[PATCH 05/12] ACPI: processor: add internal processor_physically_present()

Alex Chiang
2010-01-25T21:41:03Z

Detect if a processor is physically present before evaluating _PDC.

We want this because some BIOS will provide a _PDC even for processors
that are not present. These bogus _PDC methods then attempt to load
non-existent tables, which causes problems.

Avoid those bogus landmines.

Signed-off-by: Alex Chiang <achiang@hp.com>
---

drivers/acpi/processor_core.c | 42 +++++++++++++++++++++++++++++++++++++++++
1 files changed, 42 insertions(+), 0 deletions(-)

diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index ca12d70..e8b1246 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -194,6 +194,45 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
EXPORT_SYMBOL_GPL(acpi_get_cpuid);
#endif

+static bool processor_physically_present(acpi_handle handle)
+{
+ int cpuid, type;
+ u32 acpi_id;
+ acpi_status status;
+ acpi_object_type acpi_type;
+ unsigned long long tmp;
+ union acpi_object object = { 0 };
+ struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
+
+ status = acpi_get_type(handle, &acpi_type);
+ if (ACPI_FAILURE(status))
+ return false;
+
+ switch (acpi_type) {
+ case ACPI_TYPE_PROCESSOR:
+ status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
+ if (ACPI_FAILURE(status))
+ return false;
+ acpi_id = object.processor.proc_id;
+ break;
+ case ACPI_TYPE_DEVICE:
+ status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);
+ if (ACPI_FAILURE(status))
+ return false;
+ acpi_id = tmp;
+ break;
+ default:
+ return false;
+ }
+
+ type = (acpi_type == ACPI_TYPE_DEVICE) ? 1 : 0;
+ cpuid = acpi_get_cpuid(handle, type, acpi_id);
+
+ if (cpuid == -1)
+ return false;
+
+ return true;
+}

static void acpi_set_pdc_bits(u32 *buf)
{
@@ -335,6 +374,9 @@ static struct dmi_system_id __cpuinitdata early_pdc_optin_table[] = {
static acpi_status
early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
{
+ if (processor_physically_present(handle) == false)
+ return AE_OK;
+
acpi_processor_set_pdc(handle);
return AE_OK;
}