[PATCH v2 05/13] iommu/fsl: Constrain return value of ->attach_dev()

[Nicolin Chen]

Ensure attach_dev() callback functions only return errno values expected
from the attach_dev() op. In particular, only return -EINVAL when we are
sure that the device is incompatible with the domain.

Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
 drivers/iommu/fsl_pamu_domain.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
index 011f9ab7f743..a391ac733b5e 100644
--- a/drivers/iommu/fsl_pamu_domain.c
+++ b/drivers/iommu/fsl_pamu_domain.c
@@ -258,7 +258,7 @@ static int fsl_pamu_attach_device(struct iommu_domain *domain,
 	liodn = of_get_property(dev->of_node, "fsl,liodn", &len);
 	if (!liodn) {
 		pr_debug("missing fsl,liodn property at %pOF\n", dev->of_node);
-		return -EINVAL;
+		return -ENODEV;
 	}
 
 	spin_lock_irqsave(&dma_domain->domain_lock, flags);
@@ -267,17 +267,21 @@ static int fsl_pamu_attach_device(struct iommu_domain *domain,
 		if (liodn[i] >= PAACE_NUMBER_ENTRIES) {
 			pr_debug("Invalid liodn %d, attach device failed for %pOF\n",
 				 liodn[i], dev->of_node);
-			ret = -EINVAL;
+			ret = -ENODEV;
 			break;
 		}
 
 		attach_device(dma_domain, liodn[i], dev);
 		ret = pamu_set_liodn(dma_domain, dev, liodn[i]);
-		if (ret)
+		if (ret) {
+			ret = -ENODEV;
 			break;
+		}
 		ret = pamu_enable_liodn(liodn[i]);
-		if (ret)
+		if (ret) {
+			ret = -ENODEV;
 			break;
+		}
 	}
 	spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
 	return ret;
-- 
2.17.1