Deleted most of npxprobe(), and merged npxprobe1() back into npxprobe().

Use the normal interrupt handler (npx_intr()) instead of a special
probe-time interrupt handler, although this causes problems due to
the bus_teardown_intr() not actually even tearing down the interrupt
(these problems were avoided by doing interrupt attachment for the
special interrupt handler directly).  Fixed minor bitrot in comments.

The reason for the npxprobe()/npxprobe1() split mostly went away at
about the same time it was made (in 1992 or 1993 just before the
beginning of history).  386BSD ran all probes with interrupts completely
masked, and I didn't want to disturb this when I added an irq probe
to npxprobe().  An irq (not necessarily npx) must be acked for at least
external npx's to take the cpu out of the wait state that it enters
when an npx error occurs, so the probe must be done with a suitable
irq unmasked.  npxprobe() went to great lengths to unmask precisely
the npx irq.

Running probes with all interrupts masked was never really needed in
FreeBSD, since FreeBSD always masked interrupts well enough using
splhigh(), but it wasn't until rev.1.48 (1995/12/12) of autoconf.c
that all probes were run with CPU interrupts enabled.  This permits
npxprobe() to probe its irq using normal interrupt resources.  Note
that most drivers still can't depend on this.  It depends on the
interrupt handler being fast and the irq not being shared.

1 files changed, 49 insertions, 127 deletions

diff --git a/sys/amd64/isa/npx.c b/sys/amd64/isa/npx.c
index 7323d19..b742f50 100644
--- a/sys/amd64/isa/npx.c
+++ b/sys/amd64/isa/npx.c
@@ -75,7 +75,6 @@
 
 #ifndef SMP
 #include <i386/isa/icu.h>
-#include <i386/isa/intr_machdep.h>
 #include <i386/isa/isa.h>
 #endif
 #include <isa/isavar.h>
@@ -157,7 +156,6 @@ static	void	npx_identify	__P((driver_t *driver, device_t parent));
 static	void	npx_intr	__P((void *));
 #endif
 static	int	npx_probe	__P((device_t dev));
-static	int	npx_probe1	__P((device_t dev));
 static	void	fpusave		__P((union savefpu *));
 static	void	fpurstor	__P((union savefpu *));
 #ifdef I586_CPU_XXX
@@ -179,33 +177,9 @@ static	volatile u_int		npx_traps_while_probing;
 static	bool_t			npx_ex16;
 static	bool_t			npx_exists;
 static	bool_t			npx_irq13;
-static	int			npx_irq;	/* irq number */
 
 #ifndef SMP
-/*
- * 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 probeintr() can be moved to npxprobe().
- */
-inthand_t probeintr;
-__asm("								\n\
-	.text							\n\
-	.p2align 2,0x90						\n\
-	.type	" __XSTRING(CNAME(probeintr)) ",@function	\n\
-" __XSTRING(CNAME(probeintr)) ":				\n\
-	ss							\n\
-	incl	" __XSTRING(CNAME(npx_intrs_while_probing)) "	\n\
-	pushl	%eax						\n\
-	movb	$0x20,%al	# EOI (asm in strings loses cpp features) \n\
-	outb	%al,$0xa0	# IO_ICU2			\n\
-	outb	%al,$0x20	# IO_ICU1			\n\
-	movb	$0,%al						\n\
-	outb	%al,$0xf0	# clear BUSY# latch		\n\
-	popl	%eax						\n\
-	iret							\n\
-");
-
-inthand_t probetrap;
+alias_for_inthand_t probetrap;
 __asm("								\n\
 	.text							\n\
 	.p2align 2,0x90						\n\
@@ -243,6 +217,10 @@ npx_intr(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.
@@ -269,79 +247,44 @@ npx_intr(dummy)
 		mtx_unlock_spin(&sched_lock);
 	}
 }
-
-/*
- * XXX these "local" variables of npx_probe() are non-local so that
- * npxprobe1() can abuse them.
- */
-static	int	npx_intrno;
-static	struct	gate_descriptor save_idt_npxintr;
 #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 1 if device exists.
+ * need to use interrupts.  Return 0 if device exists.
  */
 static int
 npx_probe(dev)
 	device_t dev;
 {
-#ifdef SMP
-
-	if (resource_int_value("npx", 0, "irq", &npx_irq) != 0)
-		npx_irq = 13;
-	return npx_probe1(dev);
-
-#else /* SMP */
-
-	int	result;
-	u_long	save_eflags;
-	u_char	save_icu1_mask;
-	u_char	save_icu2_mask;
-	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.
-	 */
-	if (resource_int_value("npx", 0, "irq", &npx_irq) != 0)
-		npx_irq = 13;
-	npx_intrno = NRSVIDT + npx_irq;
-	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 | (1 << npx_irq)));
-	outb(IO_ICU2 + 1, ~((1 << npx_irq) >> 8));
-	setidt(16, probetrap, SDT_SYS386TGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
-	setidt(npx_intrno, probeintr, SDT_SYS386IGT, SEL_KPL, GSEL(GCODE_SEL, SEL_KPL));
-	enable_intr();
-	result = npx_probe1(dev);
-	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);
-
-#endif /* SMP */
-}
-
-static int
-npx_probe1(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;
-#endif
+
+	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");
+	if (resource_int_value("npx", 0, "irq", &irq_num) != 0)
+		irq_num = 13;
+	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
@@ -370,23 +313,23 @@ npx_probe1(dev)
 	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
+	 * 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_irq13 = 0;
 	npx_ex16 = hw_float = npx_exists = 1;
-	device_set_desc(dev, "math processor");
 	return (0);
 
 #else /* !SMP */
-	device_set_desc(dev, "math processor");
 
 	/*
 	 * Don't use fwait here because it might hang.
@@ -427,49 +370,14 @@ npx_probe1(dev)
 				 * Good, exception 16 works.
 				 */
 				npx_ex16 = 1;
-				return (0);
+				goto no_irq13;
 			}
 			if (npx_intrs_while_probing != 0) {
-				int	rid;
-				struct	resource *r;
-				void	*intr;
 				/*
 				 * Bad, we are stuck with IRQ13.
 				 */
 				npx_irq13 = 1;
-
-				/*
-				 * We allocate these resources permanently,
-				 * so there is no need to keep track of them.
-				 */
-				rid = 0;
-				r = bus_alloc_resource(dev, SYS_RES_IOPORT,
-						       &rid, IO_NPX, IO_NPX,
-						       IO_NPXSIZE, RF_ACTIVE);
-				if (r == 0)
-					panic("npx: can't get ports");
-				rid = 0;
-				r = bus_alloc_resource(dev, SYS_RES_IRQ,
-						       &rid, npx_irq, npx_irq,
-						       1, RF_ACTIVE);
-				if (r == 0)
-					panic("npx: can't get IRQ");
-				BUS_SETUP_INTR(device_get_parent(dev),
-					       dev, r,
-					       INTR_TYPE_MISC | INTR_FAST,
-					       npx_intr, 0, &intr);
-				if (intr == 0)
-					panic("npx: can't create intr");
-
-				/*
-				 * XXX BUS_SETUP_INTR() has changed
-				 * idt[npx_intrno] to point to Xfastintr0
-				 * instead of Xfastintr0.  Adjust
-				 * save_idt_npxintr so that npxprobe()
-				 * doesn't undo this.
-				 */
-				save_idt_npxintr = idt[npx_intrno];
-
+				idt[16] = save_idt_npxtrap;
 				return (0);
 			}
 			/*
@@ -482,7 +390,21 @@ npx_probe1(dev)
 	 * 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.
+	 */
+	INTRDIS(1 << irq_num);
+
+	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 */
 }