iommu/arm-smmu-v3: Use pci_ats_supported()

The new pci_ats_supported() function checks if a device supports ATS and
is allowed to use it.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200520152201.3309416-4-jean-philippe@linaro.orgSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/arm-smmu-v3.c

@@ -2652,26 +2652,20 @@ static void arm_smmu_install_ste_for_dev(struct arm_smmu_master *master)
 	}
 }
 
-#ifdef CONFIG_PCI_ATS
 static bool arm_smmu_ats_supported(struct arm_smmu_master *master)
 {
-	struct pci_dev *pdev;
+	struct device *dev = master->dev;
 	struct arm_smmu_device *smmu = master->smmu;
-	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(master->dev);
+	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 
-	if (!(smmu->features & ARM_SMMU_FEAT_ATS) || !dev_is_pci(master->dev) ||
-	    !(fwspec->flags & IOMMU_FWSPEC_PCI_RC_ATS) || pci_ats_disabled())
+	if (!(smmu->features & ARM_SMMU_FEAT_ATS))
 		return false;
 
-	pdev = to_pci_dev(master->dev);
-	return !pdev->untrusted && pdev->ats_cap;
-}
-#else
-static bool arm_smmu_ats_supported(struct arm_smmu_master *master)
-{
-	return false;
+	if (!(fwspec->flags & IOMMU_FWSPEC_PCI_RC_ATS))
+		return false;
+
+	return dev_is_pci(dev) && pci_ats_supported(to_pci_dev(dev));
 }
-#endif
 
 static void arm_smmu_enable_ats(struct arm_smmu_master *master)
 {