ARM/dma-mapping: return error code from .map_sg() ops

The .map_sg() op now expects an error code instead of zero on failure.
In the case of a DMA_MAPPING_ERROR, -EIO is returned. Otherwise,
-ENOMEM or -EINVAL is returned depending on the error from
__map_sg_chunk().
Signed-off-by: Martin Oliveira <martin.oliveira@eideticom.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

arch/arm/mm/dma-mapping.c

@@ -980,7 +980,7 @@ int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 	struct scatterlist *s;
-	int i, j;
+	int i, j, ret;
 
 	for_each_sg(sg, s, nents, i) {
 #ifdef CONFIG_NEED_SG_DMA_LENGTH
@@ -988,15 +988,17 @@ int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 #endif
 		s->dma_address = ops->map_page(dev, sg_page(s), s->offset,
 						s->length, dir, attrs);
-		if (dma_mapping_error(dev, s->dma_address))
+		if (dma_mapping_error(dev, s->dma_address)) {
+			ret = -EIO;
 			goto bad_mapping;
+		}
 	}
 	return nents;
 
  bad_mapping:
 	for_each_sg(sg, s, i, j)
 		ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs);
-	return 0;
+	return ret;
 }
 
 /**
@@ -1622,7 +1624,7 @@ static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 		     bool is_coherent)
 {
 	struct scatterlist *s = sg, *dma = sg, *start = sg;
-	int i, count = 0;
+	int i, count = 0, ret;
 	unsigned int offset = s->offset;
 	unsigned int size = s->offset + s->length;
 	unsigned int max = dma_get_max_seg_size(dev);
@@ -1634,8 +1636,10 @@ static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 		s->dma_length = 0;
 
 		if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) {
-			if (__map_sg_chunk(dev, start, size, &dma->dma_address,
-			    dir, attrs, is_coherent) < 0)
+			ret = __map_sg_chunk(dev, start, size,
+					     &dma->dma_address, dir, attrs,
+					     is_coherent);
+			if (ret < 0)
 				goto bad_mapping;
 
 			dma->dma_address += offset;
@@ -1648,8 +1652,9 @@ static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 		}
 		size += s->length;
 	}
-	if (__map_sg_chunk(dev, start, size, &dma->dma_address, dir, attrs,
-		is_coherent) < 0)
+	ret = __map_sg_chunk(dev, start, size, &dma->dma_address, dir, attrs,
+			     is_coherent);
+	if (ret < 0)
 		goto bad_mapping;
 
 	dma->dma_address += offset;
@@ -1660,7 +1665,9 @@ static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 bad_mapping:
 	for_each_sg(sg, s, count, i)
 		__iommu_remove_mapping(dev, sg_dma_address(s), sg_dma_len(s));
-	return 0;
+	if (ret == -ENOMEM)
+		return ret;
+	return -EINVAL;
 }
 
 /**