cpumask: factor out show_cpumap into separate helper function

Many sysfs *_show function use cpu{list,mask}_scnprintf to copy cpumap
to the buffer aligned to PAGE_SIZE, append '\n' and '\0' to return null
terminated buffer with newline.

This patch creates a new helper function cpumap_print_to_pagebuf in
cpumask.h using newly added bitmap_print_to_pagebuf and consolidates
most of those sysfs functions using the new helper function.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: x86@kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/bitmap.h

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index e1c8d08..9d5c322 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -60,6 +60,7 @@
  * bitmap_find_free_region(bitmap, bits, order)	Find and allocate bit region
  * bitmap_release_region(bitmap, pos, order)	Free specified bit region
  * bitmap_allocate_region(bitmap, pos, order)	Allocate specified bit region
+ * bitmap_print_to_pagebuf(list, buf, mask, nbits) Print bitmap src as list/hex
  */
 
 /*
@@ -145,6 +146,8 @@
 extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
 extern void bitmap_copy_le(void *dst, const unsigned long *src, int nbits);
 extern int bitmap_ord_to_pos(const unsigned long *bitmap, int n, int bits);
+extern int bitmap_print_to_pagebuf(bool list, char *buf,
+				   const unsigned long *maskp, int nmaskbits);
 
 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG))
 #define BITMAP_LAST_WORD_MASK(nbits)					\

include/linux/cpumask.h

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 0a9a6da..b950e9d 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -803,6 +803,23 @@
 }
 #endif /* NR_CPUS > BITS_PER_LONG */
 
+/**
+ * cpumap_print_to_pagebuf  - copies the cpumask into the buffer either
+ *	as comma-separated list of cpus or hex values of cpumask
+ * @list: indicates whether the cpumap must be list
+ * @mask: the cpumask to copy
+ * @buf: the buffer to copy into
+ *
+ * Returns the length of the (null-terminated) @buf string, zero if
+ * nothing is copied.
+ */
+static inline ssize_t
+cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
+{
+	return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask),
+				      nr_cpumask_bits);
+}
+
 /*
  *
  * From here down, all obsolete.  Use cpumask_ variants!