3 files changed, 57 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index e4824fd04bb7..91da283cd658 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -94,6 +94,7 @@ config PPC
        select OF_RESERVED_MEM
        select HAVE_FTRACE_MCOUNT_RECORD
        select HAVE_DYNAMIC_FTRACE
+        select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL
        select HAVE_FUNCTION_TRACER
        select HAVE_FUNCTION_GRAPH_TRACER
        select SYSCTL_EXCEPTION_TRACE
@@ -373,6 +374,24 @@ config PPC_TRANSACTIONAL_MEM
       ---help---
         Support user-mode Transactional Memory on POWERPC.
+config DISABLE_MPROFILE_KERNEL
+        bool "Disable use of mprofile-kernel for kernel tracing"
+        depends on PPC64 && CPU_LITTLE_ENDIAN
+        default y
+        help
+          Selecting this options disables use of the mprofile-kernel ABI for
+          kernel tracing. That will cause options such as live patching
+          (CONFIG_LIVEPATCH) which depend on CONFIG_DYNAMIC_FTRACE_WITH_REGS to
+          be disabled also.
+          If you have a toolchain which supports mprofile-kernel, then you can
+          enable this. Otherwise leave it disabled. If you're not sure, say
+          "N".
+config MPROFILE_KERNEL
+        depends on PPC64 && CPU_LITTLE_ENDIAN
+        def_bool !DISABLE_MPROFILE_KERNEL
 config IOMMU_HELPER
        def_bool PPC64
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 96efd8213c1c..f4e49a4153cb 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -133,6 +133,21 @@ else
 CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64
 endif
+ifdef CONFIG_MPROFILE_KERNEL
+    ifeq ($(shell $(srctree)/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh $(CC) -I$(srctree)/include -D__KERNEL__),OK)
+        CC_FLAGS_FTRACE := -pg -mprofile-kernel
+        KBUILD_CPPFLAGS += -DCC_USING_MPROFILE_KERNEL
+    else
+        # If the user asked for mprofile-kernel but the toolchain doesn't
+        # support it, emit a warning and deliberately break the build later
+        # with mprofile-kernel-not-supported. We would prefer to make this an
+        # error right here, but then the user would never be able to run
+        # oldconfig to change their configuration.
+        $(warning Compiler does not support mprofile-kernel, set CONFIG_DISABLE_MPROFILE_KERNEL)
+        CC_FLAGS_FTRACE := -mprofile-kernel-not-supported
+    endif
+endif
 CFLAGS-$(CONFIG_CELL_CPU) += $(call cc-option,-mcpu=cell)
 CFLAGS-$(CONFIG_POWER4_CPU) += $(call cc-option,-mcpu=power4)
 CFLAGS-$(CONFIG_POWER5_CPU) += $(call cc-option,-mcpu=power5)
diff --git a/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh b/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh
new file mode 100755
index 000000000000..c658d8cf760b
--- /dev/null
+++ b/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh
@@ -0,0 +1,23 @@
+#!/bin/bash
+set -e
+set -o pipefail
+# To debug, uncomment the following line
+# set -x
+# Test whether the compile option -mprofile-kernel exists and generates
+# profiling code (ie. a call to _mcount()).
+echo "int func() { return 0; }" | \
+    $* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null | \
+    grep -q "_mcount"
+# Test whether the notrace attribute correctly suppresses calls to _mcount().
+echo -e "#include <linux/compiler.h>\nnotrace int func() { return 0; }" | \
+    $* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null | \
+    grep -q "_mcount" && \
+    exit 1
+echo "OK"
+exit 0

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index e4824fd04bb7..91da283cd658 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig
@@ -94,6 +94,7 @@ config PPC
94	select OF_RESERVED_MEM	94	select OF_RESERVED_MEM
95	select HAVE_FTRACE_MCOUNT_RECORD	95	select HAVE_FTRACE_MCOUNT_RECORD
96	select HAVE_DYNAMIC_FTRACE	96	select HAVE_DYNAMIC_FTRACE
		97	select HAVE_DYNAMIC_FTRACE_WITH_REGS if MPROFILE_KERNEL
97	select HAVE_FUNCTION_TRACER	98	select HAVE_FUNCTION_TRACER
98	select HAVE_FUNCTION_GRAPH_TRACER	99	select HAVE_FUNCTION_GRAPH_TRACER
99	select SYSCTL_EXCEPTION_TRACE	100	select SYSCTL_EXCEPTION_TRACE
@@ -373,6 +374,24 @@ config PPC_TRANSACTIONAL_MEM
373	---help---	374	---help---
374	Support user-mode Transactional Memory on POWERPC.	375	Support user-mode Transactional Memory on POWERPC.
375		376
		377	config DISABLE_MPROFILE_KERNEL
		378	bool "Disable use of mprofile-kernel for kernel tracing"
		379	depends on PPC64 && CPU_LITTLE_ENDIAN
		380	default y
		381	help
		382	Selecting this options disables use of the mprofile-kernel ABI for
		383	kernel tracing. That will cause options such as live patching
		384	(CONFIG_LIVEPATCH) which depend on CONFIG_DYNAMIC_FTRACE_WITH_REGS to
		385	be disabled also.
		386
		387	If you have a toolchain which supports mprofile-kernel, then you can
		388	enable this. Otherwise leave it disabled. If you're not sure, say
		389	"N".
		390
		391	config MPROFILE_KERNEL
		392	depends on PPC64 && CPU_LITTLE_ENDIAN
		393	def_bool !DISABLE_MPROFILE_KERNEL
		394
376	config IOMMU_HELPER	395	config IOMMU_HELPER
377	def_bool PPC64	396	def_bool PPC64
378		397


diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index 96efd8213c1c..f4e49a4153cb 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile
@@ -133,6 +133,21 @@ else
133	CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64	133	CFLAGS-$(CONFIG_GENERIC_CPU) += -mcpu=powerpc64
134	endif	134	endif
135		135
		136	ifdef CONFIG_MPROFILE_KERNEL
		137	ifeq ($(shell $(srctree)/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh $(CC) -I$(srctree)/include -D__KERNEL__),OK)
		138	CC_FLAGS_FTRACE := -pg -mprofile-kernel
		139	KBUILD_CPPFLAGS += -DCC_USING_MPROFILE_KERNEL
		140	else
		141	# If the user asked for mprofile-kernel but the toolchain doesn't
		142	# support it, emit a warning and deliberately break the build later
		143	# with mprofile-kernel-not-supported. We would prefer to make this an
		144	# error right here, but then the user would never be able to run
		145	# oldconfig to change their configuration.
		146	$(warning Compiler does not support mprofile-kernel, set CONFIG_DISABLE_MPROFILE_KERNEL)
		147	CC_FLAGS_FTRACE := -mprofile-kernel-not-supported
		148	endif
		149	endif
		150
136	CFLAGS-$(CONFIG_CELL_CPU) += $(call cc-option,-mcpu=cell)	151	CFLAGS-$(CONFIG_CELL_CPU) += $(call cc-option,-mcpu=cell)
137	CFLAGS-$(CONFIG_POWER4_CPU) += $(call cc-option,-mcpu=power4)	152	CFLAGS-$(CONFIG_POWER4_CPU) += $(call cc-option,-mcpu=power4)
138	CFLAGS-$(CONFIG_POWER5_CPU) += $(call cc-option,-mcpu=power5)	153	CFLAGS-$(CONFIG_POWER5_CPU) += $(call cc-option,-mcpu=power5)


diff --git a/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh b/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh new file mode 100755 index 000000000000..c658d8cf760b --- /dev/null +++ b/arch/powerpc/scripts/gcc-check-mprofile-kernel.sh
@@ -0,0 +1,23 @@
		1	#!/bin/bash
		2
		3	set -e
		4	set -o pipefail
		5
		6	# To debug, uncomment the following line
		7	# set -x
		8
		9	# Test whether the compile option -mprofile-kernel exists and generates
		10	# profiling code (ie. a call to _mcount()).
		11	echo "int func() { return 0; }" \| \
		12	$* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null \| \
		13	grep -q "_mcount"
		14
		15	# Test whether the notrace attribute correctly suppresses calls to _mcount().
		16
		17	echo -e "#include <linux/compiler.h>\nnotrace int func() { return 0; }" \| \
		18	$* -S -x c -O2 -p -mprofile-kernel - -o - 2> /dev/null \| \
		19	grep -q "_mcount" && \
		20	exit 1
		21
		22	echo "OK"
		23	exit 0