drivers/base/memory.c: Use DEVICE_ATTR_RO and friends

mainline inclusion
from linux-5.0-rc1
commit 3f8e9178
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SK3S
CVE: NA

--------------------------------

Let's use the easier to read (and not mess up) variants:
- Use DEVICE_ATTR_RO
- Use DEVICE_ATTR_WO
- Use DEVICE_ATTR_RW
instead of the more generic DEVICE_ATTR() we're using right now.

We have to rename most callback functions. By fixing the intendations we
can even save some LOCs.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NWei Yang <richard.weiyang@gmail.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NMa Wupeng <mawupeng1@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/base/memory.c

@@ -115,7 +115,7 @@ static unsigned long get_memory_block_size(void)
  * uses.
  */
 
-static ssize_t show_mem_start_phys_index(struct device *dev,
+static ssize_t phys_index_show(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	struct memory_block *mem = to_memory_block(dev);
@@ -128,8 +128,8 @@ static ssize_t show_mem_start_phys_index(struct device *dev,
 /*
  * Show whether the section of memory is likely to be hot-removable
  */
-static ssize_t show_mem_removable(struct device *dev,
-			struct device_attribute *attr, char *buf)
+static ssize_t removable_show(struct device *dev, struct device_attribute *attr,
+			      char *buf)
 {
 	unsigned long i, pfn;
 	int ret = 1;
@@ -152,8 +152,8 @@ static ssize_t show_mem_removable(struct device *dev,
 /*
  * online, offline, going offline, etc.
  */
-static ssize_t show_mem_state(struct device *dev,
-			struct device_attribute *attr, char *buf)
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
 {
 	struct memory_block *mem = to_memory_block(dev);
 	ssize_t len = 0;
@@ -293,7 +293,7 @@ static int memory_subsys_online(struct device *dev)
 		return 0;
 
 	/*
-	 * If we are called from store_mem_state(), online_type will be
+	 * If we are called from state_store(), online_type will be
 	 * set >= 0 Otherwise we were called from the device online
 	 * attribute and need to set the online_type.
 	 */
@@ -322,9 +322,8 @@ static int memory_subsys_offline(struct device *dev)
 	return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
 }
 
-static ssize_t
-store_mem_state(struct device *dev,
-		struct device_attribute *attr, const char *buf, size_t count)
+static ssize_t state_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count)
 {
 	struct memory_block *mem = to_memory_block(dev);
 	int ret, online_type;
@@ -381,7 +380,7 @@ store_mem_state(struct device *dev,
  * s.t. if I offline all of these sections I can then
  * remove the physical device?
  */
-static ssize_t show_phys_device(struct device *dev,
+static ssize_t phys_device_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct memory_block *mem = to_memory_block(dev);
@@ -402,7 +401,7 @@ static void print_allowed_zone(char *buf, int nid, unsigned long start_pfn,
 	}
 }
 
-static ssize_t show_valid_zones(struct device *dev,
+static ssize_t valid_zones_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct memory_block *mem = to_memory_block(dev);
@@ -442,33 +441,31 @@ static ssize_t show_valid_zones(struct device *dev,
 
 	return strlen(buf);
 }
-static DEVICE_ATTR(valid_zones, 0444, show_valid_zones, NULL);
+static DEVICE_ATTR_RO(valid_zones);
 #endif
 
-static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);
-static DEVICE_ATTR(state, 0644, show_mem_state, store_mem_state);
-static DEVICE_ATTR(phys_device, 0444, show_phys_device, NULL);
-static DEVICE_ATTR(removable, 0444, show_mem_removable, NULL);
+static DEVICE_ATTR_RO(phys_index);
+static DEVICE_ATTR_RW(state);
+static DEVICE_ATTR_RO(phys_device);
+static DEVICE_ATTR_RO(removable);
 
 /*
  * Block size attribute stuff
  */
-static ssize_t
-print_block_size(struct device *dev, struct device_attribute *attr,
-		 char *buf)
+static ssize_t block_size_bytes_show(struct device *dev,
+				     struct device_attribute *attr, char *buf)
 {
 	return sprintf(buf, "%lx\n", get_memory_block_size());
 }
 
-static DEVICE_ATTR(block_size_bytes, 0444, print_block_size, NULL);
+static DEVICE_ATTR_RO(block_size_bytes);
 
 /*
  * Memory auto online policy.
  */
 
-static ssize_t
-show_auto_online_blocks(struct device *dev, struct device_attribute *attr,
-			char *buf)
+static ssize_t auto_online_blocks_show(struct device *dev,
+				       struct device_attribute *attr, char *buf)
 {
 	if (memhp_auto_online)
 		return sprintf(buf, "online\n");
@@ -476,8 +473,8 @@ show_auto_online_blocks(struct device *dev, struct device_attribute *attr,
 		return sprintf(buf, "offline\n");
 }
 
-static ssize_t
-store_auto_online_blocks(struct device *dev, struct device_attribute *attr,
+static ssize_t auto_online_blocks_store(struct device *dev,
+					struct device_attribute *attr,
 					const char *buf, size_t count)
 {
 	if (sysfs_streq(buf, "online"))
@@ -490,8 +487,7 @@ store_auto_online_blocks(struct device *dev, struct device_attribute *attr,
 	return count;
 }
 
-static DEVICE_ATTR(auto_online_blocks, 0644, show_auto_online_blocks,
-		   store_auto_online_blocks);
+static DEVICE_ATTR_RW(auto_online_blocks);
 
 /*
  * Some architectures will have custom drivers to do this, and
@@ -500,8 +496,7 @@ static DEVICE_ATTR(auto_online_blocks, 0644, show_auto_online_blocks,
  * and will require this interface.
  */
 #ifdef CONFIG_ARCH_MEMORY_PROBE
-static ssize_t
-memory_probe_store(struct device *dev, struct device_attribute *attr,
+static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
 			   const char *buf, size_t count)
 {
 	u64 phys_addr;
@@ -532,7 +527,7 @@ memory_probe_store(struct device *dev, struct device_attribute *attr,
 	return ret;
 }
 
-static DEVICE_ATTR(probe, S_IWUSR, NULL, memory_probe_store);
+static DEVICE_ATTR_WO(probe);
 #endif
 
 #ifdef CONFIG_MEMORY_FAILURE
@@ -541,8 +536,7 @@ static DEVICE_ATTR(probe, S_IWUSR, NULL, memory_probe_store);
  */
 
 /* Soft offline a page */
-static ssize_t
-store_soft_offline_page(struct device *dev,
+static ssize_t soft_offline_page_store(struct device *dev,
 				       struct device_attribute *attr,
 				       const char *buf, size_t count)
 {
@@ -563,8 +557,7 @@ store_soft_offline_page(struct device *dev,
 }
 
 /* Forcibly offline a page, including killing processes. */
-static ssize_t
-store_hard_offline_page(struct device *dev,
+static ssize_t hard_offline_page_store(struct device *dev,
 				       struct device_attribute *attr,
 				       const char *buf, size_t count)
 {
@@ -579,8 +572,8 @@ store_hard_offline_page(struct device *dev,
 	return ret ? ret : count;
 }
 
-static DEVICE_ATTR(soft_offline_page, S_IWUSR, NULL, store_soft_offline_page);
-static DEVICE_ATTR(hard_offline_page, S_IWUSR, NULL, store_hard_offline_page);
+static DEVICE_ATTR_WO(soft_offline_page);
+static DEVICE_ATTR_WO(hard_offline_page);
 #endif
 
 /*