Commit d640113f authored Dec 13, 2011 by Lin Ming Committed by Len Brown Jan 17, 2012

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: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

parent 805a6af8

drivers/acpi/processor_core.c

+24 −2

Original line number	Diff line number	Diff line
		@@ -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)
		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) {