iommu/vt-d: Convert global spinlock into per domain lock

iommu/vt-d: Convert global spinlock into per domain lock

Using a global device_domain_lock spinlock to protect per-domain device
tracking lists is an inefficient way, especially considering this lock
is also needed in the hot paths. This optimizes the locking mechanism
by converting the global lock to per domain lock.

On the other hand, as the device tracking lists are never accessed in
any interrupt context, there is no need to disable interrupts while
spinning. Replace irqsave variant with spinlock calls.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20220706025524.2904370-12-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>