Commit d640113f authored by Lin Ming's avatar Lin Ming Committed by Len Brown

ACPI: processor: fix acpi_get_cpuid for UP processor

For UP processor, it is likely that no _MAT method or MADT table defined.
So currently acpi_get_cpuid(...) always return -1 for UP processor.
This is wrong. It should return valid value for CPU0.

In the other hand, BIOS may define multiple CPU handles even for UP
processor, for example

        Scope (_PR)
        {
            Processor (CPU0, 0x00, 0x00000410, 0x06) {}
            Processor (CPU1, 0x01, 0x00000410, 0x06) {}
            Processor (CPU2, 0x02, 0x00000410, 0x06) {}
            Processor (CPU3, 0x03, 0x00000410, 0x06) {}
        }

We should only return valid value for CPU0's acpi handle.
And return invalid value for others.

http://marc.info/?t=132329819900003&r=1&w=2

Cc: stable@vger.kernel.org
Reported-and-tested-by: wallak@free.fr
Signed-off-by: default avatarLin Ming <ming.m.lin@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 805a6af8
......@@ -173,8 +173,30 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
apic_id = map_mat_entry(handle, type, acpi_id);
if (apic_id == -1)
apic_id = map_madt_entry(type, acpi_id);
if (apic_id == -1)
return apic_id;
if (apic_id == -1) {
/*
* On UP processor, there is no _MAT or MADT table.
* So above apic_id is always set to -1.
*
* BIOS may define multiple CPU handles even for UP processor.
* For example,
*
* Scope (_PR)
* {
* Processor (CPU0, 0x00, 0x00000410, 0x06) {}
* Processor (CPU1, 0x01, 0x00000410, 0x06) {}
* Processor (CPU2, 0x02, 0x00000410, 0x06) {}
* Processor (CPU3, 0x03, 0x00000410, 0x06) {}
* }
*
* Ignores apic_id and always return 0 for CPU0's handle.
* Return -1 for other CPU's handle.
*/
if (acpi_id == 0)
return acpi_id;
else
return apic_id;
}
#ifdef CONFIG_SMP
for_each_possible_cpu(i) {
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment