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Commit 34f0e908 authored by David Woodhouse's avatar David Woodhouse Committed by Greg Kroah-Hartman
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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: default avatarDavid Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/linux-iommu/549928db2de6532117f36c9c810373c14cf76f51.camel@infradead.org/


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
[ context change due to moving drivers/iommu/dmar.c to
  drivers/iommu/intel/dmar.c ]
Signed-off-by: default avatarFilippo Sironi <sironi@amazon.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 184666c9

drivers/iommu/dmar.c

+30 −14
Original line number Diff line number Diff line
@@ -1029,8 +1029,8 @@ 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) {
@@ -1055,17 +1055,28 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd) 
	}



	err = -EINVAL;

	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);

		goto err_unmap;

			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);

		goto err_unmap;

			drhd->ignored = 1;

			agaw = -1;

		}

	}

	iommu->agaw = agaw;

	iommu->msagaw = msagaw;
@@ -1092,7 +1103,12 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd) 


	raw_spin_lock_init(&iommu->register_lock);



	if (intel_iommu_enabled) {

	/*

	 * This is only for hotplug; at boot time intel_iommu_enabled won't

	 * be set yet. When intel_iommu_init() runs, it registers the units

	 * present at boot time, then sets intel_iommu_enabled.

	 */

	if (intel_iommu_enabled && !drhd->ignored) {

		err = iommu_device_sysfs_add(&iommu->iommu, NULL,

					     intel_iommu_groups,

					     "%s", iommu->name);
@@ -1121,7 +1137,7 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd) 


static void free_iommu(struct intel_iommu *iommu)

{

	if (intel_iommu_enabled) {

	if (intel_iommu_enabled && iommu->iommu.ops) {

		iommu_device_unregister(&iommu->iommu);

		iommu_device_sysfs_remove(&iommu->iommu);

	}