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authorLinus Torvalds <torvalds@linux-foundation.org>2009-07-22 10:12:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-07-22 10:12:18 -0700
commit612e900c286a9535cc17da5171b0d8dcf8f3a12f (patch)
treef6931d0c1bc6cf8f798e04437a1a9c3d59a4eea5
parentc57c3743784e08d8ceaaea928a8c84ad8b403aed (diff)
parent9ba5f005c994ad28e266a0cd14ef29354be382c9 (diff)
Merge branch 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: softirq: introduce tasklet_hrtimer infrastructure
-rw-r--r--include/linux/interrupt.h26
-rw-r--r--kernel/softirq.c64
2 files changed, 89 insertions, 1 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 88b056ac562..35e7df1e9f3 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -14,6 +14,7 @@
#include <linux/irqflags.h>
#include <linux/smp.h>
#include <linux/percpu.h>
+#include <linux/hrtimer.h>
#include <asm/atomic.h>
#include <asm/ptrace.h>
@@ -519,6 +520,31 @@ extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
extern void tasklet_init(struct tasklet_struct *t,
void (*func)(unsigned long), unsigned long data);
+struct tasklet_hrtimer {
+ struct hrtimer timer;
+ struct tasklet_struct tasklet;
+ enum hrtimer_restart (*function)(struct hrtimer *);
+};
+
+extern void
+tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
+ enum hrtimer_restart (*function)(struct hrtimer *),
+ clockid_t which_clock, enum hrtimer_mode mode);
+
+static inline
+int tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time,
+ const enum hrtimer_mode mode)
+{
+ return hrtimer_start(&ttimer->timer, time, mode);
+}
+
+static inline
+void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer)
+{
+ hrtimer_cancel(&ttimer->timer);
+ tasklet_kill(&ttimer->tasklet);
+}
+
/*
* Autoprobing for irqs:
*
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 3a94905fa5d..eb5e131a048 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -345,7 +345,9 @@ void open_softirq(int nr, void (*action)(struct softirq_action *))
softirq_vec[nr].action = action;
}
-/* Tasklets */
+/*
+ * Tasklets
+ */
struct tasklet_head
{
struct tasklet_struct *head;
@@ -493,6 +495,66 @@ void tasklet_kill(struct tasklet_struct *t)
EXPORT_SYMBOL(tasklet_kill);
+/*
+ * tasklet_hrtimer
+ */
+
+/*
+ * The trampoline is called when the hrtimer expires. If this is
+ * called from the hrtimer interrupt then we schedule the tasklet as
+ * the timer callback function expects to run in softirq context. If
+ * it's called in softirq context anyway (i.e. high resolution timers
+ * disabled) then the hrtimer callback is called right away.
+ */
+static enum hrtimer_restart __hrtimer_tasklet_trampoline(struct hrtimer *timer)
+{
+ struct tasklet_hrtimer *ttimer =
+ container_of(timer, struct tasklet_hrtimer, timer);
+
+ if (hrtimer_is_hres_active(timer)) {
+ tasklet_hi_schedule(&ttimer->tasklet);
+ return HRTIMER_NORESTART;
+ }
+ return ttimer->function(timer);
+}
+
+/*
+ * Helper function which calls the hrtimer callback from
+ * tasklet/softirq context
+ */
+static void __tasklet_hrtimer_trampoline(unsigned long data)
+{
+ struct tasklet_hrtimer *ttimer = (void *)data;
+ enum hrtimer_restart restart;
+
+ restart = ttimer->function(&ttimer->timer);
+ if (restart != HRTIMER_NORESTART)
+ hrtimer_restart(&ttimer->timer);
+}
+
+/**
+ * tasklet_hrtimer_init - Init a tasklet/hrtimer combo for softirq callbacks
+ * @ttimer: tasklet_hrtimer which is initialized
+ * @function: hrtimer callback funtion which gets called from softirq context
+ * @which_clock: clock id (CLOCK_MONOTONIC/CLOCK_REALTIME)
+ * @mode: hrtimer mode (HRTIMER_MODE_ABS/HRTIMER_MODE_REL)
+ */
+void tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
+ enum hrtimer_restart (*function)(struct hrtimer *),
+ clockid_t which_clock, enum hrtimer_mode mode)
+{
+ hrtimer_init(&ttimer->timer, which_clock, mode);
+ ttimer->timer.function = __hrtimer_tasklet_trampoline;
+ tasklet_init(&ttimer->tasklet, __tasklet_hrtimer_trampoline,
+ (unsigned long)ttimer);
+ ttimer->function = function;
+}
+EXPORT_SYMBOL_GPL(tasklet_hrtimer_init);
+
+/*
+ * Remote softirq bits
+ */
+
DEFINE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
EXPORT_PER_CPU_SYMBOL(softirq_work_list);