ALSA: usb-audio: add support for Akai MPD16

[safe/jmp/linux-2.6] / kernel / softirq.c

diff --git a/kernel/softirq.c b/kernel/softirq.c
index 258885a..0db913a 100644 (file)
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -57,7 +57,7 @@ static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp
 static DEFINE_PER_CPU(struct task_struct *, ksoftirqd);
 
 char *softirq_to_name[NR_SOFTIRQS] = {
-       "HI", "TIMER", "NET_TX", "NET_RX", "BLOCK",
+       "HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "BLOCK_IOPOLL",
        "TASKLET", "SCHED", "HRTIMER",  "RCU"
 };
 
@@ -213,6 +213,7 @@ restart:
        do {
                if (pending & 1) {
                        int prev_count = preempt_count();
+                       kstat_incr_softirqs_this_cpu(h - softirq_vec);
 
                        trace_softirq_entry(h, softirq_vec);
                        h->action(h);
@@ -226,7 +227,7 @@ restart:
                                preempt_count() = prev_count;
                        }
 
-                       rcu_bh_qsctr_inc(cpu);
+                       rcu_bh_qs(cpu);
                }
                h++;
                pending >>= 1;
@@ -301,9 +302,9 @@ void irq_exit(void)
        if (!in_interrupt() && local_softirq_pending())
                invoke_softirq();
 
+       rcu_irq_exit();
 #ifdef CONFIG_NO_HZ
        /* Make sure that timer wheel updates are propagated */
-       rcu_irq_exit();
        if (idle_cpu(smp_processor_id()) && !in_interrupt() && !need_resched())
                tick_nohz_stop_sched_tick(0);
 #endif
@@ -344,7 +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;
@@ -382,6 +385,17 @@ void __tasklet_hi_schedule(struct tasklet_struct *t)
 
 EXPORT_SYMBOL(__tasklet_hi_schedule);
 
+void __tasklet_hi_schedule_first(struct tasklet_struct *t)
+{
+       BUG_ON(!irqs_disabled());
+
+       t->next = __get_cpu_var(tasklet_hi_vec).head;
+       __get_cpu_var(tasklet_hi_vec).head = t;
+       __raise_softirq_irqoff(HI_SOFTIRQ);
+}
+
+EXPORT_SYMBOL(__tasklet_hi_schedule_first);
+
 static void tasklet_action(struct softirq_action *a)
 {
        struct tasklet_struct *list;
@@ -481,6 +495,61 @@ void tasklet_kill(struct tasklet_struct *t)
 
 EXPORT_SYMBOL(tasklet_kill);
 
+/*
+ * tasklet_hrtimer
+ */
+
+/*
+ * The trampoline is called when the hrtimer expires. It schedules a tasklet
+ * to run __tasklet_hrtimer_trampoline() which in turn will call the intended
+ * hrtimer callback, but from softirq context.
+ */
+static enum hrtimer_restart __hrtimer_tasklet_trampoline(struct hrtimer *timer)
+{
+       struct tasklet_hrtimer *ttimer =
+               container_of(timer, struct tasklet_hrtimer, timer);
+
+       tasklet_hi_schedule(&ttimer->tasklet);
+       return HRTIMER_NORESTART;
+}
+
+/*
+ * 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);
 
@@ -623,7 +692,7 @@ void __init softirq_init(void)
        open_softirq(HI_SOFTIRQ, tasklet_hi_action);
 }
 
-static int ksoftirqd(void * __bind_cpu)
+static int run_ksoftirqd(void * __bind_cpu)
 {
        set_current_state(TASK_INTERRUPTIBLE);
 
@@ -647,7 +716,7 @@ static int ksoftirqd(void * __bind_cpu)
                        preempt_enable_no_resched();
                        cond_resched();
                        preempt_disable();
-                       rcu_qsctr_inc((long)__bind_cpu);
+                       rcu_note_context_switch((long)__bind_cpu);
                }
                preempt_enable();
                set_current_state(TASK_INTERRUPTIBLE);
@@ -736,7 +805,7 @@ static int __cpuinit cpu_callback(struct notifier_block *nfb,
        switch (action) {
        case CPU_UP_PREPARE:
        case CPU_UP_PREPARE_FROZEN:
-               p = kthread_create(ksoftirqd, hcpu, "ksoftirqd/%d", hotcpu);
+               p = kthread_create(run_ksoftirqd, hcpu, "ksoftirqd/%d", hotcpu);
                if (IS_ERR(p)) {
                        printk("ksoftirqd for %i failed\n", hotcpu);
                        return NOTIFY_BAD;