Staging: comedi: initialize divisor variables

[pandora-kernel.git] / kernel / smp.c

diff --git a/kernel/smp.c b/kernel/smp.c
index 8bd618f..a8c7606 100644 (file)
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -319,6 +319,51 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
 }
 EXPORT_SYMBOL(smp_call_function_single);
 
+/*
+ * smp_call_function_any - Run a function on any of the given cpus
+ * @mask: The mask of cpus it can run on.
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @wait: If true, wait until function has completed.
+ *
+ * Returns 0 on success, else a negative status code (if no cpus were online).
+ * Note that @wait will be implicitly turned on in case of allocation failures,
+ * since we fall back to on-stack allocation.
+ *
+ * Selection preference:
+ *     1) current cpu if in @mask
+ *     2) any cpu of current node if in @mask
+ *     3) any other online cpu in @mask
+ */
+int smp_call_function_any(const struct cpumask *mask,
+                         void (*func)(void *info), void *info, int wait)
+{
+       unsigned int cpu;
+       const struct cpumask *nodemask;
+       int ret;
+
+       /* Try for same CPU (cheapest) */
+       cpu = get_cpu();
+       if (cpumask_test_cpu(cpu, mask))
+               goto call;
+
+       /* Try for same node. */
+       nodemask = cpumask_of_node(cpu);
+       for (cpu = cpumask_first_and(nodemask, mask); cpu < nr_cpu_ids;
+            cpu = cpumask_next_and(cpu, nodemask, mask)) {
+               if (cpu_online(cpu))
+                       goto call;
+       }
+
+       /* Any online will do: smp_call_function_single handles nr_cpu_ids. */
+       cpu = cpumask_any_and(mask, cpu_online_mask);
+call:
+       ret = smp_call_function_single(cpu, func, info, wait);
+       put_cpu();
+       return ret;
+}
+EXPORT_SYMBOL_GPL(smp_call_function_any);
+
 /**
  * __smp_call_function_single(): Run a function on another CPU
  * @cpu: The CPU to run on.