iommu: Remove IOMMU_CAP_INTR_REMAP

No iommu driver implements this any more, get rid of it.

Link: https://lore.kernel.org/r/9-v3-3313bb5dd3a3+10f11-secure_msi_jgg@nvidia.comTested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/iommu/iommu.c

@@ -1914,10 +1914,8 @@ bool iommu_group_has_isolated_msi(struct iommu_group *group)
 	bool ret = true;
 
 	mutex_lock(&group->mutex);
-	list_for_each_entry(group_dev, &group->devices, list) {
-		ret &= msi_device_has_isolated_msi(group_dev->dev) ||
-		       device_iommu_capable(group_dev->dev, IOMMU_CAP_INTR_REMAP);
-	}
+	list_for_each_entry(group_dev, &group->devices, list)
+		ret &= msi_device_has_isolated_msi(group_dev->dev);
 	mutex_unlock(&group->mutex);
 	return ret;
 }

include/linux/iommu.h

@@ -120,7 +120,6 @@ static inline bool iommu_is_dma_domain(struct iommu_domain *domain)
 
 enum iommu_cap {
 	IOMMU_CAP_CACHE_COHERENCY,	/* IOMMU_CACHE is supported */
-	IOMMU_CAP_INTR_REMAP,		/* IOMMU supports interrupt isolation */
 	IOMMU_CAP_NOEXEC,		/* IOMMU_NOEXEC flag */
 	IOMMU_CAP_PRE_BOOT_PROTECTION,	/* Firmware says it used the IOMMU for
 					   DMA protection and we should too */