From: David Woodhouse <d...@amazon.co.uk> commit c40aaaac1018ff1382f2d35df5129a6bcea3df6b upstream.
Instead of bailing out completely, such a unit can still be used for interrupt remapping. Signed-off-by: David Woodhouse <d...@amazon.co.uk> Reviewed-by: Lu Baolu <baolu...@linux.intel.com> Link: https://lore.kernel.org/linux-iommu/549928db2de6532117f36c9c810373c14cf76f51.ca...@infradead.org/ Signed-off-by: Joerg Roedel <jroe...@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 <sir...@amazon.de> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- drivers/iommu/dmar.c | 44 +++++++++++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 17 deletions(-) --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -1012,8 +1012,8 @@ 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) { @@ -1038,17 +1038,28 @@ 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; @@ -1077,15 +1088,13 @@ static int alloc_iommu(struct dmar_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) {
