skbuff: remove skb_dma_map/unmap

The two functions skb_dma_map/unmap are unsafe to use as they cause
problems when packets are cloned and sent to multiple devices while a HW
IOMMU is enabled.  Due to this it is best to remove the code so it is not
used by any other network driver maintainters.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 0 insertions, 66 deletions

diff --git a/net/core/Makefile b/net/core/Makefile
index 796f46eece5f..08791ac3e05a 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -6,7 +6,6 @@ obj-y := sock.o request_sock.o skbuff.o iovec.o datagram.o stream.o scm.o \
          gen_stats.o gen_estimator.o net_namespace.o
 
 obj-$(CONFIG_SYSCTL) += sysctl_net_core.o
-obj-$(CONFIG_HAS_DMA) += skb_dma_map.o
 
 obj-y                += dev.o ethtool.o dev_mcast.o dst.o netevent.o \
                         neighbour.o rtnetlink.o utils.o link_watch.o filter.o
diff --git a/net/core/skb_dma_map.c b/net/core/skb_dma_map.c
deleted file mode 100644
index 79687dfd6957..000000000000
--- a/net/core/skb_dma_map.c
+++ /dev/null
@@ -1,65 +0,0 @@
-/* skb_dma_map.c: DMA mapping helpers for socket buffers.
- *
- * Copyright (C) David S. Miller <davem@davemloft.net>
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/dma-mapping.h>
-#include <linux/skbuff.h>
-
-int skb_dma_map(struct device *dev, struct sk_buff *skb,
-                enum dma_data_direction dir)
-{
-        struct skb_shared_info *sp = skb_shinfo(skb);
-        dma_addr_t map;
-        int i;
-
-        map = dma_map_single(dev, skb->data,
-                             skb_headlen(skb), dir);
-        if (dma_mapping_error(dev, map))
-                goto out_err;
-
-        sp->dma_head = map;
-        for (i = 0; i < sp->nr_frags; i++) {
-                skb_frag_t *fp = &sp->frags[i];
-
-                map = dma_map_page(dev, fp->page, fp->page_offset,
-                                   fp->size, dir);
-                if (dma_mapping_error(dev, map))
-                        goto unwind;
-                sp->dma_maps[i] = map;
-        }
-
-        return 0;
-
-unwind:
-        while (--i >= 0) {
-                skb_frag_t *fp = &sp->frags[i];
-
-                dma_unmap_page(dev, sp->dma_maps[i],
-                               fp->size, dir);
-        }
-        dma_unmap_single(dev, sp->dma_head,
-                         skb_headlen(skb), dir);
-out_err:
-        return -ENOMEM;
-}
-EXPORT_SYMBOL(skb_dma_map);
-
-void skb_dma_unmap(struct device *dev, struct sk_buff *skb,
-                   enum dma_data_direction dir)
-{
-        struct skb_shared_info *sp = skb_shinfo(skb);
-        int i;
-
-        dma_unmap_single(dev, sp->dma_head,
-                         skb_headlen(skb), dir);
-        for (i = 0; i < sp->nr_frags; i++) {
-                skb_frag_t *fp = &sp->frags[i];
-
-                dma_unmap_page(dev, sp->dma_maps[i],
-                               fp->size, dir);
-        }
-}
-EXPORT_SYMBOL(skb_dma_unmap);