freebsd-dev/sys/i386/isa/npx.c
Rodney W. Grimes 5c644711a9 ALL:
Removed patch kit headers and rcsid strings, add $Id$.

isa.c:

Removed old #ifdef notyet isa_configure code, since it will never be
used, and I have done 90% of what it attempted to.

Add conflict checking code that searchs back through the devtab's looking
for any device that has already been found that may conflict with what
we are about to probe.  Checks are mode for I/O address, memory address,
IRQ, and DRQ.  This should stop the screwing up of any device that has
alread been found by other device probes.
Print out messages when we are not going to probe a device due to
a conflict so the user knows WHY something was not found.  For example:

aha0 not probed due to irq conflict with ahb0 at 11

Now print out a message when a device is not found so the user knows
that it was probed for, but could not be found.  For example:

ed1 not found at 0x320

For devices that have I/O address < 0x100 say that they are on the
motherboard, not on isa!  The 0x100 magic number is per ISA spec.  It
may seem funny that pc0 and sc0 report as being on the motherboard, but
this is due to the fact that the I/O address used is that of the keyboard
controller which IS on the motherboard.  We really need to split the
keyboard probe from the display probe.  It is completly legal to build
a pc with out one or the other, or even with out both!

npx.c:

Return -1 from the probe routine if we are using the Emulator so
that the i/o addresses are not printed, this is the same trick used
for 486's.

Do not print the ``Errors reported via Exception 16'', and
``Errors reported via IRQ 13'' messages any more, since these just lead
to more user confusion that anything.  It still prints the message
``Error reporting broken, using 387 emulator'' so that the person is
aware that there mother board is ill.
1993-10-13 15:59:30 +00:00

555 lines
16 KiB
C

/*-
* 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
* $Id$
*/
#include "npx.h"
#if NNPX > 0
#include "param.h"
#include "systm.h"
#include "conf.h"
#include "file.h"
#include "proc.h"
#include "machine/cpu.h"
#include "machine/pcb.h"
#include "machine/trap.h"
#include "ioctl.h"
#include "machine/specialreg.h"
#include "i386/isa/icu.h"
#include "i386/isa/isa_device.h"
#include "i386/isa/isa.h"
/*
* 387 and 287 Numeric Coprocessor Extension (NPX) Driver.
*/
#ifdef __GNUC__
#define disable_intr() __asm("cli")
#define enable_intr() __asm("sti")
#define fldcw(addr) __asm("fldcw %0" : : "m" (*addr))
#define fnclex() __asm("fnclex")
#define fninit() __asm("fninit")
#define fnsave(addr) __asm("fnsave %0" : "=m" (*addr) : "0" (*addr))
#define fnstcw(addr) __asm("fnstcw %0" : "=m" (*addr) : "0" (*addr))
#define fnstsw(addr) __asm("fnstsw %0" : "=m" (*addr) : "0" (*addr))
#define fp_divide_by_0() __asm("fldz; fld1; fdiv %st,%st(1); fwait")
#define frstor(addr) __asm("frstor %0" : : "m" (*addr))
#define fwait() __asm("fwait")
#define read_eflags() ({u_long ef; \
__asm("pushf; popl %0" : "=a" (ef)); \
ef; })
#define start_emulating() __asm("smsw %%ax; orb %0,%%al; lmsw %%ax" \
: : "n" (CR0_TS) : "ax")
#define stop_emulating() __asm("clts")
#define write_eflags(ef) __asm("pushl %0; popf" : : "a" ((u_long) ef))
#else /* not __GNUC__ */
void disable_intr __P((void));
void enable_intr __P((void));
void fldcw __P((caddr_t addr));
void fnclex __P((void));
void fninit __P((void));
void fnsave __P((caddr_t addr));
void fnstcw __P((caddr_t addr));
void fnstsw __P((caddr_t addr));
void fp_divide_by_0 __P((void));
void frstor __P((caddr_t addr));
void fwait __P((void));
u_long read_eflags __P((void));
void start_emulating __P((void));
void stop_emulating __P((void));
void write_eflags __P((u_long ef));
#endif /* __GNUC__ */
typedef u_char bool_t;
extern struct gate_descriptor idt[];
int npxdna __P((void));
void npxexit __P((struct proc *p));
void npxinit __P((u_int control));
void npxintr __P((struct intrframe frame));
void npxsave __P((struct save87 *addr));
static int npxattach __P((struct isa_device *dvp));
static int npxprobe __P((struct isa_device *dvp));
static int npxprobe1 __P((struct isa_device *dvp));
struct isa_driver npxdriver = {
npxprobe, npxattach, "npx",
};
u_int npx0mask;
struct proc *npxproc;
static bool_t npx_ex16;
static bool_t npx_exists;
static struct gate_descriptor npx_idt_probeintr;
static int npx_intrno;
static volatile u_int npx_intrs_while_probing;
static bool_t npx_irq13;
static volatile u_int npx_traps_while_probing;
/*
* Special interrupt handlers. Someday intr0-intr15 will be used to count
* interrupts. We'll still need a special exception 16 handler. The busy
* latch stuff in probintr() can be moved to npxprobe().
*/
void probeintr(void);
asm
("
.text
_probeintr:
ss
incl _npx_intrs_while_probing
pushl %eax
movb $0x20,%al /* EOI (asm in strings loses cpp features) */
outb %al,$0xa0 /* IO_ICU2 */
outb %al,$0x20 /* IO_ICU1 */
movb $0,%al
outb %al,$0xf0 /* clear BUSY# latch */
popl %eax
iret
");
void probetrap(void);
asm
("
.text
_probetrap:
ss
incl _npx_traps_while_probing
fnclex
iret
");
/*
* 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 1 if device exists.
*/
static int
npxprobe(dvp)
struct isa_device *dvp;
{
int result;
u_long save_eflags;
u_char save_icu1_mask;
u_char save_icu2_mask;
struct gate_descriptor save_idt_npxintr;
struct gate_descriptor save_idt_npxtrap;
/*
* This routine is now just a wrapper for npxprobe1(), to install
* special npx interrupt and trap handlers, to enable npx interrupts
* and to disable other interrupts. Someday isa_configure() will
* install suitable handlers and run with interrupts enabled so we
* won't need to do so much here.
*/
npx_intrno = NRSVIDT + ffs(dvp->id_irq) - 1;
save_eflags = read_eflags();
disable_intr();
save_icu1_mask = inb(IO_ICU1 + 1);
save_icu2_mask = inb(IO_ICU2 + 1);
save_idt_npxintr = idt[npx_intrno];
save_idt_npxtrap = idt[16];
outb(IO_ICU1 + 1, ~(IRQ_SLAVE | dvp->id_irq));
outb(IO_ICU2 + 1, ~(dvp->id_irq >> 8));
setidt(16, probetrap, SDT_SYS386TGT, SEL_KPL);
setidt(npx_intrno, probeintr, SDT_SYS386IGT, SEL_KPL);
npx_idt_probeintr = idt[npx_intrno];
enable_intr();
result = npxprobe1(dvp);
disable_intr();
outb(IO_ICU1 + 1, save_icu1_mask);
outb(IO_ICU2 + 1, save_icu2_mask);
idt[npx_intrno] = save_idt_npxintr;
idt[16] = save_idt_npxtrap;
write_eflags(save_eflags);
return (result);
}
static int
npxprobe1(dvp)
struct isa_device *dvp;
{
int control;
int status;
#ifdef lint
npxintr();
#endif
/*
* Partially reset the coprocessor, if any. Some BIOS's don't reset
* it after a warm boot.
*/
outb(0xf1, 0); /* full reset on some systems, NOP on others */
outb(0xf0, 0); /* clear BUSY# latch */
/*
* 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 probeintr() 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();
DELAY(1000); /* wait for any IRQ13 (fwait might hang) */
#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) {
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);
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;
dvp->id_irq = 0; /* zap the interrupt */
/*
* special return value to flag that we do not
* actually use any I/O registers
*/
return (-1);
}
if (npx_intrs_while_probing != 0) {
/*
* Bad, we are stuck with IRQ13.
*/
npx_irq13 = 1;
npx0mask = dvp->id_irq; /* npxattach too late */
return (IO_NPXSIZE);
}
/*
* 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.
*/
dvp->id_irq = 0;
/*
* special return value to flag that we do not
* actually use any I/O registers
*/
return (-1);
}
/*
* Attach routine - announce which it is, and wire into system
*/
int
npxattach(dvp)
struct isa_device *dvp;
{
if (!npx_ex16 && !npx_irq13) {
if (npx_exists)
printf("npx%d: Error reporting broken, using 387 emulator\n",dvp->id_unit);
else
printf("npx%d: 387 Emulator\n",dvp->id_unit);
}
npxinit(__INITIAL_NPXCW__);
return (1); /* XXX unused */
}
/*
* Initialize floating point unit.
*/
void
npxinit(control)
u_int control;
{
struct save87 dummy;
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. fnsave initializes
* the fpu and sets npxproc = NULL as important side effects.
*/
npxsave(&dummy);
stop_emulating();
fldcw(&control);
if (curpcb != NULL)
fnsave(&curpcb->pcb_savefpu);
start_emulating();
}
/*
* Free coprocessor (if we have it).
*/
void
npxexit(p)
struct proc *p;
{
if (p == npxproc) {
start_emulating();
npxproc = NULL;
}
}
/*
* Record the FPU state and reinitialize it all except for the control word.
* Then generate a SIGFPE.
*
* Reinitializing the state allows naive SIGFPE handlers to longjmp without
* doing any fixups.
*
* XXX there is currently no way to pass the full error state to signal
* handlers, and if this is a nested interrupt there is no way to pass even
* a status code! So there is no way to have a non-naive SIGFPE handler. At
* best a handler could do an fninit followed by an fldcw of a static value.
* fnclex would be of little use because it would leave junk on the FPU stack.
* Returning from the handler would be even less safe than usual because
* IRQ13 exception handling makes exceptions even less precise than usual.
*/
void
npxintr(frame)
struct intrframe frame;
{
int code;
if (npxproc == NULL || !npx_exists) {
/* XXX no %p in stand/printf.c. Cast to quiet gcc -Wall. */
printf("npxintr: npxproc = %lx, curproc = %lx, npx_exists = %d\n",
(u_long) npxproc, (u_long) curproc, npx_exists);
panic("npxintr from nowhere");
}
if (npxproc != curproc) {
printf("npxintr: npxproc = %lx, curproc = %lx, npx_exists = %d\n",
(u_long) npxproc, (u_long) curproc, npx_exists);
panic("npxintr from non-current process");
}
/*
* Save state. This does an implied fninit. It had better not halt
* the cpu or we'll hang.
*/
outb(0xf0, 0);
fnsave(&curpcb->pcb_savefpu);
fwait();
/*
* Restore control word (was clobbered by fnsave).
*/
fldcw(&curpcb->pcb_savefpu.sv_env.en_cw);
fwait();
/*
* Remember the exception status word and tag word. The current
* (almost fninit'ed) fpu state is in the fpu and the exception
* state just saved will soon be junk. However, the implied fninit
* doesn't change the error pointers or register contents, and we
* preserved the control word and will copy the status and tag
* words, so the complete exception state can be recovered.
*/
curpcb->pcb_savefpu.sv_ex_sw = curpcb->pcb_savefpu.sv_env.en_sw;
curpcb->pcb_savefpu.sv_ex_tw = curpcb->pcb_savefpu.sv_env.en_tw;
/*
* Pass exception to process.
*/
if (ISPL(frame.if_cs) == SEL_UPL) {
/*
* Interrupt is essentially a trap, so we can afford to call
* the SIGFPE handler (if any) as soon as the interrupt
* returns.
*
* XXX little or nothing is gained from this, and plenty is
* lost - the interrupt frame has to contain the trap frame
* (this is otherwise only necessary for the rescheduling trap
* in doreti, and the frame for that could easily be set up
* just before it is used).
*/
curproc->p_regs = (int *)&frame.if_es;
curpcb->pcb_flags |= FM_TRAP; /* used by sendsig */
#ifdef notyet
/*
* Encode the appropriate code for detailed information on
* this exception.
*/
code = XXX_ENCODE(curpcb->pcb_savefpu.sv_ex_sw);
#else
code = 0; /* XXX */
#endif
trapsignal(curproc, SIGFPE, code);
curpcb->pcb_flags &= ~FM_TRAP;
} else {
/*
* Nested interrupt. These losers occur when:
* o an IRQ13 is bogusly generated at a bogus time, e.g.:
* o immediately after an fnsave or frstor of an
* error state.
* o a couple of 386 instructions after
* "fstpl _memvar" causes a stack overflow.
* These are especially nasty when combined with a
* trace trap.
* o an IRQ13 occurs at the same time as another higher-
* priority interrupt.
*
* Treat them like a true async interrupt.
*/
psignal(npxproc, SIGFPE);
}
}
/*
* Implement device not available (DNA) exception
*
* It would be better to switch FP context here (only). This would require
* saving the state in the proc table instead of in the pcb.
*/
int
npxdna()
{
if (!npx_exists)
return (0);
if (npxproc != NULL) {
printf("npxdna: npxproc = %lx, curproc = %lx\n",
(u_long) npxproc, (u_long) curproc);
panic("npxdna");
}
stop_emulating();
/*
* Record new context early in case frstor causes an IRQ13.
*/
npxproc = curproc;
/*
* 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.
*/
frstor(&curpcb->pcb_savefpu);
return (1);
}
/*
* Wrapper for fnsave instruction to handle h/w bugs. If there is an error
* pending, then fnsave generates a bogus IRQ13 on some systems. Force
* any IRQ13 to be handled immediately, and then ignore it. This routine is
* often called at splhigh so it must not use many system services. In
* particular, it's much easier to install a special handler than to
* guarantee that it's safe to use npxintr() and its supporting code.
*/
void
npxsave(addr)
struct save87 *addr;
{
u_char icu1_mask;
u_char icu2_mask;
u_char old_icu1_mask;
u_char old_icu2_mask;
struct gate_descriptor save_idt_npxintr;
disable_intr();
old_icu1_mask = inb(IO_ICU1 + 1);
old_icu2_mask = inb(IO_ICU2 + 1);
save_idt_npxintr = idt[npx_intrno];
outb(IO_ICU1 + 1, old_icu1_mask & ~(IRQ_SLAVE | npx0mask));
outb(IO_ICU2 + 1, old_icu2_mask & ~(npx0mask >> 8));
idt[npx_intrno] = npx_idt_probeintr;
enable_intr();
stop_emulating();
fnsave(addr);
fwait();
start_emulating();
npxproc = NULL;
disable_intr();
icu1_mask = inb(IO_ICU1 + 1); /* masks may have changed */
icu2_mask = inb(IO_ICU2 + 1);
outb(IO_ICU1 + 1,
(icu1_mask & ~npx0mask) | (old_icu1_mask & npx0mask));
outb(IO_ICU2 + 1,
(icu2_mask & ~(npx0mask >> 8))
| (old_icu2_mask & (npx0mask >> 8)));
idt[npx_intrno] = save_idt_npxintr;
enable_intr(); /* back to usual state */
}
#endif /* NNPX > 0 */