xtensa: add static function tracer support
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 8852c0d..7ea6451 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -19,6 +19,7 @@
select CLONE_BACKWARDS
select IRQ_DOMAIN
select HAVE_OPROFILE
+ select HAVE_FUNCTION_TRACER
help
Xtensa processors are 32-bit RISC machines designed by Tensilica
primarily for embedded systems. These processors are both
diff --git a/arch/xtensa/boot/lib/Makefile b/arch/xtensa/boot/lib/Makefile
index ad8952e..6868f2c 100644
--- a/arch/xtensa/boot/lib/Makefile
+++ b/arch/xtensa/boot/lib/Makefile
@@ -7,6 +7,13 @@
lib-y += $(zlib:.c=.o) zmem.o
ccflags-y := -Ilib/zlib_inflate
+ifdef CONFIG_FUNCTION_TRACER
+CFLAGS_REMOVE_inflate.o = -pg
+CFLAGS_REMOVE_zmem.o = -pg
+CFLAGS_REMOVE_inftrees.o = -pg
+CFLAGS_REMOVE_inffast.o = -pg
+endif
+
quiet_cmd_copy_zlib = COPY $@
cmd_copy_zlib = cat $< > $@
diff --git a/arch/xtensa/include/asm/ftrace.h b/arch/xtensa/include/asm/ftrace.h
index 36dc7a68..73cc3f4 100644
--- a/arch/xtensa/include/asm/ftrace.h
+++ b/arch/xtensa/include/asm/ftrace.h
@@ -13,6 +13,7 @@
#include <asm/processor.h>
#define HAVE_ARCH_CALLER_ADDR
+#ifndef __ASSEMBLY__
#define CALLER_ADDR0 ({ unsigned long a0, a1; \
__asm__ __volatile__ ( \
"mov %0, a0\n" \
@@ -24,10 +25,22 @@
#define CALLER_ADDR1 return_address(1)
#define CALLER_ADDR2 return_address(2)
#define CALLER_ADDR3 return_address(3)
-#else
+#else /* CONFIG_FRAME_POINTER */
#define CALLER_ADDR1 (0)
#define CALLER_ADDR2 (0)
#define CALLER_ADDR3 (0)
-#endif
+#endif /* CONFIG_FRAME_POINTER */
+#endif /* __ASSEMBLY__ */
+
+#ifdef CONFIG_FUNCTION_TRACER
+
+#define MCOUNT_ADDR ((unsigned long)(_mcount))
+#define MCOUNT_INSN_SIZE 3
+
+#ifndef __ASSEMBLY__
+extern void _mcount(void);
+#define mcount _mcount
+#endif /* __ASSEMBLY__ */
+#endif /* CONFIG_FUNCTION_TRACER */
#endif /* _XTENSA_FTRACE_H */
diff --git a/arch/xtensa/kernel/Makefile b/arch/xtensa/kernel/Makefile
index 1e7fc87..f90265e 100644
--- a/arch/xtensa/kernel/Makefile
+++ b/arch/xtensa/kernel/Makefile
@@ -11,6 +11,7 @@
obj-$(CONFIG_KGDB) += xtensa-stub.o
obj-$(CONFIG_PCI) += pci.o
obj-$(CONFIG_MODULES) += xtensa_ksyms.o module.o
+obj-$(CONFIG_FUNCTION_TRACER) += mcount.o
AFLAGS_head.o += -mtext-section-literals
diff --git a/arch/xtensa/kernel/mcount.S b/arch/xtensa/kernel/mcount.S
new file mode 100644
index 0000000..0eeda2e
--- /dev/null
+++ b/arch/xtensa/kernel/mcount.S
@@ -0,0 +1,50 @@
+/*
+ * arch/xtensa/kernel/mcount.S
+ *
+ * Xtensa specific mcount support
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2013 Tensilica Inc.
+ */
+
+#include <linux/linkage.h>
+#include <asm/ftrace.h>
+
+/*
+ * Entry condition:
+ *
+ * a2: a0 of the caller
+ */
+
+ENTRY(_mcount)
+
+ entry a1, 16
+
+ movi a4, ftrace_trace_function
+ l32i a4, a4, 0
+ movi a3, ftrace_stub
+ bne a3, a4, 1f
+ retw
+
+1: xor a7, a2, a1
+ movi a3, 0x3fffffff
+ and a7, a7, a3
+ xor a7, a7, a1
+
+ xor a6, a0, a1
+ and a6, a6, a3
+ xor a6, a6, a1
+ addi a6, a6, -MCOUNT_INSN_SIZE
+ callx4 a4
+
+ retw
+
+ENDPROC(_mcount)
+
+ENTRY(ftrace_stub)
+ entry a1, 16
+ retw
+ENDPROC(ftrace_stub)
diff --git a/arch/xtensa/kernel/xtensa_ksyms.c b/arch/xtensa/kernel/xtensa_ksyms.c
index 42c53c87..d8507f8 100644
--- a/arch/xtensa/kernel/xtensa_ksyms.c
+++ b/arch/xtensa/kernel/xtensa_ksyms.c
@@ -124,3 +124,7 @@
extern long _spill_registers;
EXPORT_SYMBOL(common_exception_return);
EXPORT_SYMBOL(_spill_registers);
+
+#ifdef CONFIG_FUNCTION_TRACER
+EXPORT_SYMBOL(_mcount);
+#endif
