cpumask: add for_each_cpu_mask_and function

Add for_each_cpu_mask_and() function to eliminate need for a common use
of a temporary cpumask_t variable.  When the following procedure is being
used:

    funcproto(const cpumask_t *mask, ...)
    {
	cpumask_t temp;

	cpus_and(temp, mask, cpu_online_map);
	for_each_cpu_mask(cpu, temp)
		...
It then becomes:

    funcproto(cpumask_t *mask, ...)
    {
	for_each_cpu_mask_and(cpu, *mask, cpu_online_map)
		...

... eliminating the need for the temp cpumask.


Applies to linux-2.6.tip/master.

Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 9 insertions, 0 deletions

diff --git a/lib/cpumask.c b/lib/cpumask.c
index 5f97dc25ef9c..8e6f1af99fa0 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -15,6 +15,15 @@ int __next_cpu(int n, const cpumask_t *srcp)
 }
 EXPORT_SYMBOL(__next_cpu);
 
+int cpumask_next_and(int n, const cpumask_t *srcp, const cpumask_t *andp)
+{
+	while ((n = next_cpu_nr(n, *srcp)) < nr_cpu_ids)
+		if (cpu_isset(n, *andp))
+			break;
+	return n;
+}
+EXPORT_SYMBOL(cpumask_next_and);
+
 #if NR_CPUS > 64
 int __next_cpu_nr(int n, const cpumask_t *srcp)
 {