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authorPekka Paalanen <pq@iki.fi>2008-05-12 21:20:57 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-05-24 11:22:43 +0200
commitf984b51e0779a6dd30feedc41404013ca54e5d05 (patch)
treeae7e80f53707e9069a9607072a554b51c660075b /kernel/trace/trace_mmiotrace.c
parentd61fc44853f46fb002228b18aa5f30db21fcd4ac (diff)
ftrace: add mmiotrace plugin
On Sat, 22 Mar 2008 13:07:47 +0100 Ingo Molnar <mingo@elte.hu> wrote: > > > i'd suggest the following: pull x86.git and sched-devel.git into a > > > single tree [the two will combine without rejects]. Then try to add a > > > kernel/tracing/trace_mmiotrace.c ftrace plugin. The trace_sysprof.c > > > plugin might be a good example. > > > > I did this and now I have mmiotrace enabled/disabled via the tracing > > framework (what do we call this, since ftrace is one of the tracers?). > > cool! could you send the patches for that? (even if they are not fully > functional yet) Patch attached in the end. Nice to see how much code disappeared. I tried to mark all the features I had to break with XXX-comments. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/trace/trace_mmiotrace.c')
-rw-r--r--kernel/trace/trace_mmiotrace.c84
1 files changed, 84 insertions, 0 deletions
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
new file mode 100644
index 00000000000..e4dd03cc5aa
--- /dev/null
+++ b/kernel/trace/trace_mmiotrace.c
@@ -0,0 +1,84 @@
+/*
+ * Memory mapped I/O tracing
+ *
+ * Copyright (C) 2008 Pekka Paalanen <pq@iki.fi>
+ */
+
+#define DEBUG 1
+
+#include <linux/kernel.h>
+#include <linux/mmiotrace.h>
+
+#include "trace.h"
+
+extern void
+__trace_special(void *__tr, void *__data,
+ unsigned long arg1, unsigned long arg2, unsigned long arg3);
+
+static struct trace_array *mmio_trace_array;
+
+
+static void mmio_trace_init(struct trace_array *tr)
+{
+ pr_debug("in %s\n", __func__);
+ mmio_trace_array = tr;
+ if (tr->ctrl)
+ enable_mmiotrace();
+}
+
+static void mmio_trace_reset(struct trace_array *tr)
+{
+ pr_debug("in %s\n", __func__);
+ if (tr->ctrl)
+ disable_mmiotrace();
+}
+
+static void mmio_trace_ctrl_update(struct trace_array *tr)
+{
+ pr_debug("in %s\n", __func__);
+ if (tr->ctrl)
+ enable_mmiotrace();
+ else
+ disable_mmiotrace();
+}
+
+static struct tracer mmio_tracer __read_mostly =
+{
+ .name = "mmiotrace",
+ .init = mmio_trace_init,
+ .reset = mmio_trace_reset,
+ .ctrl_update = mmio_trace_ctrl_update,
+};
+
+__init static int init_mmio_trace(void)
+{
+ int ret = init_mmiotrace();
+ if (ret)
+ return ret;
+ return register_tracer(&mmio_tracer);
+}
+device_initcall(init_mmio_trace);
+
+void mmio_trace_record(u32 type, unsigned long addr, unsigned long arg)
+{
+ struct trace_array *tr = mmio_trace_array;
+ struct trace_array_cpu *data = tr->data[smp_processor_id()];
+
+ if (!current || current->pid == 0) {
+ /*
+ * XXX: This is a problem. We need to able to record, no
+ * matter what. tracing_generic_entry_update() would crash.
+ */
+ static unsigned limit;
+ if (limit++ < 12)
+ pr_err("Error in %s: no current.\n", __func__);
+ return;
+ }
+ if (!tr || !data) {
+ static unsigned limit;
+ if (limit++ < 12)
+ pr_err("%s: no tr or data\n", __func__);
+ return;
+ }
+ __trace_special(tr, data, type, addr, arg);
+}