[RFC PATCH 4/4] base/memory: pass start_section_nr to init_memory_block()

[Wei Yang <richard.weiyang@gmail.com>]

The second parameter of init_memory_block() is to calculate the
start_section_nr for the memory_block. While current implementation dose
some unnecessary transform between mem_sectioni and section_nr.

This patch simplifies the function by just passing the start_section_nr to
it. By doing so, we can also simplify add_memory_block() too.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
---
 drivers/base/memory.c  | 16 ++++++----------
 include/linux/memory.h |  2 +-
 mm/memory_hotplug.c    |  2 +-
 3 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 468e5ad1bc87..43783dbb1d5e 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -645,7 +645,7 @@ int register_memory(struct memory_block *memory)
 }
 
 static int init_memory_block(struct memory_block **memory,
-			     struct mem_section *section, unsigned long state)
+			     int start_section_nr, unsigned long state)
 {
 	struct memory_block *mem;
 	unsigned long start_pfn;
@@ -656,9 +656,7 @@ static int init_memory_block(struct memory_block **memory,
 	if (!mem)
 		return -ENOMEM;
 
-	scn_nr = __section_nr(section);
-	mem->start_section_nr =
-			base_memory_block_id(scn_nr) * sections_per_block;
+	mem->start_section_nr = start_section_nr;
 	mem->end_section_nr = mem->start_section_nr + sections_per_block - 1;
 	mem->state = state;
 	start_pfn = section_nr_to_pfn(mem->start_section_nr);
@@ -673,21 +671,19 @@ static int init_memory_block(struct memory_block **memory,
 static int add_memory_block(int base_section_nr)
 {
 	struct memory_block *mem;
-	int i, ret, section_count = 0, section_nr;
+	int i, ret, section_count = 0;
 
 	for (i = base_section_nr;
 	     (i < base_section_nr + sections_per_block) && i < NR_MEM_SECTIONS;
 	     i++) {
 		if (!present_section_nr(i))
 			continue;
-		if (section_count == 0)
-			section_nr = i;
 		section_count++;
 	}
 
 	if (section_count == 0)
 		return 0;
-	ret = init_memory_block(&mem, __nr_to_section(section_nr), MEM_ONLINE);
+	ret = init_memory_block(&mem, base_section_nr, MEM_ONLINE);
 	if (ret)
 		return ret;
 	mem->section_count = section_count;
@@ -698,14 +694,14 @@ static int add_memory_block(int base_section_nr)
  * need an interface for the VM to add new memory regions,
  * but without onlining it.
  */
-int register_new_memory(int nid, struct mem_section *section)
+int register_new_memory(int nid, int start_section_nr)
 {
 	int ret = 0;
 	struct memory_block *mem;
 
 	mutex_lock(&mem_sysfs_mutex);
 
-	ret = init_memory_block(&mem, section, MEM_OFFLINE);
+	ret = init_memory_block(&mem, start_section_nr, MEM_OFFLINE);
 	if (ret)
 		goto out;
 	mem->section_count = sections_per_block;
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 51a6355aa56d..0cbde14f7cea 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -108,7 +108,7 @@ extern int register_memory_notifier(struct notifier_block *nb);
 extern void unregister_memory_notifier(struct notifier_block *nb);
 extern int register_memory_isolate_notifier(struct notifier_block *nb);
 extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
-extern int register_new_memory(int, struct mem_section *);
+extern int register_new_memory(int, int);
 #ifdef CONFIG_MEMORY_HOTREMOVE
 extern int unregister_memory_section(struct mem_section *);
 #endif
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 14a08b980b59..fc198847dd5b 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -346,7 +346,7 @@ static int __meminit __add_memory_block(int nid, unsigned long phys_start_pfn,
 	if (!want_memblock)
 		return 0;
 
-	return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
+	return register_new_memory(nid, pfn_to_section_nr(phys_start_pfn));
 }
 
 /*
-- 
2.11.0

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