On 05/30/2018 12:52 AM, Boris Ostrovsky wrote:
On 05/25/2018 11:33 AM, Oleksandr Andrushchenko wrote:
struct unmap_notify { @@ -96,10 +104,28 @@ struct grant_map { struct gnttab_unmap_grant_ref *kunmap_ops; struct page **pages; unsigned long pages_vm_start;
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
- /*
* If dmabuf_vaddr is not NULL then this mapping is backed by DMA* capable memory.*/- /* Device for which DMA memory is allocated. */
- struct device *dma_dev;
- /* Flags used to create this DMA buffer: GNTDEV_DMABUF_FLAG_XXX. */
- bool dma_flags;
Again, I think most of the comments here can be dropped. Except possibly for the flags.
will drop most of those
- /* Virtual/CPU address of the DMA buffer. */
- void *dma_vaddr;
- /* Bus address of the DMA buffer. */
- dma_addr_t dma_bus_addr;
+#endif };
static int unmap_grant_pages(struct grant_map *map, int offset, int pages);
+static struct miscdevice gntdev_miscdev;
/* ------------------------------------------------------------------ */
static void gntdev_print_maps(struct gntdev_priv *priv,
@@ -121,8 +147,26 @@ static void gntdev_free_map(struct grant_map *map) if (map == NULL) return;
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
- if (map->dma_vaddr) {
struct gnttab_dma_alloc_args args;args.dev = map->dma_dev;args.coherent = map->dma_flags & GNTDEV_DMA_FLAG_COHERENT;args.nr_pages = map->count;args.pages = map->pages;args.vaddr = map->dma_vaddr;args.dev_bus_addr = map->dma_bus_addr;gnttab_dma_free_pages(&args);- } else if (map->pages) {
gnttab_free_pages(map->count, map->pages);- }
+#else if (map->pages) gnttab_free_pages(map->count, map->pages); +#endif
} else #endif if (map->pages) gnttab_free_pages(map->count, map->pages);
(and elsewhere)
ok, just wasn't sure if it is ok to violate kernel coding style here ;)
kfree(map->pages); kfree(map->grants); kfree(map->map_ops);
diff --git a/include/uapi/xen/gntdev.h b/include/uapi/xen/gntdev.h index 6d1163456c03..2d5a4672f07c 100644 --- a/include/uapi/xen/gntdev.h +++ b/include/uapi/xen/gntdev.h @@ -200,4 +200,19 @@ struct ioctl_gntdev_grant_copy { /* Send an interrupt on the indicated event channel */ #define UNMAP_NOTIFY_SEND_EVENT 0x2
+/*
- Flags to be used while requesting memory mapping's backing storage
- to be allocated with DMA API.
- */
+/*
- The buffer is backed with memory allocated with dma_alloc_wc.
- */
+#define GNTDEV_DMA_FLAG_WC (1 << 1)
Is there a reason you are not using bit 0?
No reason for that, will start from 0
-boris
Thank you, Oleksandr
+/*
- The buffer is backed with memory allocated with dma_alloc_coherent.
- */
+#define GNTDEV_DMA_FLAG_COHERENT (1 << 2)
- #endif /* __LINUX_PUBLIC_GNTDEV_H__ */