[PATCH-RESEND v4] memory-hotplug: create /sys/firmware/memmap entryfor new memory

From: Zheng, Shaohui
Date: Sun Jan 10 2010 - 21:01:00 EST


Resend the memmap patch v4 to mailing-list after follow up fengguang's review
comments.

memory-hotplug: create /sys/firmware/memmap entry for hot-added memory

Interface firmware_map_add was not called in explict, Remove it and add function
firmware_map_add_hotplug as hotplug interface of memmap.

When we hot-add new memory, sysfs does not export memmap entry for it. we add
a call in function add_memory to function firmware_map_add_hotplug.

Add a new function add_sysfs_fw_map_entry to create memmap entry, it can avoid
duplicated codes.

Thanks for the careful review from Fengguang Wu and Dave Hansen.

Signed-off-by: Shaohui Zheng <shaohui.zheng@xxxxxxxxx>
Acked-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Acked-by: Yasunori Goto <y-goto@xxxxxxxxxxxxxx>
Reviewed-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c
index 56f9234..11baa6d 100644
--- a/drivers/firmware/memmap.c
+++ b/drivers/firmware/memmap.c
@@ -123,20 +123,40 @@ static int firmware_map_add_entry(u64 start, u64 end,
}

/**
- * firmware_map_add() - Adds a firmware mapping entry.
+ * Add memmap entry on sysfs
+ */
+static int add_sysfs_fw_map_entry(struct firmware_map_entry *entry)
+{
+ static int map_entries_nr;
+ static struct kset *mmap_kset;
+
+ if (!mmap_kset) {
+ mmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);
+ if (!mmap_kset)
+ return -ENOMEM;
+ }
+
+ entry->kobj.kset = mmap_kset;
+ if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++))
+ kobject_put(&entry->kobj);
+
+ return 0;
+}
+
+/**
+ * firmware_map_add_early() - Adds a firmware mapping entry.
* @start: Start of the memory range.
* @end: End of the memory range (inclusive).
* @type: Type of the memory range.
*
- * This function uses kmalloc() for memory
- * allocation. Use firmware_map_add_early() if you want to use the bootmem
- * allocator.
+ * Adds a firmware mapping entry. This function uses the bootmem allocator
+ * for memory allocation.
*
* That function must be called before late_initcall.
*
* Returns 0 on success, or -ENOMEM if no memory could be allocated.
**/
-int firmware_map_add(u64 start, u64 end, const char *type)
+int __init firmware_map_add_early(u64 start, u64 end, const char *type)
{
struct firmware_map_entry *entry;

@@ -148,27 +168,31 @@ int firmware_map_add(u64 start, u64 end, const char *type)
}

/**
- * firmware_map_add_early() - Adds a firmware mapping entry.
+ * firmware_map_add_hotplug() - Adds a firmware mapping entry when we do
+ * memory hotplug.
* @start: Start of the memory range.
* @end: End of the memory range (inclusive).
* @type: Type of the memory range.
*
- * Adds a firmware mapping entry. This function uses the bootmem allocator
- * for memory allocation. Use firmware_map_add() if you want to use kmalloc().
- *
- * That function must be called before late_initcall.
+ * Adds a firmware mapping entry. This function is for memory hotplug, it is
+ * simiar with function firmware_map_add_early. the only difference is that
+ * it will create the syfs entry dynamically.
*
* Returns 0 on success, or -ENOMEM if no memory could be allocated.
**/
-int __init firmware_map_add_early(u64 start, u64 end, const char *type)
+int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
{
struct firmware_map_entry *entry;

- entry = alloc_bootmem(sizeof(struct firmware_map_entry));
- if (WARN_ON(!entry))
+ entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
+ if (!entry)
return -ENOMEM;

- return firmware_map_add_entry(start, end, type, entry);
+ firmware_map_add_entry(start, end, type, entry);
+ /* create the memmap entry */
+ add_sysfs_fw_map_entry(entry);
+
+ return 0;
}

/*
@@ -214,18 +238,10 @@ static ssize_t memmap_attr_show(struct kobject *kobj,
*/
static int __init memmap_init(void)
{
- int i = 0;
struct firmware_map_entry *entry;
- struct kset *memmap_kset;
-
- memmap_kset = kset_create_and_add("memmap", NULL, firmware_kobj);
- if (WARN_ON(!memmap_kset))
- return -ENOMEM;

list_for_each_entry(entry, &map_entries, list) {
- entry->kobj.kset = memmap_kset;
- if (kobject_add(&entry->kobj, NULL, "%d", i++))
- kobject_put(&entry->kobj);
+ add_sysfs_fw_map_entry(entry);
}

return 0;
diff --git a/include/linux/firmware-map.h b/include/linux/firmware-map.h
index 875451f..c6dcc1d 100644
--- a/include/linux/firmware-map.h
+++ b/include/linux/firmware-map.h
@@ -24,17 +24,17 @@
*/
#ifdef CONFIG_FIRMWARE_MEMMAP

-int firmware_map_add(u64 start, u64 end, const char *type);
int firmware_map_add_early(u64 start, u64 end, const char *type);
+int firmware_map_add_hotplug(u64 start, u64 end, const char *type);

#else /* CONFIG_FIRMWARE_MEMMAP */

-static inline int firmware_map_add(u64 start, u64 end, const char *type)
+static inline int firmware_map_add_early(u64 start, u64 end, const char *type)
{
return 0;
}

-static inline int firmware_map_add_early(u64 start, u64 end, const char *type)
+static inline int firmware_map_add_hotplug(u64 start, u64 end, const char *type)
{
return 0;
}
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 030ce8a..78e34e6 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -28,6 +28,7 @@
#include <linux/pfn.h>
#include <linux/suspend.h>
#include <linux/mm_inline.h>
+#include <linux/firmware-map.h>

#include <asm/tlbflush.h>

@@ -523,6 +524,9 @@ int __ref add_memory(int nid, u64 start, u64 size)
BUG_ON(ret);
}

+ /* create new memmap entry */
+ firmware_map_add_hotplug(start, start + size, "System RAM");
+
goto out;

error:

Thanks & Regards,
Shaohui



Attachment: memory-hotplug-create-sys-firmware-memmap-entry-for-new-memory-v4.patch
Description: memory-hotplug-create-sys-firmware-memmap-entry-for-new-memory-v4.patch