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author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2015-04-24 08:54:44 (GMT) |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2015-08-06 06:36:23 (GMT) |
commit | 197165d44925bd0fa892990851dee4d312a44b39 (patch) | |
tree | 5a3c35443e155b69a87456624ce458ee08a4ba08 /arch/powerpc/kernel | |
parent | 35a7f41cc6bb7013e344502b03c5583d04228bd3 (diff) | |
download | linux-197165d44925bd0fa892990851dee4d312a44b39.tar.xz |
powerpc/ftrace: add powerpc timebase as a trace clock source
Add a new powerpc-specific trace clock using the timebase register,
similar to x86-tsc. This gives us
- a fast, monotonic, hardware clock source for trace entries, and
- a clock that can be used to correlate events across cpus as well as across
hypervisor and guests.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel')
-rw-r--r-- | arch/powerpc/kernel/Makefile | 1 | ||||
-rw-r--r-- | arch/powerpc/kernel/trace_clock.c | 15 |
2 files changed, 16 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 12868b1..ba33693 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -118,6 +118,7 @@ obj-$(CONFIG_PPC_IO_WORKAROUNDS) += io-workarounds.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o +obj-$(CONFIG_TRACING) += trace_clock.o ifneq ($(CONFIG_PPC_INDIRECT_PIO),y) obj-y += iomap.o diff --git a/arch/powerpc/kernel/trace_clock.c b/arch/powerpc/kernel/trace_clock.c new file mode 100644 index 0000000..4917069 --- /dev/null +++ b/arch/powerpc/kernel/trace_clock.c @@ -0,0 +1,15 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * Copyright (C) 2015 Naveen N. Rao, IBM Corporation + */ + +#include <asm/trace_clock.h> +#include <asm/time.h> + +u64 notrace trace_clock_ppc_tb(void) +{ + return get_tb(); +} |