iommu/dma: add a new dma_map_ops of get_merge_boundary()

This patch adds a new dma_map_ops of get_merge_boundary() to
expose the DMA merge boundary if the domain type is IOMMU_DOMAIN_DMA.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index f68a62c3c32b55e1414ee5eff0cc34a452f38489..ef407e4eccdeae3fcfde0401b2affbaa63f5558a 100644 (file)
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1086,6 +1086,13 @@ static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
        return ret;
 }
 
+static unsigned long iommu_dma_get_merge_boundary(struct device *dev)
+{
+       struct iommu_domain *domain = iommu_get_dma_domain(dev);
+
+       return (1UL << __ffs(domain->pgsize_bitmap)) - 1;
+}
+
 static const struct dma_map_ops iommu_dma_ops = {
        .alloc                  = iommu_dma_alloc,
        .free                   = iommu_dma_free,
@@ -1101,6 +1108,7 @@ static const struct dma_map_ops iommu_dma_ops = {
        .sync_sg_for_device     = iommu_dma_sync_sg_for_device,
        .map_resource           = iommu_dma_map_resource,
        .unmap_resource         = iommu_dma_unmap_resource,
+       .get_merge_boundary     = iommu_dma_get_merge_boundary,
 };
 
 /*