[PATCH 1/2] drivers/base/memory: Fix comments for phys_index_show()

[Gavin Shan <gshan@redhat.com>]

According to 'admin-guide/mm/memory-hotplug.rst', the memory block ID,
instead of the section index, is shown by '/sys/devices/system/memory/
memoryX/phys_index'.

Fix the comments to match with 'admin-guide/mm/memory-hotplug.rst'.
Besides, use the existing helper memory_block_id() to convert the section
index to the memory block index.

No functional change intended.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 drivers/base/memory.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index fe98fb8d94e5..b456ac213610 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -115,18 +115,13 @@ unsigned long __weak memory_block_size_bytes(void)
 }
 EXPORT_SYMBOL_GPL(memory_block_size_bytes);
 
-/*
- * Show the first physical section index (number) of this memory block.
- */
+/* Show the memory block ID, relative to the memory block size */
 static ssize_t phys_index_show(struct device *dev,
 			       struct device_attribute *attr, char *buf)
 {
 	struct memory_block *mem = to_memory_block(dev);
-	unsigned long phys_index;
-
-	phys_index = mem->start_section_nr / sections_per_block;
 
-	return sysfs_emit(buf, "%08lx\n", phys_index);
+	return sysfs_emit(buf, "%08lx\n", memory_block_id(mem->start_section_nr));
 }
 
 /*
-- 
2.23.0