add Feather-Trace device file support

(KConfig still missing.)

1 files changed, 49 insertions, 0 deletions

diff --git a/include/litmus/ftdev.h b/include/litmus/ftdev.h
new file mode 100644
index 000000000000..7697b4616699
--- /dev/null
+++ b/include/litmus/ftdev.h
@@ -0,0 +1,49 @@
+#ifndef _LITMUS_FTDEV_H_
+#define _LITMUS_FTDEV_H_
+
+#include <litmus/feather_trace.h>
+#include <litmus/feather_buffer.h>
+#include <linux/mutex.h>
+#include <linux/cdev.h>
+
+#define MAX_FTDEV_MINORS NR_CPUS
+
+#define FTDEV_ENABLE_CMD        0
+#define FTDEV_DISABLE_CMD       1
+
+struct ftdev;
+
+/* return 0 if buffer can be opened, otherwise -$REASON */
+typedef int  (*ftdev_can_open_t)(struct ftdev* dev, unsigned int buf_no);
+/* return 0 on success, otherwise -$REASON */
+typedef int  (*ftdev_alloc_t)(struct ftdev* dev, unsigned int buf_no);
+typedef void (*ftdev_free_t)(struct ftdev* dev, unsigned int buf_no);
+
+
+struct ftdev_event;
+
+struct ftdev_minor {
+        struct ft_buffer*       buf;
+        unsigned int            readers;
+        struct mutex            lock;
+        /* FIXME: filter for authorized events */
+        struct ftdev_event*     events;
+};
+
+struct ftdev {
+        struct cdev             cdev;
+        /* FIXME: don't waste memory, allocate dynamically */
+        struct ftdev_minor      minor[MAX_FTDEV_MINORS];
+        unsigned int            minor_cnt;
+        ftdev_alloc_t           alloc;
+        ftdev_free_t            free;
+        ftdev_can_open_t        can_open;
+};
+
+struct ft_buffer* alloc_ft_buffer(unsigned int count, size_t size);
+void free_ft_buffer(struct ft_buffer* buf);
+
+void ftdev_init(struct ftdev* ftdev, struct module* owner);
+int register_ftdev(struct ftdev* ftdev, const char* name, int major);
+
+#endif