Files forgotten during last commit:

Rework nmi handling to handle ``complex'' NMI faster, and return as fast as
possible from the exception, without doing the AST and softintr dance.

This should avoid too much stack usage under load.

ok deraadt@

3 files changed, 117 insertions, 27 deletions

diff --git a/sys/arch/m88k/include/trap.h b/sys/arch/m88k/include/trap.h
index 6c65ba34f4a..642b447d1b6 100644
--- a/sys/arch/m88k/include/trap.h
+++ b/sys/arch/m88k/include/trap.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.h,v 1.8 2009/02/16 22:55:03 miod Exp $ */
+/*	$OpenBSD: trap.h,v 1.9 2009/03/01 17:43:23 miod Exp $ */
 /*
  * Mach Operating System
  * Copyright (c) 1992 Carnegie Mellon University
@@ -57,10 +57,11 @@
 
 #ifndef _LOCORE
 
-void	cache_flush(struct trapframe *);
 void	ast(struct trapframe *);
-void	nmi(struct trapframe *);
+void	cache_flush(struct trapframe *);
 void	interrupt(struct trapframe *);
+int	nmi(struct trapframe *);
+void	nmi_wrapup(struct trapframe *);
 
 void	m88100_syscall(register_t, struct trapframe *);
 void	m88100_trap(u_int, struct trapframe *);
diff --git a/sys/arch/m88k/m88k/eh_common.S b/sys/arch/m88k/m88k/eh_common.S
index 1b48c14b9a8..b122fa25c96 100644
--- a/sys/arch/m88k/m88k/eh_common.S
+++ b/sys/arch/m88k/m88k/eh_common.S
@@ -1,4 +1,4 @@
-/*   $OpenBSD: eh_common.S,v 1.52 2009/02/21 18:35:22 miod Exp $	*/
+/*   $OpenBSD: eh_common.S,v 1.53 2009/03/01 17:43:25 miod Exp $	*/
 /*
  * Mach Operating System
  * Copyright (c) 1993-1991 Carnegie Mellon University
@@ -1601,7 +1601,7 @@ GLOBAL(m88110_fpu_handler)
 GLOBAL(m88110_nonmaskable)
 	PREP88110("NMI", 11,)
 	or	r2, r0, r30
-	XCALL(_C_LABEL(nmi), _ASM_LABEL(check_ast))
+	XCALL(_C_LABEL(nmi), _ASM_LABEL(nmi_return))
 
 /* software walk data MMU read miss handler */
 GLOBAL(m88110_data_read_miss)
@@ -2213,17 +2213,15 @@ ASGLOBAL(ast_done)
 	bsr.n	_C_LABEL(setipl)
 	 ld	r2, FPTR, EF_MASK		/* get pre-exception ipl */
 
-	/*
-	 * Disable shadowing. This used to be done after all the registers
-	 * from the E.F. have been restored, but on 88110 we may receive
-	 * an NMI anytime, unless shadowing is frozen, and we rely on r31
-	 * being valid.
-	 */
-	ldcr	r1, PSR
-	set	r1, r1, 1<PSR_SHADOW_FREEZE_BIT>
-	stcr	r1, PSR
-	FLUSH_PIPELINE
+#if defined(M88100) && defined(M88110)
+	ldcr	r2, PID
+	extu	r3,  r2, 8<8>
+	bcnd	ne0, r3, _ASM_LABEL(m88110_user_rte)
+	/* FALLTHROUGH */
+#endif
 
+#ifdef M88100
+ASGLOBAL(m88100_user_rte)
 	/*
 	 * Transfer the frame pointer to r31, since we no longer need a stack.
 	 * No page faults here, and interrupts are disabled.
@@ -2260,16 +2258,13 @@ ASGLOBAL(ast_done)
 	ld	r29, r31, GENREG_OFF(29)
 	/* restore r1, r30, r31 later */
 
-	/* reload the control regs*/
-#if defined(M88100) && defined(M88110)
-	ldcr	r1, PID
-	extu	r30, r1, 8<8>
-	bcnd	ne0, r30, _ASM_LABEL(m88110_user_rte)
-	/* FALLTHROUGH */
-#endif
+	/* disable shadowing */
+	ldcr	r1, PSR
+	set	r1, r1, 1<PSR_SHADOW_FREEZE_BIT>
+	stcr	r1, PSR
+	FLUSH_PIPELINE
 
-#ifdef M88100
-ASGLOBAL(m88100_user_rte)
+	/* reload the control regs*/
 	/*
 	 * RTE will cause execution to continue first with the
 	 * instruction pointed to by the NIP and then the FIP;
@@ -2294,6 +2289,55 @@ ASGLOBAL(m88100_user_rte)
 
 #ifdef M88110
 ASGLOBAL(m88110_user_rte)
+	/*
+	 * Disable shadowing. This used to be done after all the registers
+	 * from the E.F. have been restored, but on 88110 we may receive
+	 * an NMI anytime, unless shadowing is frozen, and we rely on r31
+	 * being valid.
+	 */
+	ldcr	r1, PSR
+	set	r1, r1, 1<PSR_SHADOW_FREEZE_BIT>
+	stcr	r1, PSR
+	FLUSH_PIPELINE
+
+ASLOCAL(m88110_restore)
+	/*
+	 * Transfer the frame pointer to r31, since we no longer need a stack.
+	 * No page faults here, and interrupts are disabled.
+	 */
+	or	r31, r0,  FPTR
+	/* restore r1 later */
+	ld	r2 , r31, GENREG_OFF(2)
+	ld	r3 , r31, GENREG_OFF(3)
+	ld	r4 , r31, GENREG_OFF(4)
+	ld	r5 , r31, GENREG_OFF(5)
+	ld	r6 , r31, GENREG_OFF(6)
+	ld	r7 , r31, GENREG_OFF(7)
+	ld	r8 , r31, GENREG_OFF(8)
+	ld	r9 , r31, GENREG_OFF(9)
+	ld	r10, r31, GENREG_OFF(10)
+	ld	r11, r31, GENREG_OFF(11)
+	ld	r12, r31, GENREG_OFF(12)
+	ld	r13, r31, GENREG_OFF(13)
+	ld	r14, r31, GENREG_OFF(14)
+	ld	r15, r31, GENREG_OFF(15)
+	ld	r16, r31, GENREG_OFF(16)
+	ld	r17, r31, GENREG_OFF(17)
+	ld	r18, r31, GENREG_OFF(18)
+	ld	r19, r31, GENREG_OFF(19)
+	ld	r20, r31, GENREG_OFF(20)
+	ld	r21, r31, GENREG_OFF(21)
+	ld	r22, r31, GENREG_OFF(22)
+	ld	r23, r31, GENREG_OFF(23)
+	ld	r24, r31, GENREG_OFF(24)
+	ld	r25, r31, GENREG_OFF(25)
+	ld	r26, r31, GENREG_OFF(26)
+	ld	r27, r31, GENREG_OFF(27)
+	ld	r28, r31, GENREG_OFF(28)
+	ld	r29, r31, GENREG_OFF(29)
+	/* restore r1, r30, r31 later */
+
+	/* reload the control regs*/
 	ld	r30, r31, EF_ENIP
 	ld	r1,  r31, EF_EXIP
 	stcr	r30, ENIP
@@ -2324,4 +2368,40 @@ ASGLOBAL(m88110_user_rte)
 1:
 	NOP
 	RTE
+
+	/*
+	 * NMI return here after processing.
+	 * We then decide whether to check for AST and soft interrupts,
+	 * or not.
+	 */
+ASLOCAL(nmi_return)
+	bcnd	ne0, r2, _ASM_LABEL(check_ast)
+
+	ld	FPTR, r31, 0	/* grab exception frame pointer */
+
+	/*
+	 * Disable interrupts and shadowing. The latter used to be done
+	 * after all the registers from the E.F. have been restored, but
+	 * on 88110 we may receive an NMI anytime, unless shadowing is frozen,
+	 * and we rely on r31 being valid.
+	 */
+	ldcr	r1, PSR
+	set	r1, r1, 1<PSR_INTERRUPT_DISABLE_BIT>
+	set	r1, r1, 1<PSR_SHADOW_FREEZE_BIT>
+	stcr	r1, PSR
+	FLUSH_PIPELINE
+
+	/* now ready to return....*/
+	bsr.n	_C_LABEL(setipl)
+	 ld	r2, FPTR, EF_MASK		/* get pre-exception ipl */
+
+#ifdef MULTIPROCESSOR
+	/*
+	 * Reenable NMIs if necessary.
+	 */
+	or	r2,   FPTR,  r0
+	bsr	_C_LABEL(nmi_wrapup)
+#endif
+
+	br	_ASM_LABEL(m88110_restore)
 #endif
diff --git a/sys/arch/m88k/m88k/trap.c b/sys/arch/m88k/m88k/trap.c
index cbaacef4d26..50539debcb5 100644
--- a/sys/arch/m88k/m88k/trap.c
+++ b/sys/arch/m88k/m88k/trap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: trap.c,v 1.68 2009/02/16 22:55:03 miod Exp $	*/
+/*	$OpenBSD: trap.c,v 1.69 2009/03/01 17:43:25 miod Exp $	*/
 /*
  * Copyright (c) 2004, Miodrag Vallat.
  * Copyright (c) 1998 Steve Murphree, Jr.
@@ -191,10 +191,19 @@ interrupt(struct trapframe *frame)
 /*
  * Handle non-maskable interrupts.
  */
-void
+int
 nmi(struct trapframe *frame)
 {
-	md_nmi_func(frame);
+	return md_nmi_func(frame);
+}
+
+/*
+ * Reenable non-maskable interrupts.
+ */
+void
+nmi_wrapup(struct trapframe *frame)
+{
+	md_nmi_wrapup_func(frame);
 }
 #endif