iommu/vt-d: Fix to flush cache of PASID directory table

stable inclusion
from stable-v5.10.195
commit 3183b0cab7b52b311e4b363c3b97b8147217fdb8
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I95JOC

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3183b0cab7b52b311e4b363c3b97b8147217fdb8



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[ Upstream commit 8a3b8e63 ]

Even the PCI devices don't support pasid capability, PASID table is
mandatory for a PCI device in scalable mode. However flushing cache
of pasid directory table for these devices are not taken after pasid
table is allocated as the "size" of table is zero. Fix it by
calculating the size by page order.

Found this when reading the code, no real problem encountered for now.

Fixes: 194b3348 ("iommu/vt-d: Fix PASID directory pointer coherency")
Suggested-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Yanfei Xu <yanfei.xu@intel.com>
Link: https://lore.kernel.org/r/20230616081045.721873-1-yanfei.xu@intel.com


Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>