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freebsd-nq/sys/amd64/isa/npx.c
Matthew Dillon d74ac6819b Compromise for critical*()/cpu_critical*() recommit. Cleanup the interrupt 
disablement assumptions in kern_fork.c by adding another API call,
cpu_critical_fork_exit().  Cleanup the td_savecrit field by moving it
from MI to MD.  Temporarily move cpu_critical*() from <arch>/include/cpufunc.h
to <arch>/<arch>/critical.c (stage-2 will clean this up).

Implement interrupt deferral for i386 that allows interrupts to remain
enabled inside critical sections.  This also fixes an IPI interlock bug,
and requires uses of icu_lock to be enclosed in a true interrupt disablement.

This is the stage-1 commit.  Stage-2 will occur after stage-1 has stabilized,
and will move cpu_critical*() into its own header file(s) + other things.
This commit may break non-i386 architectures in trivial ways.  This should
be temporary.

Reviewed by:	core
Approved by:	core
2002-03-27 05:39:23 +00:00

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/*-
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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
* $FreeBSD$
*/
#include "opt_cpu.h"
#include "opt_debug_npx.h"
#include "opt_isa.h"
#include "opt_math_emulate.h"
#include "opt_npx.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <machine/bus.h>
#include <sys/rman.h>
#ifdef NPX_DEBUG
#include <sys/syslog.h>
#endif
#include <sys/signalvar.h>
#include <sys/user.h>
#ifndef SMP
#include <machine/asmacros.h>
#endif
#include <machine/cputypes.h>
#include <machine/frame.h>
#include <machine/md_var.h>
#include <machine/pcb.h>
#include <machine/psl.h>
#ifndef SMP
#include <machine/clock.h>
#endif
#include <machine/resource.h>
#include <machine/specialreg.h>
#include <machine/segments.h>
#ifndef SMP
#include <i386/isa/icu.h>
#ifdef PC98
#include <pc98/pc98/pc98.h>
#else
#include <i386/isa/isa.h>
#endif
#endif
#include <i386/isa/intr_machdep.h>
#ifdef DEV_ISA
#include <isa/isavar.h>
#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)
#define NPX_PREFER_EMULATOR (1 << 3)
#ifdef __GNUC__
#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)))
#endif
#define start_emulating() __asm("smsw %%ax; orb %0,%%al; lmsw %%ax" \
: : "n" (CR0_TS) : "ax")
#define stop_emulating() __asm("clts")
#else /* not __GNUC__ */
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 /* __GNUC__ */
#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)
#define GET_FPU_EXSW_PTR(pcb) \
(cpu_fxsr ? \
&(pcb)->pcb_save.sv_xmm.sv_ex_sw : \
&(pcb)->pcb_save.sv_87.sv_ex_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)
#define GET_FPU_EXSW_PTR(pcb) \
(&(pcb)->pcb_save.sv_87.sv_ex_sw)
#endif /* CPU_ENABLE_SSE */
typedef u_char bool_t;
static int npx_attach(device_t dev);
static void npx_identify(driver_t *driver, device_t parent);
#ifndef SMP
static void npx_intr(void *);
#endif
static int npx_probe(device_t dev);
static void fpusave(union savefpu *);
static void fpurstor(union savefpu *);
#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");
#ifndef SMP
static volatile u_int npx_intrs_while_probing;
static volatile u_int npx_traps_while_probing;
#endif
static bool_t npx_ex16;
static bool_t npx_exists;
static bool_t npx_irq13;
#ifndef SMP
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\
");
#endif /* SMP */
/*
* 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");
}
#ifndef SMP
/*
* Do minimal handling of npx interrupts to convert them to traps.
*/
static void
npx_intr(dummy)
void *dummy;
{
struct thread *td;
#ifndef SMP
npx_intrs_while_probing++;
#endif
/*
* The BUSY# latch must be cleared in all cases so that the next
* unmasked npx exception causes an interrupt.
*/
#ifdef PC98
outb(0xf8, 0);
#else
outb(0xf0, 0);
#endif
/*
* 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;
mtx_lock_spin(&sched_lock);
td->td_kse->ke_flags |= KEF_ASTPENDING;
mtx_unlock_spin(&sched_lock);
}
}
#endif /* !SMP */
/*
* Probe routine. Initialize cr0 to give correct behaviour for [f]wait
* whether the device exists or not (XXX should be elsewhere). Set flags
* to tell npxattach() what to do. Modify device struct if npx doesn't
* need to use interrupts. Return 0 if device exists.
*/
static int
npx_probe(dev)
device_t dev;
{
#ifndef SMP
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;
save_idt_npxtrap = idt[16];
setidt(16, 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, RF_ACTIVE);
if (ioport_res == NULL)
panic("npx: can't get ports");
#ifdef PC98
if (resource_int_value("npx", 0, "irq", &irq_num) != 0)
irq_num = 8;
#else
if (resource_int_value("npx", 0, "irq", &irq_num) != 0)
irq_num = 13;
#endif
irq_rid = 0;
irq_res = bus_alloc_resource(dev, SYS_RES_IRQ, &ioport_rid, irq_num,
irq_num, 1, RF_ACTIVE);
if (irq_res == NULL)
panic("npx: can't get IRQ");
if (bus_setup_intr(dev, irq_res, INTR_TYPE_MISC | INTR_FAST, npx_intr,
NULL, &irq_cookie) != 0)
panic("npx: can't create intr");
#endif /* !SMP */
/*
* Partially reset the coprocessor, if any. Some BIOS's don't reset
* it after a warm boot.
*/
#ifdef PC98
outb(0xf8,0);
#else
outb(0xf1, 0); /* full reset on some systems, NOP on others */
outb(0xf0, 0); /* clear BUSY# latch */
#endif
/*
* Prepare to trap all ESC (i.e., NPX) instructions and all WAIT
* instructions. We must set the CR0_MP bit and use the CR0_TS
* bit to control the trap, because setting the CR0_EM bit does
* not cause WAIT instructions to trap. It's important to trap
* WAIT instructions - otherwise the "wait" variants of no-wait
* control instructions would degenerate to the "no-wait" variants
* after FP context switches but work correctly otherwise. It's
* particularly important to trap WAITs when there is no NPX -
* otherwise the "wait" variants would always degenerate.
*
* Try setting CR0_NE to get correct error reporting on 486DX's.
* Setting it should fail or do nothing on lesser processors.
*/
load_cr0(rcr0() | CR0_MP | CR0_NE);
/*
* But 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();
device_set_desc(dev, "math processor");
#ifdef SMP
/*
* Exception 16 MUST work for SMP.
*/
npx_ex16 = hw_float = npx_exists = 1;
return (0);
#else /* !SMP */
/*
* 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();
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[16] = save_idt_npxtrap;
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.
*/
/* FALLTHROUGH */
no_irq13:
idt[16] = save_idt_npxtrap;
bus_teardown_intr(dev, irq_res, irq_cookie);
/*
* XXX hack around brokenness of bus_teardown_intr(). If we left the
* irq active then we would get it instead of exception 16.
*/
{
register_t crit;
crit = intr_disable();
mtx_lock_spin(&icu_lock);
INTRDIS(1 << irq_num);
mtx_unlock_spin(&icu_lock);
intr_restore(crit);
}
bus_release_resource(dev, SYS_RES_IRQ, irq_rid, irq_res);
bus_release_resource(dev, SYS_RES_IOPORT, ioport_rid, ioport_res);
return (0);
#endif /* SMP */
}
/*
* Attach routine - announce which it is, and wire into system
*/
int
npx_attach(dev)
device_t dev;
{
int flags;
if (resource_int_value("npx", 0, "flags", &flags) != 0)
flags = 0;
if (flags)
device_printf(dev, "flags 0x%x ", flags);
if (npx_irq13) {
device_printf(dev, "using IRQ 13 interface\n");
} else {
#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
if (npx_ex16) {
if (!(flags & NPX_PREFER_EMULATOR))
device_printf(dev, "INT 16 interface\n");
else {
device_printf(dev, "FPU exists, but flags request "
"emulator\n");
hw_float = npx_exists = 0;
}
} else if (npx_exists) {
device_printf(dev, "error reporting broken; using 387 emulator\n");
hw_float = npx_exists = 0;
} else
device_printf(dev, "387 emulator\n");
#else
if (npx_ex16) {
device_printf(dev, "INT 16 interface\n");
if (flags & NPX_PREFER_EMULATOR) {
device_printf(dev, "emulator requested, but none compiled "
"into kernel, using FPU\n");
}
} else
device_printf(dev, "no 387 emulator in kernel and no FPU!\n");
#endif
}
npxinit(__INITIAL_NPXCW__);
#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;
ovbcopy_vector = i586_bcopy;
}
if (!(flags & NPX_DISABLE_I586_OPTIMIZED_BZERO))
bzero = 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);
if (PCPU_GET(curpcb) != NULL)
fpusave(&PCPU_GET(curpcb)->pcb_save);
start_emulating();
intr_restore(savecrit);
}
/*
* Free coprocessor (if we have it).
*/
void
npxexit(td)
struct thread *td;
{
register_t savecrit;
savecrit = intr_disable();
if (td == PCPU_GET(fpcurthread))
npxsave(&PCPU_GET(curpcb)->pcb_save);
intr_restore(savecrit);
#ifdef NPX_DEBUG
if (npx_exists) {
u_int masked_exceptions;
masked_exceptions = PCPU_GET(curpcb)->pcb_save.sv_87.sv_env.en_cw
& PCPU_GET(curpcb)->pcb_save.sv_87.sv_env.en_sw & 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
}
/*
* 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;
u_long *exstat;
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);
}
exstat = GET_FPU_EXSW_PTR(curthread->td_pcb);
*exstat = status;
if (PCPU_GET(fpcurthread) != curthread)
GET_FPU_SW(curthread) &= ~0x80bf;
else
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.
*/
int
npxdna()
{
u_long *exstat;
register_t s;
if (!npx_exists)
return (0);
if (PCPU_GET(fpcurthread) != NULL) {
printf("npxdna: fpcurthread = %p, curthread = %p\n",
PCPU_GET(fpcurthread), curthread);
panic("npxdna");
}
s = intr_disable();
stop_emulating();
/*
* Record new context early in case frstor causes an IRQ13.
*/
PCPU_SET(fpcurthread, curthread);
exstat = GET_FPU_EXSW_PTR(PCPU_GET(curpcb));
*exstat = 0;
/*
* 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(&PCPU_GET(curpcb)->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);
}
static void
fpusave(addr)
union savefpu *addr;
{
#ifdef CPU_ENABLE_SSE
if (cpu_fxsr)
fxsave(addr);
else
#endif
fnsave(addr);
}
static void
fpurstor(addr)
union savefpu *addr;
{
#ifdef CPU_ENABLE_SSE
if (cpu_fxsr)
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;
#ifdef DEV_ISA
/*
* 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);
/*
* 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 */
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