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>

arch/ia64/Kconfig

@@ -10,6 +10,7 @@ config IA64
 	select ARCH_MIGHT_HAVE_PC_SERIO
 	select PCI if (!IA64_HP_SIM)
 	select ACPI if (!IA64_HP_SIM)
+	select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
 	select PM if (!IA64_HP_SIM)
 	select HAVE_UNSTABLE_SCHED_CLOCK
 	select HAVE_IDE

arch/x86/Kconfig

@@ -21,6 +21,7 @@ config X86_64
 ### Arch settings
 config X86
 	def_bool y
+	select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
 	select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO

drivers/acpi/Kconfig

@@ -45,6 +45,9 @@ if ACPI
 config ACPI_LEGACY_TABLES_LOOKUP
 	bool
 
+config ARCH_MIGHT_HAVE_ACPI_PDC
+	bool
+
 config ACPI_SLEEP
 	bool
 	depends on SUSPEND || HIBERNATION

drivers/acpi/Makefile

@@ -36,6 +36,7 @@ acpi-y				+= scan.o
 acpi-y				+= resource.o
 acpi-y				+= acpi_processor.o
 acpi-y				+= processor_core.o
+acpi-$(CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC) += processor_pdc.o
 acpi-y				+= ec.o
 acpi-$(CONFIG_ACPI_DOCK)	+= dock.o
 acpi-y				+= pci_root.o pci_link.o pci_irq.o

drivers/acpi/internal.h

@@ -108,7 +108,12 @@ int acpi_power_transition(struct acpi_device *device, int state);
 int acpi_device_update_power(struct acpi_device *device, int *state_p);
 
 int acpi_wakeup_device_init(void);
+
+#ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC
 void acpi_early_processor_set_pdc(void);
+#else
+static inline void acpi_early_processor_set_pdc(void) {}
+#endif
 
 /* --------------------------------------------------------------------------
                                   Embedded Controller

drivers/acpi/processor_core.c

@@ -4,17 +4,11 @@
  *
  *	Alex Chiang <achiang@hp.com>
  *	- Unified x86/ia64 implementations
- *	Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
- *	- Added _PDC for platforms with Intel CPUs
  */
 #include <linux/export.h>
-#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_core");
 
@@ -208,195 +202,3 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 	return acpi_map_cpuid(apic_id, acpi_id);
 }
 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
-
-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) {
-		printk(KERN_ERR "Memory allocation error\n");
-		return NULL;
-	}
-
-	obj = kmalloc(sizeof(union acpi_object), GFP_KERNEL);
-	if (!obj) {
-		printk(KERN_ERR "Memory allocation error\n");
-		kfree(obj_list);
-		return NULL;
-	}
-
-	buf = kmalloc(12, GFP_KERNEL);
-	if (!buf) {
-		printk(KERN_ERR "Memory allocation error\n");
-		kfree(obj);
-		kfree(obj_list);
-		return NULL;
-	}
-
-	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;
-}
-
-/*
- * _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;
-}
-
-#if defined(CONFIG_X86) || defined(CONFIG_IA64)
-static int __init set_no_mwait(const struct dmi_system_id *id)
-{
-	pr_notice(PREFIX "%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);
-}
-#else
-static inline void processor_dmi_check(void) {}
-#endif
-
-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);
-}