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authorDavid Woodhouse <dwmw@amazon.co.uk>2021-02-02 01:09:36 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-02-03 23:16:17 +0100
commite4f10aec71e59715aa94c5f25e4de6b290105adc (patch)
tree7a15c5df46223ce24d0c196a58277007fae75320 /drivers/iommu
parentee607baae70b012cc3e5efe7520ea0187ba4372c (diff)
iommu/vt-d: Gracefully handle DMAR units with no supported address widths
commit c40aaaac1018ff1382f2d35df5129a6bcea3df6b upstream. Instead of bailing out completely, such a unit can still be used for interrupt remapping. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com> Link: https://lore.kernel.org/linux-iommu/549928db2de6532117f36c9c810373c14cf76f51.camel@infradead.org/ Signed-off-by: Joerg Roedel <jroedel@suse.de> [ - context change due to moving drivers/iommu/dmar.c to drivers/iommu/intel/dmar.c - remove the unused err_unmap label - use iommu->iommu_dev instead of iommu->iommu.ops to decide whether when freeing ] Signed-off-by: Filippo Sironi <sironi@amazon.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/dmar.c42
1 files changed, 26 insertions, 16 deletions
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 00169c9eb3ee..095022923258 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1012,8 +1012,8 @@ static int alloc_iommu(struct dmar_drhd_unit *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) {
@@ -1038,17 +1038,28 @@ static int alloc_iommu(struct dmar_drhd_unit *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;
+ if (cap_sagaw(iommu->cap) == 0) {
+ pr_info("%s: No supported address widths. Not attempting DMA translation.\n",
+ iommu->name);
+ drhd->ignored = 1;
}
- 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 (!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;
@@ -1077,15 +1088,13 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd)
drhd->iommu = iommu;
- if (intel_iommu_enabled)
+ if (intel_iommu_enabled && !drhd->ignored)
iommu->iommu_dev = iommu_device_create(NULL, iommu,
intel_iommu_groups,
"%s", iommu->name);
return 0;
-err_unmap:
- unmap_iommu(iommu);
error_free_seq_id:
dmar_free_seq_id(iommu);
error:
@@ -1095,7 +1104,8 @@ 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) {