iommu/vt-d: Fix identity map bounds in si_domain_init()

Intel IOMMU operates on inclusive bounds (both generally aas well as
iommu_domain_identity_map()). Meanwhile, for_each_mem_pfn_range() uses
exclusive bounds for end_pfn. This creates an off-by-one error when
switching between the two.

Fixes: c5395d5 ("intel-iommu: Clean up iommu_domain_identity_map()")
Signed-off-by: Jon Pan-Doh <pandoh@google.com>
Tested-by: Sudheer Dantuluri <dantuluris@google.com>
Suggested-by: Gary Zibrat <gzibrat@google.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20240709234913.2749386-1-pandoh@google.com
Signed-off-by: Will Deacon <will@kernel.org>

Author: Jon Pan-Doh

drivers/iommu/intel/iommu.c

@@ -2041,7 +2041,7 @@ static int __init si_domain_init(int hw)
 		for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
 			ret = iommu_domain_identity_map(si_domain,
 					mm_to_dma_pfn_start(start_pfn),
-					mm_to_dma_pfn_end(end_pfn));
+					mm_to_dma_pfn_end(end_pfn-1));
 			if (ret)
 				return ret;
 		}