processor_core.c

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		* Evalute the processor object.  Note that it is common on SMP to
		* have the first (boot) processor with a valid PBLK address while
		* all others have a NULL address.
		*/
		status = acpi_evaluate_object(pr->handle, NULL, NULL, &buffer);
		if (ACPI_FAILURE(status)) {
			printk(KERN_ERR PREFIX "Evaluating processor object\n");
			return -ENODEV;
		}

		/*
		* TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
		*      >>> 'acpi_get_processor_id(acpi_id, &id)' in arch/xxx/acpi.c
		*/
		pr->acpi_id = object.processor.proc_id;
	}
	cpu_index = get_cpu_id(pr->handle, pr->acpi_id);

	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
	if (!cpu0_initialized && (cpu_index == -1) &&
	    (num_online_cpus() == 1)) {
		cpu_index = 0;
	}

	cpu0_initialized = 1;

	pr->id = cpu_index;

	/*
	 *  Extra Processor objects may be enumerated on MP systems with
	 *  less than the max # of CPUs. They should be ignored _iff
	 *  they are physically not present.
	 */
	if (pr->id == -1) {
		if (ACPI_FAILURE
		    (acpi_processor_hotadd_init(pr->handle, &pr->id))) {
			return -ENODEV;
		}
	}

	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Processor [%d:%d]\n", pr->id,
			  pr->acpi_id));

	if (!object.processor.pblk_address)
		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No PBLK (NULL address)\n"));
	else if (object.processor.pblk_length != 6)
		printk(KERN_ERR PREFIX "Invalid PBLK length [%d]\n",
			    object.processor.pblk_length);
	else {
		pr->throttling.address = object.processor.pblk_address;
		pr->throttling.duty_offset = acpi_gbl_FADT.duty_offset;
		pr->throttling.duty_width = acpi_gbl_FADT.duty_width;

		pr->pblk = object.processor.pblk_address;

		/*
		 * We don't care about error returns - we just try to mark
		 * these reserved so that nobody else is confused into thinking
		 * that this region might be unused..
		 *
		 * (In particular, allocating the IO range for Cardbus)
		 */
		request_region(pr->throttling.address, 6, "ACPI CPU throttle");
	}

	return 0;
}

static void *processor_device_array[NR_CPUS];

static int __cpuinit acpi_processor_start(struct acpi_device *device)
{
	int result = 0;
	acpi_status status = AE_OK;
	struct acpi_processor *pr;


	pr = acpi_driver_data(device);

	result = acpi_processor_get_info(pr, device->flags.unique_id);
	if (result) {
		/* Processor is physically not present */
		return 0;
	}

	BUG_ON((pr->id >= nr_cpu_ids) || (pr->id < 0));

	/*
	 * Buggy BIOS check
	 * ACPI id of processors can be reported wrongly by the BIOS.
	 * Don't trust it blindly
	 */
	if (processor_device_array[pr->id] != NULL &&
	    processor_device_array[pr->id] != device) {
		printk(KERN_WARNING "BIOS reported wrong ACPI id "
			"for the processor\n");
		return -ENODEV;
	}
	processor_device_array[pr->id] = device;

	processors[pr->id] = pr;

	result = acpi_processor_add_fs(device);
	if (result)
		goto end;

	status = acpi_install_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY,
					     acpi_processor_notify, pr);

	/* _PDC call should be done before doing anything else (if reqd.). */
	arch_acpi_processor_init_pdc(pr);
	acpi_processor_set_pdc(pr);
#ifdef CONFIG_CPU_FREQ
	acpi_processor_ppc_has_changed(pr);
#endif
	acpi_processor_get_throttling_info(pr);
	acpi_processor_get_limit_info(pr);


	acpi_processor_power_init(pr, device);

	if (pr->flags.throttling) {
		printk(KERN_INFO PREFIX "%s [%s] (supports",
		       acpi_device_name(device), acpi_device_bid(device));
		printk(" %d throttling states", pr->throttling.state_count);
		printk(")\n");
	}

      end:

	return result;
}

static void acpi_processor_notify(acpi_handle handle, u32 event, void *data)
{
	struct acpi_processor *pr = data;
	struct acpi_device *device = NULL;
	int saved;

	if (!pr)
		return;

	if (acpi_bus_get_device(pr->handle, &device))
		return;

	switch (event) {
	case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
		saved = pr->performance_platform_limit;
		acpi_processor_ppc_has_changed(pr);
		if (saved == pr->performance_platform_limit)
			break;
		acpi_bus_generate_proc_event(device, event,
					pr->performance_platform_limit);
		acpi_bus_generate_netlink_event(device->pnp.device_class,
						  device->dev.bus_id, event,
						  pr->performance_platform_limit);
		break;
	case ACPI_PROCESSOR_NOTIFY_POWER:
		acpi_processor_cst_has_changed(pr);
		acpi_bus_generate_proc_event(device, event, 0);
		acpi_bus_generate_netlink_event(device->pnp.device_class,
						  device->dev.bus_id, event, 0);
		break;
	case ACPI_PROCESSOR_NOTIFY_THROTTLING:
		acpi_processor_tstate_has_changed(pr);
		acpi_bus_generate_proc_event(device, event, 0);
		acpi_bus_generate_netlink_event(device->pnp.device_class,
						  device->dev.bus_id, event, 0);
	default:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "Unsupported event [0x%x]\n", event));
		break;
	}

	return;
}

static int acpi_cpu_soft_notify(struct notifier_block *nfb,
		unsigned long action, void *hcpu)
{
	unsigned int cpu = (unsigned long)hcpu;
	struct acpi_processor *pr = processors[cpu];

	if (action == CPU_ONLINE && pr) {
		acpi_processor_ppc_has_changed(pr);
		acpi_processor_cst_has_changed(pr);
		acpi_processor_tstate_has_changed(pr);
	}
	return NOTIFY_OK;
}

static struct notifier_block acpi_cpu_notifier =
{
	    .notifier_call = acpi_cpu_soft_notify,
};

static int acpi_processor_add(struct acpi_device *device)
{
	struct acpi_processor *pr = NULL;


	if (!device)
		return -EINVAL;

	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
	if (!pr)
		return -ENOMEM;

	pr->handle = device->handle;
	strcpy(acpi_device_name(device), ACPI_PROCESSOR_DEVICE_NAME);
	strcpy(acpi_device_class(device), ACPI_PROCESSOR_CLASS);
	acpi_driver_data(device) = pr;

	return 0;
}

static int acpi_processor_remove(struct acpi_device *device, int type)
{
	acpi_status status = AE_OK;
	struct acpi_processor *pr = NULL;


	if (!device || !acpi_driver_data(device))
		return -EINVAL;

	pr = acpi_driver_data(device);

	if (pr->id >= nr_cpu_ids) {
		kfree(pr);
		return 0;
	}

	if (type == ACPI_BUS_REMOVAL_EJECT) {
		if (acpi_processor_handle_eject(pr))
			return -EINVAL;
	}

	acpi_processor_power_exit(pr, device);

	status = acpi_remove_notify_handler(pr->handle, ACPI_DEVICE_NOTIFY,
					    acpi_processor_notify);

	acpi_processor_remove_fs(device);

	processors[pr->id] = NULL;

	kfree(pr);

	return 0;
}

#ifdef CONFIG_ACPI_HOTPLUG_CPU
/****************************************************************************
 * 	Acpi processor hotplug support 				       	    *
 ****************************************************************************/

static int is_processor_present(acpi_handle handle);

static int is_processor_present(acpi_handle handle)
{
	acpi_status status;
	unsigned long sta = 0;


	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
	if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_PRESENT)) {
		ACPI_EXCEPTION((AE_INFO, status, "Processor Device is not present"));
		return 0;
	}
	return 1;
}

static
int acpi_processor_device_add(acpi_handle handle, struct acpi_device **device)
{
	acpi_handle phandle;
	struct acpi_device *pdev;
	struct acpi_processor *pr;


	if (acpi_get_parent(handle, &phandle)) {
		return -ENODEV;
	}

	if (acpi_bus_get_device(phandle, &pdev)) {
		return -ENODEV;
	}

	if (acpi_bus_add(device, pdev, handle, ACPI_BUS_TYPE_PROCESSOR)) {
		return -ENODEV;
	}

	acpi_bus_start(*device);

	pr = acpi_driver_data(*device);
	if (!pr)
		return -ENODEV;

	if ((pr->id >= 0) && (pr->id < nr_cpu_ids)) {
		kobject_uevent(&(*device)->dev.kobj, KOBJ_ONLINE);
	}
	return 0;
}

static void
acpi_processor_hotplug_notify(acpi_handle handle, u32 event, void *data)
{
	struct acpi_processor *pr;
	struct acpi_device *device = NULL;
	int result;


	switch (event) {
	case ACPI_NOTIFY_BUS_CHECK:
	case ACPI_NOTIFY_DEVICE_CHECK:
		printk("Processor driver received %s event\n",
		       (event == ACPI_NOTIFY_BUS_CHECK) ?
		       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK");

		if (!is_processor_present(handle))
			break;

		if (acpi_bus_get_device(handle, &device)) {
			result = acpi_processor_device_add(handle, &device);
			if (result)
				printk(KERN_ERR PREFIX
					    "Unable to add the device\n");
			break;
		}

		pr = acpi_driver_data(device);
		if (!pr) {
			printk(KERN_ERR PREFIX "Driver data is NULL\n");
			break;
		}

		if (pr->id >= 0 && (pr->id < nr_cpu_ids)) {
			kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
			break;
		}

		result = acpi_processor_start(device);
		if ((!result) && ((pr->id >= 0) && (pr->id < nr_cpu_ids))) {
			kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
		} else {
			printk(KERN_ERR PREFIX "Device [%s] failed to start\n",
				    acpi_device_bid(device));
		}
		break;
	case ACPI_NOTIFY_EJECT_REQUEST:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "received ACPI_NOTIFY_EJECT_REQUEST\n"));

		if (acpi_bus_get_device(handle, &device)) {
			printk(KERN_ERR PREFIX
				    "Device don't exist, dropping EJECT\n");
			break;
		}
		pr = acpi_driver_data(device);
		if (!pr) {
			printk(KERN_ERR PREFIX
				    "Driver data is NULL, dropping EJECT\n");
			return;
		}

		if ((pr->id < nr_cpu_ids) && (cpu_present(pr->id)))
			kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
		break;
	default:
		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
				  "Unsupported event [0x%x]\n", event));
		break;
	}

	return;
}

static acpi_status
processor_walk_namespace_cb(acpi_handle handle,
			    u32 lvl, void *context, void **rv)
{
	acpi_status status;
	int *action = context;
	acpi_object_type type = 0;

	status = acpi_get_type(handle, &type);
	if (ACPI_FAILURE(status))
		return (AE_OK);

	if (type != ACPI_TYPE_PROCESSOR)
		return (AE_OK);

	switch (*action) {
	case INSTALL_NOTIFY_HANDLER:
		acpi_install_notify_handler(handle,
					    ACPI_SYSTEM_NOTIFY,
					    acpi_processor_hotplug_notify,
					    NULL);
		break;
	case UNINSTALL_NOTIFY_HANDLER:
		acpi_remove_notify_handler(handle,
					   ACPI_SYSTEM_NOTIFY,
					   acpi_processor_hotplug_notify);
		break;
	default:
		break;
	}

	return (AE_OK);
}

static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
{

	if (!is_processor_present(handle)) {
		return AE_ERROR;
	}

	if (acpi_map_lsapic(handle, p_cpu))
		return AE_ERROR;

	if (arch_register_cpu(*p_cpu)) {
		acpi_unmap_lsapic(*p_cpu);
		return AE_ERROR;
	}

	return AE_OK;
}

static int acpi_processor_handle_eject(struct acpi_processor *pr)
{
	if (cpu_online(pr->id)) {
		return (-EINVAL);
	}
	arch_unregister_cpu(pr->id);
	acpi_unmap_lsapic(pr->id);
	return (0);
}
#else
static acpi_status acpi_processor_hotadd_init(acpi_handle handle, int *p_cpu)
{
	return AE_ERROR;
}
static int acpi_processor_handle_eject(struct acpi_processor *pr)
{
	return (-EINVAL);
}
#endif

static
void acpi_processor_install_hotplug_notify(void)
{
#ifdef CONFIG_ACPI_HOTPLUG_CPU
	int action = INSTALL_NOTIFY_HANDLER;
	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
			    ACPI_ROOT_OBJECT,
			    ACPI_UINT32_MAX,
			    processor_walk_namespace_cb, &action, NULL);
#endif
	register_hotcpu_notifier(&acpi_cpu_notifier);
}

static
void acpi_processor_uninstall_hotplug_notify(void)
{
#ifdef CONFIG_ACPI_HOTPLUG_CPU
	int action = UNINSTALL_NOTIFY_HANDLER;
	acpi_walk_namespace(ACPI_TYPE_PROCESSOR,
			    ACPI_ROOT_OBJECT,
			    ACPI_UINT32_MAX,
			    processor_walk_namespace_cb, &action, NULL);
#endif
	unregister_hotcpu_notifier(&acpi_cpu_notifier);
}

/*
 * We keep the driver loaded even when ACPI is not running.
 * This is needed for the powernow-k8 driver, that works even without
 * ACPI, but needs symbols from this driver
 */

static int __init acpi_processor_init(void)
{
	int result = 0;


	memset(&processors, 0, sizeof(processors));
	memset(&errata, 0, sizeof(errata));

#ifdef CONFIG_SMP
	if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_MADT, 0,
				(struct acpi_table_header **)&madt)))
		madt = NULL;
#endif

	acpi_processor_dir = proc_mkdir(ACPI_PROCESSOR_CLASS, acpi_root_dir);
	if (!acpi_processor_dir)
		return -ENOMEM;
	acpi_processor_dir->owner = THIS_MODULE;

	result = cpuidle_register_driver(&acpi_idle_driver);
	if (result < 0)
		goto out_proc;

	result = acpi_bus_register_driver(&acpi_processor_driver);
	if (result < 0)
		goto out_cpuidle;

	acpi_processor_install_hotplug_notify();

	acpi_thermal_cpufreq_init();

	acpi_processor_ppc_init();

	return 0;

out_cpuidle:
	cpuidle_unregister_driver(&acpi_idle_driver);

out_proc:
	remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);

	return result;
}

static void __exit acpi_processor_exit(void)
{
	acpi_processor_ppc_exit();

	acpi_thermal_cpufreq_exit();

	acpi_processor_uninstall_hotplug_notify();

	acpi_bus_unregister_driver(&acpi_processor_driver);

	cpuidle_unregister_driver(&acpi_idle_driver);

	remove_proc_entry(ACPI_PROCESSOR_CLASS, acpi_root_dir);

	return;
}

module_init(acpi_processor_init);
module_exit(acpi_processor_exit);

EXPORT_SYMBOL(acpi_processor_set_thermal_limit);

MODULE_ALIAS("processor");