[I/OAT]: Setup the networking subsystem as a DMA client

Attempts to allocate per-CPU DMA channels

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netdevice.h

@@ -37,6 +37,7 @@
 #include <linux/config.h>
 #include <linux/device.h>
 #include <linux/percpu.h>
+#include <linux/dmaengine.h>
 
 struct divert_blk;
 struct vlan_group;
@@ -593,6 +594,9 @@ struct softnet_data
 	struct sk_buff		*completion_queue;
 
 	struct net_device	backlog_dev;	/* Sorry. 8) */
+#ifdef CONFIG_NET_DMA
+	struct dma_chan		*net_dma;
+#endif
 };
 
 DECLARE_PER_CPU(struct softnet_data,softnet_data);

include/net/netdma.h

@@ -0,0 +1,38 @@
+/*
+ * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * The full GNU General Public License is included in this distribution in the
+ * file called COPYING.
+ */
+#ifndef NETDMA_H
+#define NETDMA_H
+#include <linux/config.h>
+#ifdef CONFIG_NET_DMA
+#include <linux/dmaengine.h>
+
+static inline struct dma_chan *get_softnet_dma(void)
+{
+	struct dma_chan *chan;
+	rcu_read_lock();
+	chan = rcu_dereference(__get_cpu_var(softnet_data.net_dma));
+	if (chan)
+		dma_chan_get(chan);
+	rcu_read_unlock();
+	return chan;
+}
+#endif /* CONFIG_NET_DMA */
+#endif /* NETDMA_H */