Deferred: Use deferred_data instead of function pointer

Previously calls to hook_call_deferred were passed the function to call,
which was then looked up in the .rodata.deferred section with a linear
search.  This linear search can be replaced with a subtract by passing
the pointer to the deferred_data object created when DECLARE_DEFERRED
was invoked.

Signed-off-by: Anton Staaf <robotboy@chromium.org>

BRANCH=None
BUG=None
CQ-DEPEND=CL:*255812
TEST=make buildall -j

Change-Id: I951dd1541302875b102dd086154cf05591694440
Reviewed-on: https://chromium-review.googlesource.com/334315
Commit-Ready: Bill Richardson <wfrichar@chromium.org>
Tested-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

1 files changed, 20 insertions, 14 deletions

diff --git a/include/hooks.h b/include/hooks.h
index 3a7af06f3c..142926e6a9 100644
--- a/include/hooks.h
+++ b/include/hooks.h
@@ -190,22 +190,26 @@ struct hook_data {
  */
 void hook_notify(enum hook_type type);
 
+struct deferred_data {
+	/* Deferred function pointer */
+	void (*routine)(void);
+};
+
 /**
  * Start a timer to call a deferred routine.
  *
  * The routine will be called after at least the specified delay, in the
  * context of the hook task.
  *
- * @param routine	Routine to call; must have been declared with
- *			DECLARE_DEFERRED().
- * @param us		Delay in microseconds until routine will be called.
- *			If the routine is already pending, subsequent calls
- *			will change the delay.  Pass us=0 to call as soon as
- *			possible, or -1 to cancel the deferred call.
+ * @param data	The deferred_data struct created by invoking DECLARE_DEFERRED().
+ * @param us	Delay in microseconds until routine will be called.  If the
+ *		routine is already pending, subsequent calls will change the
+ *		delay.  Pass us=0 to call as soon as possible, or -1 to cancel
+ *		the deferred call.
  *
  * @return non-zero if error.
  */
-int hook_call_deferred(void (*routine)(void), int us);
+int hook_call_deferred(const struct deferred_data *data, int us);
 
 #ifdef CONFIG_COMMON_RUNTIME
 /**
@@ -239,18 +243,20 @@ int hook_call_deferred(void (*routine)(void), int us);
 	__attribute__((section(".rodata." STRINGIFY(hooktype))))	\
 	     = {routine, priority}
 
-
-struct deferred_data {
-	/* Deferred function pointer */
-	void (*routine)(void);
-};
-
 /**
  * Register a deferred function call.
  *
  * Note that if you declare a bunch of these, you may need to override
  * DEFERRABLE_MAX_COUNT in your board.h.
  *
+ * DECLARE_DEFERRED creates a new deferred_data struct with a name constructed
+ * by concatenating _data to the name of the routine passed.
+ *
+ * To call a deferred routine defined as:
+ *     DECLARE_DEFERRED(foo)
+ * You would call
+ *     hook_call_deferred(&foo_data, delay_in_microseconds);
+ *
  * NOTE: Deferred function call routines must be careful not to leave resources
  * locked which may be needed by other hook routines or deferred function
  * calls.  This can cause a deadlock, because most hooks and all deferred
@@ -260,7 +266,7 @@ struct deferred_data {
  * @param routine	Function pointer, with prototype void routine(void)
  */
 #define DECLARE_DEFERRED(routine)					\
-	const struct deferred_data __keep CONCAT2(__deferred_, routine)	\
+	const struct deferred_data __keep CONCAT2(routine, _data)	\
 	__attribute__((section(".rodata.deferred")))			\
 	     = {routine}