[Nouveau] [PATCH 16/18] dma-mapping: add new {alloc, free}_noncoherent dma_map_ops methods

[Christoph Hellwig]

This will allow IOMMU drivers to allocate non-contigous memory and
return a vmapped virtual address.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 include/linux/dma-mapping.h |  5 +++++
 kernel/dma/mapping.c        | 33 +++++++++++++++++++++++++++------
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index bf592cf0db4acb..b4b5d75260d6dc 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -80,6 +80,11 @@ struct dma_map_ops {
                        gfp_t gfp);
        void (*free_pages)(struct device *dev, size_t size, struct page *vaddr,
                        dma_addr_t dma_handle, enum dma_data_direction dir);
+       void* (*alloc_noncoherent)(struct device *dev, size_t size,
+                       dma_addr_t *dma_handle, enum dma_data_direction dir,
+                       gfp_t gfp);
+       void (*free_noncoherent)(struct device *dev, size_t size, void *vaddr,
+                       dma_addr_t dma_handle, enum dma_data_direction dir);
        int (*mmap)(struct device *, struct vm_area_struct *,
                          void *, dma_addr_t, size_t,
                          unsigned long attrs);
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 6f86c925b8251d..8614d7d2ee59a9 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -502,19 +502,40 @@ EXPORT_SYMBOL_GPL(dma_free_pages);
 void *dma_alloc_noncoherent(struct device *dev, size_t size,
                dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
 {
-       struct page *page;
+       const struct dma_map_ops *ops = get_dma_ops(dev);
+       void *vaddr;
 
-       page = dma_alloc_pages(dev, size, dma_handle, dir, gfp);
-       if (!page)
-               return NULL;
-       return page_address(page);
+       if (!ops || !ops->alloc_noncoherent) {
+               struct page *page;
+
+               page = dma_alloc_pages(dev, size, dma_handle, dir, gfp);
+               if (!page)
+                       return NULL;
+               return page_address(page);
+       }
+
+       size = PAGE_ALIGN(size);
+       vaddr = ops->alloc_noncoherent(dev, size, dma_handle, dir, gfp);
+       if (vaddr)
+               debug_dma_map_page(dev, virt_to_page(vaddr), 0, size, dir,
+                                  *dma_handle);
+       return vaddr;
 }
 EXPORT_SYMBOL_GPL(dma_alloc_noncoherent);
 
 void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
                dma_addr_t dma_handle, enum dma_data_direction dir)
 {
-       dma_free_pages(dev, size, virt_to_page(vaddr), dma_handle, dir);
+       const struct dma_map_ops *ops = get_dma_ops(dev);
+
+       if (!ops || !ops->free_noncoherent) {
+               dma_free_pages(dev, size, virt_to_page(vaddr), dma_handle, dir);
+               return;
+       }
+
+       size = PAGE_ALIGN(size);
+       debug_dma_unmap_page(dev, dma_handle, size, dir);
+       ops->free_noncoherent(dev, size, vaddr, dma_handle, dir);
 }
 EXPORT_SYMBOL_GPL(dma_free_noncoherent);
 
-- 
2.28.0

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