ACPI / processor: Introduce ARCH_MIGHT_HAVE_ACPI_PDC

The use of _PDC is deprecated in ACPI 3.0 in favor of _OSC,
as ARM platform is supported only in ACPI 5.0 or higher version,
_PDC will not be used in ARM platform, so make Make _PDC only for
platforms with Intel CPUs.

Introduce ARCH_MIGHT_HAVE_ACPI_PDC and move _PDC related code in
ACPI processor driver into a single file processor_pdc.c, make x86
and ia64 select it when ACPI is enabled.

This patch also use pr_* to replace printk to fix the checkpatch
warning and factor acpi_processor_alloc_pdc() a little bit to
avoid duplicate pr_err() code.

Suggested-by: Robert Richter <rric@kernel.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 206 insertions, 0 deletions

diff --git a/drivers/acpi/processor_pdc.c b/drivers/acpi/processor_pdc.c
new file mode 100644
index 0000000..e5dd808
--- /dev/null
+++ b/drivers/acpi/processor_pdc.c
@@ -0,0 +1,206 @@
+/*
+ * Copyright (C) 2005 Intel Corporation
+ * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
+ *
+ *      Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
+ *      - Added _PDC for platforms with Intel CPUs
+ */
+
+#define pr_fmt(fmt) "ACPI: " fmt
+
+#include <linux/dmi.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <acpi/processor.h>
+
+#include "internal.h"
+
+#define _COMPONENT              ACPI_PROCESSOR_COMPONENT
+ACPI_MODULE_NAME("processor_pdc");
+
+static bool __init 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)
+{
+	buf[0] = ACPI_PDC_REVISION_ID;
+	buf[1] = 1;
+
+	/* Enable coordination with firmware's _TSD info */
+	buf[2] = ACPI_PDC_SMP_T_SWCOORD;
+
+	/* Twiddle arch-specific bits needed for _PDC */
+	arch_acpi_set_pdc_bits(buf);
+}
+
+static struct acpi_object_list *acpi_processor_alloc_pdc(void)
+{
+	struct acpi_object_list *obj_list;
+	union acpi_object *obj;
+	u32 *buf;
+
+	/* allocate and initialize pdc. It will be used later. */
+	obj_list = kmalloc(sizeof(struct acpi_object_list), GFP_KERNEL);
+	if (!obj_list)
+		goto out;
+
+	obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
+	if (!obj) {
+		kfree(obj_list);
+		goto out;
+	}
+
+	buf = kmalloc(12, GFP_KERNEL);
+	if (!buf) {
+		kfree(obj);
+		kfree(obj_list);
+		goto out;
+	}
+
+	acpi_set_pdc_bits(buf);
+
+	obj->type = ACPI_TYPE_BUFFER;
+	obj->buffer.length = 12;
+	obj->buffer.pointer = (u8 *) buf;
+	obj_list->count = 1;
+	obj_list->pointer = obj;
+
+	return obj_list;
+out:
+	pr_err("Memory allocation error\n");
+	return NULL;
+}
+
+/*
+ * _PDC is required for a BIOS-OS handshake for most of the newer
+ * ACPI processor features.
+ */
+static acpi_status
+acpi_processor_eval_pdc(acpi_handle handle, struct acpi_object_list *pdc_in)
+{
+	acpi_status status = AE_OK;
+
+	if (boot_option_idle_override == 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(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(acpi_handle handle)
+{
+	struct acpi_object_list *obj_list;
+
+	if (arch_has_acpi_pdc() == false)
+		return;
+
+	obj_list = acpi_processor_alloc_pdc();
+	if (!obj_list)
+		return;
+
+	acpi_processor_eval_pdc(handle, obj_list);
+
+	kfree(obj_list->pointer->buffer.pointer);
+	kfree(obj_list->pointer);
+	kfree(obj_list);
+}
+
+static acpi_status __init
+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;
+}
+
+static int __init set_no_mwait(const struct dmi_system_id *id)
+{
+	pr_notice("%s detected - disabling mwait for CPU C-states\n",
+		  id->ident);
+	boot_option_idle_override = IDLE_NOMWAIT;
+	return 0;
+}
+
+static struct dmi_system_id processor_idle_dmi_table[] __initdata = {
+	{
+	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},
+	{},
+};
+
+static void __init processor_dmi_check(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);
+}
+
+void __init acpi_early_processor_set_pdc(void)
+{
+	processor_dmi_check();
+
+	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
+			    ACPI_UINT32_MAX,
+			    early_init_pdc, NULL, NULL, NULL);
+	acpi_get_devices(ACPI_PROCESSOR_DEVICE_HID, early_init_pdc, NULL, NULL);
+}