From: Chuck Lever <chuck.lever@xxxxxxxxxx>
Cc: iommu@xxxxxxxxxxxxxxx
Cc: linux-rdma@xxxxxxxxxxxxxxx
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
include/linux/dma-map-ops.h | 4 +++
include/linux/dma-mapping.h | 4 +++
kernel/dma/mapping.c | 65 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 73 insertions(+)
diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h
index de2a50d9207a..69ecfd403249 100644
--- a/include/linux/dma-map-ops.h
+++ b/include/linux/dma-map-ops.h
@@ -60,6 +60,10 @@ struct dma_map_ops {
enum dma_data_direction dir, unsigned long attrs);
void (*unmap_sg)(struct device *dev, struct scatterlist *sg, int nents,
enum dma_data_direction dir, unsigned long attrs);
+ int (*map_bvecs)(struct device *dev, struct bio_vec *bvecs, int nents,
+ enum dma_data_direction dir, unsigned long attrs);
+ void (*unmap_bvecs)(struct device *dev, struct bio_vec *bvecs, int nents,
+ enum dma_data_direction dir, unsigned long attrs);
dma_addr_t (*map_resource)(struct device *dev, phys_addr_t phys_addr,
size_t size, enum dma_data_direction dir,
unsigned long attrs);
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 9fb422f376b6..6f522a82cfe3 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -114,6 +114,10 @@ void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
unsigned long attrs);
int dma_map_sgtable(struct device *dev, struct sg_table *sgt,
enum dma_data_direction dir, unsigned long attrs);
+unsigned int dma_map_bvecs_attrs(struct device *dev, struct bio_vec *bvecs,
+ int nents, enum dma_data_direction dir, unsigned long attrs);
+void dma_unmap_bvecs_attrs(struct device *dev, struct bio_vec *bvecs,
+ int nents, enum dma_data_direction dir, unsigned long attrs);
dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr,
size_t size, enum dma_data_direction dir, unsigned long attrs);
void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size,
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 94cffc9b45a5..f53cc4da2797 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -296,6 +296,71 @@ void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg,
}
EXPORT_SYMBOL(dma_unmap_sg_attrs);
+/**
+ * dma_map_sg_attrs - Map the given buffer for DMA
+ * @dev: The device for which to perform the DMA operation
+ * @bvecs: The bio_vec array describing the buffer
+ * @nents: Number of bio_vecs to map
+ * @dir: DMA direction
+ * @attrs: Optional DMA attributes for the map operation
+ *
+ * Maps a buffer described by a bio_vec array passed in the bvecs
+ * argument with nents segments for the @dir DMA operation by the
+ * @dev device.
+ *
+ * Returns the number of mapped entries (which can be less than nents)
+ * on success. Zero is returned for any error.
+ *
+ * dma_unmap_bvecs_attrs() should be used to unmap the buffer with the
+ * original bvecs and original nents (not the value returned by this
+ * function).
+ */
+unsigned int dma_map_bvecs_attrs(struct device *dev, struct bio_vec *bvecs,
+ int nents, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ const struct dma_map_ops *ops = get_dma_ops(dev);
+ int ents;
+
+ BUG_ON(!valid_dma_direction(dir));
+
+ if (WARN_ON_ONCE(!dev->dma_mask))
+ return 0;
+
+ if (dma_map_direct(dev, ops))
+ ents = dma_direct_map_bvecs(dev, bvecs, nents, dir, attrs);
+ else
+ ents = ops->map_bvecs(dev, bvecs, nents, dir, attrs);
+
+ if (ents > 0) {
+ kmsan_handle_dma_bvecs(bvecs, nents, dir);
+ debug_dma_map_bvecs(dev, bvecs, nents, ents, dir, attrs);
+ } else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM &&
+ ents != -EIO && ents != -EREMOTEIO)) {
+ return -EIO;
+ }
+
+ return ents;
+}
+EXPORT_SYMBOL_GPL(dma_map_bvecs_attrs);
+
+void dma_unmap_bvecs_attrs(struct device *dev, struct bio_vec *bvecs,
+ int nents, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ const struct dma_map_ops *ops = get_dma_ops(dev);
+
+ BUG_ON(!valid_dma_direction(dir));
+
+ debug_dma_unmap_bvecs(dev, bvecs, nents, dir);
+
+ if (dma_map_direct(dev, ops))
+ dma_direct_unmap_bvecs(dev, bvecs, nents, dir, attrs);
+ else if (ops->unmap_bvecs)
+ ops->unmap_bvecs(dev, bvecs, nents, dir, attrs);
+}
+EXPORT_SYMBOL(dma_unmap_bvecs_attrs);
+
dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
