Merge tag 'iommu-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull iommu fixes from Will Deacon:
 "Here's another round of IOMMU fixes for -rc6 consisting mainly of a
  bunch of independent driver fixes. Thomas agreed for me to take the
  x86 'tboot' fix here, as it fixes a regression introduced by a vt-d
  change.

   - Fix intel iommu driver when running on devices without VCCAP_REG

   - Fix swiotlb and "iommu=pt" interaction under TXT (tboot)

   - Fix missing return value check during device probe()

   - Fix probe ordering for Qualcomm SMMU implementation

   - Ensure page-sized mappings are used for AMD IOMMU buffers with SNP
     RMP"

* tag 'iommu-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  iommu/vt-d: Don't read VCCAP register unless it exists
  x86/tboot: Don't disable swiotlb when iommu is forced on
  iommu: Check return of __iommu_attach_device()
  arm-smmu-qcom: Ensure the qcom_scm driver has finished probing
  iommu/amd: Enforce 4k mapping for certain IOMMU data structures

2 files changed, 4 insertions, 3 deletions

diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
index 11319e4dce4a..b46dbfa6d0ed 100644
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -986,7 +986,8 @@ static int map_iommu(struct intel_iommu *iommu, u64 phys_addr)
 		warn_invalid_dmar(phys_addr, " returns all ones");
 		goto unmap;
 	}
-	iommu->vccap = dmar_readq(iommu->reg + DMAR_VCCAP_REG);
+	if (ecap_vcs(iommu->ecap))
+		iommu->vccap = dmar_readq(iommu->reg + DMAR_VCCAP_REG);
 
 	/* the registers might be more than one page */
 	map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index c71a9c279a33..a49afa11673c 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1833,7 +1833,7 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
 		if (ecap_prs(iommu->ecap))
 			intel_svm_finish_prq(iommu);
 	}
-	if (ecap_vcs(iommu->ecap) && vccap_pasid(iommu->vccap))
+	if (vccap_pasid(iommu->vccap))
 		ioasid_unregister_allocator(&iommu->pasid_allocator);
 
 #endif
@@ -3212,7 +3212,7 @@ static void register_pasid_allocator(struct intel_iommu *iommu)
 	 * is active. All vIOMMU allocators will eventually be calling the same
 	 * host allocator.
 	 */
-	if (!ecap_vcs(iommu->ecap) || !vccap_pasid(iommu->vccap))
+	if (!vccap_pasid(iommu->vccap))
 		return;
 
 	pr_info("Register custom PASID allocator\n");