#ifndef EVENT_BUFFER_H
#define EVENT_BUFFER_H
-#include <linux/types.h>
-#include <asm/semaphore.h>
-
+#include <linux/types.h>
+#include <asm/mutex.h>
+
int alloc_event_buffer(void);
void free_event_buffer(void);
-
-/* wake up the process sleeping on the event file */
-void wake_up_buffer_waiter(void);
-
-/* Each escaped entry is prefixed by ESCAPE_CODE
- * then one of the following codes, then the
- * relevant data.
+
+/**
+ * Add data to the event buffer.
+ * The data passed is free-form, but typically consists of
+ * file offsets, dcookies, context information, and ESCAPE codes.
*/
-#define ESCAPE_CODE ~0UL
-#define CTX_SWITCH_CODE 1
-#define CPU_SWITCH_CODE 2
-#define COOKIE_SWITCH_CODE 3
-#define KERNEL_ENTER_SWITCH_CODE 4
-#define KERNEL_EXIT_SWITCH_CODE 5
-#define MODULE_LOADED_CODE 6
-#define CTX_TGID_CODE 7
-#define TRACE_BEGIN_CODE 8
-#define TRACE_END_CODE 9
-
-/* add data to the event buffer */
void add_event_entry(unsigned long data);
-
-extern struct file_operations event_buffer_fops;
-
+
+/* wake up the process sleeping on the event file */
+void wake_up_buffer_waiter(void);
+
+#define INVALID_COOKIE ~0UL
+#define NO_COOKIE 0UL
+
+extern const struct file_operations event_buffer_fops;
+
/* mutex between sync_cpu_buffers() and the
* file reading code.
*/
-extern struct semaphore buffer_sem;
-
+extern struct mutex buffer_mutex;
+
#endif /* EVENT_BUFFER_H */