[Xen-devel] [RFC 2/3] xen/grant-table: Extend API to work with DMA buffers

[Oleksandr Andrushchenko <andr2000@xxxxxxxxx>]

From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
---
 drivers/xen/grant-table.c | 49 +++++++++++++++++++++++++++++++++++++++
 include/xen/grant_table.h |  7 ++++++
 2 files changed, 56 insertions(+)

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index bb36b1e1dbcc..c27bcc420575 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -729,6 +729,55 @@ void gnttab_free_pages(int nr_pages, struct page **pages)
 }
 EXPORT_SYMBOL(gnttab_free_pages);
 
+int gnttab_dma_alloc_pages(struct device *dev, bool coherent,
+                          int nr_pages, struct page **pages,
+                          void **vaddr, dma_addr_t *dev_bus_addr)
+{
+       int i;
+       int ret;
+
+       ret = alloc_dma_xenballooned_pages(dev, coherent, nr_pages, pages,
+                                          vaddr, dev_bus_addr);
+       if (ret < 0)
+               return ret;
+
+       for (i = 0; i < nr_pages; i++) {
+#if BITS_PER_LONG < 64
+               struct xen_page_foreign *foreign;
+
+               foreign = kzalloc(sizeof(*foreign), GFP_KERNEL);
+               if (!foreign) {
+                       gnttab_dma_free_pages(dev, flags, nr_pages, pages,
+                                             *vaddr, *dev_bus_addr);
+                       return -ENOMEM;
+               }
+               set_page_private(pages[i], (unsigned long)foreign);
+#endif
+               SetPagePrivate(pages[i]);
+       }
+       return 0;
+}
+EXPORT_SYMBOL(gnttab_dma_alloc_pages);
+
+void gnttab_dma_free_pages(struct device *dev, bool coherent,
+                          int nr_pages, struct page **pages,
+                          void *vaddr, dma_addr_t dev_bus_addr)
+{
+       int i;
+
+       for (i = 0; i < nr_pages; i++) {
+               if (PagePrivate(pages[i])) {
+#if BITS_PER_LONG < 64
+                       kfree((void *)page_private(pages[i]));
+#endif
+                       ClearPagePrivate(pages[i]);
+               }
+       }
+       free_dma_xenballooned_pages(dev, coherent, nr_pages, pages,
+                                   vaddr, dev_bus_addr);
+}
+EXPORT_SYMBOL(gnttab_dma_free_pages);
+
 /* Handling of paged out grant targets (GNTST_eagain) */
 #define MAX_DELAY 256
 static inline void
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index 34b1379f9777..20ee2b5ba965 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -195,6 +195,13 @@ void gnttab_free_auto_xlat_frames(void);
 int gnttab_alloc_pages(int nr_pages, struct page **pages);
 void gnttab_free_pages(int nr_pages, struct page **pages);
 
+int gnttab_dma_alloc_pages(struct device *dev, bool coherent,
+                          int nr_pages, struct page **pages,
+                          void **vaddr, dma_addr_t *dev_bus_addr);
+void gnttab_dma_free_pages(struct device *dev, bool coherent,
+                          int nr_pages, struct page **pages,
+                          void *vaddr, dma_addr_t dev_bus_addr);
+
 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
                    struct gnttab_map_grant_ref *kmap_ops,
                    struct page **pages, unsigned int count);
-- 
2.17.0


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel