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

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

[Zheng, Shaohui]

[-- Attachment #1: Type: text/plain, Size: 5843 bytes --]

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@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
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 #2: memory-hotplug-create-sys-firmware-memmap-entry-for-new-memory-v4.patch --]
[-- Type: application/octet-stream, Size: 5538 bytes --]

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@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
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:

Re: [PATCH-RESEND v4] memory-hotplug: create /sys/firmware/memmap entry for new memory

[Andrew Morton]

On Mon, 11 Jan 2010 10:00:11 +0800
"Zheng, Shaohui" <shaohui.zheng@intel.com> wrote:

> 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.
> 

Please describe the format of the proposed sysfs file.  Example output
would be suitable.

> @@ -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;
> +	}

This is a bit racy if two threads execute it at the same time.  I guess
it doesn't matter.


> +	entry->kobj.kset = mmap_kset;
> +	if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++))
> +		kobject_put(&entry->kobj);

hm.  Is this refcounting correct?

> +
> +	return 0;
> +}

One caller of add_sysfs_fw_map_entry() is __meminit and the other is
__init.  So this function can be __meminit?

> +/**
> + * 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

s/simiar/similar/
s/with/to/
s/the/The/
s/function firmware_map_add_early/firmware_map_add_early()/

> + * 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);
>  	}

The braces are now unneeded.  checkpatch used to warn about this I
think.  Either someone broke checkpatch or it doesn't understand
list_for_each_entry().

>
> ...
>

RE: [PATCH-RESEND v4] memory-hotplug: create /sys/firmware/memmap entry for new memory

[Zheng, Shaohui]

On Mon, 11 Jan 2010 10:00:11 +0800
"Zheng, Shaohui" <shaohui.zheng@intel.com> wrote:

> 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.
> 

Please describe the format of the proposed sysfs file.  Example output
would be suitable.

> @@ -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;
> +	}

This is a bit racy if two threads execute it at the same time.  I guess
it doesn't matter.
[Zheng, Shaohui] function add_sysfs_fw_map_entry will be called when OS boots up and we hot-add memory, it never has chance to be execute in two threads, it should be okay.


> +	entry->kobj.kset = mmap_kset;
> +	if (kobject_add(&entry->kobj, NULL, "%d", map_entries_nr++))
> +		kobject_put(&entry->kobj);

hm.  Is this refcounting correct?
[Zheng, Shaohui] all objects of firmware_map_entry shares the same kset, I use a static pointer to store it. When create next entry, we can get the reference easier. I already test it, it works fine.

> +
> +	return 0;
> +}

One caller of add_sysfs_fw_map_entry() is __meminit and the other is
__init.  So this function can be __meminit?
[Zheng, Shaohui] function add_sysfs_fw_map_entry() should be still here after booting up, it will be called when we hot-add new memory, so it can not be _init. __meminit should be the correct since this function is related memory hot-plug.

> +/**
> + * 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

s/simiar/similar/
s/with/to/
s/the/The/
s/function firmware_map_add_early/firmware_map_add_early()/
[Zheng, Shaohui] sorry for my carelessness.
	
> + * 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);
>  	}

The braces are now unneeded.  checkpatch used to warn about this I
think.  Either someone broke checkpatch or it doesn't understand
list_for_each_entry().
[Zheng, Shaohui] I will remove the unneeded braces.

>
> ...
>

[PATCH-RESEND v5] memory-hotplug: create /sys/firmware/memmap entry for new memory

[Zheng, Shaohui]

[-- Attachment #1: Type: text/plain, Size: 6053 bytes --]

memory-hotplug: create /sys/firmware/memmap entry for new memory

A memmap is a directory in sysfys which includes 3 text files: start, end and
 type. For example:
start: 	0x100000
end:	0x7e7b1cff
type:	System RAM

Each memory entry has a memmap in sysfs, 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.

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

Add a new function add_sysfs_fw_map_entry() to create memmap entry, it will be
called when initialize memmap and hot-add memory.

Signed-off-by: Shaohui Zheng <shaohui.zheng@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c
index 56f9234..2d1812f 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
+ * similar to 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;
 }
 
 /*
@@ -214,19 +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);
-	}
+	list_for_each_entry(entry, &map_entries, list)
+		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 #2: memory-hotplug-create-sys-firmware-memmap-entry-for-new-memory-v5.patch --]
[-- Type: application/octet-stream, Size: 5837 bytes --]

memory-hotplug: create /sys/firmware/memmap entry for new memory

A memmap is a directory in sysfys which includes 3 text files: start, end and
 type. For example:
start: 	0x100000
end:	0x7e7b1cff
type:	System RAM

Each memory entry has a memmap in sysfs, 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.

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

Add a new function add_sysfs_fw_map_entry() to create memmap entry, it will be
called when initialize memmap and hot-add memory.

Signed-off-by: Shaohui Zheng <shaohui.zheng@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c
index 56f9234..2d1812f 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
+ * similar to 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;
 }
 
 /*
@@ -214,19 +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);
-	}
+	list_for_each_entry(entry, &map_entries, list)
+		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:

Re: [PATCH-RESEND v4] memory-hotplug: create /sys/firmware/memmap entry for new memory

[Andrew Morton]

On Mon, 11 Jan 2010 10:00:11 +0800
"Zheng, Shaohui" <shaohui.zheng@intel.com> wrote:

> 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.

The patch causes an early exception in kmem_cache_alloc_notrace() -
probably due to a null cache pointer.

config: http://master.kernel.org/~akpm/config-akpm2.txt

RE: [PATCH-RESEND v4] memory-hotplug: create /sys/firmware/memmap entry for new memory

[Zheng, Shaohui]

It is very strange issue since I already test it before sending it out, I will retry it in local.

Thanks & Regards,
Shaohui


-----Original Message-----
From: Andrew Morton [mailto:akpm@linux-foundation.org] 
Sent: Saturday, January 16, 2010 6:38 AM
To: Zheng, Shaohui
Cc: linux-mm@kvack.org; linux-kernel@vger.kernel.org; ak@linux.intel.com; y-goto@jp.fujitsu.com; Dave Hansen; Wu, Fengguang; x86@kernel.org
Subject: Re: [PATCH-RESEND v4] memory-hotplug: create /sys/firmware/memmap entry for new memory

On Mon, 11 Jan 2010 10:00:11 +0800
"Zheng, Shaohui" <shaohui.zheng@intel.com> wrote:

> 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.

The patch causes an early exception in kmem_cache_alloc_notrace() -
probably due to a null cache pointer.

config: http://master.kernel.org/~akpm/config-akpm2.txt

RE: [PATCH-RESEND v4] memory-hotplug: create /sys/firmware/memmap entry for new memory

[Zheng, Shaohui]

I did some investigation for my patch, I see that there is an error when I make v4 patch from v3, I change the function firmware_map_add_early() by carelessness, 
The code 
	entry = alloc_bootmem(sizeof(struct firmware_map_entry));
was changed to 
	entry = kmalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);


The modification from v3 to v4 is minor, so I did not do full testing for v4 patch, I apologize for my fault.	

The patch works after I correct the this code. I will resend it. 

Thanks & Regards,
Shaohui


-----Original Message-----
From: Andrew Morton [mailto:akpm@linux-foundation.org] 
Sent: Saturday, January 16, 2010 6:38 AM
To: Zheng, Shaohui
Cc: linux-mm@kvack.org; linux-kernel@vger.kernel.org; ak@linux.intel.com; y-goto@jp.fujitsu.com; Dave Hansen; Wu, Fengguang; x86@kernel.org
Subject: Re: [PATCH-RESEND v4] memory-hotplug: create /sys/firmware/memmap entry for new memory

On Mon, 11 Jan 2010 10:00:11 +0800
"Zheng, Shaohui" <shaohui.zheng@intel.com> wrote:

> 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.

The patch causes an early exception in kmem_cache_alloc_notrace() -
probably due to a null cache pointer.

config: http://master.kernel.org/~akpm/config-akpm2.txt

RE: [PATCH-RESEND v4] memory-hotplug: create /sys/firmware/memmap entry for new memory

[Zheng, Shaohui]

[-- Attachment #1: Type: text/plain, Size: 5648 bytes --]

Resend the v6 memmap patch after resolve the early exception. This patch was tested 
on DELL Studio XPS(Core i7), I will always be careful to valid each patch before 
sending it out.


memory-hotplug: create /sys/firmware/memmap entry for new memory

A memmap is a directory in sysfs which includes 3 text files: start, end and
 type. For example:
start: 	0x100000
end:	0x7e7b1cff
type:	System RAM

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

Each memory entry has a memmap in sysfs, 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 will be
called when initialize memmap and hot-add memory.

Signed-off-by: Shaohui Zheng <shaohui.zheng@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c
index 56f9234..821db6f 100644
--- a/drivers/firmware/memmap.c
+++ b/drivers/firmware/memmap.c
@@ -123,28 +123,52 @@ 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_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.
  *
- * This function uses kmalloc() for memory
- * allocation. Use firmware_map_add_early() if you want to use the bootmem
- * allocator.
- *
- * That function must be called before late_initcall.
+ * Adds a firmware mapping entry. This function is for memory hotplug, it is
+ * similar to 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 firmware_map_add(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 = kmalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
+	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;
 }
 
 /**
@@ -154,7 +178,7 @@ int firmware_map_add(u64 start, u64 end, const char *type)
  * @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().
+ * for memory allocation.
  *
  * That function must be called before late_initcall.
  *
@@ -214,19 +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);
-	}
+	list_for_each_entry(entry, &map_entries, list)
+		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 #2: memory-hotplug-create-sys-firmware-memmap-entry-for-new-memory-v6.patch --]
[-- Type: application/octet-stream, Size: 5258 bytes --]

memory-hotplug: create /sys/firmware/memmap entry for new memory

A memmap is a directory in sysfs which includes 3 text files: start, end and
 type. For example:
start: 	0x100000
end:	0x7e7b1cff
type:	System RAM

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

Each memory entry has a memmap in sysfs, 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 will be
called when initialize memmap and hot-add memory.

Signed-off-by: Shaohui Zheng <shaohui.zheng@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c
index 56f9234..821db6f 100644
--- a/drivers/firmware/memmap.c
+++ b/drivers/firmware/memmap.c
@@ -123,28 +123,52 @@ 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_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.
  *
- * This function uses kmalloc() for memory
- * allocation. Use firmware_map_add_early() if you want to use the bootmem
- * allocator.
- *
- * That function must be called before late_initcall.
+ * Adds a firmware mapping entry. This function is for memory hotplug, it is
+ * similar to 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 firmware_map_add(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 = kmalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
+	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;
 }
 
 /**
@@ -154,7 +178,7 @@ int firmware_map_add(u64 start, u64 end, const char *type)
  * @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().
+ * for memory allocation.
  *
  * That function must be called before late_initcall.
  *
@@ -214,19 +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);
-	}
+	list_for_each_entry(entry, &map_entries, list)
+		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: