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@xxxxxxxxxx>
---
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
