diff options
| author | Lin Ming <ming.m.lin@intel.com> | 2011-12-13 02:36:03 +0100 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2012-01-17 11:25:08 +0100 |
| commit | d640113fe80e45ebd4a5b420b220d3f6bf37f682 (patch) | |
| tree | 5786b877c62ce19e0a282c51d14d69373c2814e6 /drivers/acpi | |
| parent | Linux 3.2 (diff) | |
| download | linux-d640113fe80e45ebd4a5b420b220d3f6bf37f682.tar.xz linux-d640113fe80e45ebd4a5b420b220d3f6bf37f682.zip | |
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>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/processor_core.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c index 3a0428e8435c..c850de4c9a14 100644 --- a/drivers/acpi/processor_core.c +++ b/drivers/acpi/processor_core.c @@ -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) { |