Merge tag 'dma-mapping-6.12-2024-09-24' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - sort out a few issues with the direct calls to iommu-dma (Christoph
   Hellwig, Leon Romanovsky)

* tag 'dma-mapping-6.12-2024-09-24' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: report unlimited DMA addressing in IOMMU DMA path
  iommu/dma: remove most stubs in iommu-dma.h
  dma-mapping: fix vmap and mmap of noncontiougs allocations

1 files changed, 33 insertions, 0 deletions

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 3672d619bcb6..2a9fa0c8cc00 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1038,6 +1038,21 @@ out_unmap:
 	return NULL;
 }
 
+/*
+ * This is the actual return value from the iommu_dma_alloc_noncontiguous.
+ *
+ * The users of the DMA API should only care about the sg_table, but to make
+ * the DMA-API internal vmaping and freeing easier we stash away the page
+ * array as well (except for the fallback case).  This can go away any time,
+ * e.g. when a vmap-variant that takes a scatterlist comes along.
+ */
+struct dma_sgt_handle {
+	struct sg_table sgt;
+	struct page **pages;
+};
+#define sgt_handle(sgt) \
+	container_of((sgt), struct dma_sgt_handle, sgt)
+
 struct sg_table *iommu_dma_alloc_noncontiguous(struct device *dev, size_t size,
 	       enum dma_data_direction dir, gfp_t gfp, unsigned long attrs)
 {
@@ -1066,6 +1081,24 @@ void iommu_dma_free_noncontiguous(struct device *dev, size_t size,
 	kfree(sh);
 }
 
+void *iommu_dma_vmap_noncontiguous(struct device *dev, size_t size,
+		struct sg_table *sgt)
+{
+	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+	return vmap(sgt_handle(sgt)->pages, count, VM_MAP, PAGE_KERNEL);
+}
+
+int iommu_dma_mmap_noncontiguous(struct device *dev, struct vm_area_struct *vma,
+		size_t size, struct sg_table *sgt)
+{
+	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+	if (vma->vm_pgoff >= count || vma_pages(vma) > count - vma->vm_pgoff)
+		return -ENXIO;
+	return vm_map_pages(vma, sgt_handle(sgt)->pages, count);
+}
+
 void iommu_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
 		size_t size, enum dma_data_direction dir)
 {