[ACPI] enable C2 and C3 idle power states on SMP

[linux-2.6] / drivers / acpi / processor_core.c

diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index f4778747e889bd6dae32f77287b3580a042081b1..e421842888b919575a751231ee380f1db772ada2 100644 (file)
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -255,6 +255,43 @@ acpi_processor_errata (
 }
 
 
+/* --------------------------------------------------------------------------
+                              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)
    -------------------------------------------------------------------------- */