[PATCH 21/31] Add debugger entry points for MIPS

[Jeffrey Merkey]

This patch series adds an export which can be set by system debuggers to
direct the hard lockup and soft lockup detector to trigger a breakpoint
exception and enter a debugger if one is active.  It is assumed that if
someone sets this variable, then an breakpoint handler of some sort will
be actively loaded or registered via the notify die handler chain.

This addition is extremely useful for debugging hard and soft lockups
real time and quickly from a console debugger.

Signed-off-by: Jeffrey Merkey <jeffmerkey@xxxxxxxxx>
---
 arch/mips/include/asm/kdebug.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/mips/include/asm/kdebug.h b/arch/mips/include/asm/kdebug.h
index 8e3d08e..af5999e 100644
--- a/arch/mips/include/asm/kdebug.h
+++ b/arch/mips/include/asm/kdebug.h
@@ -16,4 +16,16 @@ enum die_val {
 	DIE_UPROBE_XOL,
 };
 
+
+void arch_breakpoint(void)
+{
+	__asm__ __volatile__(
+		".globl breakinst\n\t"
+		".set\tnoreorder\n\t"
+		"nop\n"
+		"breakinst:\tbreak\n\t"
+		"nop\n\t"
+		".set\treorder");
+}
+
 #endif /* _ASM_MIPS_KDEBUG_H */
-- 
1.8.3.1