[ACPI] enable C2 and C3 idle power states on SMP
http://bugzilla.kernel.org/show_bug.cgi?id=4401
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index f477874..e421842 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -256,6 +256,43 @@
/* --------------------------------------------------------------------------
+ Common ACPI processor fucntions
+ -------------------------------------------------------------------------- */
+
+/*
+ * _PDC is required for a BIOS-OS handshake for most of the newer
+ * ACPI processor features.
+ */
+
+int acpi_processor_set_pdc(struct acpi_processor *pr,
+ struct acpi_object_list *pdc_in)
+{
+ acpi_status status = AE_OK;
+ u32 arg0_buf[3];
+ union acpi_object arg0 = {ACPI_TYPE_BUFFER};
+ struct acpi_object_list no_object = {1, &arg0};
+ struct acpi_object_list *pdc;
+
+ ACPI_FUNCTION_TRACE("acpi_processor_set_pdc");
+
+ arg0.buffer.length = 12;
+ arg0.buffer.pointer = (u8 *) arg0_buf;
+ arg0_buf[0] = ACPI_PDC_REVISION_ID;
+ arg0_buf[1] = 0;
+ arg0_buf[2] = 0;
+
+ pdc = (pdc_in) ? pdc_in : &no_object;
+
+ status = acpi_evaluate_object(pr->handle, "_PDC", pdc, NULL);
+
+ if ((ACPI_FAILURE(status)) && (pdc_in))
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Error evaluating _PDC, using legacy perf. control...\n"));
+
+ return_VALUE(status);
+}
+
+
+/* --------------------------------------------------------------------------
FS Interface (/proc)
-------------------------------------------------------------------------- */