/*- * Copyright (c) 1990 William Jolitz. * Copyright (c) 1991 The Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)npx.c 7.2 (Berkeley) 5/12/91 */ #include __FBSDID("$FreeBSD$"); #include "opt_cpu.h" #include "opt_isa.h" #include "opt_npx.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef NPX_DEBUG #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #ifdef XEN #include #include #endif #ifdef DEV_ISA #include #endif #if !defined(CPU_DISABLE_SSE) && defined(I686_CPU) #define CPU_ENABLE_SSE #endif /* * 387 and 287 Numeric Coprocessor Extension (NPX) Driver. */ /* Configuration flags. */ #define NPX_DISABLE_I586_OPTIMIZED_BCOPY (1 << 0) #define NPX_DISABLE_I586_OPTIMIZED_BZERO (1 << 1) #define NPX_DISABLE_I586_OPTIMIZED_COPYIO (1 << 2) #if defined(__GNUCLIKE_ASM) && !defined(lint) #define fldcw(addr) __asm("fldcw %0" : : "m" (*(addr))) #define fnclex() __asm("fnclex") #define fninit() __asm("fninit") #define fnsave(addr) __asm __volatile("fnsave %0" : "=m" (*(addr))) #define fnstcw(addr) __asm __volatile("fnstcw %0" : "=m" (*(addr))) #define fnstsw(addr) __asm __volatile("fnstsw %0" : "=m" (*(addr))) #define fp_divide_by_0() __asm("fldz; fld1; fdiv %st,%st(1); fnop") #define frstor(addr) __asm("frstor %0" : : "m" (*(addr))) #ifdef CPU_ENABLE_SSE #define fxrstor(addr) __asm("fxrstor %0" : : "m" (*(addr))) #define fxsave(addr) __asm __volatile("fxsave %0" : "=m" (*(addr))) #define ldmxcsr(__csr) __asm __volatile("ldmxcsr %0" : : "m" (__csr)) #endif #ifdef XEN #define start_emulating() (HYPERVISOR_fpu_taskswitch(1)) #define stop_emulating() (HYPERVISOR_fpu_taskswitch(0)) #else #define start_emulating() __asm("smsw %%ax; orb %0,%%al; lmsw %%ax" \ : : "n" (CR0_TS) : "ax") #define stop_emulating() __asm("clts") #endif #else /* !(__GNUCLIKE_ASM && !lint) */ void fldcw(caddr_t addr); void fnclex(void); void fninit(void); void fnsave(caddr_t addr); void fnstcw(caddr_t addr); void fnstsw(caddr_t addr); void fp_divide_by_0(void); void frstor(caddr_t addr); #ifdef CPU_ENABLE_SSE void fxsave(caddr_t addr); void fxrstor(caddr_t addr); #endif void start_emulating(void); void stop_emulating(void); #endif /* __GNUCLIKE_ASM && !lint */ #ifdef CPU_ENABLE_SSE #define GET_FPU_CW(thread) \ (cpu_fxsr ? \ (thread)->td_pcb->pcb_save.sv_xmm.sv_env.en_cw : \ (thread)->td_pcb->pcb_save.sv_87.sv_env.en_cw) #define GET_FPU_SW(thread) \ (cpu_fxsr ? \ (thread)->td_pcb->pcb_save.sv_xmm.sv_env.en_sw : \ (thread)->td_pcb->pcb_save.sv_87.sv_env.en_sw) #else /* CPU_ENABLE_SSE */ #define GET_FPU_CW(thread) \ (thread->td_pcb->pcb_save.sv_87.sv_env.en_cw) #define GET_FPU_SW(thread) \ (thread->td_pcb->pcb_save.sv_87.sv_env.en_sw) #endif /* CPU_ENABLE_SSE */ typedef u_char bool_t; #ifdef CPU_ENABLE_SSE static void fpu_clean_state(void); #endif static void fpusave(union savefpu *); static void fpurstor(union savefpu *); static int npx_attach(device_t dev); static void npx_identify(driver_t *driver, device_t parent); static int npx_intr(void *); static int npx_probe(device_t dev); #ifdef I586_CPU_XXX static long timezero(const char *funcname, void (*func)(void *buf, size_t len)); #endif /* I586_CPU */ int hw_float; /* XXX currently just alias for npx_exists */ SYSCTL_INT(_hw,HW_FLOATINGPT, floatingpoint, CTLFLAG_RD, &hw_float, 0, "Floatingpoint instructions executed in hardware"); static volatile u_int npx_intrs_while_probing; static volatile u_int npx_traps_while_probing; static union savefpu npx_cleanstate; static bool_t npx_cleanstate_ready; static bool_t npx_ex16; static bool_t npx_exists; static bool_t npx_irq13; alias_for_inthand_t probetrap; __asm(" \n\ .text \n\ .p2align 2,0x90 \n\ .type " __XSTRING(CNAME(probetrap)) ",@function \n\ " __XSTRING(CNAME(probetrap)) ": \n\ ss \n\ incl " __XSTRING(CNAME(npx_traps_while_probing)) " \n\ fnclex \n\ iret \n\ "); /* * Identify routine. Create a connection point on our parent for probing. */ static void npx_identify(driver, parent) driver_t *driver; device_t parent; { device_t child; child = BUS_ADD_CHILD(parent, 0, "npx", 0); if (child == NULL) panic("npx_identify"); } /* * Do minimal handling of npx interrupts to convert them to traps. */ static int npx_intr(dummy) void *dummy; { struct thread *td; npx_intrs_while_probing++; /* * The BUSY# latch must be cleared in all cases so that the next * unmasked npx exception causes an interrupt. */ outb(IO_NPX, 0); /* * fpcurthread is normally non-null here. In that case, schedule an * AST to finish the exception handling in the correct context * (this interrupt may occur after the thread has entered the * kernel via a syscall or an interrupt). Otherwise, the npx * state of the thread that caused this interrupt must have been * pushed to the thread's pcb, and clearing of the busy latch * above has finished the (essentially null) handling of this * interrupt. Control will eventually return to the instruction * that caused it and it will repeat. We will eventually (usually * soon) win the race to handle the interrupt properly. */ td = PCPU_GET(fpcurthread); if (td != NULL) { td->td_pcb->pcb_flags |= PCB_NPXTRAP; thread_lock(td); td->td_flags |= TDF_ASTPENDING; thread_unlock(td); } return (FILTER_HANDLED); } /* * Probe routine. Set flags to tell npxattach() what to do. Set up an * interrupt handler if npx needs to use interrupts. */ static int npx_probe(dev) device_t dev; { struct gate_descriptor save_idt_npxtrap; struct resource *ioport_res, *irq_res; void *irq_cookie; int ioport_rid, irq_num, irq_rid; u_short control; u_short status; device_set_desc(dev, "math processor"); /* * Modern CPUs all have an FPU that uses the INT16 interface * and provide a simple way to verify that, so handle the * common case right away. */ if (cpu_feature & CPUID_FPU) { hw_float = npx_exists = 1; npx_ex16 = 1; device_quiet(dev); return (0); } save_idt_npxtrap = idt[IDT_MF]; setidt(IDT_MF, probetrap, SDT_SYS386TGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL)); ioport_rid = 0; ioport_res = bus_alloc_resource(dev, SYS_RES_IOPORT, &ioport_rid, IO_NPX, IO_NPX + IO_NPXSIZE - 1, IO_NPXSIZE, RF_ACTIVE); if (ioport_res == NULL) panic("npx: can't get ports"); if (resource_int_value("npx", 0, "irq", &irq_num) != 0) irq_num = IRQ_NPX; irq_rid = 0; irq_res = bus_alloc_resource(dev, SYS_RES_IRQ, &irq_rid, irq_num, irq_num, 1, RF_ACTIVE); if (irq_res != NULL) { if (bus_setup_intr(dev, irq_res, INTR_TYPE_MISC, npx_intr, NULL, NULL, &irq_cookie) != 0) panic("npx: can't create intr"); } /* * Partially reset the coprocessor, if any. Some BIOS's don't reset * it after a warm boot. */ npx_full_reset(); outb(IO_NPX, 0); /* * Don't trap while we're probing. */ stop_emulating(); /* * Finish resetting the coprocessor, if any. If there is an error * pending, then we may get a bogus IRQ13, but npx_intr() will handle * it OK. Bogus halts have never been observed, but we enabled * IRQ13 and cleared the BUSY# latch early to handle them anyway. */ fninit(); /* * Don't use fwait here because it might hang. * Don't use fnop here because it usually hangs if there is no FPU. */ DELAY(1000); /* wait for any IRQ13 */ #ifdef DIAGNOSTIC if (npx_intrs_while_probing != 0) printf("fninit caused %u bogus npx interrupt(s)\n", npx_intrs_while_probing); if (npx_traps_while_probing != 0) printf("fninit caused %u bogus npx trap(s)\n", npx_traps_while_probing); #endif /* * Check for a status of mostly zero. */ status = 0x5a5a; fnstsw(&status); if ((status & 0xb8ff) == 0) { /* * Good, now check for a proper control word. */ control = 0x5a5a; fnstcw(&control); if ((control & 0x1f3f) == 0x033f) { hw_float = npx_exists = 1; /* * We have an npx, now divide by 0 to see if exception * 16 works. */ control &= ~(1 << 2); /* enable divide by 0 trap */ fldcw(&control); #ifdef FPU_ERROR_BROKEN /* * FPU error signal doesn't work on some CPU * accelerator board. */ npx_ex16 = 1; return (0); #endif npx_traps_while_probing = npx_intrs_while_probing = 0; fp_divide_by_0(); DELAY(1000); /* wait for any IRQ13 */ if (npx_traps_while_probing != 0) { /* * Good, exception 16 works. */ npx_ex16 = 1; goto no_irq13; } if (npx_intrs_while_probing != 0) { /* * Bad, we are stuck with IRQ13. */ npx_irq13 = 1; idt[IDT_MF] = save_idt_npxtrap; #ifdef SMP if (mp_ncpus > 1) panic("npx0 cannot use IRQ 13 on an SMP system"); #endif return (0); } /* * Worse, even IRQ13 is broken. Use emulator. */ } } /* * Probe failed, but we want to get to npxattach to initialize the * emulator and say that it has been installed. XXX handle devices * that aren't really devices better. */ #ifdef SMP if (mp_ncpus > 1) panic("npx0 cannot be emulated on an SMP system"); #endif /* FALLTHROUGH */ no_irq13: idt[IDT_MF] = save_idt_npxtrap; if (irq_res != NULL) { bus_teardown_intr(dev, irq_res, irq_cookie); bus_release_resource(dev, SYS_RES_IRQ, irq_rid, irq_res); } bus_release_resource(dev, SYS_RES_IOPORT, ioport_rid, ioport_res); return (0); } /* * Attach routine - announce which it is, and wire into system */ static int npx_attach(dev) device_t dev; { int flags; register_t s; flags = device_get_flags(dev); if (npx_irq13) device_printf(dev, "IRQ 13 interface\n"); else if (!npx_ex16) device_printf(dev, "WARNING: no FPU!\n"); else if (!device_is_quiet(dev) || bootverbose) device_printf(dev, "INT 16 interface\n"); npxinit(__INITIAL_NPXCW__); if (npx_cleanstate_ready == 0) { s = intr_disable(); stop_emulating(); fpusave(&npx_cleanstate); start_emulating(); #ifdef CPU_ENABLE_SSE if (cpu_fxsr) { if (npx_cleanstate.sv_xmm.sv_env.en_mxcsr_mask) cpu_mxcsr_mask = npx_cleanstate.sv_xmm.sv_env.en_mxcsr_mask; else cpu_mxcsr_mask = 0xFFBF; } #endif npx_cleanstate_ready = 1; intr_restore(s); } #ifdef I586_CPU_XXX if (cpu_class == CPUCLASS_586 && npx_ex16 && npx_exists && timezero("i586_bzero()", i586_bzero) < timezero("bzero()", bzero) * 4 / 5) { if (!(flags & NPX_DISABLE_I586_OPTIMIZED_BCOPY)) bcopy_vector = i586_bcopy; if (!(flags & NPX_DISABLE_I586_OPTIMIZED_BZERO)) bzero_vector = i586_bzero; if (!(flags & NPX_DISABLE_I586_OPTIMIZED_COPYIO)) { copyin_vector = i586_copyin; copyout_vector = i586_copyout; } } #endif return (0); /* XXX unused */ } /* * Initialize floating point unit. */ void npxinit(control) u_short control; { static union savefpu dummy; register_t savecrit; if (!npx_exists) return; /* * fninit has the same h/w bugs as fnsave. Use the detoxified * fnsave to throw away any junk in the fpu. npxsave() initializes * the fpu and sets fpcurthread = NULL as important side effects. */ savecrit = intr_disable(); npxsave(&dummy); stop_emulating(); #ifdef CPU_ENABLE_SSE /* XXX npxsave() doesn't actually initialize the fpu in the SSE case. */ if (cpu_fxsr) fninit(); #endif fldcw(&control); start_emulating(); intr_restore(savecrit); } /* * Free coprocessor (if we have it). */ void npxexit(td) struct thread *td; { register_t savecrit; savecrit = intr_disable(); if (curthread == PCPU_GET(fpcurthread)) npxsave(&PCPU_GET(curpcb)->pcb_save); intr_restore(savecrit); #ifdef NPX_DEBUG if (npx_exists) { u_int masked_exceptions; masked_exceptions = GET_FPU_CW(td) & GET_FPU_SW(td) & 0x7f; /* * Log exceptions that would have trapped with the old * control word (overflow, divide by 0, and invalid operand). */ if (masked_exceptions & 0x0d) log(LOG_ERR, "pid %d (%s) exited with masked floating point exceptions 0x%02x\n", td->td_proc->p_pid, td->td_proc->p_comm, masked_exceptions); } #endif } int npxformat() { if (!npx_exists) return (_MC_FPFMT_NODEV); #ifdef CPU_ENABLE_SSE if (cpu_fxsr) return (_MC_FPFMT_XMM); #endif return (_MC_FPFMT_387); } /* * The following mechanism is used to ensure that the FPE_... value * that is passed as a trapcode to the signal handler of the user * process does not have more than one bit set. * * Multiple bits may be set if the user process modifies the control * word while a status word bit is already set. While this is a sign * of bad coding, we have no choise than to narrow them down to one * bit, since we must not send a trapcode that is not exactly one of * the FPE_ macros. * * The mechanism has a static table with 127 entries. Each combination * of the 7 FPU status word exception bits directly translates to a * position in this table, where a single FPE_... value is stored. * This FPE_... value stored there is considered the "most important" * of the exception bits and will be sent as the signal code. The * precedence of the bits is based upon Intel Document "Numerical * Applications", Chapter "Special Computational Situations". * * The macro to choose one of these values does these steps: 1) Throw * away status word bits that cannot be masked. 2) Throw away the bits * currently masked in the control word, assuming the user isn't * interested in them anymore. 3) Reinsert status word bit 7 (stack * fault) if it is set, which cannot be masked but must be presered. * 4) Use the remaining bits to point into the trapcode table. * * The 6 maskable bits in order of their preference, as stated in the * above referenced Intel manual: * 1 Invalid operation (FP_X_INV) * 1a Stack underflow * 1b Stack overflow * 1c Operand of unsupported format * 1d SNaN operand. * 2 QNaN operand (not an exception, irrelavant here) * 3 Any other invalid-operation not mentioned above or zero divide * (FP_X_INV, FP_X_DZ) * 4 Denormal operand (FP_X_DNML) * 5 Numeric over/underflow (FP_X_OFL, FP_X_UFL) * 6 Inexact result (FP_X_IMP) */ static char fpetable[128] = { 0, FPE_FLTINV, /* 1 - INV */ FPE_FLTUND, /* 2 - DNML */ FPE_FLTINV, /* 3 - INV | DNML */ FPE_FLTDIV, /* 4 - DZ */ FPE_FLTINV, /* 5 - INV | DZ */ FPE_FLTDIV, /* 6 - DNML | DZ */ FPE_FLTINV, /* 7 - INV | DNML | DZ */ FPE_FLTOVF, /* 8 - OFL */ FPE_FLTINV, /* 9 - INV | OFL */ FPE_FLTUND, /* A - DNML | OFL */ FPE_FLTINV, /* B - INV | DNML | OFL */ FPE_FLTDIV, /* C - DZ | OFL */ FPE_FLTINV, /* D - INV | DZ | OFL */ FPE_FLTDIV, /* E - DNML | DZ | OFL */ FPE_FLTINV, /* F - INV | DNML | DZ | OFL */ FPE_FLTUND, /* 10 - UFL */ FPE_FLTINV, /* 11 - INV | UFL */ FPE_FLTUND, /* 12 - DNML | UFL */ FPE_FLTINV, /* 13 - INV | DNML | UFL */ FPE_FLTDIV, /* 14 - DZ | UFL */ FPE_FLTINV, /* 15 - INV | DZ | UFL */ FPE_FLTDIV, /* 16 - DNML | DZ | UFL */ FPE_FLTINV, /* 17 - INV | DNML | DZ | UFL */ FPE_FLTOVF, /* 18 - OFL | UFL */ FPE_FLTINV, /* 19 - INV | OFL | UFL */ FPE_FLTUND, /* 1A - DNML | OFL | UFL */ FPE_FLTINV, /* 1B - INV | DNML | OFL | UFL */ FPE_FLTDIV, /* 1C - DZ | OFL | UFL */ FPE_FLTINV, /* 1D - INV | DZ | OFL | UFL */ FPE_FLTDIV, /* 1E - DNML | DZ | OFL | UFL */ FPE_FLTINV, /* 1F - INV | DNML | DZ | OFL | UFL */ FPE_FLTRES, /* 20 - IMP */ FPE_FLTINV, /* 21 - INV | IMP */ FPE_FLTUND, /* 22 - DNML | IMP */ FPE_FLTINV, /* 23 - INV | DNML | IMP */ FPE_FLTDIV, /* 24 - DZ | IMP */ FPE_FLTINV, /* 25 - INV | DZ | IMP */ FPE_FLTDIV, /* 26 - DNML | DZ | IMP */ FPE_FLTINV, /* 27 - INV | DNML | DZ | IMP */ FPE_FLTOVF, /* 28 - OFL | IMP */ FPE_FLTINV, /* 29 - INV | OFL | IMP */ FPE_FLTUND, /* 2A - DNML | OFL | IMP */ FPE_FLTINV, /* 2B - INV | DNML | OFL | IMP */ FPE_FLTDIV, /* 2C - DZ | OFL | IMP */ FPE_FLTINV, /* 2D - INV | DZ | OFL | IMP */ FPE_FLTDIV, /* 2E - DNML | DZ | OFL | IMP */ FPE_FLTINV, /* 2F - INV | DNML | DZ | OFL | IMP */ FPE_FLTUND, /* 30 - UFL | IMP */ FPE_FLTINV, /* 31 - INV | UFL | IMP */ FPE_FLTUND, /* 32 - DNML | UFL | IMP */ FPE_FLTINV, /* 33 - INV | DNML | UFL | IMP */ FPE_FLTDIV, /* 34 - DZ | UFL | IMP */ FPE_FLTINV, /* 35 - INV | DZ | UFL | IMP */ FPE_FLTDIV, /* 36 - DNML | DZ | UFL | IMP */ FPE_FLTINV, /* 37 - INV | DNML | DZ | UFL | IMP */ FPE_FLTOVF, /* 38 - OFL | UFL | IMP */ FPE_FLTINV, /* 39 - INV | OFL | UFL | IMP */ FPE_FLTUND, /* 3A - DNML | OFL | UFL | IMP */ FPE_FLTINV, /* 3B - INV | DNML | OFL | UFL | IMP */ FPE_FLTDIV, /* 3C - DZ | OFL | UFL | IMP */ FPE_FLTINV, /* 3D - INV | DZ | OFL | UFL | IMP */ FPE_FLTDIV, /* 3E - DNML | DZ | OFL | UFL | IMP */ FPE_FLTINV, /* 3F - INV | DNML | DZ | OFL | UFL | IMP */ FPE_FLTSUB, /* 40 - STK */ FPE_FLTSUB, /* 41 - INV | STK */ FPE_FLTUND, /* 42 - DNML | STK */ FPE_FLTSUB, /* 43 - INV | DNML | STK */ FPE_FLTDIV, /* 44 - DZ | STK */ FPE_FLTSUB, /* 45 - INV | DZ | STK */ FPE_FLTDIV, /* 46 - DNML | DZ | STK */ FPE_FLTSUB, /* 47 - INV | DNML | DZ | STK */ FPE_FLTOVF, /* 48 - OFL | STK */ FPE_FLTSUB, /* 49 - INV | OFL | STK */ FPE_FLTUND, /* 4A - DNML | OFL | STK */ FPE_FLTSUB, /* 4B - INV | DNML | OFL | STK */ FPE_FLTDIV, /* 4C - DZ | OFL | STK */ FPE_FLTSUB, /* 4D - INV | DZ | OFL | STK */ FPE_FLTDIV, /* 4E - DNML | DZ | OFL | STK */ FPE_FLTSUB, /* 4F - INV | DNML | DZ | OFL | STK */ FPE_FLTUND, /* 50 - UFL | STK */ FPE_FLTSUB, /* 51 - INV | UFL | STK */ FPE_FLTUND, /* 52 - DNML | UFL | STK */ FPE_FLTSUB, /* 53 - INV | DNML | UFL | STK */ FPE_FLTDIV, /* 54 - DZ | UFL | STK */ FPE_FLTSUB, /* 55 - INV | DZ | UFL | STK */ FPE_FLTDIV, /* 56 - DNML | DZ | UFL | STK */ FPE_FLTSUB, /* 57 - INV | DNML | DZ | UFL | STK */ FPE_FLTOVF, /* 58 - OFL | UFL | STK */ FPE_FLTSUB, /* 59 - INV | OFL | UFL | STK */ FPE_FLTUND, /* 5A - DNML | OFL | UFL | STK */ FPE_FLTSUB, /* 5B - INV | DNML | OFL | UFL | STK */ FPE_FLTDIV, /* 5C - DZ | OFL | UFL | STK */ FPE_FLTSUB, /* 5D - INV | DZ | OFL | UFL | STK */ FPE_FLTDIV, /* 5E - DNML | DZ | OFL | UFL | STK */ FPE_FLTSUB, /* 5F - INV | DNML | DZ | OFL | UFL | STK */ FPE_FLTRES, /* 60 - IMP | STK */ FPE_FLTSUB, /* 61 - INV | IMP | STK */ FPE_FLTUND, /* 62 - DNML | IMP | STK */ FPE_FLTSUB, /* 63 - INV | DNML | IMP | STK */ FPE_FLTDIV, /* 64 - DZ | IMP | STK */ FPE_FLTSUB, /* 65 - INV | DZ | IMP | STK */ FPE_FLTDIV, /* 66 - DNML | DZ | IMP | STK */ FPE_FLTSUB, /* 67 - INV | DNML | DZ | IMP | STK */ FPE_FLTOVF, /* 68 - OFL | IMP | STK */ FPE_FLTSUB, /* 69 - INV | OFL | IMP | STK */ FPE_FLTUND, /* 6A - DNML | OFL | IMP | STK */ FPE_FLTSUB, /* 6B - INV | DNML | OFL | IMP | STK */ FPE_FLTDIV, /* 6C - DZ | OFL | IMP | STK */ FPE_FLTSUB, /* 6D - INV | DZ | OFL | IMP | STK */ FPE_FLTDIV, /* 6E - DNML | DZ | OFL | IMP | STK */ FPE_FLTSUB, /* 6F - INV | DNML | DZ | OFL | IMP | STK */ FPE_FLTUND, /* 70 - UFL | IMP | STK */ FPE_FLTSUB, /* 71 - INV | UFL | IMP | STK */ FPE_FLTUND, /* 72 - DNML | UFL | IMP | STK */ FPE_FLTSUB, /* 73 - INV | DNML | UFL | IMP | STK */ FPE_FLTDIV, /* 74 - DZ | UFL | IMP | STK */ FPE_FLTSUB, /* 75 - INV | DZ | UFL | IMP | STK */ FPE_FLTDIV, /* 76 - DNML | DZ | UFL | IMP | STK */ FPE_FLTSUB, /* 77 - INV | DNML | DZ | UFL | IMP | STK */ FPE_FLTOVF, /* 78 - OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 79 - INV | OFL | UFL | IMP | STK */ FPE_FLTUND, /* 7A - DNML | OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 7B - INV | DNML | OFL | UFL | IMP | STK */ FPE_FLTDIV, /* 7C - DZ | OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 7D - INV | DZ | OFL | UFL | IMP | STK */ FPE_FLTDIV, /* 7E - DNML | DZ | OFL | UFL | IMP | STK */ FPE_FLTSUB, /* 7F - INV | DNML | DZ | OFL | UFL | IMP | STK */ }; /* * Preserve the FP status word, clear FP exceptions, then generate a SIGFPE. * * Clearing exceptions is necessary mainly to avoid IRQ13 bugs. We now * depend on longjmp() restoring a usable state. Restoring the state * or examining it might fail if we didn't clear exceptions. * * The error code chosen will be one of the FPE_... macros. It will be * sent as the second argument to old BSD-style signal handlers and as * "siginfo_t->si_code" (second argument) to SA_SIGINFO signal handlers. * * XXX the FP state is not preserved across signal handlers. So signal * handlers cannot afford to do FP unless they preserve the state or * longjmp() out. Both preserving the state and longjmp()ing may be * destroyed by IRQ13 bugs. Clearing FP exceptions is not an acceptable * solution for signals other than SIGFPE. */ int npxtrap() { register_t savecrit; u_short control, status; if (!npx_exists) { printf("npxtrap: fpcurthread = %p, curthread = %p, npx_exists = %d\n", PCPU_GET(fpcurthread), curthread, npx_exists); panic("npxtrap from nowhere"); } savecrit = intr_disable(); /* * Interrupt handling (for another interrupt) may have pushed the * state to memory. Fetch the relevant parts of the state from * wherever they are. */ if (PCPU_GET(fpcurthread) != curthread) { control = GET_FPU_CW(curthread); status = GET_FPU_SW(curthread); } else { fnstcw(&control); fnstsw(&status); } if (PCPU_GET(fpcurthread) == curthread) fnclex(); intr_restore(savecrit); return (fpetable[status & ((~control & 0x3f) | 0x40)]); } /* * Implement device not available (DNA) exception * * It would be better to switch FP context here (if curthread != fpcurthread) * and not necessarily for every context switch, but it is too hard to * access foreign pcb's. */ static int err_count = 0; int npxdna() { struct pcb *pcb; register_t s; #ifdef CPU_ENABLE_SSE int mxcsr; #endif u_short control; if (!npx_exists) return (0); if (PCPU_GET(fpcurthread) == curthread) { printf("npxdna: fpcurthread == curthread %d times\n", ++err_count); stop_emulating(); return (1); } if (PCPU_GET(fpcurthread) != NULL) { printf("npxdna: fpcurthread = %p (%d), curthread = %p (%d)\n", PCPU_GET(fpcurthread), PCPU_GET(fpcurthread)->td_proc->p_pid, curthread, curthread->td_proc->p_pid); panic("npxdna"); } s = intr_disable(); stop_emulating(); /* * Record new context early in case frstor causes an IRQ13. */ PCPU_SET(fpcurthread, curthread); pcb = PCPU_GET(curpcb); if ((pcb->pcb_flags & PCB_NPXINITDONE) == 0) { /* * This is the first time this thread has used the FPU or * the PCB doesn't contain a clean FPU state. Explicitly * initialize the FPU and load the default control word. */ fninit(); control = __INITIAL_NPXCW__; fldcw(&control); #ifdef CPU_ENABLE_SSE if (cpu_fxsr) { mxcsr = __INITIAL_MXCSR__; ldmxcsr(mxcsr); } #endif pcb->pcb_flags |= PCB_NPXINITDONE; } else { /* * The following frstor may cause an IRQ13 when the state * being restored has a pending error. The error will * appear to have been triggered by the current (npx) user * instruction even when that instruction is a no-wait * instruction that should not trigger an error (e.g., * fnclex). On at least one 486 system all of the no-wait * instructions are broken the same as frstor, so our * treatment does not amplify the breakage. On at least * one 386/Cyrix 387 system, fnclex works correctly while * frstor and fnsave are broken, so our treatment breaks * fnclex if it is the first FPU instruction after a context * switch. */ fpurstor(&pcb->pcb_save); } intr_restore(s); return (1); } /* * Wrapper for fnsave instruction, partly to handle hardware bugs. When npx * exceptions are reported via IRQ13, spurious IRQ13's may be triggered by * no-wait npx instructions. See the Intel application note AP-578 for * details. This doesn't cause any additional complications here. IRQ13's * are inherently asynchronous unless the CPU is frozen to deliver them -- * one that started in userland may be delivered many instructions later, * after the process has entered the kernel. It may even be delivered after * the fnsave here completes. A spurious IRQ13 for the fnsave is handled in * the same way as a very-late-arriving non-spurious IRQ13 from user mode: * it is normally ignored at first because we set fpcurthread to NULL; it is * normally retriggered in npxdna() after return to user mode. * * npxsave() must be called with interrupts disabled, so that it clears * fpcurthread atomically with saving the state. We require callers to do the * disabling, since most callers need to disable interrupts anyway to call * npxsave() atomically with checking fpcurthread. * * A previous version of npxsave() went to great lengths to excecute fnsave * with interrupts enabled in case executing it froze the CPU. This case * can't happen, at least for Intel CPU/NPX's. Spurious IRQ13's don't imply * spurious freezes. */ void npxsave(addr) union savefpu *addr; { stop_emulating(); fpusave(addr); start_emulating(); PCPU_SET(fpcurthread, NULL); } /* * This should be called with interrupts disabled and only when the owning * FPU thread is non-null. */ void npxdrop() { struct thread *td; /* * Discard pending exceptions in the !cpu_fxsr case so that unmasked * ones don't cause a panic on the next frstor. */ #ifdef CPU_ENABLE_SSE if (!cpu_fxsr) #endif fnclex(); td = PCPU_GET(fpcurthread); PCPU_SET(fpcurthread, NULL); td->td_pcb->pcb_flags &= ~PCB_NPXINITDONE; start_emulating(); } /* * Get the state of the FPU without dropping ownership (if possible). * It returns the FPU ownership status. */ int npxgetregs(td, addr) struct thread *td; union savefpu *addr; { register_t s; if (!npx_exists) return (_MC_FPOWNED_NONE); if ((td->td_pcb->pcb_flags & PCB_NPXINITDONE) == 0) { if (npx_cleanstate_ready) bcopy(&npx_cleanstate, addr, sizeof(npx_cleanstate)); else bzero(addr, sizeof(*addr)); return (_MC_FPOWNED_NONE); } s = intr_disable(); if (td == PCPU_GET(fpcurthread)) { fpusave(addr); #ifdef CPU_ENABLE_SSE if (!cpu_fxsr) #endif /* * fnsave initializes the FPU and destroys whatever * context it contains. Make sure the FPU owner * starts with a clean state next time. */ npxdrop(); intr_restore(s); return (_MC_FPOWNED_FPU); } else { intr_restore(s); bcopy(&td->td_pcb->pcb_save, addr, sizeof(*addr)); return (_MC_FPOWNED_PCB); } } /* * Set the state of the FPU. */ void npxsetregs(td, addr) struct thread *td; union savefpu *addr; { register_t s; if (!npx_exists) return; s = intr_disable(); if (td == PCPU_GET(fpcurthread)) { #ifdef CPU_ENABLE_SSE if (!cpu_fxsr) #endif fnclex(); /* As in npxdrop(). */ fpurstor(addr); intr_restore(s); } else { intr_restore(s); bcopy(addr, &td->td_pcb->pcb_save, sizeof(*addr)); } curthread->td_pcb->pcb_flags |= PCB_NPXINITDONE; } static void fpusave(addr) union savefpu *addr; { #ifdef CPU_ENABLE_SSE if (cpu_fxsr) fxsave(addr); else #endif fnsave(addr); } #ifdef CPU_ENABLE_SSE /* * On AuthenticAMD processors, the fxrstor instruction does not restore * the x87's stored last instruction pointer, last data pointer, and last * opcode values, except in the rare case in which the exception summary * (ES) bit in the x87 status word is set to 1. * * In order to avoid leaking this information across processes, we clean * these values by performing a dummy load before executing fxrstor(). */ static double dummy_variable = 0.0; static void fpu_clean_state(void) { u_short status; /* * Clear the ES bit in the x87 status word if it is currently * set, in order to avoid causing a fault in the upcoming load. */ fnstsw(&status); if (status & 0x80) fnclex(); /* * Load the dummy variable into the x87 stack. This mangles * the x87 stack, but we don't care since we're about to call * fxrstor() anyway. */ __asm __volatile("ffree %%st(7); fld %0" : : "m" (dummy_variable)); } #endif /* CPU_ENABLE_SSE */ static void fpurstor(addr) union savefpu *addr; { #ifdef CPU_ENABLE_SSE if (cpu_fxsr) { fpu_clean_state(); fxrstor(addr); } else #endif frstor(addr); } #ifdef I586_CPU_XXX static long timezero(funcname, func) const char *funcname; void (*func)(void *buf, size_t len); { void *buf; #define BUFSIZE 1048576 long usec; struct timeval finish, start; buf = malloc(BUFSIZE, M_TEMP, M_NOWAIT); if (buf == NULL) return (BUFSIZE); microtime(&start); (*func)(buf, BUFSIZE); microtime(&finish); usec = 1000000 * (finish.tv_sec - start.tv_sec) + finish.tv_usec - start.tv_usec; if (usec <= 0) usec = 1; if (bootverbose) printf("%s bandwidth = %u kBps\n", funcname, (u_int32_t)(((BUFSIZE >> 10) * 1000000) / usec)); free(buf, M_TEMP); return (usec); } #endif /* I586_CPU */ static device_method_t npx_methods[] = { /* Device interface */ DEVMETHOD(device_identify, npx_identify), DEVMETHOD(device_probe, npx_probe), DEVMETHOD(device_attach, npx_attach), DEVMETHOD(device_detach, bus_generic_detach), DEVMETHOD(device_shutdown, bus_generic_shutdown), DEVMETHOD(device_suspend, bus_generic_suspend), DEVMETHOD(device_resume, bus_generic_resume), { 0, 0 } }; static driver_t npx_driver = { "npx", npx_methods, 1, /* no softc */ }; static devclass_t npx_devclass; /* * We prefer to attach to the root nexus so that the usual case (exception 16) * doesn't describe the processor as being `on isa'. */ DRIVER_MODULE(npx, nexus, npx_driver, npx_devclass, 0, 0); #ifdef DEV_ISA /* * This sucks up the legacy ISA support assignments from PNPBIOS/ACPI. */ static struct isa_pnp_id npxisa_ids[] = { { 0x040cd041, "Legacy ISA coprocessor support" }, /* PNP0C04 */ { 0 } }; static int npxisa_probe(device_t dev) { int result; if ((result = ISA_PNP_PROBE(device_get_parent(dev), dev, npxisa_ids)) <= 0) { device_quiet(dev); } return(result); } static int npxisa_attach(device_t dev) { return (0); } static device_method_t npxisa_methods[] = { /* Device interface */ DEVMETHOD(device_probe, npxisa_probe), DEVMETHOD(device_attach, npxisa_attach), DEVMETHOD(device_detach, bus_generic_detach), DEVMETHOD(device_shutdown, bus_generic_shutdown), DEVMETHOD(device_suspend, bus_generic_suspend), DEVMETHOD(device_resume, bus_generic_resume), { 0, 0 } }; static driver_t npxisa_driver = { "npxisa", npxisa_methods, 1, /* no softc */ }; static devclass_t npxisa_devclass; DRIVER_MODULE(npxisa, isa, npxisa_driver, npxisa_devclass, 0, 0); #ifndef PC98 DRIVER_MODULE(npxisa, acpi, npxisa_driver, npxisa_devclass, 0, 0); #endif #endif /* DEV_ISA */