[PATCH 29/31] cpumask: implement cpumask_parse()

Tejun Heo
2013-03-02T03:26:24Z

We have cpulist_parse() but not cpumask_parse(). Implement it using
bitmap_parse().

bitmap_parse() is weird in that it takes @len for a string in
kernel-memory which also is inconsistent with bitmap_parselist().
Make cpumask_parse() calculate the length and don't expose the
inconsistency to cpumask users. Maybe we can fix up bitmap_parse()
later.

This will be used to expose workqueue cpumask knobs to userland via
sysfs.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
---
Rusty, if this looks okay to you, would it be okay for me to route it
together with the rest of workqueue changes?

Thanks.

include/linux/cpumask.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 0325602..d08e4d2 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -591,6 +591,21 @@ static inline int cpulist_scnprintf(char *buf, int len,
}

/**
+ * cpumask_parse - extract a cpumask from from a string
+ * @buf: the buffer to extract from
+ * @dstp: the cpumask to set.
+ *
+ * Returns -errno, or 0 for success.
+ */
+static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
+{
+ char *nl = strchr(buf, '\n');
+ int len = nl ? nl - buf : strlen(buf);
+
+ return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
+}
+
+/**
* cpulist_parse - extract a cpumask from a user string of ranges
* @buf: the buffer to extract from
* @dstp: the cpumask to set.
--
1.8.1.2