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>

3 files changed, 7 insertions, 34 deletions

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 006b1bc5297d..4d8a56406fbb 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -207,11 +207,8 @@ static ssize_t show_cpus_attr(struct device *dev,
 			      char *buf)
 {
 	struct cpu_attr *ca = container_of(attr, struct cpu_attr, attr);
-	int n = cpulist_scnprintf(buf, PAGE_SIZE-2, *(ca->map));
 
-	buf[n++] = '\n';
-	buf[n] = '\0';
-	return n;
+	return cpumap_print_to_pagebuf(true, buf, *ca->map);
 }
 
 #define _CPU_ATTR(name, map) \
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 472168cd0c97..a3b82e9c7f20 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -25,32 +25,26 @@ static struct bus_type node_subsys = {
 };
 
 
-static ssize_t node_read_cpumap(struct device *dev, int type, char *buf)
+static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf)
 {
 	struct node *node_dev = to_node(dev);
 	const struct cpumask *mask = cpumask_of_node(node_dev->dev.id);
-	int len;
 
 	/* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
 	BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
 
-	len = type?
-		cpulist_scnprintf(buf, PAGE_SIZE-2, mask) :
-		cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
- 	buf[len++] = '\n';
- 	buf[len] = '\0';
-	return len;
+	return cpumap_print_to_pagebuf(list, buf, mask);
 }
 
 static inline ssize_t node_read_cpumask(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
-	return node_read_cpumap(dev, 0, buf);
+	return node_read_cpumap(dev, false, buf);
 }
 static inline ssize_t node_read_cpulist(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
-	return node_read_cpumap(dev, 1, buf);
+	return node_read_cpumap(dev, true, buf);
 }
 
 static DEVICE_ATTR(cpumap,  S_IRUGO, node_read_cpumask, NULL);
diff --git a/drivers/base/topology.c b/drivers/base/topology.c
index be7c1fb7c0c9..f7c353843ddf 100644
--- a/drivers/base/topology.c
+++ b/drivers/base/topology.c
@@ -42,29 +42,11 @@ static ssize_t show_##name(struct device *dev,			\
 	return sprintf(buf, "%d\n", topology_##name(dev->id));	\
 }
 
-#if defined(topology_thread_cpumask) || defined(topology_core_cpumask) || \
-    defined(topology_book_cpumask)
-static ssize_t show_cpumap(int type, const struct cpumask *mask, char *buf)
-{
-	ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
-	int n = 0;
-
-	if (len > 1) {
-		n = type?
-			cpulist_scnprintf(buf, len-2, mask) :
-			cpumask_scnprintf(buf, len-2, mask);
-		buf[n++] = '\n';
-		buf[n] = '\0';
-	}
-	return n;
-}
-#endif
-
 #define define_siblings_show_map(name)					\
 static ssize_t show_##name(struct device *dev,				\
 			   struct device_attribute *attr, char *buf)	\
 {									\
-	return show_cpumap(0, topology_##name(dev->id), buf);		\
+	return cpumap_print_to_pagebuf(false, buf, topology_##name(dev->id));\
 }
 
 #define define_siblings_show_list(name)					\
@@ -72,7 +54,7 @@ static ssize_t show_##name##_list(struct device *dev,			\
 				  struct device_attribute *attr,	\
 				  char *buf)				\
 {									\
-	return show_cpumap(1, topology_##name(dev->id), buf);		\
+	return cpumap_print_to_pagebuf(true, buf, topology_##name(dev->id));\
 }
 
 #define define_siblings_show_func(name)		\