[patch] iommu/vt-d: unlock on error in intel_iommu_load_translation_tables()

[Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>]

Smatch found some error paths that don't unlock.  Also we can return
-ENOMEM instead of -1 if we don't have an old root entry.

Fixes: 5908f10af4b9 ('iommu/vt-d: datatypes and functions used for kdump')
Signed-off-by: Dan Carpenter <dan.carpenter-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
---
Releasing the lock is good, but we might need to do other error handling
as well.  Presumably this function always succeeds anyway?  It seems
like it might be essential for booting.

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 2926907..0e2e635 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5151,22 +5151,24 @@ static int intel_iommu_load_translation_tables(struct intel_iommu *iommu)
 		iommu->root_entry =
 			(struct root_entry *)alloc_pgtable_page(iommu->node);
 		if (!iommu->root_entry) {
-			spin_unlock_irqrestore(&iommu->lock, flags);
-			return -ENOMEM;
+			ret = -ENOMEM;
+			goto err_unlock;
 		}
 	}
 
 	iommu->root_entry_old_phys = q & VTD_PAGE_MASK;
 	if (!iommu->root_entry_old_phys) {
 		pr_err("Could not read old root entry address.");
-		return -1;
+		ret = -ENOMEM;
+		goto err_unlock;
 	}
 
 	iommu->root_entry_old_virt = ioremap_cache(iommu->root_entry_old_phys,
 						VTD_PAGE_SIZE);
 	if (!iommu->root_entry_old_virt) {
 		pr_err("Could not map the old root entry.");
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto err_unlock;
 	}
 
 	__iommu_load_old_root_entry(iommu);
@@ -5179,6 +5181,10 @@ static int intel_iommu_load_translation_tables(struct intel_iommu *iommu)
 	__iommu_free_mapped_mem();
 
 	return ret;
+
+err_unlock:
+	spin_unlock_irqrestore(&iommu->lock, flags);
+	return ret;
 }
 
 static void unmap_device_dma(struct dmar_domain *domain,