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authorDavid Woodhouse <dwmw@amazon.co.uk>2021-02-02 01:07:06 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-02-03 23:19:51 +0100
commit9bae48cca4aa549ab2a97d5ed21333e4163ee3cc (patch)
tree6ea519323556518b0e0e614cc6c4799ac5c1802d
parentdd163aa3bc796ed1cbeaee4492ebc059b6871ac6 (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 - 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>
-rw-r--r--drivers/iommu/dmar.c40
1 files changed, 26 insertions, 14 deletions
diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 977070ce4fe97..a68e3b4fdd6e2 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1024,8 +1024,8 @@ 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) {
@@ -1050,17 +1050,28 @@ 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;
@@ -1087,7 +1098,7 @@ static int alloc_iommu(struct dmar_drhd_unit *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) {