- struct smp_call_struct data;
- unsigned long timeout;
- static DEFINE_SPINLOCK(lock);
- int retries = 0;
-
- if (num_online_cpus() < 2)
- return 0;
-
- /* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
-
- /* can also deadlock if IPIs are disabled */
- WARN_ON((get_eiem() & (1UL<<(CPU_IRQ_MAX - IPI_IRQ))) == 0);
-
-
- data.func = func;
- data.info = info;
- data.wait = wait;
- atomic_set(&data.unstarted_count, num_online_cpus() - 1);
- atomic_set(&data.unfinished_count, num_online_cpus() - 1);
-
- if (retry) {
- spin_lock (&lock);
- while (smp_call_function_data != 0)
- barrier();
- }
- else {
- spin_lock (&lock);
- if (smp_call_function_data) {
- spin_unlock (&lock);
- return -EBUSY;
- }
- }
-
- smp_call_function_data = &data;
- spin_unlock (&lock);
-
- /* Send a message to all other CPUs and wait for them to respond */
- send_IPI_allbutself(IPI_CALL_FUNC);
-
- retry:
- /* Wait for response */
- timeout = jiffies + HZ;
- while ( (atomic_read (&data.unstarted_count) > 0) &&
- time_before (jiffies, timeout) )
- barrier ();
-
- if (atomic_read (&data.unstarted_count) > 0) {
- printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d), try %d\n",
- smp_processor_id(), ++retries);
- goto retry;
- }
- /* We either got one or timed out. Release the lock */
-
- mb();
- smp_call_function_data = NULL;
-
- while (wait && atomic_read (&data.unfinished_count) > 0)
- barrier ();
-
- return 0;