[Hotplug_sig] acpi emulation for memory hotplug

[y-goto at jp.fujitsu.com (Yasunori Goto)]

Hello.

> The test case specified in
> http://lists.osdl.org/pipermail/hotplug_sig/2006-June/000614.html
> 
> shows how to add 1GB of memory to the kernel that has been booted with just 2 GB
> memory.
> 
> 1. Is it possible to specify the *STARTING ADDRESS* of the memory to be added in
> addition to the *SIZE*.

Yes. _CRS method of ACPI'S DSDT can return address and size.
In this example, This is written in "2. Write Memory object"

                Method(_CRS) {
                        Name(RT0,ResourceTemplate() {
                                            :
                                        0x100000000, <- start address
                                        0x13fffffff,
                                        0,
                                        0x40000000,  <- size
                                            :
                }

> This emulates memory hot add in hardware when I
> physically plug-in memory DIMM into a particular DIMM slot.

Yes.

> 2. Is the same feature available to emulate hot remove of memory DIMMS?

ACPI has the _EJ0 method. If it is described for DIMM's for DSDT,
it should be called after completion of memory remove by OS.

Thanks.

-- 
Yasunori Goto