I wrote a patch to avoid redundant memory hot-add call at boot time.  This
was cause of strange fail message of memory hotplug like "ACPI: add_memory
failed".  Memory is recognized by early boot code with EFI/E820.

But, if DSDT describes memory devices for them, then hot-add code is called
for already recognized memory, and it shows fail messages with -EEXIST.
So, sys admin will misunderstand this message as something wrong by it.

This patch avoids them by preventing redundant hot-add call until
completion of driver initialization.

[akpm@osdl.org: cleanups]
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

I suppose this message seems quite useless except debugging.  It just shows
"Hotplug Mem Device".  System admin can't know anything by this message.
So, I would like to change it to KERN_DEBUG.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

In cases where the acpi memory-add event does not containe the pxm (node)
infomation allow the driver to look up node info based on the address.  The
acpi_get_node call returns -1 if it can't decode the pxm info, this causes
add_memory to panic.  acpi_get_node would have to decode the resource from the
handle (a lenghty proposition).  This seems to be the cleanist point to
interject the hook.

[kamezawa.hiroyu@jp.fujitsu.com: build fixes]
[y-goto@jp.fujitsu.com: build fixes]
Signed-off-by: Keith Mannthey <kmannth@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

This is to remove noisy useless message at boot.  The message is a ton of
"ACPI Exception (acpi_memory-0492): AE_ERROR, handle is no memory device"

In my emulation, number of memory devices are not so many (only 6), but,
this messages are displayed 114 times.

It is showed by acpi_memory_register_notify_handler() which is called by
acpi_walk_namespace().

acpi_walk_namespace() parses all of ACPI's namespace and execute
acpi_memory_register_notify_handler().  So, it is called for all of the
device which is defined in namespace.  If the parsing device is not memory,
acpi_memhotplug ignores it due to "no match" and will parse next device.
This is normal route, not an exception.

Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>

both of acpi_memory_enable_device() and acpi_memory_add_device() may evaluate
_CRS method.

We should avoid evaluate device's resource twice if we could get it
successfully in past.

Signed-off-by: KAMEZWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Keith Mannthey <kmannth@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

add_memory() does all necessary check to avoid collision.  then, acpi layer
doesn't have to check region by itself.

(*) pfn_valid() just returns page struct is valid or not. It returns 0
    if a section has been already added even is ioresource is not added.
    ioresource collision check in mm/memory_hotplug.c can do more precise
    collistion check.
    added enabled bit check just for sanity check..

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Keith Mannthey <kmannth@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>

Signed-off-by: Len Brown <len.brown@intel.com>