timer: Permit statically-declared work with deferrable timers

[mv-sheeva.git] / include / linux / timer.h

diff --git a/include/linux/timer.h b/include/linux/timer.h
index 1794674c1a525328fcd5f1c279c006265100729f..cbfb7a355d30c9198f77c3ae9f8147a75c69732e 100644 (file)
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -48,6 +48,18 @@ extern struct tvec_base boot_tvec_bases;
 #define __TIMER_LOCKDEP_MAP_INITIALIZER(_kn)
 #endif
 
+/*
+ * Note that all tvec_bases are 2 byte aligned and lower bit of
+ * base in timer_list is guaranteed to be zero. Use the LSB to
+ * indicate whether the timer is deferrable.
+ *
+ * A deferrable timer will work normally when the system is busy, but
+ * will not cause a CPU to come out of idle just to service it; instead,
+ * the timer will be serviced when the CPU eventually wakes up with a
+ * subsequent non-deferrable timer.
+ */
+#define TBASE_DEFERRABLE_FLAG          (0x1)
+
 #define TIMER_INITIALIZER(_function, _expires, _data) {                \
                .entry = { .prev = TIMER_ENTRY_STATIC },        \
                .function = (_function),                        \
@@ -59,6 +71,19 @@ extern struct tvec_base boot_tvec_bases;
                        __FILE__ ":" __stringify(__LINE__))     \
        }
 
+#define TBASE_MAKE_DEFERRED(ptr) ((struct tvec_base *)         \
+                 ((unsigned char *)(ptr) + TBASE_DEFERRABLE_FLAG))
+
+#define TIMER_DEFERRED_INITIALIZER(_function, _expires, _data) {\
+               .entry = { .prev = TIMER_ENTRY_STATIC },        \
+               .function = (_function),                        \
+               .expires = (_expires),                          \
+               .data = (_data),                                \
+               .base = TBASE_MAKE_DEFERRED(&boot_tvec_bases),  \
+               __TIMER_LOCKDEP_MAP_INITIALIZER(                \
+                       __FILE__ ":" __stringify(__LINE__))     \
+       }
+
 #define DEFINE_TIMER(_name, _function, _expires, _data)                \
        struct timer_list _name =                               \
                TIMER_INITIALIZER(_function, _expires, _data)