ftrace: set up trace event hash infrastructure

Impact: simplify/generalize/refactor trace.c

The trace.c file is becoming more difficult to maintain due to the
growing number of events. There is several formats that an event may
be printed. This patch sets up the infrastructure of an event hash to
allow for events to register how they should be printed.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 43 insertions, 0 deletions

diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
new file mode 100644
index 000000000000..1fcc76e1378e
--- /dev/null
+++ b/kernel/trace/trace_output.h
@@ -0,0 +1,43 @@
+#ifndef __TRACE_EVENTS_H
+#define __TRACE_EVENTS_H
+
+#include "trace.h"
+
+typedef int (*trace_print_func)(struct trace_seq *s, struct trace_entry *entry,
+                                int flags);
+
+struct trace_event {
+        struct hlist_node       node;
+        int                     type;
+        trace_print_func        trace;
+        trace_print_func        latency_trace;
+        trace_print_func        raw;
+        trace_print_func        hex;
+        trace_print_func        binary;
+};
+
+extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
+extern int
+seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
+                unsigned long sym_flags);
+extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
+                                 size_t cnt);
+int trace_seq_puts(struct trace_seq *s, const char *str);
+int trace_seq_putc(struct trace_seq *s, unsigned char c);
+int trace_seq_putmem(struct trace_seq *s, void *mem, size_t len);
+int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len);
+int trace_seq_path(struct trace_seq *s, struct path *path);
+int seq_print_userip_objs(const struct userstack_entry *entry,
+                          struct trace_seq *s, unsigned long sym_flags);
+int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
+                      unsigned long ip, unsigned long sym_flags);
+
+struct trace_event *ftrace_find_event(int type);
+int register_ftrace_event(struct trace_event *event);
+int unregister_ftrace_event(struct trace_event *event);
+
+#define MAX_MEMHEX_BYTES        8
+#define HEX_CHARS               (MAX_MEMHEX_BYTES*2 + 1)
+
+#endif
+