[PATCH v2 06/11] iommu/amd: Use pci_ats_supported()

[Jean-Philippe Brucker <jean-philippe@linaro.org>]

The pci_ats_supported() function checks if a device supports ATS and is
allowed to use it.  In addition to checking that the device has an ATS
capability and that the global pci=noats is not set
(pci_ats_disabled()), it also checks if a device is untrusted (plugged
into an external-facing port such as thunderbolt).

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
 drivers/iommu/amd_iommu.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index aac132bd1ef0..084f0b2e132e 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -291,16 +291,15 @@ static struct iommu_group *acpihid_device_group(struct device *dev)
 static bool pci_iommuv2_capable(struct pci_dev *pdev)
 {
 	static const int caps[] = {
-		PCI_EXT_CAP_ID_ATS,
 		PCI_EXT_CAP_ID_PRI,
 		PCI_EXT_CAP_ID_PASID,
 	};
 	int i, pos;
 
-	if (pci_ats_disabled())
+	if (!pci_ats_supported(pdev))
 		return false;
 
-	for (i = 0; i < 3; ++i) {
+	for (i = 0; i < 2; ++i) {
 		pos = pci_find_ext_capability(pdev, caps[i]);
 		if (pos == 0)
 			return false;
@@ -3040,11 +3039,8 @@ int amd_iommu_device_info(struct pci_dev *pdev,
 
 	memset(info, 0, sizeof(*info));
 
-	if (!pci_ats_disabled()) {
-		pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS);
-		if (pos)
-			info->flags |= AMD_IOMMU_DEVICE_FLAG_ATS_SUP;
-	}
+	if (pci_ats_supported(pdev))
+		info->flags |= AMD_IOMMU_DEVICE_FLAG_ATS_SUP;
 
 	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
 	if (pos)
-- 
2.25.1