Add ``guarded'' word read and write routines, to be used by machine-dependent

code soon. Similar to what ddb does, but does not need ddb to be compiled in.

3 files changed, 46 insertions, 4 deletions

diff --git a/sys/arch/mips64/include/cpu.h b/sys/arch/mips64/include/cpu.h
index 629c4bf8766..d320ef5a309 100644
--- a/sys/arch/mips64/include/cpu.h
+++ b/sys/arch/mips64/include/cpu.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cpu.h,v 1.23 2008/04/07 22:29:16 miod Exp $	*/
+/*	$OpenBSD: cpu.h,v 1.24 2008/04/07 22:37:16 miod Exp $	*/
 
 /*-
  * Copyright (c) 1992, 1993
@@ -545,10 +545,12 @@ int	tlb_update(vaddr_t, unsigned);
 void	tlb_read(int, struct tlb_entry *);
 
 void	savectx(struct user *, int);
-void	switch_exit(struct proc *);
 void	MipsSaveCurFPState(struct proc *);
 void	MipsSaveCurFPState16(struct proc *);
 
+int	guarded_read_4(paddr_t, uint32_t *);
+int	guarded_write_4(paddr_t, uint32_t);
+
 extern u_int32_t cpu_counter_interval;  /* Number of counter ticks/tick */
 extern u_int32_t cpu_counter_last;      /* Last compare value loaded    */
 
diff --git a/sys/arch/mips64/include/trap.h b/sys/arch/mips64/include/trap.h
index 2fd793bd754..8095310ad01 100644
--- a/sys/arch/mips64/include/trap.h
+++ b/sys/arch/mips64/include/trap.h
@@ -1,4 +1,4 @@
-/*      $OpenBSD: trap.h,v 1.8 2007/05/20 14:34:21 miod Exp $	*/
+/*      $OpenBSD: trap.h,v 1.9 2008/04/07 22:37:16 miod Exp $	*/
 
 /*
  * Copyright (c) 1988 University of Utah.
@@ -77,6 +77,7 @@
 #define	KT_COPYERR	1		/* User space copy error */
 #define	KT_KCOPYERR	2		/* Kernel space copy error */
 #define	KT_DDBERR	3		/* DDB access error */
+#define	KT_GUARDERR	4		/* guarded access error */
 
 #ifndef _LOCORE
 
diff --git a/sys/arch/mips64/mips64/lcore_access.S b/sys/arch/mips64/mips64/lcore_access.S
index 9da36ec7b38..a6e2b25cdbc 100644
--- a/sys/arch/mips64/mips64/lcore_access.S
+++ b/sys/arch/mips64/mips64/lcore_access.S
@@ -1,4 +1,4 @@
-/*	$OpenBSD: lcore_access.S,v 1.13 2008/02/20 21:34:19 miod Exp $ */
+/*	$OpenBSD: lcore_access.S,v 1.14 2008/04/07 22:37:18 miod Exp $ */
 
 /*
  * Copyright (c) 2001-2003 Opsycon AB  (www.opsycon.se / www.opsycon.com)
@@ -64,6 +64,7 @@ onfault_table:
 #else
 	PTR_VAL	0
 #endif
+	PTR_VAL	_guarderr
 	.text
 
 /*
@@ -330,3 +331,41 @@ _kcopyerr:
 	PTR_ADDU sp, sp, FRAMESZ(CF_SZ + REGSZ)
 	j	ra
 	li	v0, EFAULT		# return error
+
+/*
+ * Guarded ``memory'' access routines
+ * int guarded_read_4(paddr_t address, uint32_t *dest);
+ * int guarded_write_4(paddr_t address, uint32_t src);
+ */
+
+LEAF(guarded_read_4, 0)
+	PTR_L	t3, curprocpaddr
+	li	v0, KT_GUARDERR
+	lw	v1, PCB_ONFAULT(t3)
+	sw	v0, PCB_ONFAULT(t3)
+
+	lw	v0, 0(a0)
+	sw	v0, 0(a1)
+	
+	sw	v1, PCB_ONFAULT(t3)
+	j	ra
+	move	v0, zero
+END(guarded_read_4)
+
+LEAF(guarded_write_4, 0)
+	PTR_L	t3, curprocpaddr
+	li	v0, KT_GUARDERR
+	lw	v1, PCB_ONFAULT(t3)
+	sw	v0, PCB_ONFAULT(t3)
+
+	sw	a1, 0(a0)
+	
+	sw	v1, PCB_ONFAULT(t3)
+	j	ra
+	move	v0, zero
+END(guarded_write_4)
+
+_guarderr:
+	sw	v1, PCB_ONFAULT(t3)
+	j	ra
+	li	v0, EFAULT		# return error