New try at a level based irq system.

7 files changed, 137 insertions, 87 deletions

diff --git a/sys/arch/i386/i386/autoconf.c b/sys/arch/i386/i386/autoconf.c
index 02663b62c6e..34726fb23d3 100644
--- a/sys/arch/i386/i386/autoconf.c
+++ b/sys/arch/i386/i386/autoconf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: autoconf.c,v 1.38 2001/11/18 20:46:49 aaron Exp $	*/
+/*	$OpenBSD: autoconf.c,v 1.39 2001/12/04 00:00:36 niklas Exp $	*/
 /*	$NetBSD: autoconf.c,v 1.20 1996/05/03 19:41:56 christos Exp $	*/
 
 /*-
@@ -87,9 +87,8 @@ cpu_configure()
 	if (config_rootfound("mainbus", NULL) == NULL)
 		panic("cpu_configure: mainbus not configured");
 
-	printf("biomask %x netmask %x ttymask %x\n",
-	    (u_short)imask[IPL_BIO], (u_short)imask[IPL_NET],
-	    (u_short)imask[IPL_TTY]);
+	printf("biomask %x netmask %x ttymask %x\n", (u_short)IMASK(IPL_BIO),
+	    (u_short)IMASK(IPL_NET), (u_short)IMASK(IPL_TTY));
 
 	spl0();
 
diff --git a/sys/arch/i386/include/intr.h b/sys/arch/i386/include/intr.h
index 552de36e257..d8e716507f0 100644
--- a/sys/arch/i386/include/intr.h
+++ b/sys/arch/i386/include/intr.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: intr.h,v 1.9 2001/11/18 20:46:49 aaron Exp $	*/
+/*	$OpenBSD: intr.h,v 1.10 2001/12/04 00:00:36 niklas Exp $	*/
 /*	$NetBSD: intr.h,v 1.5 1996/05/13 06:11:28 mycroft Exp $	*/
 
 /*
@@ -33,19 +33,54 @@
 #ifndef _I386_INTR_H_
 #define _I386_INTR_H_
 
-/* Interrupt priority `levels'; not mutually exclusive. */
-#define	IPL_NONE	0	/* nothing */
-#define	IPL_BIO		1	/* block I/O */
-#define	IPL_NET		2	/* network */
-#define	IPL_TTY		3	/* terminal */
-#define	IPL_IMP		4	/* memory allocation */
-#define	IPL_AUDIO	5	/* audio */
-#define	IPL_CLOCK	6	/* clock */
-#define	IPL_HIGH	7	/* everything */
+/*
+ * Intel APICs (advanced programmable interrupt controllers) have
+ * bytesized priority registers where the upper nibble is the actual
+ * interrupt priority level (a.k.a. IPL).  Interrupt vectors are
+ * closely tied to these levels as interrupts whose vectors' upper
+ * nibble is lower than or equal to the current level are blocked.
+ * Not all 256 possible vectors are available for interrupts in
+ * APIC systems, only
+ *
+ * For systems where instead the older ICU (interrupt controlling
+ * unit, a.k.a. PIC or 82C59) is used, the IPL is not directly useful,
+ * since the interrupt blocking is handled via interrupt masks instead
+ * of levels.  However the IPL is easily used as an offset into arrays
+ * of masks.
+ */
+#define IPLSHIFT 4	/* The upper nibble of vectors is the IPL.	*/
+#define NIPL 16		/* Four bits of information gives as much.	*/
+#define IPL(level) ((level) >> IPLSHIFT)	/* Extract the IPL.	*/
+/* XXX Maybe this IDTVECOFF definition should be elsewhere? */
+#define IDTVECOFF 0x20	/* The lower 32 IDT vectors are reserved.	*/
 
-#ifndef _LOCORE
-int imask[IPL_HIGH+1];
-#endif
+/*
+ * This macro is only defined for 0 <= x < 14, i.e. there are fourteen
+ * distinct priority levels available for interrupts.
+ */
+#define MAKEIPL(priority) (IDTVECOFF + ((priority) << IPLSHIFT))
+
+/*
+ * Interrupt priority levels.
+ * XXX We are somewhat sloppy about what we mean by IPLs, sometimes
+ * XXX we refer to the eight-bit value suitable for storing into APICs'
+ * XXX priority registers, other times about the four-bit entity found
+ * XXX in the former values' upper nibble, which can be used as offsets
+ * XXX in various arrays of our implementation.  We are hoping that
+ * XXX the context will provide enough information to not make this
+ * XXX sloppy naming a real problem.
+ */
+#define	IPL_NONE	0		/* nothing */
+#define	IPL_SOFTCLOCK	MAKEIPL(0)	/* timeouts */
+#define	IPL_SOFTNET	MAKEIPL(1)	/* protocol stacks */
+#define	IPL_BIO		MAKEIPL(2)	/* block I/O */
+#define	IPL_NET		MAKEIPL(3)	/* network */
+#define	IPL_SOFTTTY	MAKEIPL(4)	/* delayed terminal handling */
+#define	IPL_TTY		MAKEIPL(5)	/* terminal */
+#define	IPL_IMP		MAKEIPL(6)	/* memory allocation */
+#define	IPL_AUDIO	MAKEIPL(7)	/* audio */
+#define	IPL_CLOCK	MAKEIPL(8)	/* clock */
+#define	IPL_HIGH	MAKEIPL(9)	/* everything */
 
 /* Interrupt sharing types. */
 #define	IST_NONE	0	/* none */
@@ -55,16 +90,19 @@ int imask[IPL_HIGH+1];
 
 /* Soft interrupt masks. */
 #define	SIR_CLOCK	31
-#define	SIR_CLOCKMASK	((1 << SIR_CLOCK))
 #define	SIR_NET		30
-#define	SIR_NETMASK	((1 << SIR_NET) | SIR_CLOCKMASK)
 #define	SIR_TTY		29
-#define	SIR_TTYMASK	((1 << SIR_TTY) | SIR_CLOCKMASK)
-#define	SIR_ALLMASK	(SIR_CLOCKMASK | SIR_NETMASK | SIR_TTYMASK)
 
 #ifndef _LOCORE
 
-volatile int cpl, ipending, astpending;
+volatile int cpl;	/* Current interrupt priority level.		*/
+volatile int ipending;	/* Interrupts pending.				*/
+volatile int astpending;/* Asynchronous software traps (softints) pending. */
+int imask[NIPL];	/* Bitmasks telling what interrupts are blocked. */
+int iunmask[NIPL];	/* Bitmasks telling what interrupts are accepted. */
+
+#define IMASK(level) imask[IPL(level)]
+#define IUNMASK(level) iunmask[IPL(level)]
 
 extern void Xspllower __P((void));
 
@@ -74,7 +112,7 @@ static __inline void splx __P((int));
 static __inline void softintr __P((int));
 
 /*
- * Add a mask to cpl, and return the old value of cpl.
+ * Raise current interrupt priority level, and return the old one.
  */
 static __inline int
 splraise(ncpl)
@@ -82,21 +120,21 @@ splraise(ncpl)
 {
 	register int ocpl = cpl;
 
-	cpl = ocpl | ncpl;
+	if (ncpl > ocpl)
+		cpl = ncpl;
 	return (ocpl);
 }
 
 /*
- * Restore a value to cpl (unmasking interrupts).  If any unmasked
+ * Restore an old interrupt priority level.  If any thereby unmasked
  * interrupts are pending, call Xspllower() to process them.
  */
 static __inline void
 splx(ncpl)
 	register int ncpl;
 {
-
 	cpl = ncpl;
-	if (ipending & ~ncpl)
+	if (ipending & IUNMASK(ncpl))
 		Xspllower();
 }
 
@@ -110,20 +148,18 @@ spllower(ncpl)
 {
 	register int ocpl = cpl;
 
-	cpl = ncpl;
-	if (ipending & ~ncpl)
-		Xspllower();
+	splx(ncpl);
 	return (ocpl);
 }
 
 /*
  * Hardware interrupt masks
  */
-#define	splbio()	splraise(imask[IPL_BIO])
-#define	splnet()	splraise(imask[IPL_NET])
-#define	spltty()	splraise(imask[IPL_TTY])
-#define	splaudio()	splraise(imask[IPL_AUDIO])
-#define	splclock()	splraise(imask[IPL_CLOCK])
+#define	splbio()	splraise(IPL_BIO)
+#define	splnet()	splraise(IPL_NET)
+#define	spltty()	splraise(IPL_TTY)
+#define	splaudio()	splraise(IPL_AUDIO)
+#define	splclock()	splraise(IPL_CLOCK)
 #define	splstatclock()	splhigh()
 
 /*
@@ -132,18 +168,18 @@ spllower(ncpl)
  * NOTE: spllowersoftclock() is used by hardclock() to lower the priority from
  * clock to softclock before it calls softclock().
  */
-#define	spllowersoftclock()	spllower(SIR_CLOCKMASK)
-#define	splsoftclock()		splraise(SIR_CLOCKMASK)
-#define	splsoftnet()		splraise(SIR_NETMASK)
-#define	splsofttty()		splraise(SIR_TTYMASK)
+#define	spllowersoftclock()	spllower(IPL_SOFTCLOCK)
+#define	splsoftclock()		splraise(IPL_SOFTCLOCK)
+#define	splsoftnet()		splraise(IPL_SOFTNET)
+#define	splsofttty()		splraise(IPL_SOFTTTY)
 
 /*
  * Miscellaneous
  */
-#define	splimp()	splraise(imask[IPL_IMP])
-#define	splvm()		splraise(imask[IPL_IMP])
-#define	splhigh()	splraise(imask[IPL_HIGH])
-#define	spl0()		spllower(0)
+#define	splimp()	splraise(IPL_IMP)
+#define	splvm()		splraise(IPL_IMP)
+#define	splhigh()	splraise(IPL_HIGH)
+#define	spl0()		spllower(IPL_NONE)
 
 /*
  * Software interrupt registration
@@ -154,7 +190,6 @@ static __inline void
 softintr(mask)
 	register int mask;
 {
-
 	__asm __volatile("orl %0,_ipending" : : "ir" (mask));
 }
 
diff --git a/sys/arch/i386/isa/icu.h b/sys/arch/i386/isa/icu.h
index 231a4404cbc..5279822d3cd 100644
--- a/sys/arch/i386/isa/icu.h
+++ b/sys/arch/i386/isa/icu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: icu.h,v 1.6 2001/11/18 20:46:49 aaron Exp $	*/
+/*	$OpenBSD: icu.h,v 1.7 2001/12/04 00:00:36 niklas Exp $	*/
 /*	$NetBSD: icu.h,v 1.19 1996/02/01 22:31:21 mycroft Exp $	*/
 
 /*-
@@ -65,6 +65,9 @@ extern	unsigned imen;		/* interrupt mask enable */
 
 /*
  * Interrupt Control offset into Interrupt descriptor table (IDT)
+ * XXX ICU_OFFSET is actually a property of our architecture not of the ICU
+ * XXX and therefore ought to use the architecture manifest constant IDTVECOFF
+ * XXX for its definition instead.
  */
 #define	ICU_OFFSET	32		/* 0-31 are processor exceptions */
 #define	ICU_LEN		16		/* 32-47 are ISA interrupts */
diff --git a/sys/arch/i386/isa/icu.s b/sys/arch/i386/isa/icu.s
index 8be1d64520b..57b11456f29 100644
--- a/sys/arch/i386/isa/icu.s
+++ b/sys/arch/i386/isa/icu.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: icu.s,v 1.17 2001/11/18 20:46:49 aaron Exp $	*/
+/*	$OpenBSD: icu.s,v 1.18 2001/12/04 00:00:36 niklas Exp $	*/
 /*	$NetBSD: icu.s,v 1.45 1996/01/07 03:59:34 mycroft Exp $	*/
 
 /*-
@@ -45,7 +45,7 @@ _C_LABEL(imen):
 
 	ALIGN_TEXT
 _C_LABEL(splhigh):
-	movl	$-1,%eax
+	movl	$IPL_HIGH,%eax
 	xchgl	%eax,_C_LABEL(cpl)
 	ret
 
@@ -72,8 +72,9 @@ IDTVEC(spllower)
 	pushl	%edi
 	movl	_C_LABEL(cpl),%ebx	# save priority
 	movl	$1f,%esi		# address to resume loop at
-1:	movl	%ebx,%eax
-	notl	%eax
+1:	movl	%ebx,%eax		# get cpl
+	shrl	$4,%eax			# find its mask.
+	movl	_C_LABEL(iunmask)(,%eax,4),%eax
 	andl	_C_LABEL(ipending),%eax
 	jz	2f
 	bsfl	%eax,%eax
@@ -97,8 +98,9 @@ IDTVEC(doreti)
 	popl	%ebx			# get previous priority
 	movl	%ebx,_C_LABEL(cpl)
 	movl	$1f,%esi		# address to resume loop at
-1:	movl	%ebx,%eax
-	notl	%eax
+1:	movl	%ebx,%eax		# get cpl
+	shrl	$4,%eax			# find its mask
+	movl	_C_LABEL(iunmask)(,%eax,4),%eax
 	andl	_C_LABEL(ipending),%eax
 	jz	2f
 	bsfl    %eax,%eax               # slow, but not worth optimizing
@@ -132,7 +134,7 @@ IDTVEC(doreti)
 
 IDTVEC(softtty)
 #if NPCCOM > 0
-	leal	SIR_TTYMASK(%ebx),%eax
+	movl	$IPL_SOFTTTY,%eax
 	movl	%eax,_C_LABEL(cpl)
 	call	_C_LABEL(comsoft)
 	movl	%ebx,_C_LABEL(cpl)
@@ -147,7 +149,7 @@ IDTVEC(softtty)
 1:
 
 IDTVEC(softnet)
-	leal	SIR_NETMASK(%ebx),%eax
+	movl	$IPL_SOFTNET,%eax
 	movl	%eax,_C_LABEL(cpl)
 	xorl	%edi,%edi
 	xchgl	_C_LABEL(netisr),%edi
@@ -157,7 +159,7 @@ IDTVEC(softnet)
 #undef DONETISR
 
 IDTVEC(softclock)
-	leal	SIR_CLOCKMASK(%ebx),%eax
+	movl	$IPL_SOFTCLOCK,%eax
 	movl	%eax,_C_LABEL(cpl)
 	call	_C_LABEL(softclock)
 	movl	%ebx,_C_LABEL(cpl)
diff --git a/sys/arch/i386/isa/isa_machdep.c b/sys/arch/i386/isa/isa_machdep.c
index 19d352fe8ad..2ca2f0173af 100644
--- a/sys/arch/i386/isa/isa_machdep.c
+++ b/sys/arch/i386/isa/isa_machdep.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: isa_machdep.c,v 1.42 2001/11/18 20:46:49 aaron Exp $	*/
+/*	$OpenBSD: isa_machdep.c,v 1.43 2001/12/04 00:00:36 niklas Exp $	*/
 /*	$NetBSD: isa_machdep.c,v 1.22 1997/06/12 23:57:32 thorpej Exp $	*/
 
 #define ISA_DMA_STATS
@@ -129,6 +129,7 @@
 #define _I386_BUS_DMA_PRIVATE
 #include <machine/bus.h>
 
+#include <machine/intr.h>
 #include <machine/pio.h>
 #include <machine/cpufunc.h>
 
@@ -221,8 +222,8 @@ isa_defaultirq()
 
 	/* icu vectors */
 	for (i = 0; i < ICU_LEN; i++)
-		setgate(&idt[ICU_OFFSET + i], IDTVEC(intr)[i], 0, SDT_SYS386IGT,
-		    SEL_KPL, GICODE_SEL);
+		setgate(&idt[ICU_OFFSET + i], IDTVEC(intr)[i], 0,
+		    SDT_SYS386IGT, SEL_KPL, GICODE_SEL);
   
 	/* initialize 8259's */
 	outb(IO_ICU1, 0x11);		/* reset; program device, four bytes */
@@ -260,13 +261,13 @@ isa_defaultirq()
 int
 isa_nmi()
 {
-
 	/* This is historic garbage; these ports are not readable */
 	log(LOG_CRIT, "No-maskable interrupt, may be parity error\n");
 	return(0);
 }
 
-u_long	intrstray[ICU_LEN] = {0};
+u_long  intrstray[ICU_LEN];
+
 /*
  * Caught a stray interrupt, notify
  */
@@ -287,6 +288,7 @@ isa_strayintr(irq)
 
 int fastvec;
 int intrtype[ICU_LEN], intrmask[ICU_LEN], intrlevel[ICU_LEN];
+int iminlevel[ICU_LEN], imaxlevel[ICU_LEN];
 struct intrhand *intrhand[ICU_LEN];
 
 /*
@@ -305,45 +307,49 @@ intr_calculatemasks()
 	for (irq = 0; irq < ICU_LEN; irq++) {
 		register int levels = 0;
 		for (q = intrhand[irq]; q; q = q->ih_next)
-			levels |= 1 << q->ih_level;
+			levels |= 1 << IPL(q->ih_level);
 		intrlevel[irq] = levels;
 	}
 
 	/* Then figure out which IRQs use each level. */
-	for (level = 0; level < 5; level++) {
+	for (level = 0; level < NIPL; level++) {
 		register int irqs = 0;
 		for (irq = 0; irq < ICU_LEN; irq++)
 			if (intrlevel[irq] & (1 << level))
 				irqs |= 1 << irq;
-		imask[level] = irqs | SIR_ALLMASK;
+		imask[level] = irqs;
 	}
 
 	/*
-	 * There are tty, network and disk drivers that use free() at interrupt
-	 * time, so imp > (tty | net | bio).
+	 * Initialize soft interrupt masks to block themselves.
 	 */
-	imask[IPL_IMP] |= imask[IPL_TTY] | imask[IPL_NET] | imask[IPL_BIO];
-	imask[IPL_AUDIO] |= imask[IPL_IMP];
+	IMASK(IPL_SOFTCLOCK) |= 1 << SIR_CLOCK;
+	IMASK(IPL_SOFTNET) |= 1 << SIR_NET;
+	IMASK(IPL_SOFTTTY) |= 1 << SIR_TTY;
 
 	/*
 	 * Enforce a hierarchy that gives slow devices a better chance at not
 	 * dropping data.
 	 */
-	imask[IPL_TTY] |= imask[IPL_NET] | imask[IPL_BIO];
-	imask[IPL_NET] |= imask[IPL_BIO];
-
-	/*
-	 * These are pseudo-levels.
-	 */
-	imask[IPL_NONE] = 0x00000000;
-	imask[IPL_HIGH] = 0xffffffff;
+	for (level = 0; level < NIPL - 1; level++)
+		imask[level + 1] |= imask[level];
 
 	/* And eventually calculate the complete masks. */
 	for (irq = 0; irq < ICU_LEN; irq++) {
 		register int irqs = 1 << irq;
-		for (q = intrhand[irq]; q; q = q->ih_next)
-			irqs |= imask[q->ih_level];
-		intrmask[irq] = irqs | SIR_ALLMASK;
+		int minlevel = IPL_NONE;
+		int maxlevel = IPL_NONE;
+
+		for (q = intrhand[irq]; q; q = q->ih_next) {
+			irqs |= IMASK(q->ih_level);
+			if (minlevel == IPL_NONE || q->ih_level < minlevel)
+				minlevel = q->ih_level;
+			if (q->ih_level > maxlevel)
+				maxlevel = q->ih_level;
+		}
+		intrmask[irq] = irqs;
+		iminlevel[irq] = minlevel;
+		imaxlevel[irq] = maxlevel;
 	}
 
 	/* Lastly, determine which IRQs are actually in use. */
@@ -357,13 +363,16 @@ intr_calculatemasks()
 		imen = ~irqs;
 		SET_ICUS();
 	}
+
+	/* For speed of splx, provide the inverse of the interrupt masks. */
+	for (irq = 0; irq < ICU_LEN; irq++)
+		iunmask[irq] = ~imask[irq];
 }
 
 int
 fakeintr(arg)
 	void *arg;
 {
-
 	return 0;
 }
 
diff --git a/sys/arch/i386/isa/npx.c b/sys/arch/i386/isa/npx.c
index 04fb03b0533..b6fa7145ff1 100644
--- a/sys/arch/i386/isa/npx.c
+++ b/sys/arch/i386/isa/npx.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: npx.c,v 1.22 2001/11/18 20:46:49 aaron Exp $	*/
+/*	$OpenBSD: npx.c,v 1.23 2001/12/04 00:00:36 niklas Exp $	*/
 /*	$NetBSD: npx.c,v 1.57 1996/05/12 23:12:24 mycroft Exp $	*/
 
 #if 0
@@ -537,7 +537,7 @@ npxdna(p)
 	}
 
 #ifdef DIAGNOSTIC
-	if (cpl != 0 || npx_nointr != 0)
+	if (cpl != IPL_NONE || npx_nointr != 0)
 		panic("npxdna: masked");
 #endif
 
@@ -612,7 +612,7 @@ npxsave()
 {
 
 #ifdef DIAGNOSTIC
-	if (cpl != 0 || npx_nointr != 0)
+	if (cpl != IPL_NONE || npx_nointr != 0)
 		panic("npxsave: masked");
 #endif
 	iprintf(("Fork"));
diff --git a/sys/arch/i386/isa/vector.s b/sys/arch/i386/isa/vector.s
index 664477530e9..b445c720ef1 100644
--- a/sys/arch/i386/isa/vector.s
+++ b/sys/arch/i386/isa/vector.s
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vector.s,v 1.13 2001/11/18 20:46:49 aaron Exp $	*/
+/*	$OpenBSD: vector.s,v 1.14 2001/12/04 00:00:36 niklas Exp $	*/
 /*	$NetBSD: vector.s,v 1.32 1996/01/07 21:29:47 mycroft Exp $	*/
 
 /*
@@ -218,13 +218,15 @@ _Xintr/**/irq_num/**/:							;\
 	MASK(irq_num, icu)		/* mask it in hardware */	;\
 	ack(irq_num)			/* and allow other intrs */	;\
 	incl	MY_COUNT+V_INTR		/* statistical info */		;\
-	testb	$IRQ_BIT(irq_num),_cpl + IRQ_BYTE(irq_num)		;\
-	jnz	_Xhold/**/irq_num	/* currently masked; hold it */	;\
+	movl	_C_LABEL(iminlevel) + (irq_num) * 4, %eax			;\
+	movzbl	_C_LABEL(cpl),%ebx					;\
+	cmpl	%eax,%ebx						;\
+	jae	_C_LABEL(Xhold/**/irq_num)/* currently masked; hold it */;\
 _Xresume/**/irq_num/**/:						;\
-	movl	_cpl,%eax		/* cpl to restore on exit */	;\
+	movzbl	_C_LABEL(cpl),%eax	/* cpl to restore on exit */	;\
 	pushl	%eax							;\
-	orl	_intrmask + (irq_num) * 4,%eax				;\
-	movl	%eax,_cpl		/* add in this intr's mask */	;\
+	movl	_C_LABEL(imaxlevel) + (irq_num) * 4,%eax			;\
+	movl	%eax,_C_LABEL(cpl)	/* block enough for this irq */	;\
 	sti				/* safe to take intrs now */	;\
 	movl	_intrhand + (irq_num) * 4,%ebx	/* head of chain */	;\
 	testl	%ebx,%ebx						;\