1 files changed, 108 insertions, 0 deletions
diff --git a/drivers/acpi/processor_pdc.c b/drivers/acpi/processor_pdc.c
new file mode 100644
index 00000000000..b416c32dda0
--- /dev/null
+++ b/drivers/acpi/processor_pdc.c
@@ -0,0 +1,108 @@
+#include <linux/dmi.h>
+
+#include <acpi/acpi_drivers.h>
+#include <acpi/processor.h>
+
+#include "internal.h"
+
+#define PREFIX			"ACPI: "
+#define _COMPONENT		ACPI_PROCESSOR_COMPONENT
+ACPI_MODULE_NAME("processor_pdc");
+
+static int set_no_mwait(const struct dmi_system_id *id)
+{
+	printk(KERN_NOTICE PREFIX "%s detected - "
+		"disabling mwait for CPU C-states\n", id->ident);
+	idle_nomwait = 1;
+	return 0;
+}
+
+static struct dmi_system_id __cpuinitdata processor_idle_dmi_table[] = {
+	{
+	set_no_mwait, "IFL91 board", {
+	DMI_MATCH(DMI_BIOS_VENDOR, "COMPAL"),
+	DMI_MATCH(DMI_SYS_VENDOR, "ZEPTO"),
+	DMI_MATCH(DMI_PRODUCT_VERSION, "3215W"),
+	DMI_MATCH(DMI_BOARD_NAME, "IFL91") }, NULL},
+	{
+	set_no_mwait, "Extensa 5220", {
+	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
+	DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+	DMI_MATCH(DMI_PRODUCT_VERSION, "0100"),
+	DMI_MATCH(DMI_BOARD_NAME, "Columbia") }, NULL},
+	{},
+};
+
+/*
+ * _PDC is required for a BIOS-OS handshake for most of the newer
+ * ACPI processor features.
+ */
+static int acpi_processor_eval_pdc(struct acpi_processor *pr)
+{
+	struct acpi_object_list *pdc_in = pr->pdc;
+	acpi_status status = AE_OK;
+
+	if (!pdc_in)
+		return status;
+	if (idle_nomwait) {
+		/*
+		 * If mwait is disabled for CPU C-states, the C2C3_FFH access
+		 * mode will be disabled in the parameter of _PDC object.
+		 * Of course C1_FFH access mode will also be disabled.
+		 */
+		union acpi_object *obj;
+		u32 *buffer = NULL;
+
+		obj = pdc_in->pointer;
+		buffer = (u32 *)(obj->buffer.pointer);
+		buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
+
+	}
+	status = acpi_evaluate_object(pr->handle, "_PDC", pdc_in, NULL);
+
+	if (ACPI_FAILURE(status))
+		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+		    "Could not evaluate _PDC, using legacy perf. control.\n"));
+
+	return status;
+}
+
+void acpi_processor_set_pdc(struct acpi_processor *pr)
+{
+	arch_acpi_processor_init_pdc(pr);
+	acpi_processor_eval_pdc(pr);
+	arch_acpi_processor_cleanup_pdc(pr);
+}
+EXPORT_SYMBOL_GPL(acpi_processor_set_pdc);
+
+static acpi_status
+early_init_pdc(acpi_handle handle, u32 lvl, void *context, void **rv)
+{
+	struct acpi_processor pr;
+
+	pr.handle = handle;
+
+	/* x86 implementation looks at pr.id to determine some
+	 * CPU capabilites. We can just hard code to 0 since we're
+	 * assuming the CPUs in the system are homogenous and all
+	 * have the same capabilities.
+	 */
+	pr.id = 0;
+
+	acpi_processor_set_pdc(&pr);
+
+	return AE_OK;
+}
+
+void acpi_early_processor_set_pdc(void)
+{
+	/*
+	 * Check whether the system is DMI table. If yes, OSPM
+	 * should not use mwait for CPU-states.
+	 */
+	dmi_check_system(processor_idle_dmi_table);
+
+	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
+			    ACPI_UINT32_MAX,
+			    early_init_pdc, NULL, NULL, NULL);
+}