1 files changed, 40 insertions, 7 deletions

diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index db7244291b74..49cbf3e33de7 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -197,7 +197,7 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
 	if (ents > 0)
 		debug_dma_map_sg(dev, sg, nents, ents, dir, attrs);
 	else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM &&
-			      ents != -EIO))
+			      ents != -EIO && ents != -EREMOTEIO))
 		return -EIO;
 
 	return ents;
@@ -249,12 +249,15 @@ EXPORT_SYMBOL(dma_map_sg_attrs);
  * Returns 0 on success or a negative error code on error. The following
  * error codes are supported with the given meaning:
  *
- *   -EINVAL	An invalid argument, unaligned access or other error
- *		in usage. Will not succeed if retried.
- *   -ENOMEM	Insufficient resources (like memory or IOVA space) to
- *		complete the mapping. Should succeed if retried later.
- *   -EIO	Legacy error code with an unknown meaning. eg. this is
- *		returned if a lower level call returned DMA_MAPPING_ERROR.
+ *   -EINVAL		An invalid argument, unaligned access or other error
+ *			in usage. Will not succeed if retried.
+ *   -ENOMEM		Insufficient resources (like memory or IOVA space) to
+ *			complete the mapping. Should succeed if retried later.
+ *   -EIO		Legacy error code with an unknown meaning. eg. this is
+ *			returned if a lower level call returned
+ *			DMA_MAPPING_ERROR.
+ *   -EREMOTEIO		The DMA device cannot access P2PDMA memory specified
+ *			in the sg_table. This will not succeed if retried.
  */
 int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
 		    enum dma_data_direction dir, unsigned long attrs)
@@ -720,6 +723,24 @@ int dma_supported(struct device *dev, u64 mask)
 }
 EXPORT_SYMBOL(dma_supported);
 
+bool dma_pci_p2pdma_supported(struct device *dev)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	/* if ops is not set, dma direct will be used which supports P2PDMA */
+	if (!ops)
+		return true;
+
+	/*
+	 * Note: dma_ops_bypass is not checked here because P2PDMA should
+	 * not be used with dma mapping ops that do not have support even
+	 * if the specific device is bypassing them.
+	 */
+
+	return ops->flags & DMA_F_PCI_P2PDMA_SUPPORTED;
+}
+EXPORT_SYMBOL_GPL(dma_pci_p2pdma_supported);
+
 #ifdef CONFIG_ARCH_HAS_DMA_SET_MASK
 void arch_dma_set_mask(struct device *dev, u64 mask);
 #else
@@ -773,6 +794,18 @@ size_t dma_max_mapping_size(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(dma_max_mapping_size);
 
+size_t dma_opt_mapping_size(struct device *dev)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+	size_t size = SIZE_MAX;
+
+	if (ops && ops->opt_mapping_size)
+		size = ops->opt_mapping_size();
+
+	return min(dma_max_mapping_size(dev), size);
+}
+EXPORT_SYMBOL_GPL(dma_opt_mapping_size);
+
 bool dma_need_sync(struct device *dev, dma_addr_t dma_addr)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);