[kvm-unit-tests PATCH 2/4] lib/powerpc: Add generic decrementer exception handler

[Suraj Jitindar Singh <sjitindarsingh@gmail.com>]

Add the lib/powerpc/handlers.c file and associated header files as a place
to implement generic exception handler functions for inclusion in tests.

Add a generic exception handler for a decrementer (0x900) interrupt which
will reset the decrementer to its maximum value.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
---
 lib/powerpc/asm/handlers.h |  8 ++++++++
 lib/powerpc/handlers.c     | 26 ++++++++++++++++++++++++++
 lib/ppc64/asm/handlers.h   |  1 +
 powerpc/Makefile.common    |  1 +
 4 files changed, 36 insertions(+)
 create mode 100644 lib/powerpc/asm/handlers.h
 create mode 100644 lib/powerpc/handlers.c
 create mode 100644 lib/ppc64/asm/handlers.h

diff --git a/lib/powerpc/asm/handlers.h b/lib/powerpc/asm/handlers.h
new file mode 100644
index 0000000..1475052
--- /dev/null
+++ b/lib/powerpc/asm/handlers.h
@@ -0,0 +1,8 @@
+#ifndef _ASMPOWERPC_HANDLERS_H_
+#define _ASMPOWERPC_HANDLERS_H_
+
+#include <asm/ptrace.h>
+
+extern void dec_except_handler(struct pt_regs *regs, void *data);
+
+#endif /* _ASMPOWERPC_HANDLERS_H_ */
diff --git a/lib/powerpc/handlers.c b/lib/powerpc/handlers.c
new file mode 100644
index 0000000..1fb35d7
--- /dev/null
+++ b/lib/powerpc/handlers.c
@@ -0,0 +1,26 @@
+/*
+ * Generic exception handlers for registration and use in tests
+ *
+ * Copyright 2016 Suraj Jitindar Singh, IBM.
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.
+ */
+
+#include <libcflat.h>
+#include <asm/handlers.h>
+#include <asm/ptrace.h>
+
+/*
+ * Generic handler for decrementer exceptions (0x900)
+ * Just reset the decrementer back to its maximum value (0x7FFFFFFF)
+ */
+void dec_except_handler(__attribute__ ((unused)) struct pt_regs *regs,
+			__attribute__ ((unused)) void *data)
+{
+	uint32_t dec = 0x7FFFFFFF;
+
+	asm volatile ( "mtdec %0"	:
+					: "r" (dec)
+					:
+		     );
+}
diff --git a/lib/ppc64/asm/handlers.h b/lib/ppc64/asm/handlers.h
new file mode 100644
index 0000000..92e6fb2
--- /dev/null
+++ b/lib/ppc64/asm/handlers.h
@@ -0,0 +1 @@
+#include "../../powerpc/asm/handlers.h"
diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common
index 3f8887d..404194b 100644
--- a/powerpc/Makefile.common
+++ b/powerpc/Makefile.common
@@ -36,6 +36,7 @@ cflatobjs += lib/powerpc/hcall.o
 cflatobjs += lib/powerpc/setup.o
 cflatobjs += lib/powerpc/rtas.o
 cflatobjs += lib/powerpc/processor.o
+cflatobjs += lib/powerpc/handlers.o
 
 FLATLIBS = $(libcflat) $(LIBFDT_archive)
 %.elf: CFLAGS += $(arch_CFLAGS)
-- 
2.5.5