[SeaBIOS] Alt SeaBIOS SSDT cpu hotplug

[Liu, Jinsong]

Avi Kivity wrote:
> On 07/07/2010 07:57 AM, Kevin O'Connor wrote:
>> Hi,
>> 
>> I've been playing with the cpu hotplug SSDT changes.  Attached is a
>> proposal for an alternative method of adding ACPI support.
>> 
>> The idea is to continue to build a dynamic SSDT based on CountCPUs
>> and MaxCountCPUs.  The dynamic SSDT entries just call methods in the
>> main DSDT. 
>> 
>> This is completely untested.  Hopefully the patch will demonstrate
>> the idea though. 
>> 
>> The objective is to dynamically build an SSDT that looks something
>> like: 
>> 
>> =========================================================== {
>>      Scope (_SB) {
>>          External(CPMA, MethodObj)
>>          External(CPST, MethodObj)
>>          External(CPEJ, MethodObj)
>> #define DefCPU(nr)                                      \
>>          Processor (CP##nr, 0x##nr, 0x0000b010, 0x06) {  \
>>              Name (_HID, "ACPI0007")                     \
>>              Name (ID, 0x##nr)                           \
>>              Method(_MAT, 0) {                           \
>>                  Return(CPMA(ID))                        \
>>              }                                           \
>>              Method (_STA) {                             \
>>                  Return(CPST(ID))                        \
>>              }                                           \
>>              Method (_EJ0, 1, NotSerialized) {           \
>>                  Return(CPEJ(ID, Arg0))                  \
>>              }                                           \          }
>>          DefCPU(00)
>>          DefCPU(01)
>>          DefCPU(02)
>>          DefCPU(03)
>>          DefCPU(AA)
>>          Name(CPUS, Package() {
>>              CP00, CP01, CP02, CP03, CPAA,
>>          })
>>          Name(CPON, Package() {
>>              One, One, One, Zero, Zero
>>          })
>>      }
>> }
>> ===========================================================
>> 
>> with a dynamic number of cpus.
>> 
>> The "CPUS" package stores references to the Processor objects, and
>> the "CPON" package stores the state of which cpus are active.  With
>> this info, hopefully there is no need to update the MADT tables.
>> 
>> Thoughts?
>> 
> 
> Very nice.  I thought about doing this but abandoned it as
> unmaintainable.  Using external functions and the ID variable,
> however, reduces the mess to tolerable proportions, and gains us a
> lot of flexibility.  We can now have any combinations of sockets and
> installed cpus.

Agree, only 1 concern
will it bring debugable/ scalable issue by hardcode aml code?

Thanks,
Jinsong