Re: [Qemu-devel] [PATCH v2 1/4] acpi: Add ACPI_CPU_HOTPLUG_ID_LIMIT macro

[Laszlo Ersek]

On 03/12/14 22:17, Laszlo Ersek wrote:
> On 03/12/14 19:28, Eduardo Habkost wrote:
>> The new macro will be helpful to allow us to detect too large SMP limits
>> before it is too late.
>>
>> Signed-off-by: Eduardo Habkost <address@hidden>
>> ---
>>  include/hw/acpi/cpu_hotplug_defs.h | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>>
>> diff --git a/include/hw/acpi/cpu_hotplug_defs.h 
>> b/include/hw/acpi/cpu_hotplug_defs.h
>> index 2725b50..9f33663 100644
>> --- a/include/hw/acpi/cpu_hotplug_defs.h
>> +++ b/include/hw/acpi/cpu_hotplug_defs.h
>> @@ -17,7 +17,15 @@
>>   * between C and ASL code.
>>   */
>>  #define ACPI_CPU_HOTPLUG_STATUS 4
>> +
>> +/* Limit for CPU arch IDs for CPU hotplug. All hotpluggable CPUs should
>> + * have CPUClass.get_arch_id() < ACPI_CPU_HOTPLUG_ID_LIMIT.
>> + */
>> +#define ACPI_CPU_HOTPLUG_ID_LIMIT 256
>> +
>> +/* 256 CPU IDs, 8 bits per entry: */
>>  #define ACPI_GPE_PROC_LEN 32
>> +
>>  #define ICH9_CPU_HOTPLUG_IO_BASE 0x0CD8
>>  #define PIIX4_CPU_HOTPLUG_IO_BASE 0xaf00
>>  
>>
> 
> You could actually derive ACPI_GPE_PROC_LEN from
> ACPI_CPU_HOTPLUG_ID_LIMIT, by dividing with CHAR_BIT.


(Or vice versa -- get the limit from PROC_LEN by multiplication.)
L.