[PATCH v1 6/7] iommu/vt-d: Remove misleading "domain 0" test from domain_exit()

[Bjorn Helgaas]

From: Bjorn Helgaas <bhelg...@google.com>

The "Domain 0 is reserved, so dont process it" comment suggests that a NULL
pointer corresponds to domain 0.  I don't think that's true, and in any
case, every caller supplies a non-NULL domain pointer that has already been
dereferenced, so the test is unnecessary.

Remove the test for a null "domain" pointer.  No functional change
intended.

This null pointer check was added by 5e98c4b1d6e8 ("Allocation and free
functions of virtual machine domain").

Signed-off-by: Bjorn Helgaas <bhelg...@google.com>
---
 drivers/iommu/intel-iommu.c |    4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 6e9f277bfd6d..b0860a8c48d4 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1903,10 +1903,6 @@ static void domain_exit(struct dmar_domain *domain)
 {
        struct page *freelist;
 
-       /* Domain 0 is reserved, so dont process it */
-       if (!domain)
-               return;
-
        /* Remove associated devices and clear attached or cached domains */
        rcu_read_lock();
        domain_remove_dev_info(domain);