xen: Use DEVICE_ATTR_*() macro

Use DEVICE_ATTR_*() helper instead of plain DEVICE_ATTR(),
which makes the code a bit shorter and easier to read.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20210526141019.13752-1-yuehaibing@huawei.comSigned-off-by: Juergen Gross <jgross@suse.com>

drivers/xen/pcpu.c

@@ -92,7 +92,7 @@ static int xen_pcpu_up(uint32_t cpu_id)
 	return HYPERVISOR_platform_op(&op);
 }
 
-static ssize_t show_online(struct device *dev,
+static ssize_t online_show(struct device *dev,
 			   struct device_attribute *attr,
 			   char *buf)
 {
@@ -101,7 +101,7 @@ static ssize_t show_online(struct device *dev,
 	return sprintf(buf, "%u\n", !!(cpu->flags & XEN_PCPU_FLAGS_ONLINE));
 }
 
-static ssize_t __ref store_online(struct device *dev,
+static ssize_t __ref online_store(struct device *dev,
 				  struct device_attribute *attr,
 				  const char *buf, size_t count)
 {
@@ -130,7 +130,7 @@ static ssize_t __ref store_online(struct device *dev,
 		ret = count;
 	return ret;
 }
-static DEVICE_ATTR(online, S_IRUGO | S_IWUSR, show_online, store_online);
+static DEVICE_ATTR_RW(online);
 
 static struct attribute *pcpu_dev_attrs[] = {
 	&dev_attr_online.attr,

drivers/xen/xen-balloon.c

@@ -134,13 +134,13 @@ void xen_balloon_init(void)
 EXPORT_SYMBOL_GPL(xen_balloon_init);
 
 #define BALLOON_SHOW(name, format, args...)				\
-	static ssize_t show_##name(struct device *dev,			\
+	static ssize_t name##_show(struct device *dev,			\
 				   struct device_attribute *attr,	\
 				   char *buf)				\
 	{								\
 		return sprintf(buf, format, ##args);			\
 	}								\
-	static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
+	static DEVICE_ATTR_RO(name)
 
 BALLOON_SHOW(current_kb, "%lu\n", PAGES2KB(balloon_stats.current_pages));
 BALLOON_SHOW(low_kb, "%lu\n", PAGES2KB(balloon_stats.balloon_low));
@@ -152,16 +152,15 @@ static DEVICE_ULONG_ATTR(retry_count, 0444, balloon_stats.retry_count);
 static DEVICE_ULONG_ATTR(max_retry_count, 0644, balloon_stats.max_retry_count);
 static DEVICE_BOOL_ATTR(scrub_pages, 0644, xen_scrub_pages);
 
-static ssize_t show_target_kb(struct device *dev, struct device_attribute *attr,
+static ssize_t target_kb_show(struct device *dev, struct device_attribute *attr,
 			      char *buf)
 {
 	return sprintf(buf, "%lu\n", PAGES2KB(balloon_stats.target_pages));
 }
 
-static ssize_t store_target_kb(struct device *dev,
+static ssize_t target_kb_store(struct device *dev,
 			       struct device_attribute *attr,
-			       const char *buf,
-			       size_t count)
+			       const char *buf, size_t count)
 {
 	char *endchar;
 	unsigned long long target_bytes;
@@ -176,11 +175,9 @@ static ssize_t store_target_kb(struct device *dev,
 	return count;
 }
 
-static DEVICE_ATTR(target_kb, S_IRUGO | S_IWUSR,
-		   show_target_kb, store_target_kb);
+static DEVICE_ATTR_RW(target_kb);
 
-
-static ssize_t show_target(struct device *dev, struct device_attribute *attr,
+static ssize_t target_show(struct device *dev, struct device_attribute *attr,
 			   char *buf)
 {
 	return sprintf(buf, "%llu\n",
@@ -188,10 +185,9 @@ static ssize_t show_target(struct device *dev, struct device_attribute *attr,
 		       << PAGE_SHIFT);
 }
 
-static ssize_t store_target(struct device *dev,
+static ssize_t target_store(struct device *dev,
 			    struct device_attribute *attr,
-			    const char *buf,
-			    size_t count)
+			    const char *buf, size_t count)
 {
 	char *endchar;
 	unsigned long long target_bytes;
@@ -206,9 +202,7 @@ static ssize_t store_target(struct device *dev,
 	return count;
 }
 
-static DEVICE_ATTR(target, S_IRUGO | S_IWUSR,
-		   show_target, store_target);
-
+static DEVICE_ATTR_RW(target);
 
 static struct attribute *balloon_attrs[] = {
 	&dev_attr_target_kb.attr,

drivers/xen/xenbus/xenbus_probe.c

@@ -207,7 +207,7 @@ void xenbus_otherend_changed(struct xenbus_watch *watch,
 EXPORT_SYMBOL_GPL(xenbus_otherend_changed);
 
 #define XENBUS_SHOW_STAT(name)						\
-static ssize_t show_##name(struct device *_dev,				\
+static ssize_t name##_show(struct device *_dev,				\
 			   struct device_attribute *attr,		\
 			   char *buf)					\
 {									\
@@ -215,14 +215,14 @@ static ssize_t show_##name(struct device *_dev,				\
 									\
 	return sprintf(buf, "%d\n", atomic_read(&dev->name));		\
 }									\
-static DEVICE_ATTR(name, 0444, show_##name, NULL)
+static DEVICE_ATTR_RO(name)
 
 XENBUS_SHOW_STAT(event_channels);
 XENBUS_SHOW_STAT(events);
 XENBUS_SHOW_STAT(spurious_events);
 XENBUS_SHOW_STAT(jiffies_eoi_delayed);
 
-static ssize_t show_spurious_threshold(struct device *_dev,
+static ssize_t spurious_threshold_show(struct device *_dev,
 				       struct device_attribute *attr,
 				       char *buf)
 {
@@ -231,7 +231,7 @@ static ssize_t show_spurious_threshold(struct device *_dev,
 	return sprintf(buf, "%d\n", dev->spurious_threshold);
 }
 
-static ssize_t set_spurious_threshold(struct device *_dev,
+static ssize_t spurious_threshold_store(struct device *_dev,
 					struct device_attribute *attr,
 					const char *buf, size_t count)
 {
@@ -248,8 +248,7 @@ static ssize_t set_spurious_threshold(struct device *_dev,
 	return count;
 }
 
-static DEVICE_ATTR(spurious_threshold, 0644, show_spurious_threshold,
-		   set_spurious_threshold);
+static DEVICE_ATTR_RW(spurious_threshold);
 
 static struct attribute *xenbus_attrs[] = {
 	&dev_attr_event_channels.attr,