* 26 - DNML | DZ | IMP */ 680 FPE_FLTINV, /* 27 - INV | DNML | DZ | IMP */ 681 FPE_FLTOVF, /* 28 - OFL | IMP */ 682 FPE_FLTINV, /* 29 - INV | OFL | IMP */ 683 FPE_FLTUND, /* 2A - DNML | OFL | IMP */ 684 FPE_FLTINV, /* 2B - INV | DNML | OFL | IMP */ 685 FPE_FLTDIV, /* 2C - DZ | OFL | IMP */ 686 FPE_FLTINV, /* 2D - INV | DZ | OFL | IMP */ 687 FPE_FLTDIV, /* 2E - DNML | DZ | OFL | IMP */ 688 FPE_FLTINV, /* 2F - INV | DNML | DZ | OFL | IMP */ 689 FPE_FLTUND, /* 30 - UFL | IMP */ 690 FPE_FLTINV, /* 31 - INV | UFL | IMP */ 691 FPE_FLTUND, /* 32 - DNML | UFL | IMP */ 692 FPE_FLTINV, /* 33 - INV | DNML | UFL | IMP */ 693 FPE_FLTDIV, /* 34 - DZ | UFL | IMP */ 694 FPE_FLTINV, /* 35 - INV | DZ | UFL | IMP */ 695 FPE_FLTDIV, /* 36 - DNML | DZ | UFL | IMP */ 696 FPE_FLTINV, /* 37 - INV | DNML | DZ | UFL | IMP */ 697 FPE_FLTOVF, /* 38 - OFL | UFL | IMP */ 698 FPE_FLTINV, /* 39 - INV | OFL | UFL | IMP */ 699 FPE_FLTUND, /* 3A - DNML | OFL | UFL | IMP */ 700 FPE_FLTINV, /* 3B - INV | DNML | OFL | UFL | IMP */ 701 FPE_FLTDIV, /* 3C - DZ | OFL | UFL | IMP */ 702 FPE_FLTINV, /* 3D - INV | DZ | OFL | UFL | IMP */ 703 FPE_FLTDIV, /* 3E - DNML | DZ | OFL | UFL | IMP */ 704 FPE_FLTINV, /* 3F - INV | DNML | DZ | OFL | UFL | IMP */ 705 FPE_FLTSUB, /* 40 - STK */ 706 FPE_FLTSUB, /* 41 - INV | STK */ 707 FPE_FLTUND, /* 42 - DNML | STK */ 708 FPE_FLTSUB, /* 43 - INV | DNML | STK */ 709 FPE_FLTDIV, /* 44 - DZ | STK */ 710 FPE_FLTSUB, /* 45 - INV | DZ | STK */ 711 FPE_FLTDIV, /* 46 - DNML | DZ | STK */ 712 FPE_FLTSUB, /* 47 - INV | DNML | DZ | STK */ 713 FPE_FLTOVF, /* 48 - OFL | STK */ 714 FPE_FLTSUB, /* 49 - INV | OFL | STK */ 715 FPE_FLTUND, /* 4A - DNML | OFL | STK */ 716 FPE_FLTSUB, /* 4B - INV | DNML | OFL | STK */ 717 FPE_FLTDIV, /* 4C - DZ | OFL | STK */ 718 FPE_FLTSUB, /* 4D - INV | DZ | OFL | STK */ 719 FPE_FLTDIV, /* 4E - DNML | DZ | OFL | STK */ 720 FPE_FLTSUB, /* 4F - INV | DNML | DZ | OFL | STK */ 721 FPE_FLTUND, /* 50 - UFL | STK */ 722 FPE_FLTSUB, /* 51 - INV | UFL | STK */ 723 FPE_FLTUND, /* 52 - DNML | UFL | STK */ 724 FPE_FLTSUB, /* 53 - INV | DNML | UFL | STK */ 725 FPE_FLTDIV, /* 54 - DZ | UFL | STK */ 726 FPE_FLTSUB, /* 55 - INV | DZ | UFL | STK */ 727 FPE_FLTDIV, /* 56 - DNML | DZ | UFL | STK */ 728 FPE_FLTSUB, /* 57 - INV | DNML | DZ | UFL | STK */ 729 FPE_FLTOVF, /* 58 - OFL | UFL | STK */ 730 FPE_FLTSUB, /* 59 - INV | OFL | UFL | STK */ 731 FPE_FLTUND, /* 5A - DNML | OFL | UFL | STK */ 732 FPE_FLTSUB, /* 5B - INV | DNML | OFL | UFL | STK */ 733 FPE_FLTDIV, /* 5C - DZ | OFL | UFL | STK */ 734 FPE_FLTSUB, /* 5D - INV | DZ | OFL | UFL | STK */ 735 FPE_FLTDIV, /* 5E - DNML | DZ | OFL | UFL | STK */ 736 FPE_FLTSUB, /* 5F - INV | DNML | DZ | OFL | UFL | STK */ 737 FPE_FLTRES, /* 60 - IMP | STK */ 738 FPE_FLTSUB, /* 61 - INV | IMP | STK */ 739 FPE_FLTUND, /* 62 - DNML | IMP | STK */ 740 FPE_FLTSUB, /* 63 - INV | DNML | IMP | STK */ 741 FPE_FLTDIV, /* 64 - DZ | IMP | STK */ 742 FPE_FLTSUB, /* 65 - INV | DZ | IMP | STK */ 743 FPE_FLTDIV, /* 66 - DNML | DZ | IMP | STK */ 744 FPE_FLTSUB, /* 67 - INV | DNML | DZ | IMP | STK */ 745 FPE_FLTOVF, /* 68 - OFL | IMP | STK */ 746 FPE_FLTSUB, /* 69 - INV | OFL | IMP | STK */ 747 FPE_FLTUND, /* 6A - DNML | OFL | IMP | STK */ 748 FPE_FLTSUB, /* 6B - INV | DNML | OFL | IMP | STK */ 749 FPE_FLTDIV, /* 6C - DZ | OFL | IMP | STK */ 750 FPE_FLTSUB, /* 6D - INV | DZ | OFL | IMP | STK */ 751 FPE_FLTDIV, /* 6E - DNML | DZ | OFL | IMP | STK */ 752 FPE_FLTSUB, /* 6F - INV | DNML | DZ | OFL | IMP | STK */ 753 FPE_FLTUND, /* 70 - UFL | IMP | STK */ 754 FPE_FLTSUB, /* 71 - INV | UFL | IMP | STK */ 755 FPE_FLTUND, /* 72 - DNML | UFL | IMP | STK */ 756 FPE_FLTSUB, /* 73 - INV | DNML | UFL | IMP | STK */ 757 FPE_FLTDIV, /* 74 - DZ | UFL | IMP | STK */ 758 FPE_FLTSUB, /* 75 - INV | DZ | UFL | IMP | STK */ 759 FPE_FLTDIV, /* 76 - DNML | DZ | UFL | IMP | STK */ 760 FPE_FLTSUB, /* 77 - INV | DNML | DZ | UFL | IMP | STK */ 761 FPE_FLTOVF, /* 78 - OFL | UFL | IMP | STK */ 762 FPE_FLTSUB, /* 79 - INV | OFL | UFL | IMP | STK */ 763 FPE_FLTUND, /* 7A - DNML | OFL | UFL | IMP | STK */ 764 FPE_FLTSUB, /* 7B - INV | DNML | OFL | UFL | IMP | STK */ 765 FPE_FLTDIV, /* 7C - DZ | OFL | UFL | IMP | STK */ 766 FPE_FLTSUB, /* 7D - INV | DZ | OFL | UFL | IMP | STK */ 767 FPE_FLTDIV, /* 7E - DNML | DZ | OFL | UFL | IMP | STK */ 768 FPE_FLTSUB, /* 7F - INV | DNML | DZ | OFL | UFL | IMP | STK */ 769}; 770 771/* 772 * Preserve the FP status word, clear FP exceptions, then generate a SIGFPE. 773 * 774 * Clearing exceptions is necessary mainly to avoid IRQ13 bugs. We now 775 * depend on longjmp() restoring a usable state. Restoring the state 776 * or examining it might fail if we didn't clear exceptions. 777 * 778 * The error code chosen will be one of the FPE_... macros. It will be 779 * sent as the second argument to old BSD-style signal handlers and as 780 * "siginfo_t->si_code" (second argument) to SA_SIGINFO signal handlers. 781 * 782 * XXX the FP state is not preserved across signal handlers. So signal 783 * handlers cannot afford to do FP unless they preserve the state or 784 * longjmp() out. Both preserving the state and longjmp()ing may be 785 * destroyed by IRQ13 bugs. Clearing FP exceptions is not an acceptable 786 * solution for signals other than SIGFPE. 787 */ 788int 789npxtrap() 790{ 791 register_t savecrit; 792 u_short control, status; 793 794 if (!npx_exists) { 795 printf("npxtrap: fpcurthread = %p, curthread = %p, npx_exists = %d\n", 796 PCPU_GET(fpcurthread), curthread, npx_exists); 797 panic("npxtrap from nowhere"); 798 } 799 savecrit = intr_disable(); 800 801 /* 802 * Interrupt handling (for another interrupt) may have pushed the 803 * state to memory. Fetch the relevant parts of the state from 804 * wherever they are. 805 */ 806 if (PCPU_GET(fpcurthread) != curthread) { 807 control = GET_FPU_CW(curthread); 808 status = GET_FPU_SW(curthread); 809 } else { 810 fnstcw(&control); 811 fnstsw(&status); 812 } 813 814 if (PCPU_GET(fpcurthread) == curthread) 815 fnclex(); 816 intr_restore(savecrit); 817 return (fpetable[status & ((~control & 0x3f) | 0x40)]); 818} 819 820/* 821 * Implement device not available (DNA) exception 822 * 823 * It would be better to switch FP context here (if curthread != fpcurthread) 824 * and not necessarily for every context switch, but it is too hard to 825 * access foreign pcb's. 826 */ 827 828static int err_count = 0; 829 830int 831npxdna() 832{ 833 struct pcb *pcb; 834 register_t s; 835 u_short control; 836 837 if (!npx_exists) 838 return (0); 839 if (PCPU_GET(fpcurthread) == curthread) { 840 printf("npxdna: fpcurthread == curthread %d times\n", 841 ++err_count); 842 stop_emulating(); 843 return (1); 844 } 845 if (PCPU_GET(fpcurthread) != NULL) { 846 printf("npxdna: fpcurthread = %p (%d), curthread = %p (%d)\n", 847 PCPU_GET(fpcurthread), 848 PCPU_GET(fpcurthread)->td_proc->p_pid, 849 curthread, curthread->td_proc->p_pid); 850 panic("npxdna"); 851 } 852 s = intr_disable(); 853 stop_emulating(); 854 /* 855 * Record new context early in case frstor causes an IRQ13. 856 */ 857 PCPU_SET(fpcurthread, curthread); 858 pcb = PCPU_GET(curpcb); 859 860 if ((pcb->pcb_flags & PCB_NPXINITDONE) == 0) { 861 /* 862 * This is the first time this thread has used the FPU or 863 * the PCB doesn't contain a clean FPU state. Explicitly 864 * initialize the FPU and load the default control word. 865 */ 866 fninit(); 867 control = __INITIAL_NPXCW__; 868 fldcw(&control); 869 pcb->pcb_flags |= PCB_NPXINITDONE; 870 } else { 871 /* 872 * The following frstor may cause an IRQ13 when the state 873 * being restored has a pending error. The error will 874 * appear to have been triggered by the current (npx) user 875 * instruction even when that instruction is a no-wait 876 * instruction that should not trigger an error (e.g., 877 * fnclex). On at least one 486 system all of the no-wait 878 * instructions are broken the same as frstor, so our 879 * treatment does not amplify the breakage. On at least 880 * one 386/Cyrix 387 system, fnclex works correctly while 881 * frstor and fnsave are broken, so our treatment breaks 882 * fnclex if it is the first FPU instruction after a context 883 * switch. 884 */ 885 fpurstor(&pcb->pcb_save); 886 } 887 intr_restore(s); 888 889 return (1); 890} 891 892/* 893 * Wrapper for fnsave instruction, partly to handle hardware bugs. When npx 894 * exceptions are reported via IRQ13, spurious IRQ13's may be triggered by 895 * no-wait npx instructions. See the Intel application note AP-578 for 896 * details. This doesn't cause any additional complications here. IRQ13's 897 * are inherently asynchronous unless the CPU is frozen to deliver them -- 898 * one that started in userland may be delivered many instructions later, 899 * after the process has entered the kernel. It may even be delivered after 900 * the fnsave here completes. A spurious IRQ13 for the fnsave is handled in 901 * the same way as a very-late-arriving non-spurious IRQ13 from user mode: 902 * it is normally ignored at first because we set fpcurthread to NULL; it is 903 * normally retriggered in npxdna() after return to user mode. 904 * 905 * npxsave() must be called with interrupts disabled, so that it clears 906 * fpcurthread atomically with saving the state. We require callers to do the 907 * disabling, since most callers need to disable interrupts anyway to call 908 * npxsave() atomically with checking fpcurthread. 909 * 910 * A previous version of npxsave() went to great lengths to excecute fnsave 911 * with interrupts enabled in case executing it froze the CPU. This case 912 * can't happen, at least for Intel CPU/NPX's. Spurious IRQ13's don't imply 913 * spurious freezes. 914 */ 915void 916npxsave(addr) 917 union savefpu *addr; 918{ 919 920 stop_emulating(); 921 fpusave(addr); 922 923 start_emulating(); 924 PCPU_SET(fpcurthread, NULL); 925} 926 927/* 928 * This should be called with interrupts disabled and only when the owning 929 * FPU thread is non-null. 930 */ 931void 932npxdrop() 933{ 934 struct thread *td; 935 936 td = PCPU_GET(fpcurthread); 937 PCPU_SET(fpcurthread, NULL); 938 td->td_pcb->pcb_flags &= ~PCB_NPXINITDONE; 939 start_emulating(); 940} 941 942/* 943 * Get the state of the FPU without dropping ownership (if possible). 944 * It returns the FPU ownership status. 945 */ 946int 947npxgetregs(td, addr) 948 struct thread *td; 949 union savefpu *addr; 950{ 951 register_t s; 952 953 if (!npx_exists) 954 return (_MC_FPOWNED_NONE); 955 956 if ((td->td_pcb->pcb_flags & PCB_NPXINITDONE) == 0) { 957 if (npx_cleanstate_ready) 958 bcopy(&npx_cleanstate, addr, sizeof(npx_cleanstate)); 959 else 960 bzero(addr, sizeof(*addr)); 961 return (_MC_FPOWNED_NONE); 962 } 963 s = intr_disable(); 964 if (td == PCPU_GET(fpcurthread)) { 965 fpusave(addr); 966#ifdef CPU_ENABLE_SSE 967 if (!cpu_fxsr) 968#endif 969 /* 970 * fnsave initializes the FPU and destroys whatever 971 * context it contains. Make sure the FPU owner 972 * starts with a clean state next time. 973 */ 974 npxdrop(); 975 intr_restore(s); 976 return (_MC_FPOWNED_FPU); 977 } else { 978 intr_restore(s); 979 bcopy(&td->td_pcb->pcb_save, addr, sizeof(*addr)); 980 return (_MC_FPOWNED_PCB); 981 } 982} 983 984/* 985 * Set the state of the FPU. 986 */ 987void 988npxsetregs(td, addr) 989 struct thread *td; 990 union savefpu *addr; 991{ 992 register_t s; 993 994 if (!npx_exists) 995 return; 996 997 s = intr_disable(); 998 if (td == PCPU_GET(fpcurthread)) { 999 fpurstor(addr); 1000 intr_restore(s); 1001 } else { 1002 intr_restore(s); 1003 bcopy(addr, &td->td_pcb->pcb_save, sizeof(*addr)); 1004 } 1005 curthread->td_pcb->pcb_flags |= PCB_NPXINITDONE; 1006} 1007 1008static void 1009fpusave(addr) 1010 union savefpu *addr; 1011{ 1012 1013#ifdef CPU_ENABLE_SSE 1014 if (cpu_fxsr) 1015 fxsave(addr); 1016 else 1017#endif 1018 fnsave(addr); 1019} 1020 1021static void 1022fpurstor(addr) 1023 union savefpu *addr; 1024{ 1025 1026#ifdef CPU_ENABLE_SSE 1027 if (cpu_fxsr) 1028 fxrstor(addr); 1029 else 1030#endif 1031 frstor(addr); 1032} 1033 1034#ifdef I586_CPU_XXX 1035static long 1036timezero(funcname, func) 1037 const char *funcname; 1038 void (*func)(void *buf, size_t len); 1039 1040{ 1041 void *buf; 1042#define BUFSIZE 1048576 1043 long usec; 1044 struct timeval finish, start; 1045 1046 buf = malloc(BUFSIZE, M_TEMP, M_NOWAIT); 1047 if (buf == NULL) 1048 return (BUFSIZE); 1049 microtime(&start); 1050 (*func)(buf, BUFSIZE); 1051 microtime(&finish); 1052 usec = 1000000 * (finish.tv_sec - start.tv_sec) + 1053 finish.tv_usec - start.tv_usec; 1054 if (usec <= 0) 1055 usec = 1; 1056 if (bootverbose) 1057 printf("%s bandwidth = %u kBps\n", funcname, 1058 (u_int32_t)(((BUFSIZE >> 10) * 1000000) / usec)); 1059 free(buf, M_TEMP); 1060 return (usec); 1061} 1062#endif /* I586_CPU */ 1063 1064static device_method_t npx_methods[] = { 1065 /* Device interface */ 1066 DEVMETHOD(device_identify, npx_identify), 1067 DEVMETHOD(device_probe, npx_probe), 1068 DEVMETHOD(device_attach, npx_attach), 1069 DEVMETHOD(device_detach, bus_generic_detach), 1070 DEVMETHOD(device_shutdown, bus_generic_shutdown), 1071 DEVMETHOD(device_suspend, bus_generic_suspend), 1072 DEVMETHOD(device_resume, bus_generic_resume), 1073 1074 { 0, 0 } 1075}; 1076 1077static driver_t npx_driver = { 1078 "npx", 1079 npx_methods, 1080 1, /* no softc */ 1081}; 1082 1083static devclass_t npx_devclass; 1084 1085#ifdef DEV_ISA 1086/* 1087 * We prefer to attach to the root nexus so that the usual case (exception 16) 1088 * doesn't describe the processor as being `on isa'. 1089 */ 1090DRIVER_MODULE(npx, nexus, npx_driver, npx_devclass, 0, 0); 1091 1092/* 1093 * This sucks up the legacy ISA support assignments from PNPBIOS/ACPI. 1094 */ 1095static struct isa_pnp_id npxisa_ids[] = { 1096 { 0x040cd041, "Legacy ISA coprocessor support" }, /* PNP0C04 */ 1097 { 0 } 1098}; 1099 1100static int 1101npxisa_probe(device_t dev) 1102{ 1103 int result; 1104 if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, npxisa_ids)) <= 0) { 1105 device_quiet(dev); 1106 } 1107 return(result); 1108} 1109 1110static int 1111npxisa_attach(device_t dev) 1112{ 1113 return (0); 1114} 1115 1116static device_method_t npxisa_methods[] = { 1117 /* Device interface */ 1118 DEVMETHOD(device_probe, npxisa_probe), 1119 DEVMETHOD(device_attach, npxisa_attach), 1120 DEVMETHOD(device_detach, bus_generic_detach), 1121 DEVMETHOD(device_shutdown, bus_generic_shutdown), 1122 DEVMETHOD(device_suspend, bus_generic_suspend), 1123 DEVMETHOD(device_resume, bus_generic_resume), 1124 1125 { 0, 0 } 1126}; 1127 1128static driver_t npxisa_driver = { 1129 "npxisa", 1130 npxisa_methods, 1131 1, /* no softc */ 1132}; 1133 1134static devclass_t npxisa_devclass; 1135 1136DRIVER_MODULE(npxisa, isa, npxisa_driver, npxisa_devclass, 0, 0); 1137#ifndef PC98 1138DRIVER_MODULE(npxisa, acpi, npxisa_driver, npxisa_devclass, 0, 0); 1139#endif 1140#endif /* DEV_ISA */ 1141