+/*
+ * Softirq action handler - move entries to local list and loop over them
+ * while passing them to the queue registered handler.
+ */
+static void blk_done_softirq(struct softirq_action *h)
+{
+ struct list_head *cpu_list, local_list;
+
+ local_irq_disable();
+ cpu_list = &__get_cpu_var(blk_cpu_done);
+ list_replace_init(cpu_list, &local_list);
+ local_irq_enable();
+
+ while (!list_empty(&local_list)) {
+ struct request *rq;
+
+ rq = list_entry(local_list.next, struct request, csd.list);
+ list_del_init(&rq->csd.list);
+ rq->q->softirq_done_fn(rq);
+ }
+}
+
+#if defined(CONFIG_SMP) && defined(CONFIG_USE_GENERIC_SMP_HELPERS)
+static void trigger_softirq(void *data)
+{
+ struct request *rq = data;
+ unsigned long flags;
+ struct list_head *list;
+
+ local_irq_save(flags);
+ list = &__get_cpu_var(blk_cpu_done);
+ list_add_tail(&rq->csd.list, list);
+
+ if (list->next == &rq->csd.list)
+ raise_softirq_irqoff(BLOCK_SOFTIRQ);
+
+ local_irq_restore(flags);
+}
+
+/*
+ * Setup and invoke a run of 'trigger_softirq' on the given cpu.
+ */
+static int raise_blk_irq(int cpu, struct request *rq)
+{
+ if (cpu_online(cpu)) {
+ struct call_single_data *data = &rq->csd;
+
+ data->func = trigger_softirq;
+ data->info = rq;
+ data->flags = 0;
+
+ __smp_call_function_single(cpu, data);
+ return 0;
+ }
+
+ return 1;
+}
+#else /* CONFIG_SMP && CONFIG_USE_GENERIC_SMP_HELPERS */
+static int raise_blk_irq(int cpu, struct request *rq)
+{
+ return 1;
+}
+#endif
+