1 files changed, 101 insertions, 0 deletions

diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
new file mode 100644
index 000000000000..c65ef8ffd6b4
--- /dev/null
+++ b/kernel/trace/trace_boot.c
@@ -0,0 +1,101 @@
+/*
+ * ring buffer based initcalls tracer
+ *
+ * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <linux/ftrace.h>
+
+#include "trace.h"
+
+static struct trace_array *boot_trace;
+static int trace_boot_enabled;
+
+
+/* Should be started after do_pre_smp_initcalls() in init/main.c */
+void start_boot_trace(void)
+{
+        trace_boot_enabled = 1;
+}
+
+void stop_boot_trace(struct trace_array *tr)
+{
+        trace_boot_enabled = 0;
+}
+
+static void boot_trace_init(struct trace_array *tr)
+{
+        int cpu;
+        boot_trace = tr;
+
+        trace_boot_enabled = 0;
+
+        for_each_cpu_mask(cpu, cpu_possible_map)
+                tracing_reset(tr->data[cpu]);
+}
+
+static void boot_trace_ctrl_update(struct trace_array *tr)
+{
+        if (tr->ctrl)
+                start_boot_trace();
+        else
+                stop_boot_trace(tr);
+}
+
+static int initcall_print_line(struct trace_iterator *iter)
+{
+        int ret = 1;
+        struct trace_entry *entry = iter->ent;
+        struct boot_trace *it = &entry->field.initcall;
+        struct trace_seq *s = &iter->seq;
+
+        if (iter->ent->type == TRACE_BOOT)
+                ret = trace_seq_printf(s, "%pF called from %i "
+                                       "returned %d after %lld msecs\n",
+                                       it->func, it->caller, it->result,
+                                       it->duration);
+        if (ret)
+                return 1;
+        return 0;
+}
+
+struct tracer boot_tracer __read_mostly =
+{
+        .name           = "initcall",
+        .init           = boot_trace_init,
+        .reset          = stop_boot_trace,
+        .ctrl_update    = boot_trace_ctrl_update,
+        .print_line     = initcall_print_line,
+};
+
+
+void trace_boot(struct boot_trace *it)
+{
+        struct trace_entry *entry;
+        struct trace_array_cpu *data;
+        unsigned long irq_flags;
+        struct trace_array *tr = boot_trace;
+
+        if (!trace_boot_enabled)
+                return;
+
+        preempt_disable();
+        data = tr->data[smp_processor_id()];
+
+        raw_local_irq_save(irq_flags);
+        __raw_spin_lock(&data->lock);
+
+        entry = tracing_get_trace_entry(tr, data);
+        tracing_generic_entry_update(entry, 0);
+        entry->type = TRACE_BOOT;
+        entry->field.initcall = *it;
+
+        __raw_spin_unlock(&data->lock);
+        raw_local_irq_restore(irq_flags);
+        trace_wake_up();
+
+        preempt_enable();
+}