2 * Copyright (c) 1990 William Jolitz.
3 * Copyright (c) 1991 The Regents of the University of California.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * from: @(#)npx.c 7.2 (Berkeley) 5/12/91
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
40 #include <sys/param.h>
41 #include <sys/systm.h>
43 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 #include <sys/module.h>
47 #include <sys/mutex.h>
48 #include <sys/mutex.h>
51 #include <sys/sysctl.h>
52 #include <machine/bus.h>
55 #include <sys/syslog.h>
57 #include <sys/signalvar.h>
60 #include <machine/asmacros.h>
61 #include <machine/cputypes.h>
62 #include <machine/frame.h>
63 #include <machine/md_var.h>
64 #include <machine/pcb.h>
65 #include <machine/psl.h>
66 #include <machine/resource.h>
67 #include <machine/specialreg.h>
68 #include <machine/segments.h>
69 #include <machine/ucontext.h>
71 #include <machine/intr_machdep.h>
74 #include <isa/isavar.h>
78 * 387 and 287 Numeric Coprocessor Extension (NPX) Driver.
81 #if defined(__GNUCLIKE_ASM) && !defined(lint)
83 #define fldcw(cw) __asm __volatile("fldcw %0" : : "m" (cw))
84 #define fnclex() __asm __volatile("fnclex")
85 #define fninit() __asm __volatile("fninit")
86 #define fnsave(addr) __asm __volatile("fnsave %0" : "=m" (*(addr)))
87 #define fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr)))
88 #define fnstsw(addr) __asm __volatile("fnstsw %0" : "=am" (*(addr)))
89 #define fp_divide_by_0() __asm __volatile( \
90 "fldz; fld1; fdiv %st,%st(1); fnop")
91 #define frstor(addr) __asm __volatile("frstor %0" : : "m" (*(addr)))
92 #define fxrstor(addr) __asm __volatile("fxrstor %0" : : "m" (*(addr)))
93 #define fxsave(addr) __asm __volatile("fxsave %0" : "=m" (*(addr)))
94 #define ldmxcsr(csr) __asm __volatile("ldmxcsr %0" : : "m" (csr))
95 #define stmxcsr(addr) __asm __volatile("stmxcsr %0" : : "m" (*(addr)))
98 xrstor(char *addr, uint64_t mask)
104 __asm __volatile("xrstor %0" : : "m" (*addr), "a" (low), "d" (hi));
108 xsave(char *addr, uint64_t mask)
114 __asm __volatile("xsave %0" : "=m" (*addr) : "a" (low), "d" (hi) :
119 xsaveopt(char *addr, uint64_t mask)
125 __asm __volatile("xsaveopt %0" : "=m" (*addr) : "a" (low), "d" (hi) :
128 #else /* !(__GNUCLIKE_ASM && !lint) */
130 void fldcw(u_short cw);
133 void fnsave(caddr_t addr);
134 void fnstcw(caddr_t addr);
135 void fnstsw(caddr_t addr);
136 void fp_divide_by_0(void);
137 void frstor(caddr_t addr);
138 void fxsave(caddr_t addr);
139 void fxrstor(caddr_t addr);
140 void ldmxcsr(u_int csr);
141 void stmxcsr(u_int *csr);
142 void xrstor(char *addr, uint64_t mask);
143 void xsave(char *addr, uint64_t mask);
144 void xsaveopt(char *addr, uint64_t mask);
146 #endif /* __GNUCLIKE_ASM && !lint */
148 #define start_emulating() load_cr0(rcr0() | CR0_TS)
149 #define stop_emulating() clts()
151 #define GET_FPU_CW(thread) \
153 (thread)->td_pcb->pcb_save->sv_xmm.sv_env.en_cw : \
154 (thread)->td_pcb->pcb_save->sv_87.sv_env.en_cw)
155 #define GET_FPU_SW(thread) \
157 (thread)->td_pcb->pcb_save->sv_xmm.sv_env.en_sw : \
158 (thread)->td_pcb->pcb_save->sv_87.sv_env.en_sw)
159 #define SET_FPU_CW(savefpu, value) do { \
161 (savefpu)->sv_xmm.sv_env.en_cw = (value); \
163 (savefpu)->sv_87.sv_env.en_cw = (value); \
166 CTASSERT(sizeof(union savefpu) == 512);
167 CTASSERT(sizeof(struct xstate_hdr) == 64);
168 CTASSERT(sizeof(struct savefpu_ymm) == 832);
171 * This requirement is to make it easier for asm code to calculate
172 * offset of the fpu save area from the pcb address. FPU save area
173 * must be 64-byte aligned.
175 CTASSERT(sizeof(struct pcb) % XSAVE_AREA_ALIGN == 0);
178 * Ensure the copy of XCR0 saved in a core is contained in the padding
181 CTASSERT(X86_XSTATE_XCR0_OFFSET >= offsetof(struct savexmm, sv_pad) &&
182 X86_XSTATE_XCR0_OFFSET + sizeof(uint64_t) <= sizeof(struct savexmm));
184 static void fpu_clean_state(void);
186 static void fpusave(union savefpu *);
187 static void fpurstor(union savefpu *);
191 SYSCTL_INT(_hw, HW_FLOATINGPT, floatingpoint, CTLFLAG_RD,
192 &hw_float, 0, "Floating point instructions executed in hardware");
196 static uma_zone_t fpu_save_area_zone;
197 static union savefpu *npx_initialstate;
199 struct xsave_area_elm_descr {
204 static int use_xsaveopt;
206 static volatile u_int npx_traps_while_probing;
208 alias_for_inthand_t probetrap;
212 .type " __XSTRING(CNAME(probetrap)) ",@function \n\
213 " __XSTRING(CNAME(probetrap)) ": \n\
215 incl " __XSTRING(CNAME(npx_traps_while_probing)) " \n\
221 * Determine if an FPU is present and how to use it.
226 struct gate_descriptor save_idt_npxtrap;
227 u_short control, status;
230 * Modern CPUs all have an FPU that uses the INT16 interface
231 * and provide a simple way to verify that, so handle the
232 * common case right away.
234 if (cpu_feature & CPUID_FPU) {
239 save_idt_npxtrap = idt[IDT_MF];
240 setidt(IDT_MF, probetrap, SDT_SYS386IGT, SEL_KPL,
241 GSEL(GCODE_SEL, SEL_KPL));
244 * Don't trap while we're probing.
249 * Finish resetting the coprocessor, if any. If there is an error
250 * pending, then we may get a bogus IRQ13, but npx_intr() will handle
251 * it OK. Bogus halts have never been observed, but we enabled
252 * IRQ13 and cleared the BUSY# latch early to handle them anyway.
257 * Don't use fwait here because it might hang.
258 * Don't use fnop here because it usually hangs if there is no FPU.
260 DELAY(1000); /* wait for any IRQ13 */
262 if (npx_traps_while_probing != 0)
263 printf("fninit caused %u bogus npx trap(s)\n",
264 npx_traps_while_probing);
267 * Check for a status of mostly zero.
271 if ((status & 0xb8ff) == 0) {
273 * Good, now check for a proper control word.
277 if ((control & 0x1f3f) == 0x033f) {
279 * We have an npx, now divide by 0 to see if exception
282 control &= ~(1 << 2); /* enable divide by 0 trap */
284 npx_traps_while_probing = 0;
286 if (npx_traps_while_probing != 0) {
288 * Good, exception 16 works.
294 "FPU does not use exception 16 for error reporting\n");
300 * Probe failed. Floating point simply won't work.
301 * Notify user and disable FPU/MMX/SSE instruction execution.
303 printf("WARNING: no FPU!\n");
304 __asm __volatile("smsw %%ax; orb %0,%%al; lmsw %%ax" : :
305 "n" (CR0_EM | CR0_MP) : "ax");
308 idt[IDT_MF] = save_idt_npxtrap;
313 * Enable XSAVE if supported and allowed by user.
314 * Calculate the xsave_mask.
320 uint64_t xsave_mask_user;
322 if (cpu_fxsr && (cpu_feature2 & CPUID2_XSAVE) != 0) {
324 TUNABLE_INT_FETCH("hw.use_xsave", &use_xsave);
329 cpuid_count(0xd, 0x0, cp);
330 xsave_mask = XFEATURE_ENABLED_X87 | XFEATURE_ENABLED_SSE;
331 if ((cp[0] & xsave_mask) != xsave_mask)
332 panic("CPU0 does not support X87 or SSE: %x", cp[0]);
333 xsave_mask = ((uint64_t)cp[3] << 32) | cp[0];
334 xsave_mask_user = xsave_mask;
335 TUNABLE_QUAD_FETCH("hw.xsave_mask", &xsave_mask_user);
336 xsave_mask_user |= XFEATURE_ENABLED_X87 | XFEATURE_ENABLED_SSE;
337 xsave_mask &= xsave_mask_user;
338 if ((xsave_mask & XFEATURE_AVX512) != XFEATURE_AVX512)
339 xsave_mask &= ~XFEATURE_AVX512;
340 if ((xsave_mask & XFEATURE_MPX) != XFEATURE_MPX)
341 xsave_mask &= ~XFEATURE_MPX;
343 cpuid_count(0xd, 0x1, cp);
344 if ((cp[0] & CPUID_EXTSTATE_XSAVEOPT) != 0)
350 * Calculate the fpu save area size.
358 cpuid_count(0xd, 0x0, cp);
359 cpu_max_ext_state_size = cp[1];
362 * Reload the cpu_feature2, since we enabled OSXSAVE.
365 cpu_feature2 = cp[2];
367 cpu_max_ext_state_size = sizeof(union savefpu);
371 * Initialize floating point unit.
376 static union savefpu dummy;
388 load_cr4(rcr4() | CR4_XSAVE);
389 load_xcr(XCR0, xsave_mask);
393 * XCR0 shall be set up before CPU can report the save area size.
399 * fninit has the same h/w bugs as fnsave. Use the detoxified
400 * fnsave to throw away any junk in the fpu. fpusave() initializes
403 * It is too early for critical_enter() to work on AP.
405 saveintr = intr_disable();
411 control = __INITIAL_NPXCW__;
414 mxcsr = __INITIAL_MXCSR__;
418 intr_restore(saveintr);
422 * On the boot CPU we generate a clean state that is used to
423 * initialize the floating point unit when it is first used by a
427 npxinitstate(void *arg __unused)
430 int cp[4], i, max_ext_n;
435 npx_initialstate = malloc(cpu_max_ext_state_size, M_DEVBUF,
437 saveintr = intr_disable();
440 fpusave(npx_initialstate);
442 if (npx_initialstate->sv_xmm.sv_env.en_mxcsr_mask)
444 npx_initialstate->sv_xmm.sv_env.en_mxcsr_mask;
446 cpu_mxcsr_mask = 0xFFBF;
449 * The fninit instruction does not modify XMM
450 * registers or x87 registers (MM/ST). The fpusave
451 * call dumped the garbage contained in the registers
452 * after reset to the initial state saved. Clear XMM
453 * and x87 registers file image to make the startup
454 * program state and signal handler XMM/x87 register
455 * content predictable.
457 bzero(npx_initialstate->sv_xmm.sv_fp,
458 sizeof(npx_initialstate->sv_xmm.sv_fp));
459 bzero(npx_initialstate->sv_xmm.sv_xmm,
460 sizeof(npx_initialstate->sv_xmm.sv_xmm));
462 bzero(npx_initialstate->sv_87.sv_ac,
463 sizeof(npx_initialstate->sv_87.sv_ac));
466 * Create a table describing the layout of the CPU Extended
470 if (xsave_mask >> 32 != 0)
471 max_ext_n = fls(xsave_mask >> 32) + 32;
473 max_ext_n = fls(xsave_mask);
474 xsave_area_desc = malloc(max_ext_n * sizeof(struct
475 xsave_area_elm_descr), M_DEVBUF, M_WAITOK | M_ZERO);
477 xsave_area_desc[0].offset = 0;
478 xsave_area_desc[0].size = 160;
480 xsave_area_desc[1].offset = 160;
481 xsave_area_desc[1].size = 288 - 160;
483 for (i = 2; i < max_ext_n; i++) {
484 cpuid_count(0xd, i, cp);
485 xsave_area_desc[i].offset = cp[1];
486 xsave_area_desc[i].size = cp[0];
490 fpu_save_area_zone = uma_zcreate("FPU_save_area",
491 cpu_max_ext_state_size, NULL, NULL, NULL, NULL,
492 XSAVE_AREA_ALIGN - 1, 0);
495 intr_restore(saveintr);
497 SYSINIT(npxinitstate, SI_SUB_DRIVERS, SI_ORDER_ANY, npxinitstate, NULL);
500 * Free coprocessor (if we have it).
503 npxexit(struct thread *td)
507 if (curthread == PCPU_GET(fpcurthread)) {
509 fpusave(curpcb->pcb_save);
511 PCPU_SET(fpcurthread, NULL);
516 u_int masked_exceptions;
518 masked_exceptions = GET_FPU_CW(td) & GET_FPU_SW(td) & 0x7f;
520 * Log exceptions that would have trapped with the old
521 * control word (overflow, divide by 0, and invalid operand).
523 if (masked_exceptions & 0x0d)
525 "pid %d (%s) exited with masked floating point exceptions 0x%02x\n",
526 td->td_proc->p_pid, td->td_proc->p_comm,
537 return (_MC_FPFMT_NODEV);
539 return (_MC_FPFMT_XMM);
540 return (_MC_FPFMT_387);
544 * The following mechanism is used to ensure that the FPE_... value
545 * that is passed as a trapcode to the signal handler of the user
546 * process does not have more than one bit set.
548 * Multiple bits may be set if the user process modifies the control
549 * word while a status word bit is already set. While this is a sign
550 * of bad coding, we have no choise than to narrow them down to one
551 * bit, since we must not send a trapcode that is not exactly one of
554 * The mechanism has a static table with 127 entries. Each combination
555 * of the 7 FPU status word exception bits directly translates to a
556 * position in this table, where a single FPE_... value is stored.
557 * This FPE_... value stored there is considered the "most important"
558 * of the exception bits and will be sent as the signal code. The
559 * precedence of the bits is based upon Intel Document "Numerical
560 * Applications", Chapter "Special Computational Situations".
562 * The macro to choose one of these values does these steps: 1) Throw
563 * away status word bits that cannot be masked. 2) Throw away the bits
564 * currently masked in the control word, assuming the user isn't
565 * interested in them anymore. 3) Reinsert status word bit 7 (stack
566 * fault) if it is set, which cannot be masked but must be presered.
567 * 4) Use the remaining bits to point into the trapcode table.
569 * The 6 maskable bits in order of their preference, as stated in the
570 * above referenced Intel manual:
571 * 1 Invalid operation (FP_X_INV)
574 * 1c Operand of unsupported format
576 * 2 QNaN operand (not an exception, irrelavant here)
577 * 3 Any other invalid-operation not mentioned above or zero divide
578 * (FP_X_INV, FP_X_DZ)
579 * 4 Denormal operand (FP_X_DNML)
580 * 5 Numeric over/underflow (FP_X_OFL, FP_X_UFL)
581 * 6 Inexact result (FP_X_IMP)
583 static char fpetable[128] = {
585 FPE_FLTINV, /* 1 - INV */
586 FPE_FLTUND, /* 2 - DNML */
587 FPE_FLTINV, /* 3 - INV | DNML */
588 FPE_FLTDIV, /* 4 - DZ */
589 FPE_FLTINV, /* 5 - INV | DZ */
590 FPE_FLTDIV, /* 6 - DNML | DZ */
591 FPE_FLTINV, /* 7 - INV | DNML | DZ */
592 FPE_FLTOVF, /* 8 - OFL */
593 FPE_FLTINV, /* 9 - INV | OFL */
594 FPE_FLTUND, /* A - DNML | OFL */
595 FPE_FLTINV, /* B - INV | DNML | OFL */
596 FPE_FLTDIV, /* C - DZ | OFL */
597 FPE_FLTINV, /* D - INV | DZ | OFL */
598 FPE_FLTDIV, /* E - DNML | DZ | OFL */
599 FPE_FLTINV, /* F - INV | DNML | DZ | OFL */
600 FPE_FLTUND, /* 10 - UFL */
601 FPE_FLTINV, /* 11 - INV | UFL */
602 FPE_FLTUND, /* 12 - DNML | UFL */
603 FPE_FLTINV, /* 13 - INV | DNML | UFL */
604 FPE_FLTDIV, /* 14 - DZ | UFL */
605 FPE_FLTINV, /* 15 - INV | DZ | UFL */
606 FPE_FLTDIV, /* 16 - DNML | DZ | UFL */
607 FPE_FLTINV, /* 17 - INV | DNML | DZ | UFL */
608 FPE_FLTOVF, /* 18 - OFL | UFL */
609 FPE_FLTINV, /* 19 - INV | OFL | UFL */
610 FPE_FLTUND, /* 1A - DNML | OFL | UFL */
611 FPE_FLTINV, /* 1B - INV | DNML | OFL | UFL */
612 FPE_FLTDIV, /* 1C - DZ | OFL | UFL */
613 FPE_FLTINV, /* 1D - INV | DZ | OFL | UFL */
614 FPE_FLTDIV, /* 1E - DNML | DZ | OFL | UFL */
615 FPE_FLTINV, /* 1F - INV | DNML | DZ | OFL | UFL */
616 FPE_FLTRES, /* 20 - IMP */
617 FPE_FLTINV, /* 21 - INV | IMP */
618 FPE_FLTUND, /* 22 - DNML | IMP */
619 FPE_FLTINV, /* 23 - INV | DNML | IMP */
620 FPE_FLTDIV, /* 24 - DZ | IMP */
621 FPE_FLTINV, /* 25 - INV | DZ | IMP */
622 FPE_FLTDIV, /* 26 - DNML | DZ | IMP */
623 FPE_FLTINV, /* 27 - INV | DNML | DZ | IMP */
624 FPE_FLTOVF, /* 28 - OFL | IMP */
625 FPE_FLTINV, /* 29 - INV | OFL | IMP */
626 FPE_FLTUND, /* 2A - DNML | OFL | IMP */
627 FPE_FLTINV, /* 2B - INV | DNML | OFL | IMP */
628 FPE_FLTDIV, /* 2C - DZ | OFL | IMP */
629 FPE_FLTINV, /* 2D - INV | DZ | OFL | IMP */
630 FPE_FLTDIV, /* 2E - DNML | DZ | OFL | IMP */
631 FPE_FLTINV, /* 2F - INV | DNML | DZ | OFL | IMP */
632 FPE_FLTUND, /* 30 - UFL | IMP */
633 FPE_FLTINV, /* 31 - INV | UFL | IMP */
634 FPE_FLTUND, /* 32 - DNML | UFL | IMP */
635 FPE_FLTINV, /* 33 - INV | DNML | UFL | IMP */
636 FPE_FLTDIV, /* 34 - DZ | UFL | IMP */
637 FPE_FLTINV, /* 35 - INV | DZ | UFL | IMP */
638 FPE_FLTDIV, /* 36 - DNML | DZ | UFL | IMP */
639 FPE_FLTINV, /* 37 - INV | DNML | DZ | UFL | IMP */
640 FPE_FLTOVF, /* 38 - OFL | UFL | IMP */
641 FPE_FLTINV, /* 39 - INV | OFL | UFL | IMP */
642 FPE_FLTUND, /* 3A - DNML | OFL | UFL | IMP */
643 FPE_FLTINV, /* 3B - INV | DNML | OFL | UFL | IMP */
644 FPE_FLTDIV, /* 3C - DZ | OFL | UFL | IMP */
645 FPE_FLTINV, /* 3D - INV | DZ | OFL | UFL | IMP */
646 FPE_FLTDIV, /* 3E - DNML | DZ | OFL | UFL | IMP */
647 FPE_FLTINV, /* 3F - INV | DNML | DZ | OFL | UFL | IMP */
648 FPE_FLTSUB, /* 40 - STK */
649 FPE_FLTSUB, /* 41 - INV | STK */
650 FPE_FLTUND, /* 42 - DNML | STK */
651 FPE_FLTSUB, /* 43 - INV | DNML | STK */
652 FPE_FLTDIV, /* 44 - DZ | STK */
653 FPE_FLTSUB, /* 45 - INV | DZ | STK */
654 FPE_FLTDIV, /* 46 - DNML | DZ | STK */
655 FPE_FLTSUB, /* 47 - INV | DNML | DZ | STK */
656 FPE_FLTOVF, /* 48 - OFL | STK */
657 FPE_FLTSUB, /* 49 - INV | OFL | STK */
658 FPE_FLTUND, /* 4A - DNML | OFL | STK */
659 FPE_FLTSUB, /* 4B - INV | DNML | OFL | STK */
660 FPE_FLTDIV, /* 4C - DZ | OFL | STK */
661 FPE_FLTSUB, /* 4D - INV | DZ | OFL | STK */
662 FPE_FLTDIV, /* 4E - DNML | DZ | OFL | STK */
663 FPE_FLTSUB, /* 4F - INV | DNML | DZ | OFL | STK */
664 FPE_FLTUND, /* 50 - UFL | STK */
665 FPE_FLTSUB, /* 51 - INV | UFL | STK */
666 FPE_FLTUND, /* 52 - DNML | UFL | STK */
667 FPE_FLTSUB, /* 53 - INV | DNML | UFL | STK */
668 FPE_FLTDIV, /* 54 - DZ | UFL | STK */
669 FPE_FLTSUB, /* 55 - INV | DZ | UFL | STK */
670 FPE_FLTDIV, /* 56 - DNML | DZ | UFL | STK */
671 FPE_FLTSUB, /* 57 - INV | DNML | DZ | UFL | STK */
672 FPE_FLTOVF, /* 58 - OFL | UFL | STK */
673 FPE_FLTSUB, /* 59 - INV | OFL | UFL | STK */
674 FPE_FLTUND, /* 5A - DNML | OFL | UFL | STK */
675 FPE_FLTSUB, /* 5B - INV | DNML | OFL | UFL | STK */
676 FPE_FLTDIV, /* 5C - DZ | OFL | UFL | STK */
677 FPE_FLTSUB, /* 5D - INV | DZ | OFL | UFL | STK */
678 FPE_FLTDIV, /* 5E - DNML | DZ | OFL | UFL | STK */
679 FPE_FLTSUB, /* 5F - INV | DNML | DZ | OFL | UFL | STK */
680 FPE_FLTRES, /* 60 - IMP | STK */
681 FPE_FLTSUB, /* 61 - INV | IMP | STK */
682 FPE_FLTUND, /* 62 - DNML | IMP | STK */
683 FPE_FLTSUB, /* 63 - INV | DNML | IMP | STK */
684 FPE_FLTDIV, /* 64 - DZ | IMP | STK */
685 FPE_FLTSUB, /* 65 - INV | DZ | IMP | STK */
686 FPE_FLTDIV, /* 66 - DNML | DZ | IMP | STK */
687 FPE_FLTSUB, /* 67 - INV | DNML | DZ | IMP | STK */
688 FPE_FLTOVF, /* 68 - OFL | IMP | STK */
689 FPE_FLTSUB, /* 69 - INV | OFL | IMP | STK */
690 FPE_FLTUND, /* 6A - DNML | OFL | IMP | STK */
691 FPE_FLTSUB, /* 6B - INV | DNML | OFL | IMP | STK */
692 FPE_FLTDIV, /* 6C - DZ | OFL | IMP | STK */
693 FPE_FLTSUB, /* 6D - INV | DZ | OFL | IMP | STK */
694 FPE_FLTDIV, /* 6E - DNML | DZ | OFL | IMP | STK */
695 FPE_FLTSUB, /* 6F - INV | DNML | DZ | OFL | IMP | STK */
696 FPE_FLTUND, /* 70 - UFL | IMP | STK */
697 FPE_FLTSUB, /* 71 - INV | UFL | IMP | STK */
698 FPE_FLTUND, /* 72 - DNML | UFL | IMP | STK */
699 FPE_FLTSUB, /* 73 - INV | DNML | UFL | IMP | STK */
700 FPE_FLTDIV, /* 74 - DZ | UFL | IMP | STK */
701 FPE_FLTSUB, /* 75 - INV | DZ | UFL | IMP | STK */
702 FPE_FLTDIV, /* 76 - DNML | DZ | UFL | IMP | STK */
703 FPE_FLTSUB, /* 77 - INV | DNML | DZ | UFL | IMP | STK */
704 FPE_FLTOVF, /* 78 - OFL | UFL | IMP | STK */
705 FPE_FLTSUB, /* 79 - INV | OFL | UFL | IMP | STK */
706 FPE_FLTUND, /* 7A - DNML | OFL | UFL | IMP | STK */
707 FPE_FLTSUB, /* 7B - INV | DNML | OFL | UFL | IMP | STK */
708 FPE_FLTDIV, /* 7C - DZ | OFL | UFL | IMP | STK */
709 FPE_FLTSUB, /* 7D - INV | DZ | OFL | UFL | IMP | STK */
710 FPE_FLTDIV, /* 7E - DNML | DZ | OFL | UFL | IMP | STK */
711 FPE_FLTSUB, /* 7F - INV | DNML | DZ | OFL | UFL | IMP | STK */
715 * Read the FP status and control words, then generate si_code value
716 * for SIGFPE. The error code chosen will be one of the
717 * FPE_... macros. It will be sent as the second argument to old
718 * BSD-style signal handlers and as "siginfo_t->si_code" (second
719 * argument) to SA_SIGINFO signal handlers.
721 * Some time ago, we cleared the x87 exceptions with FNCLEX there.
722 * Clearing exceptions was necessary mainly to avoid IRQ13 bugs. The
723 * usermode code which understands the FPU hardware enough to enable
724 * the exceptions, can also handle clearing the exception state in the
725 * handler. The only consequence of not clearing the exception is the
726 * rethrow of the SIGFPE on return from the signal handler and
727 * reexecution of the corresponding instruction.
729 * For XMM traps, the exceptions were never cleared.
734 u_short control, status;
738 "npxtrap_x87: fpcurthread = %p, curthread = %p, hw_float = %d\n",
739 PCPU_GET(fpcurthread), curthread, hw_float);
740 panic("npxtrap from nowhere");
745 * Interrupt handling (for another interrupt) may have pushed the
746 * state to memory. Fetch the relevant parts of the state from
749 if (PCPU_GET(fpcurthread) != curthread) {
750 control = GET_FPU_CW(curthread);
751 status = GET_FPU_SW(curthread);
757 return (fpetable[status & ((~control & 0x3f) | 0x40)]);
767 "npxtrap_sse: fpcurthread = %p, curthread = %p, hw_float = %d\n",
768 PCPU_GET(fpcurthread), curthread, hw_float);
769 panic("npxtrap from nowhere");
772 if (PCPU_GET(fpcurthread) != curthread)
773 mxcsr = curthread->td_pcb->pcb_save->sv_xmm.sv_env.en_mxcsr;
777 return (fpetable[(mxcsr & (~mxcsr >> 7)) & 0x3f]);
781 * Implement device not available (DNA) exception
783 * It would be better to switch FP context here (if curthread != fpcurthread)
784 * and not necessarily for every context switch, but it is too hard to
785 * access foreign pcb's.
788 static int err_count = 0;
797 if (PCPU_GET(fpcurthread) == curthread) {
798 printf("npxdna: fpcurthread == curthread %d times\n",
804 if (PCPU_GET(fpcurthread) != NULL) {
805 printf("npxdna: fpcurthread = %p (%d), curthread = %p (%d)\n",
806 PCPU_GET(fpcurthread),
807 PCPU_GET(fpcurthread)->td_proc->p_pid,
808 curthread, curthread->td_proc->p_pid);
813 * Record new context early in case frstor causes a trap.
815 PCPU_SET(fpcurthread, curthread);
820 if ((curpcb->pcb_flags & PCB_NPXINITDONE) == 0) {
822 * This is the first time this thread has used the FPU or
823 * the PCB doesn't contain a clean FPU state. Explicitly
824 * load an initial state.
826 * We prefer to restore the state from the actual save
827 * area in PCB instead of directly loading from
828 * npx_initialstate, to ignite the XSAVEOPT
831 bcopy(npx_initialstate, curpcb->pcb_save, cpu_max_ext_state_size);
832 fpurstor(curpcb->pcb_save);
833 if (curpcb->pcb_initial_npxcw != __INITIAL_NPXCW__)
834 fldcw(curpcb->pcb_initial_npxcw);
835 curpcb->pcb_flags |= PCB_NPXINITDONE;
836 if (PCB_USER_FPU(curpcb))
837 curpcb->pcb_flags |= PCB_NPXUSERINITDONE;
839 fpurstor(curpcb->pcb_save);
847 * Wrapper for fpusave() called from context switch routines.
849 * npxsave() must be called with interrupts disabled, so that it clears
850 * fpcurthread atomically with saving the state. We require callers to do the
851 * disabling, since most callers need to disable interrupts anyway to call
852 * npxsave() atomically with checking fpcurthread.
861 xsaveopt((char *)addr, xsave_mask);
865 PCPU_SET(fpcurthread, NULL);
869 * Unconditionally save the current co-processor state across suspend and
873 npxsuspend(union savefpu *addr)
879 if (PCPU_GET(fpcurthread) == NULL) {
880 bcopy(npx_initialstate, addr, cpu_max_ext_state_size);
890 npxresume(union savefpu *addr)
910 * Discard pending exceptions in the !cpu_fxsr case so that unmasked
911 * ones don't cause a panic on the next frstor.
916 td = PCPU_GET(fpcurthread);
917 KASSERT(td == curthread, ("fpudrop: fpcurthread != curthread"));
919 PCPU_SET(fpcurthread, NULL);
920 td->td_pcb->pcb_flags &= ~PCB_NPXINITDONE;
925 * Get the user state of the FPU into pcb->pcb_user_save without
926 * dropping ownership (if possible). It returns the FPU ownership
930 npxgetregs(struct thread *td)
933 uint64_t *xstate_bv, bit;
939 return (_MC_FPOWNED_NONE);
942 if ((pcb->pcb_flags & PCB_NPXINITDONE) == 0) {
943 bcopy(npx_initialstate, get_pcb_user_save_pcb(pcb),
944 cpu_max_ext_state_size);
945 SET_FPU_CW(get_pcb_user_save_pcb(pcb), pcb->pcb_initial_npxcw);
947 return (_MC_FPOWNED_PCB);
950 if (td == PCPU_GET(fpcurthread)) {
951 fpusave(get_pcb_user_save_pcb(pcb));
954 * fnsave initializes the FPU and destroys whatever
955 * context it contains. Make sure the FPU owner
956 * starts with a clean state next time.
959 owned = _MC_FPOWNED_FPU;
961 owned = _MC_FPOWNED_PCB;
966 * Handle partially saved state.
968 sa = (char *)get_pcb_user_save_pcb(pcb);
969 xstate_bv = (uint64_t *)(sa + sizeof(union savefpu) +
970 offsetof(struct xstate_hdr, xstate_bv));
971 if (xsave_mask >> 32 != 0)
972 max_ext_n = fls(xsave_mask >> 32) + 32;
974 max_ext_n = fls(xsave_mask);
975 for (i = 0; i < max_ext_n; i++) {
977 if ((xsave_mask & bit) == 0 || (*xstate_bv & bit) != 0)
979 bcopy((char *)npx_initialstate +
980 xsave_area_desc[i].offset,
981 sa + xsave_area_desc[i].offset,
982 xsave_area_desc[i].size);
990 npxuserinited(struct thread *td)
995 if (PCB_USER_FPU(pcb))
996 pcb->pcb_flags |= PCB_NPXINITDONE;
997 pcb->pcb_flags |= PCB_NPXUSERINITDONE;
1001 npxsetxstate(struct thread *td, char *xfpustate, size_t xfpustate_size)
1003 struct xstate_hdr *hdr, *ehdr;
1004 size_t len, max_len;
1007 /* XXXKIB should we clear all extended state in xstate_bv instead ? */
1008 if (xfpustate == NULL)
1011 return (EOPNOTSUPP);
1013 len = xfpustate_size;
1014 if (len < sizeof(struct xstate_hdr))
1016 max_len = cpu_max_ext_state_size - sizeof(union savefpu);
1020 ehdr = (struct xstate_hdr *)xfpustate;
1021 bv = ehdr->xstate_bv;
1026 if (bv & ~xsave_mask)
1029 hdr = (struct xstate_hdr *)(get_pcb_user_save_td(td) + 1);
1031 hdr->xstate_bv = bv;
1032 bcopy(xfpustate + sizeof(struct xstate_hdr),
1033 (char *)(hdr + 1), len - sizeof(struct xstate_hdr));
1039 npxsetregs(struct thread *td, union savefpu *addr, char *xfpustate,
1040 size_t xfpustate_size)
1050 if (td == PCPU_GET(fpcurthread) && PCB_USER_FPU(pcb)) {
1051 error = npxsetxstate(td, xfpustate, xfpustate_size);
1057 fnclex(); /* As in npxdrop(). */
1058 bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr));
1059 fpurstor(get_pcb_user_save_td(td));
1061 pcb->pcb_flags |= PCB_NPXUSERINITDONE | PCB_NPXINITDONE;
1064 error = npxsetxstate(td, xfpustate, xfpustate_size);
1067 bcopy(addr, get_pcb_user_save_td(td), sizeof(*addr));
1075 union savefpu *addr;
1079 xsave((char *)addr, xsave_mask);
1087 npx_fill_fpregs_xmm1(struct savexmm *sv_xmm, struct save87 *sv_87)
1089 struct env87 *penv_87;
1090 struct envxmm *penv_xmm;
1093 penv_87 = &sv_87->sv_env;
1094 penv_xmm = &sv_xmm->sv_env;
1096 /* FPU control/status */
1097 penv_87->en_cw = penv_xmm->en_cw;
1098 penv_87->en_sw = penv_xmm->en_sw;
1099 penv_87->en_fip = penv_xmm->en_fip;
1100 penv_87->en_fcs = penv_xmm->en_fcs;
1101 penv_87->en_opcode = penv_xmm->en_opcode;
1102 penv_87->en_foo = penv_xmm->en_foo;
1103 penv_87->en_fos = penv_xmm->en_fos;
1105 /* FPU registers and tags */
1106 penv_87->en_tw = 0xffff;
1107 for (i = 0; i < 8; ++i) {
1108 sv_87->sv_ac[i] = sv_xmm->sv_fp[i].fp_acc;
1109 if ((penv_xmm->en_tw & (1 << i)) != 0)
1110 /* zero and special are set as valid */
1111 penv_87->en_tw &= ~(3 << i * 2);
1116 npx_fill_fpregs_xmm(struct savexmm *sv_xmm, struct save87 *sv_87)
1119 bzero(sv_87, sizeof(*sv_87));
1120 npx_fill_fpregs_xmm1(sv_xmm, sv_87);
1124 npx_set_fpregs_xmm(struct save87 *sv_87, struct savexmm *sv_xmm)
1126 struct env87 *penv_87;
1127 struct envxmm *penv_xmm;
1130 penv_87 = &sv_87->sv_env;
1131 penv_xmm = &sv_xmm->sv_env;
1133 /* FPU control/status */
1134 penv_xmm->en_cw = penv_87->en_cw;
1135 penv_xmm->en_sw = penv_87->en_sw;
1136 penv_xmm->en_fip = penv_87->en_fip;
1137 penv_xmm->en_fcs = penv_87->en_fcs;
1138 penv_xmm->en_opcode = penv_87->en_opcode;
1139 penv_xmm->en_foo = penv_87->en_foo;
1140 penv_xmm->en_fos = penv_87->en_fos;
1143 * FPU registers and tags.
1144 * Abridged / Full translation (values in binary), see FXSAVE spec.
1148 penv_xmm->en_tw = 0;
1149 for (i = 0; i < 8; ++i) {
1150 sv_xmm->sv_fp[i].fp_acc = sv_87->sv_ac[i];
1151 if ((penv_87->en_tw & (3 << i * 2)) != (3 << i * 2))
1152 penv_xmm->en_tw |= 1 << i;
1157 npx_get_fsave(void *addr)
1164 sv = get_pcb_user_save_td(td);
1166 npx_fill_fpregs_xmm1(&sv->sv_xmm, addr);
1168 bcopy(sv, addr, sizeof(struct env87) +
1169 sizeof(struct fpacc87[8]));
1173 npx_set_fsave(void *addr)
1178 bzero(&sv, sizeof(sv));
1180 npx_set_fpregs_xmm(addr, &sv.sv_xmm);
1182 bcopy(addr, &sv, sizeof(struct env87) +
1183 sizeof(struct fpacc87[8]));
1184 error = npxsetregs(curthread, &sv, NULL, 0);
1189 * On AuthenticAMD processors, the fxrstor instruction does not restore
1190 * the x87's stored last instruction pointer, last data pointer, and last
1191 * opcode values, except in the rare case in which the exception summary
1192 * (ES) bit in the x87 status word is set to 1.
1194 * In order to avoid leaking this information across processes, we clean
1195 * these values by performing a dummy load before executing fxrstor().
1198 fpu_clean_state(void)
1200 static float dummy_variable = 0.0;
1204 * Clear the ES bit in the x87 status word if it is currently
1205 * set, in order to avoid causing a fault in the upcoming load.
1212 * Load the dummy variable into the x87 stack. This mangles
1213 * the x87 stack, but we don't care since we're about to call
1216 __asm __volatile("ffree %%st(7); flds %0" : : "m" (dummy_variable));
1220 fpurstor(union savefpu *addr)
1224 xrstor((char *)addr, xsave_mask);
1233 * This sucks up the legacy ISA support assignments from PNPBIOS/ACPI.
1235 static struct isa_pnp_id npxisa_ids[] = {
1236 { 0x040cd041, "Legacy ISA coprocessor support" }, /* PNP0C04 */
1241 npxisa_probe(device_t dev)
1244 if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, npxisa_ids)) <= 0) {
1251 npxisa_attach(device_t dev)
1256 static device_method_t npxisa_methods[] = {
1257 /* Device interface */
1258 DEVMETHOD(device_probe, npxisa_probe),
1259 DEVMETHOD(device_attach, npxisa_attach),
1260 DEVMETHOD(device_detach, bus_generic_detach),
1261 DEVMETHOD(device_shutdown, bus_generic_shutdown),
1262 DEVMETHOD(device_suspend, bus_generic_suspend),
1263 DEVMETHOD(device_resume, bus_generic_resume),
1268 static driver_t npxisa_driver = {
1274 static devclass_t npxisa_devclass;
1276 DRIVER_MODULE(npxisa, isa, npxisa_driver, npxisa_devclass, 0, 0);
1277 DRIVER_MODULE(npxisa, acpi, npxisa_driver, npxisa_devclass, 0, 0);
1278 #endif /* DEV_ISA */
1280 static MALLOC_DEFINE(M_FPUKERN_CTX, "fpukern_ctx",
1281 "Kernel contexts for FPU state");
1283 #define FPU_KERN_CTX_NPXINITDONE 0x01
1284 #define FPU_KERN_CTX_DUMMY 0x02
1285 #define FPU_KERN_CTX_INUSE 0x04
1287 struct fpu_kern_ctx {
1288 union savefpu *prev;
1293 struct fpu_kern_ctx *
1294 fpu_kern_alloc_ctx(u_int flags)
1296 struct fpu_kern_ctx *res;
1299 sz = sizeof(struct fpu_kern_ctx) + XSAVE_AREA_ALIGN +
1300 cpu_max_ext_state_size;
1301 res = malloc(sz, M_FPUKERN_CTX, ((flags & FPU_KERN_NOWAIT) ?
1302 M_NOWAIT : M_WAITOK) | M_ZERO);
1307 fpu_kern_free_ctx(struct fpu_kern_ctx *ctx)
1310 KASSERT((ctx->flags & FPU_KERN_CTX_INUSE) == 0, ("free'ing inuse ctx"));
1311 /* XXXKIB clear the memory ? */
1312 free(ctx, M_FPUKERN_CTX);
1315 static union savefpu *
1316 fpu_kern_ctx_savefpu(struct fpu_kern_ctx *ctx)
1320 p = (vm_offset_t)&ctx->hwstate1;
1321 p = roundup2(p, XSAVE_AREA_ALIGN);
1322 return ((union savefpu *)p);
1326 fpu_kern_enter(struct thread *td, struct fpu_kern_ctx *ctx, u_int flags)
1330 KASSERT((ctx->flags & FPU_KERN_CTX_INUSE) == 0, ("using inuse ctx"));
1332 if ((flags & FPU_KERN_KTHR) != 0 && is_fpu_kern_thread(0)) {
1333 ctx->flags = FPU_KERN_CTX_DUMMY | FPU_KERN_CTX_INUSE;
1337 KASSERT(!PCB_USER_FPU(pcb) || pcb->pcb_save ==
1338 get_pcb_user_save_pcb(pcb), ("mangled pcb_save"));
1339 ctx->flags = FPU_KERN_CTX_INUSE;
1340 if ((pcb->pcb_flags & PCB_NPXINITDONE) != 0)
1341 ctx->flags |= FPU_KERN_CTX_NPXINITDONE;
1343 ctx->prev = pcb->pcb_save;
1344 pcb->pcb_save = fpu_kern_ctx_savefpu(ctx);
1345 pcb->pcb_flags |= PCB_KERNNPX;
1346 pcb->pcb_flags &= ~PCB_NPXINITDONE;
1351 fpu_kern_leave(struct thread *td, struct fpu_kern_ctx *ctx)
1355 KASSERT((ctx->flags & FPU_KERN_CTX_INUSE) != 0,
1356 ("leaving not inuse ctx"));
1357 ctx->flags &= ~FPU_KERN_CTX_INUSE;
1359 if (is_fpu_kern_thread(0) && (ctx->flags & FPU_KERN_CTX_DUMMY) != 0)
1363 if (curthread == PCPU_GET(fpcurthread))
1366 pcb->pcb_save = ctx->prev;
1367 if (pcb->pcb_save == get_pcb_user_save_pcb(pcb)) {
1368 if ((pcb->pcb_flags & PCB_NPXUSERINITDONE) != 0)
1369 pcb->pcb_flags |= PCB_NPXINITDONE;
1371 pcb->pcb_flags &= ~PCB_NPXINITDONE;
1372 pcb->pcb_flags &= ~PCB_KERNNPX;
1374 if ((ctx->flags & FPU_KERN_CTX_NPXINITDONE) != 0)
1375 pcb->pcb_flags |= PCB_NPXINITDONE;
1377 pcb->pcb_flags &= ~PCB_NPXINITDONE;
1378 KASSERT(!PCB_USER_FPU(pcb), ("unpaired fpu_kern_leave"));
1384 fpu_kern_thread(u_int flags)
1387 KASSERT((curthread->td_pflags & TDP_KTHREAD) != 0,
1388 ("Only kthread may use fpu_kern_thread"));
1389 KASSERT(curpcb->pcb_save == get_pcb_user_save_pcb(curpcb),
1390 ("mangled pcb_save"));
1391 KASSERT(PCB_USER_FPU(curpcb), ("recursive call"));
1393 curpcb->pcb_flags |= PCB_KERNNPX;
1398 is_fpu_kern_thread(u_int flags)
1401 if ((curthread->td_pflags & TDP_KTHREAD) == 0)
1403 return ((curpcb->pcb_flags & PCB_KERNNPX) != 0);
1407 * FPU save area alloc/free/init utility routines
1410 fpu_save_area_alloc(void)
1413 return (uma_zalloc(fpu_save_area_zone, 0));
1417 fpu_save_area_free(union savefpu *fsa)
1420 uma_zfree(fpu_save_area_zone, fsa);
1424 fpu_save_area_reset(union savefpu *fsa)
1427 bcopy(npx_initialstate, fsa, cpu_max_ext_state_size);