@@ -1024,8 +1024,8 @@ static int alloc_iommu(struct dmar_drhd_
{
struct intel_iommu *iommu;
u32 ver, sts;
- int agaw = 0;
- int msagaw = 0;
+ int agaw = -1;
+ int msagaw = -1;
int err;
if (!drhd->reg_base_addr) {
@@ -1050,17 +1050,28 @@ static int alloc_iommu(struct dmar_drhd_
}
err = -EINVAL;
- agaw = iommu_calculate_agaw(iommu);
- if (agaw < 0) {
- pr_err("Cannot get a valid agaw for iommu (seq_id = %d)\n",
- iommu->seq_id);
- goto err_unmap;
- }
- msagaw = iommu_calculate_max_sagaw(iommu);
- if (msagaw < 0) {
- pr_err("Cannot get a valid max agaw for iommu (seq_id = %d)\n",
- iommu->seq_id);
- goto err_unmap;
+ if (cap_sagaw(iommu->cap) == 0) {
+ pr_info("%s: No supported address widths. Not attempting DMA translation.\n",
+ iommu->name);
+ drhd->ignored = 1;
+ }
+
+ if (!drhd->ignored) {
+ agaw = iommu_calculate_agaw(iommu);
+ if (agaw < 0) {
+ pr_err("Cannot get a valid agaw for iommu (seq_id = %d)\n",
+ iommu->seq_id);
+ drhd->ignored = 1;
+ }
+ }
+ if (!drhd->ignored) {
+ msagaw = iommu_calculate_max_sagaw(iommu);
+ if (msagaw < 0) {
+ pr_err("Cannot get a valid max agaw for iommu (seq_id = %d)\n",
+ iommu->seq_id);
+ drhd->ignored = 1;
+ agaw = -1;
+ }
}
iommu->agaw = agaw;
iommu->msagaw = msagaw;
@@ -1087,7 +1098,7 @@ static int alloc_iommu(struct dmar_drhd_
raw_spin_lock_init(&iommu->register_lock);
- if (intel_iommu_enabled) {
+ if (intel_iommu_enabled && !drhd->ignored) {
iommu->iommu_dev = iommu_device_create(NULL, iommu,
intel_iommu_groups,
"%s", iommu->name);
@@ -1113,7 +1124,8 @@ error:
static void free_iommu(struct intel_iommu *iommu)
{
- iommu_device_destroy(iommu->iommu_dev);
+ if (intel_iommu_enabled && iommu->iommu_dev)
+ iommu_device_destroy(iommu->iommu_dev);
if (iommu->irq) {
if (iommu->pr_irq) {