1 files changed, 81 insertions, 0 deletions
diff --git a/src/include/ipxe/retry.h b/src/include/ipxe/retry.h
new file mode 100644
index 000000000..370a599ce
--- /dev/null
+++ b/src/include/ipxe/retry.h
@@ -0,0 +1,81 @@
+#ifndef _IPXE_RETRY_H
+#define _IPXE_RETRY_H
+
+/** @file
+ *
+ * Retry timers
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <ipxe/list.h>
+
+/** Default timeout value */
+#define DEFAULT_MIN_TIMEOUT ( TICKS_PER_SEC / 4 )
+
+/** Limit after which the timeout will be deemed permanent */
+#define DEFAULT_MAX_TIMEOUT ( 10 * TICKS_PER_SEC )
+
+/** A retry timer */
+struct retry_timer {
+	/** List of active timers */
+	struct list_head list;
+	/** Timer is currently running */
+	unsigned int running;
+	/** Timeout value (in ticks) */
+	unsigned long timeout;
+	/** Minimum timeout value (in ticks)
+	 *
+	 * A value of zero means "use default timeout."
+	 */
+	unsigned long min_timeout;
+	/** Maximum timeout value before failure (in ticks)
+	 *
+	 * A value of zero means "use default timeout."
+	 */
+	unsigned long max_timeout;
+	/** Start time (in ticks) */
+	unsigned long start;
+	/** Retry count */
+	unsigned int count;
+	/** Timer expired callback
+	 *
+	 * @v timer	Retry timer
+	 * @v fail	Failure indicator
+	 *
+	 * The timer will already be stopped when this method is
+	 * called.  The failure indicator will be True if the retry
+	 * timeout has already exceeded @c MAX_TIMEOUT.
+	 */
+	void ( * expired ) ( struct retry_timer *timer, int over );
+};
+
+extern void start_timer ( struct retry_timer *timer );
+extern void start_timer_fixed ( struct retry_timer *timer,
+				unsigned long timeout );
+extern void stop_timer ( struct retry_timer *timer );
+
+/**
+ * Start timer with no delay
+ *
+ * @v timer		Retry timer
+ *
+ * This starts the timer running with a zero timeout value.
+ */
+static inline void start_timer_nodelay ( struct retry_timer *timer ) {
+	start_timer_fixed ( timer, 0 );
+}
+
+/**
+ * Test to see if timer is currently running
+ *
+ * @v timer		Retry timer
+ * @ret running		Non-zero if timer is running
+ */
+static inline __attribute__ (( always_inline )) unsigned long
+timer_running ( struct retry_timer *timer ) {
+	return ( timer->running );
+}
+
+#endif /* _IPXE_RETRY_H */