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| author | Lin Ming <ming.m.lin@intel.com> | 2011-12-13 09:36:03 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2012-01-25 17:24:59 -0800 |
| commit | 68e6689b9b35c8a2fa73e00947238d2c5cb0387c (patch) | |
| tree | 1a25d95e681074d2e507326a0e06a3e9dfd67ab0 /drivers | |
| parent | 55bd02eb4c6e40c2870aee19c5e36d1a85713be8 (diff) | |
| download | lwn-68e6689b9b35c8a2fa73e00947238d2c5cb0387c.tar.gz lwn-68e6689b9b35c8a2fa73e00947238d2c5cb0387c.zip | |
ACPI: processor: fix acpi_get_cpuid for UP processor
commit d640113fe80e45ebd4a5b420b220d3f6bf37f682 upstream.
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
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
| -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 02d2a4c9084d..0c0669fb1cc4 100644 --- a/drivers/acpi/processor_core.c +++ b/drivers/acpi/processor_core.c @@ -172,8 +172,30 @@ 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) { |