From 826ff5f0606b303e9bac0b26adcc8acdffb4cdfd Mon Sep 17 00:00:00 2001
From: bjh21 <bjh21@NetBSD.org>
Date: Wed, 27 Sep 2006 21:21:09 +0000
Subject: [PATCH] Make db_validate_address() work, even when called from within
 an interrupt handler.  This should make debugging prefetch aborts slightly
 simpler.

---
 sys/arch/acorn26/acorn26/db_interface.c | 14 ++++++++++----
 sys/arch/acorn26/acorn26/except.c       | 25 +++++++++++++------------
 sys/arch/acorn26/include/db_machdep.h   |  4 +++-
 3 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/sys/arch/acorn26/acorn26/db_interface.c b/sys/arch/acorn26/acorn26/db_interface.c
index 215f75ab04a9..6c0aae1bbbd6 100644
--- a/sys/arch/acorn26/acorn26/db_interface.c
+++ b/sys/arch/acorn26/acorn26/db_interface.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: db_interface.c,v 1.9 2006/04/06 17:29:49 he Exp $	*/
+/*	$NetBSD: db_interface.c,v 1.10 2006/09/27 21:21:09 bjh21 Exp $	*/
 
 /* 
  * Copyright (c) 1996 Scott K. Stevens
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: db_interface.c,v 1.9 2006/04/06 17:29:49 he Exp $");
+__KERNEL_RCSID(0, "$NetBSD: db_interface.c,v 1.10 2006/09/27 21:21:09 bjh21 Exp $");
 
 #include "opt_ddb.h"
 
@@ -169,14 +169,20 @@ kdb_trap(type, regs)
 	return (1);
 }
 
+volatile boolean_t db_validating, db_faulted;
 
 int
 db_validate_address(addr)
 	vm_offset_t addr;
 {
+	volatile uint8_t tmp;
 
-	/* FIXME */
-	return 0;
+	db_faulted = FALSE;
+	db_validating = TRUE;
+	asm("" : : : "r14"); /* Make sure R14 is saved over the page fault */
+	tmp = *(uint8_t *)addr;
+	db_validating = FALSE;
+	return db_faulted;
 }
 
 /*
diff --git a/sys/arch/acorn26/acorn26/except.c b/sys/arch/acorn26/acorn26/except.c
index 26f47292f6b1..73c291d0cc05 100644
--- a/sys/arch/acorn26/acorn26/except.c
+++ b/sys/arch/acorn26/acorn26/except.c
@@ -1,4 +1,4 @@
-/* $NetBSD: except.c,v 1.15 2006/09/24 23:38:59 bjh21 Exp $ */
+/* $NetBSD: except.c,v 1.16 2006/09/27 21:21:09 bjh21 Exp $ */
 /*-
  * Copyright (c) 1998, 1999, 2000 Ben Harris
  * All rights reserved.
@@ -31,7 +31,7 @@
 
 #include <sys/param.h>
 
-__KERNEL_RCSID(0, "$NetBSD: except.c,v 1.15 2006/09/24 23:38:59 bjh21 Exp $");
+__KERNEL_RCSID(0, "$NetBSD: except.c,v 1.16 2006/09/27 21:21:09 bjh21 Exp $");
 
 #include "opt_ddb.h"
 
@@ -204,16 +204,11 @@ do_fault(struct trapframe *tf, struct lwp *l,
 	if (pmap_fault(map->pmap, va, atype))
 		return;
 
-#ifdef DDB
 	if (current_intr_depth != 0) {
-		db_printf("Data abort in interrupt handler\n");
-		kdb_trap(T_FAULT, tf);
-	}
-#else
-	KASSERT(current_intr_depth == 0);
-#endif
-
-	error = uvm_fault(map, va, atype);
+		KASSERT((tf->tf_r15 & R15_MODE) != R15_MODE_USR);
+		error = EFAULT;
+	} else
+		error = uvm_fault(map, va, atype);
 
 	if (error != 0) {
 		ksiginfo_t ksi;
@@ -225,7 +220,13 @@ do_fault(struct trapframe *tf, struct lwp *l,
 			    (register_t)cur_pcb->pcb_onfault;
 			return;
 		}
-
+#ifdef DDB
+		if (db_validating) {
+			db_faulted = TRUE;
+			tf->tf_r15 += INSN_SIZE;
+			return;
+		}
+#endif
 		if ((tf->tf_r15 & R15_MODE) != R15_MODE_USR) {
 #ifdef DDB
 			db_printf("Unhandled data abort in kernel mode\n");
diff --git a/sys/arch/acorn26/include/db_machdep.h b/sys/arch/acorn26/include/db_machdep.h
index 4a6c0f9639d0..f47a90116ae7 100644
--- a/sys/arch/acorn26/include/db_machdep.h
+++ b/sys/arch/acorn26/include/db_machdep.h
@@ -1,4 +1,4 @@
-/* $NetBSD: db_machdep.h,v 1.3 2005/12/11 12:16:04 christos Exp $ */
+/* $NetBSD: db_machdep.h,v 1.4 2006/09/27 21:21:09 bjh21 Exp $ */
 
 #include <arm/db_machdep.h>
 
@@ -11,3 +11,5 @@ void db_show_panic_cmd	__P((db_expr_t, int, db_expr_t, const char *));
 void db_show_frame_cmd	__P((db_expr_t, int, db_expr_t, const char *));
 void db_bus_write_cmd	__P((db_expr_t, int, db_expr_t, const char *));
 void db_irqstat_cmd	__P((db_expr_t, int, db_expr_t, const char *));
+
+extern volatile boolean_t db_validating, db_faulted;