From 24afc360d535a866b8865f7796e13d954b7c697a Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Thu, 11 Sep 2008 04:51:14 -0700
Subject: [PATCH] --- yaml --- r: 111599 b: refs/heads/master c:
 a40c24a13366e324bc0ff8c3bb107db89312c984 h: refs/heads/master i:   111597:
 58b3a98eaafde2b63aca9049f7ad2fa769555560   111595:
 69a0e98244a9589bc8af3a1df97b13daf40704f4   111591:
 2e5b4dd1c4de64ad7886df7dbad81dadbd0e8b23   111583:
 52b50f0454a26efee88097aa721eab34a83c9fbe v: v3

---
 [refs]                       |  2 +-
 trunk/include/linux/skbuff.h |  8 +++++
 trunk/net/core/Makefile      |  1 +
 trunk/net/core/skb_dma_map.c | 66 ++++++++++++++++++++++++++++++++++++
 4 files changed, 76 insertions(+), 1 deletion(-)
 create mode 100644 trunk/net/core/skb_dma_map.c

diff --git a/[refs] b/[refs]
index 83a77c94df9f..c98278756a2f 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 271bff7afbb2cbaa81e744006ad2fff1f3e10b1b
+refs/heads/master: a40c24a13366e324bc0ff8c3bb107db89312c984
diff --git a/trunk/include/linux/skbuff.h b/trunk/include/linux/skbuff.h
index 4b2be23903c4..aa80ad9cbc88 100644
--- a/trunk/include/linux/skbuff.h
+++ b/trunk/include/linux/skbuff.h
@@ -359,6 +359,14 @@ struct sk_buff {
 
 #include <asm/system.h>
 
+#ifdef CONFIG_HAS_DMA
+#include <linux/dma-mapping.h>
+extern int skb_dma_map(struct device *dev, struct sk_buff *skb,
+		       enum dma_data_direction dir);
+extern void skb_dma_unmap(struct device *dev, struct sk_buff *skb,
+			  enum dma_data_direction dir);
+#endif
+
 extern void kfree_skb(struct sk_buff *skb);
 extern void	       __kfree_skb(struct sk_buff *skb);
 extern struct sk_buff *__alloc_skb(unsigned int size,
diff --git a/trunk/net/core/Makefile b/trunk/net/core/Makefile
index b1332f6d0042..26a37cb31923 100644
--- a/trunk/net/core/Makefile
+++ b/trunk/net/core/Makefile
@@ -6,6 +6,7 @@ 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/trunk/net/core/skb_dma_map.c b/trunk/net/core/skb_dma_map.c
new file mode 100644
index 000000000000..1f49afcd8e86
--- /dev/null
+++ b/trunk/net/core/skb_dma_map.c
@@ -0,0 +1,66 @@
+/* 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_maps[0] = 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 + 1] = map;
+	}
+	sp->num_dma_maps = i + 1;
+
+	return 0;
+
+unwind:
+	while (i-- >= 0) {
+		skb_frag_t *fp = &sp->frags[i];
+
+		dma_unmap_page(dev, sp->dma_maps[i + 1],
+			       fp->size, dir);
+	}
+	dma_unmap_single(dev, sp->dma_maps[0],
+			 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_maps[0],
+			 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 + 1],
+			       fp->size, dir);
+	}
+}
+EXPORT_SYMBOL(skb_dma_unmap);