1 files changed, 76 insertions, 51 deletions

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 4f91a740c15f..6c02f93422ce 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2443,8 +2443,8 @@ out_set_count:
 	return pgsize;
 }
 
-static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
-		       phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+int iommu_map_nosync(struct iommu_domain *domain, unsigned long iova,
+		phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
 {
 	const struct iommu_domain_ops *ops = domain->ops;
 	unsigned long orig_iova = iova;
@@ -2453,12 +2453,19 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
 	phys_addr_t orig_paddr = paddr;
 	int ret = 0;
 
+	might_sleep_if(gfpflags_allow_blocking(gfp));
+
 	if (unlikely(!(domain->type & __IOMMU_DOMAIN_PAGING)))
 		return -EINVAL;
 
 	if (WARN_ON(!ops->map_pages || domain->pgsize_bitmap == 0UL))
 		return -ENODEV;
 
+	/* Discourage passing strange GFP flags */
+	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
+				__GFP_HIGHMEM)))
+		return -EINVAL;
+
 	/* find out the minimum page size supported */
 	min_pagesz = 1 << __ffs(domain->pgsize_bitmap);
 
@@ -2506,31 +2513,27 @@ static int __iommu_map(struct iommu_domain *domain, unsigned long iova,
 	return ret;
 }
 
-int iommu_map(struct iommu_domain *domain, unsigned long iova,
-	      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+int iommu_sync_map(struct iommu_domain *domain, unsigned long iova, size_t size)
 {
 	const struct iommu_domain_ops *ops = domain->ops;
-	int ret;
-
-	might_sleep_if(gfpflags_allow_blocking(gfp));
 
-	/* Discourage passing strange GFP flags */
-	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
-				__GFP_HIGHMEM)))
-		return -EINVAL;
+	if (!ops->iotlb_sync_map)
+		return 0;
+	return ops->iotlb_sync_map(domain, iova, size);
+}
 
-	ret = __iommu_map(domain, iova, paddr, size, prot, gfp);
-	if (ret == 0 && ops->iotlb_sync_map) {
-		ret = ops->iotlb_sync_map(domain, iova, size);
-		if (ret)
-			goto out_err;
-	}
+int iommu_map(struct iommu_domain *domain, unsigned long iova,
+	      phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+{
+	int ret;
 
-	return ret;
+	ret = iommu_map_nosync(domain, iova, paddr, size, prot, gfp);
+	if (ret)
+		return ret;
 
-out_err:
-	/* undo mappings already done */
-	iommu_unmap(domain, iova, size);
+	ret = iommu_sync_map(domain, iova, size);
+	if (ret)
+		iommu_unmap(domain, iova, size);
 
 	return ret;
 }
@@ -2618,6 +2621,25 @@ size_t iommu_unmap(struct iommu_domain *domain,
 }
 EXPORT_SYMBOL_GPL(iommu_unmap);
 
+/**
+ * iommu_unmap_fast() - Remove mappings from a range of IOVA without IOTLB sync
+ * @domain: Domain to manipulate
+ * @iova: IO virtual address to start
+ * @size: Length of the range starting from @iova
+ * @iotlb_gather: range information for a pending IOTLB flush
+ *
+ * iommu_unmap_fast() will remove a translation created by iommu_map().
+ * It can't subdivide a mapping created by iommu_map(), so it should be
+ * called with IOVA ranges that match what was passed to iommu_map(). The
+ * range can aggregate contiguous iommu_map() calls so long as no individual
+ * range is split.
+ *
+ * Basically iommu_unmap_fast() is the same as iommu_unmap() but for callers
+ * which manage the IOTLB flushing externally to perform a batched sync.
+ *
+ * Returns: Number of bytes of IOVA unmapped. iova + res will be the point
+ * unmapping stopped.
+ */
 size_t iommu_unmap_fast(struct iommu_domain *domain,
 			unsigned long iova, size_t size,
 			struct iommu_iotlb_gather *iotlb_gather)
@@ -2630,26 +2652,17 @@ ssize_t iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
 		     struct scatterlist *sg, unsigned int nents, int prot,
 		     gfp_t gfp)
 {
-	const struct iommu_domain_ops *ops = domain->ops;
 	size_t len = 0, mapped = 0;
 	phys_addr_t start;
 	unsigned int i = 0;
 	int ret;
 
-	might_sleep_if(gfpflags_allow_blocking(gfp));
-
-	/* Discourage passing strange GFP flags */
-	if (WARN_ON_ONCE(gfp & (__GFP_COMP | __GFP_DMA | __GFP_DMA32 |
-				__GFP_HIGHMEM)))
-		return -EINVAL;
-
 	while (i <= nents) {
 		phys_addr_t s_phys = sg_phys(sg);
 
 		if (len && s_phys != start + len) {
-			ret = __iommu_map(domain, iova + mapped, start,
+			ret = iommu_map_nosync(domain, iova + mapped, start,
 					len, prot, gfp);
-
 			if (ret)
 				goto out_err;
 
@@ -2672,11 +2685,10 @@ next:
 			sg = sg_next(sg);
 	}
 
-	if (ops->iotlb_sync_map) {
-		ret = ops->iotlb_sync_map(domain, iova, mapped);
-		if (ret)
-			goto out_err;
-	}
+	ret = iommu_sync_map(domain, iova, mapped);
+	if (ret)
+		goto out_err;
+
 	return mapped;
 
 out_err:
@@ -3366,10 +3378,12 @@ static int __iommu_set_group_pasid(struct iommu_domain *domain,
 	int ret;
 
 	for_each_group_device(group, device) {
-		ret = domain->ops->set_dev_pasid(domain, device->dev,
-						 pasid, old);
-		if (ret)
-			goto err_revert;
+		if (device->dev->iommu->max_pasids > 0) {
+			ret = domain->ops->set_dev_pasid(domain, device->dev,
+							 pasid, old);
+			if (ret)
+				goto err_revert;
+		}
 	}
 
 	return 0;
@@ -3379,15 +3393,18 @@ err_revert:
 	for_each_group_device(group, device) {
 		if (device == last_gdev)
 			break;
-		/*
-		 * If no old domain, undo the succeeded devices/pasid.
-		 * Otherwise, rollback the succeeded devices/pasid to the old
-		 * domain. And it is a driver bug to fail attaching with a
-		 * previously good domain.
-		 */
-		if (!old || WARN_ON(old->ops->set_dev_pasid(old, device->dev,
+		if (device->dev->iommu->max_pasids > 0) {
+			/*
+			 * If no old domain, undo the succeeded devices/pasid.
+			 * Otherwise, rollback the succeeded devices/pasid to
+			 * the old domain. And it is a driver bug to fail
+			 * attaching with a previously good domain.
+			 */
+			if (!old ||
+			    WARN_ON(old->ops->set_dev_pasid(old, device->dev,
 							    pasid, domain)))
-			iommu_remove_dev_pasid(device->dev, pasid, domain);
+				iommu_remove_dev_pasid(device->dev, pasid, domain);
+		}
 	}
 	return ret;
 }
@@ -3398,8 +3415,10 @@ static void __iommu_remove_group_pasid(struct iommu_group *group,
 {
 	struct group_device *device;
 
-	for_each_group_device(group, device)
-		iommu_remove_dev_pasid(device->dev, pasid, domain);
+	for_each_group_device(group, device) {
+		if (device->dev->iommu->max_pasids > 0)
+			iommu_remove_dev_pasid(device->dev, pasid, domain);
+	}
 }
 
 /*
@@ -3440,7 +3459,13 @@ int iommu_attach_device_pasid(struct iommu_domain *domain,
 
 	mutex_lock(&group->mutex);
 	for_each_group_device(group, device) {
-		if (pasid >= device->dev->iommu->max_pasids) {
+		/*
+		 * Skip PASID validation for devices without PASID support
+		 * (max_pasids = 0). These devices cannot issue transactions
+		 * with PASID, so they don't affect group's PASID usage.
+		 */
+		if ((device->dev->iommu->max_pasids > 0) &&
+		    (pasid >= device->dev->iommu->max_pasids)) {
 			ret = -EINVAL;
 			goto out_unlock;
 		}