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>

5 files changed, 20 insertions, 68 deletions

diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index f148a0580e04..c7b105c0e1d3 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -350,12 +350,10 @@ static ssize_t acpi_pad_idlecpus_store(struct device *dev,
 static ssize_t acpi_pad_idlecpus_show(struct device *dev,
         struct device_attribute *attr, char *buf)
 {
-        int n = 0;
-        n = cpumask_scnprintf(buf, PAGE_SIZE-2, to_cpumask(pad_busy_cpus_bits));
-        buf[n++] = '\n';
-        buf[n] = '\0';
-        return n;
+        return cpumap_print_to_pagebuf(false, buf,
+                                       to_cpumask(pad_busy_cpus_bits));
 }
+
 static DEVICE_ATTR(idlecpus, S_IRUGO|S_IWUSR,
         acpi_pad_idlecpus_show,
         acpi_pad_idlecpus_store);
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)         \
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 2c6643fdc0cf..368bdac42603 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -77,11 +77,10 @@ static ssize_t broken_parity_status_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(broken_parity_status);
 
-static ssize_t pci_dev_show_local_cpu(struct device *dev, int type,
+static ssize_t pci_dev_show_local_cpu(struct device *dev, bool list,
                                       struct device_attribute *attr, char *buf)
 {
         const struct cpumask *mask;
-        int len;
 
 #ifdef CONFIG_NUMA
         mask = (dev_to_node(dev) == -1) ? cpu_online_mask :
@@ -89,59 +88,41 @@ static ssize_t pci_dev_show_local_cpu(struct device *dev, int type,
 #else
         mask = cpumask_of_pcibus(to_pci_dev(dev)->bus);
 #endif
-        len = type ?
-                cpumask_scnprintf(buf, PAGE_SIZE-2, mask) :
-                cpulist_scnprintf(buf, PAGE_SIZE-2, mask);
-
-        buf[len++] = '\n';
-        buf[len] = '\0';
-        return len;
+        return cpumap_print_to_pagebuf(list, buf, mask);
 }
 
 static ssize_t local_cpus_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
 {
-        return pci_dev_show_local_cpu(dev, 1, attr, buf);
+        return pci_dev_show_local_cpu(dev, false, attr, buf);
 }
 static DEVICE_ATTR_RO(local_cpus);
 
 static ssize_t local_cpulist_show(struct device *dev,
                                   struct device_attribute *attr, char *buf)
 {
-        return pci_dev_show_local_cpu(dev, 0, attr, buf);
+        return pci_dev_show_local_cpu(dev, true, attr, buf);
 }
 static DEVICE_ATTR_RO(local_cpulist);
 
 /*
  * PCI Bus Class Devices
  */
-static ssize_t pci_bus_show_cpuaffinity(struct device *dev, int type,
-                                        struct device_attribute *attr,
-                                        char *buf)
-{
-        int ret;
-        const struct cpumask *cpumask;
-
-        cpumask = cpumask_of_pcibus(to_pci_bus(dev));
-        ret = type ?
-                cpulist_scnprintf(buf, PAGE_SIZE-2, cpumask) :
-                cpumask_scnprintf(buf, PAGE_SIZE-2, cpumask);
-        buf[ret++] = '\n';
-        buf[ret] = '\0';
-        return ret;
-}
-
 static ssize_t cpuaffinity_show(struct device *dev,
                                 struct device_attribute *attr, char *buf)
 {
-        return pci_bus_show_cpuaffinity(dev, 0, attr, buf);
+        const struct cpumask *cpumask = cpumask_of_pcibus(to_pci_bus(dev));
+
+        return cpumap_print_to_pagebuf(false, buf, cpumask);
 }
 static DEVICE_ATTR_RO(cpuaffinity);
 
 static ssize_t cpulistaffinity_show(struct device *dev,
                                     struct device_attribute *attr, char *buf)
 {
-        return pci_bus_show_cpuaffinity(dev, 1, attr, buf);
+        const struct cpumask *cpumask = cpumask_of_pcibus(to_pci_bus(dev));
+
+        return cpumap_print_to_pagebuf(true, buf, cpumask);
 }
 static DEVICE_ATTR_RO(cpulistaffinity);