ACPI: processor: add internal processor_physically_present()

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.

Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 9ae5cc21f258..f0c68c1b86dd 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;
 }