net_dma: simple removal

Per commit "77873803363c net_dma: mark broken" net_dma is no longer used
and there is no plan to fix it.

This is the mechanical removal of bits in CONFIG_NET_DMA ifdef guards.
Reverting the remainder of the net_dma induced changes is deferred to
subsequent patches.

Marked for stable due to Roman's report of a memory leak in
dma_pin_iovec_pages():

    https://lkml.org/lkml/2014/9/3/177

Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: David Whipple <whipple@securedatainnovations.ch>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: <stable@vger.kernel.org>
Reported-by: Roman Gushchin <klamm@yandex-team.ru>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

4 files changed, 0 insertions, 148 deletions

diff --git a/net/core/Makefile b/net/core/Makefile
index 9628c20acff6..5038f1ea0349 100644
--- a/net/core/Makefile
+++ b/net/core/Makefile
@@ -16,7 +16,6 @@ obj-y += net-sysfs.o
 obj-$(CONFIG_PROC_FS) += net-procfs.o
 obj-$(CONFIG_NET_PKTGEN) += pktgen.o
 obj-$(CONFIG_NETPOLL) += netpoll.o
-obj-$(CONFIG_NET_DMA) += user_dma.o
 obj-$(CONFIG_FIB_RULES) += fib_rules.o
 obj-$(CONFIG_TRACEPOINTS) += net-traces.o
 obj-$(CONFIG_NET_DROP_MONITOR) += drop_monitor.o
diff --git a/net/core/dev.c b/net/core/dev.c
index b1b0c8d4d7df..5e37e9abe8c5 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1266,7 +1266,6 @@ static int __dev_open(struct net_device *dev)
 		clear_bit(__LINK_STATE_START, &dev->state);
 	else {
 		dev->flags |= IFF_UP;
-		net_dmaengine_get();
 		dev_set_rx_mode(dev);
 		dev_activate(dev);
 		add_device_randomness(dev->dev_addr, dev->addr_len);
@@ -1342,7 +1341,6 @@ static int __dev_close_many(struct list_head *head)
 			ops->ndo_stop(dev);
 
 		dev->flags &= ~IFF_UP;
-		net_dmaengine_put();
 	}
 
 	return 0;
@@ -4405,14 +4403,6 @@ static void net_rx_action(struct softirq_action *h)
 out:
 	net_rps_action_and_irq_enable(sd);
 
-#ifdef CONFIG_NET_DMA
-	/*
-	 * There may not be any more sk_buffs coming right now, so push
-	 * any pending DMA copies to hardware
-	 */
-	dma_issue_pending_all();
-#endif
-
 	return;
 
 softnet_break:
diff --git a/net/core/sock.c b/net/core/sock.c
index c0fc6bdad1e3..2f143c3b190a 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1452,9 +1452,6 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
 		atomic_set(&newsk->sk_omem_alloc, 0);
 		skb_queue_head_init(&newsk->sk_receive_queue);
 		skb_queue_head_init(&newsk->sk_write_queue);
-#ifdef CONFIG_NET_DMA
-		skb_queue_head_init(&newsk->sk_async_wait_queue);
-#endif
 
 		spin_lock_init(&newsk->sk_dst_lock);
 		rwlock_init(&newsk->sk_callback_lock);
@@ -2265,9 +2262,6 @@ void sock_init_data(struct socket *sock, struct sock *sk)
 	skb_queue_head_init(&sk->sk_receive_queue);
 	skb_queue_head_init(&sk->sk_write_queue);
 	skb_queue_head_init(&sk->sk_error_queue);
-#ifdef CONFIG_NET_DMA
-	skb_queue_head_init(&sk->sk_async_wait_queue);
-#endif
 
 	sk->sk_send_head	=	NULL;
 
diff --git a/net/core/user_dma.c b/net/core/user_dma.c
deleted file mode 100644
index 1b5fefdb8198..000000000000
--- a/net/core/user_dma.c
+++ /dev/null
@@ -1,131 +0,0 @@
-/*
- * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved.
- * Portions based on net/core/datagram.c and copyrighted by their authors.
- *
- * 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.
- */
-
-/*
- * This code allows the net stack to make use of a DMA engine for
- * skb to iovec copies.
- */
-
-#include <linux/dmaengine.h>
-#include <linux/socket.h>
-#include <linux/export.h>
-#include <net/tcp.h>
-#include <net/netdma.h>
-
-#define NET_DMA_DEFAULT_COPYBREAK 4096
-
-int sysctl_tcp_dma_copybreak = NET_DMA_DEFAULT_COPYBREAK;
-EXPORT_SYMBOL(sysctl_tcp_dma_copybreak);
-
-/**
- *	dma_skb_copy_datagram_iovec - Copy a datagram to an iovec.
- *	@skb - buffer to copy
- *	@offset - offset in the buffer to start copying from
- *	@iovec - io vector to copy to
- *	@len - amount of data to copy from buffer to iovec
- *	@pinned_list - locked iovec buffer data
- *
- *	Note: the iovec is modified during the copy.
- */
-int dma_skb_copy_datagram_iovec(struct dma_chan *chan,
-			struct sk_buff *skb, int offset, struct iovec *to,
-			size_t len, struct dma_pinned_list *pinned_list)
-{
-	int start = skb_headlen(skb);
-	int i, copy = start - offset;
-	struct sk_buff *frag_iter;
-	dma_cookie_t cookie = 0;
-
-	/* Copy header. */
-	if (copy > 0) {
-		if (copy > len)
-			copy = len;
-		cookie = dma_memcpy_to_iovec(chan, to, pinned_list,
-					    skb->data + offset, copy);
-		if (cookie < 0)
-			goto fault;
-		len -= copy;
-		if (len == 0)
-			goto end;
-		offset += copy;
-	}
-
-	/* Copy paged appendix. Hmm... why does this look so complicated? */
-	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
-		int end;
-		const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
-
-		WARN_ON(start > offset + len);
-
-		end = start + skb_frag_size(frag);
-		copy = end - offset;
-		if (copy > 0) {
-			struct page *page = skb_frag_page(frag);
-
-			if (copy > len)
-				copy = len;
-
-			cookie = dma_memcpy_pg_to_iovec(chan, to, pinned_list, page,
-					frag->page_offset + offset - start, copy);
-			if (cookie < 0)
-				goto fault;
-			len -= copy;
-			if (len == 0)
-				goto end;
-			offset += copy;
-		}
-		start = end;
-	}
-
-	skb_walk_frags(skb, frag_iter) {
-		int end;
-
-		WARN_ON(start > offset + len);
-
-		end = start + frag_iter->len;
-		copy = end - offset;
-		if (copy > 0) {
-			if (copy > len)
-				copy = len;
-			cookie = dma_skb_copy_datagram_iovec(chan, frag_iter,
-							     offset - start,
-							     to, copy,
-							     pinned_list);
-			if (cookie < 0)
-				goto fault;
-			len -= copy;
-			if (len == 0)
-				goto end;
-			offset += copy;
-		}
-		start = end;
-	}
-
-end:
-	if (!len) {
-		skb->dma_cookie = cookie;
-		return cookie;
-	}
-
-fault:
-	return -EFAULT;
-}