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authorMichal Simek <monstr@monstr.eu>2009-11-16 10:34:15 +0100
committerMichal Simek <monstr@monstr.eu>2009-12-14 08:44:54 +0100
commit4f911b0daf0f7028a4fe792b701a48d10da36d84 (patch)
tree746315895bc446df02b1d7e2c1b70550468cab28 /arch/microblaze
parenta0d3e66522e8f6119f002cf31e5d92d7ae73b409 (diff)
downloadlinux-linaro-stable-4f911b0daf0f7028a4fe792b701a48d10da36d84.tar.gz
microblaze: ftrace: Add dynamic function graph tracer
This patch add support for dynamic function graph tracer. There is one my expactation that I can do flush_icache after all code modification. On microblaze is this safer than do flush for every entry. For icache is used name flush but correct should be invalidation - this will be fix in upcomming new cache implementaion and WB support. Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'arch/microblaze')
-rw-r--r--arch/microblaze/kernel/ftrace.c28
-rw-r--r--arch/microblaze/kernel/mcount.S6
2 files changed, 34 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/ftrace.c b/arch/microblaze/kernel/ftrace.c
index 0952a8b52c35..388b31ca65a1 100644
--- a/arch/microblaze/kernel/ftrace.c
+++ b/arch/microblaze/kernel/ftrace.c
@@ -206,4 +206,32 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
return ret;
}
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+unsigned int old_jump; /* saving place for jump instruction */
+
+int ftrace_enable_ftrace_graph_caller(void)
+{
+ unsigned int ret;
+ unsigned long ip = (unsigned long)(&ftrace_call_graph);
+
+ old_jump = *(unsigned int *)ip; /* save jump over instruction */
+ ret = ftrace_modify_code(ip, MICROBLAZE_NOP);
+ flush_icache();
+
+ pr_debug("%s: Replace instruction: 0x%x\n", __func__, old_jump);
+ return ret;
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+ unsigned int ret;
+ unsigned long ip = (unsigned long)(&ftrace_call_graph);
+
+ ret = ftrace_modify_code(ip, old_jump);
+ flush_icache();
+
+ pr_debug("%s\n", __func__);
+ return ret;
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#endif /* CONFIG_DYNAMIC_FTRACE */
diff --git a/arch/microblaze/kernel/mcount.S b/arch/microblaze/kernel/mcount.S
index 84a19458c74d..e7eaa7a8cbd3 100644
--- a/arch/microblaze/kernel/mcount.S
+++ b/arch/microblaze/kernel/mcount.S
@@ -97,6 +97,7 @@ ENTRY(ftrace_caller)
nop;
/* MS: HAVE_FUNCTION_TRACE_MCOUNT_TEST end of checking */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+#ifndef CONFIG_DYNAMIC_FTRACE
lwi r5, r0, ftrace_graph_return;
addik r6, r0, ftrace_stub; /* asm implementation */
cmpu r5, r5, r6; /* ftrace_graph_return != ftrace_stub */
@@ -108,6 +109,11 @@ ENTRY(ftrace_caller)
cmpu r5, r5, r6; /* ftrace_graph_entry != ftrace_graph_entry_stub */
beqid r5, end_graph_tracer;
nop;
+#else /* CONFIG_DYNAMIC_FTRACE */
+NOALIGN_ENTRY(ftrace_call_graph)
+ /* MS: jump over graph function - replaced from C code */
+ bri end_graph_tracer
+#endif /* CONFIG_DYNAMIC_FTRACE */
addik r5, r1, 120; /* MS: load parent addr */
addik r6, r15, 0; /* MS: load current function addr */
bralid r15, prepare_ftrace_return;