Commit f39c4280 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Greg Kroah-Hartman
Browse files

Drivers: hv: vmbus: use cpu_hotplug_enable/disable 



Commit e513229b ("Drivers: hv: vmbus: prevent cpu offlining on newer
hypervisors") was altering smp_ops.cpu_disable to prevent CPU offlining.
We can bo better by using cpu_hotplug_enable/disable functions instead of
such hard-coding.

Reported-by: default avatarRadim Kr.má <rkrcmar@redhat.com>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 32145c46

drivers/hv/vmbus_drv.c

+4 −34
Original line number Diff line number Diff line
@@ -828,38 +828,6 @@ static void vmbus_isr(void) 
	}

}



#ifdef CONFIG_HOTPLUG_CPU

static int hyperv_cpu_disable(void)

{

	return -ENOSYS;

}



static void hv_cpu_hotplug_quirk(bool vmbus_loaded)

{

	static void *previous_cpu_disable;



	/*

	 * Offlining a CPU when running on newer hypervisors (WS2012R2, Win8,

	 * ...) is not supported at this moment as channel interrupts are

	 * distributed across all of them.

	 */



	if ((vmbus_proto_version == VERSION_WS2008) ||

	    (vmbus_proto_version == VERSION_WIN7))

		return;



	if (vmbus_loaded) {

		previous_cpu_disable = smp_ops.cpu_disable;

		smp_ops.cpu_disable = hyperv_cpu_disable;

		pr_notice("CPU offlining is not supported by hypervisor\n");

	} else if (previous_cpu_disable)

		smp_ops.cpu_disable = previous_cpu_disable;

}

#else

static void hv_cpu_hotplug_quirk(bool vmbus_loaded)

{

}

#endif



/*

 * vmbus_bus_init -Main vmbus driver initialization routine.
@@ -901,7 +869,8 @@ static int vmbus_bus_init(int irq) 
	if (ret)

		goto err_alloc;



	hv_cpu_hotplug_quirk(true);

	if (vmbus_proto_version > VERSION_WIN7)

		cpu_hotplug_disable();



	/*

	 * Only register if the crash MSRs are available
@@ -1364,7 +1333,8 @@ static void __exit vmbus_exit(void) 
	}

	hv_synic_free();

	acpi_bus_unregister_driver(&vmbus_acpi_driver);

	hv_cpu_hotplug_quirk(false);

	if (vmbus_proto_version > VERSION_WIN7)

		cpu_hotplug_enable();

}

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