V4L/DVB (3693): Fix msp3400c and bttv stereo/mono/bilingual detection/handling
[safe/jmp/linux-2.6] / kernel / rcupdate.c
index fedf5e3..13458bb 100644 (file)
 #include <linux/notifier.h>
 #include <linux/rcupdate.h>
 #include <linux/cpu.h>
+#include <linux/mutex.h>
 
 /* Definition for rcupdate control block. */
-struct rcu_ctrlblk rcu_ctrlblk = {
+static struct rcu_ctrlblk rcu_ctrlblk = {
        .cur = -300,
        .completed = -300,
        .lock = SPIN_LOCK_UNLOCKED,
        .cpumask = CPU_MASK_NONE,
 };
-struct rcu_ctrlblk rcu_bh_ctrlblk = {
+static struct rcu_ctrlblk rcu_bh_ctrlblk = {
        .cur = -300,
        .completed = -300,
        .lock = SPIN_LOCK_UNLOCKED,
@@ -75,7 +76,7 @@ static int rsinterval = 1000;
 #endif
 
 static atomic_t rcu_barrier_cpu_count;
-static struct semaphore rcu_barrier_sema;
+static DEFINE_MUTEX(rcu_barrier_mutex);
 static struct completion rcu_barrier_completion;
 
 #ifdef CONFIG_SMP
@@ -207,13 +208,13 @@ static void rcu_barrier_func(void *notused)
 void rcu_barrier(void)
 {
        BUG_ON(in_interrupt());
-       /* Take cpucontrol semaphore to protect against CPU hotplug */
-       down(&rcu_barrier_sema);
+       /* Take cpucontrol mutex to protect against CPU hotplug */
+       mutex_lock(&rcu_barrier_mutex);
        init_completion(&rcu_barrier_completion);
        atomic_set(&rcu_barrier_cpu_count, 0);
        on_each_cpu(rcu_barrier_func, NULL, 0, 1);
        wait_for_completion(&rcu_barrier_completion);
-       up(&rcu_barrier_sema);
+       mutex_unlock(&rcu_barrier_mutex);
 }
 EXPORT_SYMBOL_GPL(rcu_barrier);
 
@@ -415,8 +416,8 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp,
                rdp->curtail = &rdp->curlist;
        }
 
-       local_irq_disable();
        if (rdp->nxtlist && !rdp->curlist) {
+               local_irq_disable();
                rdp->curlist = rdp->nxtlist;
                rdp->curtail = rdp->nxttail;
                rdp->nxtlist = NULL;
@@ -441,9 +442,8 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp,
                        rcu_start_batch(rcp);
                        spin_unlock(&rcp->lock);
                }
-       } else {
-               local_irq_enable();
        }
+
        rcu_check_quiescent_state(rcp, rdp);
        if (rdp->donelist)
                rcu_do_batch(rdp);
@@ -549,7 +549,6 @@ static struct notifier_block __devinitdata rcu_nb = {
  */
 void __init rcu_init(void)
 {
-       sema_init(&rcu_barrier_sema, 1);
        rcu_cpu_notify(&rcu_nb, CPU_UP_PREPARE,
                        (void *)(long)smp_processor_id());
        /* Register notifier for non-boot CPUs */