iommu/amd: Don't take domain->lock recursivly

commit e33acde9 upstream.

The domain_flush_devices() function takes the domain->lock.
But this function is only called from update_domain() which
itself is already called unter the domain->lock. This causes
a deadlock situation when the dma-address-space of a domain
grows larger than 1GB.
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

arch/x86/kernel/amd_iommu.c

@@ -773,14 +773,9 @@ static void domain_flush_complete(struct protection_domain *domain)
 static void domain_flush_devices(struct protection_domain *domain)
 {
 	struct iommu_dev_data *dev_data;
-	unsigned long flags;
-
-	spin_lock_irqsave(&domain->lock, flags);
 
 	list_for_each_entry(dev_data, &domain->dev_list, list)
 		device_flush_dte(dev_data->dev);
-
-	spin_unlock_irqrestore(&domain->lock, flags);
 }
 
 /****************************************************************************