[3.13.y.z extended stable] Patch "net_dma: simple removal" has been added to staging queue

Kamal Mostafa kamal at canonical.com
Tue Oct 21 20:09:24 UTC 2014


This is a note to let you know that I have just added a patch titled

    net_dma: simple removal

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.10.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 0520847cc69fd793cb9eb4f873e5a82e3b8c8b90 Mon Sep 17 00:00:00 2001
From: Dan Williams <dan.j.williams at intel.com>
Date: Mon, 30 Dec 2013 12:37:29 -0800
Subject: net_dma: simple removal

commit 7bced397510ab569d31de4c70b39e13355046387 upstream.

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 at intel.com>
Cc: Vinod Koul <vinod.koul at intel.com>
Cc: David Whipple <whipple at securedatainnovations.ch>
Cc: Alexander Duyck <alexander.h.duyck at intel.com>
Reported-by: Roman Gushchin <klamm at yandex-team.ru>
Acked-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Dan Williams <dan.j.williams at intel.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 Documentation/ABI/removed/net_dma      |   8 +
 Documentation/networking/ip-sysctl.txt |   6 -
 drivers/dma/Kconfig                    |  12 --
 drivers/dma/Makefile                   |   1 -
 drivers/dma/dmaengine.c                | 104 ------------
 drivers/dma/ioat/dma.c                 |   1 -
 drivers/dma/ioat/dma.h                 |   7 -
 drivers/dma/ioat/dma_v2.c              |   1 -
 drivers/dma/ioat/dma_v3.c              |   1 -
 drivers/dma/iovlock.c                  | 280 ---------------------------------
 include/linux/dmaengine.h              |  22 +--
 include/linux/skbuff.h                 |   8 +-
 include/linux/tcp.h                    |   8 -
 include/net/netdma.h                   |  32 ----
 include/net/sock.h                     |  19 +--
 include/net/tcp.h                      |   8 -
 kernel/sysctl_binary.c                 |   1 -
 net/core/Makefile                      |   1 -
 net/core/dev.c                         |  10 --
 net/core/sock.c                        |   6 -
 net/core/user_dma.c                    | 131 ---------------
 net/dccp/proto.c                       |   4 +-
 net/ipv4/sysctl_net_ipv4.c             |   9 --
 net/ipv4/tcp.c                         | 147 ++---------------
 net/ipv4/tcp_input.c                   |  61 -------
 net/ipv4/tcp_ipv4.c                    |  18 +--
 net/ipv6/tcp_ipv6.c                    |  13 +-
 net/llc/af_llc.c                       |  10 +-
 28 files changed, 35 insertions(+), 894 deletions(-)
 create mode 100644 Documentation/ABI/removed/net_dma
 delete mode 100644 drivers/dma/iovlock.c
 delete mode 100644 include/net/netdma.h
 delete mode 100644 net/core/user_dma.c

diff --git a/Documentation/ABI/removed/net_dma b/Documentation/ABI/removed/net_dma
new file mode 100644
index 0000000..a173aec
--- /dev/null
+++ b/Documentation/ABI/removed/net_dma
@@ -0,0 +1,8 @@
+What:		tcp_dma_copybreak sysctl
+Date:		Removed in kernel v3.13
+Contact:	Dan Williams <dan.j.williams at intel.com>
+Description:
+	Formerly the lower limit, in bytes, of the size of socket reads
+	that will be offloaded to a DMA copy engine.  Removed due to
+	coherency issues of the cpu potentially touching the buffers
+	while dma is in flight.
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 8a984e9..b4be7fd 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -542,12 +542,6 @@ tcp_workaround_signed_windows - BOOLEAN
 	not receive a window scaling option from them.
 	Default: 0

-tcp_dma_copybreak - INTEGER
-	Lower limit, in bytes, of the size of socket reads that will be
-	offloaded to a DMA copy engine, if one is present in the system
-	and CONFIG_NET_DMA is enabled.
-	Default: 4096
-
 tcp_thin_linear_timeouts - BOOLEAN
 	Enable dynamic triggering of linear timeouts for thin streams.
 	If set, a check is performed upon retransmission by timeout to
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index c823daa..b24f131 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -351,18 +351,6 @@ config DMA_OF
 comment "DMA Clients"
 	depends on DMA_ENGINE

-config NET_DMA
-	bool "Network: TCP receive copy offload"
-	depends on DMA_ENGINE && NET
-	default (INTEL_IOATDMA || FSL_DMA)
-	depends on BROKEN
-	help
-	  This enables the use of DMA engines in the network stack to
-	  offload receive copy-to-user operations, freeing CPU cycles.
-
-	  Say Y here if you enabled INTEL_IOATDMA or FSL_DMA, otherwise
-	  say N.
-
 config ASYNC_TX_DMA
 	bool "Async_tx: Offload support for the async_tx api"
 	depends on DMA_ENGINE
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 0ce2da9..024b008 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -6,7 +6,6 @@ obj-$(CONFIG_DMA_VIRTUAL_CHANNELS) += virt-dma.o
 obj-$(CONFIG_DMA_ACPI) += acpi-dma.o
 obj-$(CONFIG_DMA_OF) += of-dma.o

-obj-$(CONFIG_NET_DMA) += iovlock.o
 obj-$(CONFIG_INTEL_MID_DMAC) += intel_mid_dma.o
 obj-$(CONFIG_DMATEST) += dmatest.o
 obj-$(CONFIG_INTEL_IOATDMA) += ioat/
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index b4c711d..4fd4269 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -1031,110 +1031,6 @@ dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags)
 }
 EXPORT_SYMBOL(dmaengine_get_unmap_data);

-/**
- * dma_async_memcpy_pg_to_pg - offloaded copy from page to page
- * @chan: DMA channel to offload copy to
- * @dest_pg: destination page
- * @dest_off: offset in page to copy to
- * @src_pg: source page
- * @src_off: offset in page to copy from
- * @len: length
- *
- * Both @dest_page/@dest_off and @src_page/@src_off must be mappable to a bus
- * address according to the DMA mapping API rules for streaming mappings.
- * Both @dest_page/@dest_off and @src_page/@src_off must stay memory resident
- * (kernel memory or locked user space pages).
- */
-dma_cookie_t
-dma_async_memcpy_pg_to_pg(struct dma_chan *chan, struct page *dest_pg,
-	unsigned int dest_off, struct page *src_pg, unsigned int src_off,
-	size_t len)
-{
-	struct dma_device *dev = chan->device;
-	struct dma_async_tx_descriptor *tx;
-	struct dmaengine_unmap_data *unmap;
-	dma_cookie_t cookie;
-	unsigned long flags;
-
-	unmap = dmaengine_get_unmap_data(dev->dev, 2, GFP_NOWAIT);
-	if (!unmap)
-		return -ENOMEM;
-
-	unmap->to_cnt = 1;
-	unmap->from_cnt = 1;
-	unmap->addr[0] = dma_map_page(dev->dev, src_pg, src_off, len,
-				      DMA_TO_DEVICE);
-	unmap->addr[1] = dma_map_page(dev->dev, dest_pg, dest_off, len,
-				      DMA_FROM_DEVICE);
-	unmap->len = len;
-	flags = DMA_CTRL_ACK;
-	tx = dev->device_prep_dma_memcpy(chan, unmap->addr[1], unmap->addr[0],
-					 len, flags);
-
-	if (!tx) {
-		dmaengine_unmap_put(unmap);
-		return -ENOMEM;
-	}
-
-	dma_set_unmap(tx, unmap);
-	cookie = tx->tx_submit(tx);
-	dmaengine_unmap_put(unmap);
-
-	preempt_disable();
-	__this_cpu_add(chan->local->bytes_transferred, len);
-	__this_cpu_inc(chan->local->memcpy_count);
-	preempt_enable();
-
-	return cookie;
-}
-EXPORT_SYMBOL(dma_async_memcpy_pg_to_pg);
-
-/**
- * dma_async_memcpy_buf_to_buf - offloaded copy between virtual addresses
- * @chan: DMA channel to offload copy to
- * @dest: destination address (virtual)
- * @src: source address (virtual)
- * @len: length
- *
- * Both @dest and @src must be mappable to a bus address according to the
- * DMA mapping API rules for streaming mappings.
- * Both @dest and @src must stay memory resident (kernel memory or locked
- * user space pages).
- */
-dma_cookie_t
-dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest,
-			    void *src, size_t len)
-{
-	return dma_async_memcpy_pg_to_pg(chan, virt_to_page(dest),
-					 (unsigned long) dest & ~PAGE_MASK,
-					 virt_to_page(src),
-					 (unsigned long) src & ~PAGE_MASK, len);
-}
-EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf);
-
-/**
- * dma_async_memcpy_buf_to_pg - offloaded copy from address to page
- * @chan: DMA channel to offload copy to
- * @page: destination page
- * @offset: offset in page to copy to
- * @kdata: source address (virtual)
- * @len: length
- *
- * Both @page/@offset and @kdata must be mappable to a bus address according
- * to the DMA mapping API rules for streaming mappings.
- * Both @page/@offset and @kdata must stay memory resident (kernel memory or
- * locked user space pages)
- */
-dma_cookie_t
-dma_async_memcpy_buf_to_pg(struct dma_chan *chan, struct page *page,
-			   unsigned int offset, void *kdata, size_t len)
-{
-	return dma_async_memcpy_pg_to_pg(chan, page, offset,
-					 virt_to_page(kdata),
-					 (unsigned long) kdata & ~PAGE_MASK, len);
-}
-EXPORT_SYMBOL(dma_async_memcpy_buf_to_pg);
-
 void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
 	struct dma_chan *chan)
 {
diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index 4e3549a..c1bceee 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -1222,7 +1222,6 @@ int ioat1_dma_probe(struct ioatdma_device *device, int dca)
 	err = ioat_probe(device);
 	if (err)
 		return err;
-	ioat_set_tcp_copy_break(4096);
 	err = ioat_register(device);
 	if (err)
 		return err;
diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
index e982f00..d63f68b 100644
--- a/drivers/dma/ioat/dma.h
+++ b/drivers/dma/ioat/dma.h
@@ -214,13 +214,6 @@ __dump_desc_dbg(struct ioat_chan_common *chan, struct ioat_dma_descriptor *hw,
 #define dump_desc_dbg(c, d) \
 	({ if (d) __dump_desc_dbg(&c->base, d->hw, &d->txd, desc_id(d)); 0; })

-static inline void ioat_set_tcp_copy_break(unsigned long copybreak)
-{
-	#ifdef CONFIG_NET_DMA
-	sysctl_tcp_dma_copybreak = copybreak;
-	#endif
-}
-
 static inline struct ioat_chan_common *
 ioat_chan_by_index(struct ioatdma_device *device, int index)
 {
diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c
index 8d10580..83169b6 100644
--- a/drivers/dma/ioat/dma_v2.c
+++ b/drivers/dma/ioat/dma_v2.c
@@ -899,7 +899,6 @@ int ioat2_dma_probe(struct ioatdma_device *device, int dca)
 	err = ioat_probe(device);
 	if (err)
 		return err;
-	ioat_set_tcp_copy_break(2048);

 	list_for_each_entry(c, &dma->channels, device_node) {
 		chan = to_chan_common(c);
diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c
index b9b38a1..d057372 100644
--- a/drivers/dma/ioat/dma_v3.c
+++ b/drivers/dma/ioat/dma_v3.c
@@ -1655,7 +1655,6 @@ int ioat3_dma_probe(struct ioatdma_device *device, int dca)
 	err = ioat_probe(device);
 	if (err)
 		return err;
-	ioat_set_tcp_copy_break(262144);

 	list_for_each_entry(c, &dma->channels, device_node) {
 		chan = to_chan_common(c);
diff --git a/drivers/dma/iovlock.c b/drivers/dma/iovlock.c
deleted file mode 100644
index bb48a57..0000000
--- a/drivers/dma/iovlock.c
+++ /dev/null
@@ -1,280 +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/pagemap.h>
-#include <linux/slab.h>
-#include <net/tcp.h> /* for memcpy_toiovec */
-#include <asm/io.h>
-#include <asm/uaccess.h>
-
-static int num_pages_spanned(struct iovec *iov)
-{
-	return
-	((PAGE_ALIGN((unsigned long)iov->iov_base + iov->iov_len) -
-	((unsigned long)iov->iov_base & PAGE_MASK)) >> PAGE_SHIFT);
-}
-
-/*
- * Pin down all the iovec pages needed for len bytes.
- * Return a struct dma_pinned_list to keep track of pages pinned down.
- *
- * We are allocating a single chunk of memory, and then carving it up into
- * 3 sections, the latter 2 whose size depends on the number of iovecs and the
- * total number of pages, respectively.
- */
-struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len)
-{
-	struct dma_pinned_list *local_list;
-	struct page **pages;
-	int i;
-	int ret;
-	int nr_iovecs = 0;
-	int iovec_len_used = 0;
-	int iovec_pages_used = 0;
-
-	/* don't pin down non-user-based iovecs */
-	if (segment_eq(get_fs(), KERNEL_DS))
-		return NULL;
-
-	/* determine how many iovecs/pages there are, up front */
-	do {
-		iovec_len_used += iov[nr_iovecs].iov_len;
-		iovec_pages_used += num_pages_spanned(&iov[nr_iovecs]);
-		nr_iovecs++;
-	} while (iovec_len_used < len);
-
-	/* single kmalloc for pinned list, page_list[], and the page arrays */
-	local_list = kmalloc(sizeof(*local_list)
-		+ (nr_iovecs * sizeof (struct dma_page_list))
-		+ (iovec_pages_used * sizeof (struct page*)), GFP_KERNEL);
-	if (!local_list)
-		goto out;
-
-	/* list of pages starts right after the page list array */
-	pages = (struct page **) &local_list->page_list[nr_iovecs];
-
-	local_list->nr_iovecs = 0;
-
-	for (i = 0; i < nr_iovecs; i++) {
-		struct dma_page_list *page_list = &local_list->page_list[i];
-
-		len -= iov[i].iov_len;
-
-		if (!access_ok(VERIFY_WRITE, iov[i].iov_base, iov[i].iov_len))
-			goto unpin;
-
-		page_list->nr_pages = num_pages_spanned(&iov[i]);
-		page_list->base_address = iov[i].iov_base;
-
-		page_list->pages = pages;
-		pages += page_list->nr_pages;
-
-		/* pin pages down */
-		down_read(&current->mm->mmap_sem);
-		ret = get_user_pages(
-			current,
-			current->mm,
-			(unsigned long) iov[i].iov_base,
-			page_list->nr_pages,
-			1,	/* write */
-			0,	/* force */
-			page_list->pages,
-			NULL);
-		up_read(&current->mm->mmap_sem);
-
-		if (ret != page_list->nr_pages)
-			goto unpin;
-
-		local_list->nr_iovecs = i + 1;
-	}
-
-	return local_list;
-
-unpin:
-	dma_unpin_iovec_pages(local_list);
-out:
-	return NULL;
-}
-
-void dma_unpin_iovec_pages(struct dma_pinned_list *pinned_list)
-{
-	int i, j;
-
-	if (!pinned_list)
-		return;
-
-	for (i = 0; i < pinned_list->nr_iovecs; i++) {
-		struct dma_page_list *page_list = &pinned_list->page_list[i];
-		for (j = 0; j < page_list->nr_pages; j++) {
-			set_page_dirty_lock(page_list->pages[j]);
-			page_cache_release(page_list->pages[j]);
-		}
-	}
-
-	kfree(pinned_list);
-}
-
-
-/*
- * We have already pinned down the pages we will be using in the iovecs.
- * Each entry in iov array has corresponding entry in pinned_list->page_list.
- * Using array indexing to keep iov[] and page_list[] in sync.
- * Initial elements in iov array's iov->iov_len will be 0 if already copied into
- *   by another call.
- * iov array length remaining guaranteed to be bigger than len.
- */
-dma_cookie_t dma_memcpy_to_iovec(struct dma_chan *chan, struct iovec *iov,
-	struct dma_pinned_list *pinned_list, unsigned char *kdata, size_t len)
-{
-	int iov_byte_offset;
-	int copy;
-	dma_cookie_t dma_cookie = 0;
-	int iovec_idx;
-	int page_idx;
-
-	if (!chan)
-		return memcpy_toiovec(iov, kdata, len);
-
-	iovec_idx = 0;
-	while (iovec_idx < pinned_list->nr_iovecs) {
-		struct dma_page_list *page_list;
-
-		/* skip already used-up iovecs */
-		while (!iov[iovec_idx].iov_len)
-			iovec_idx++;
-
-		page_list = &pinned_list->page_list[iovec_idx];
-
-		iov_byte_offset = ((unsigned long)iov[iovec_idx].iov_base & ~PAGE_MASK);
-		page_idx = (((unsigned long)iov[iovec_idx].iov_base & PAGE_MASK)
-			 - ((unsigned long)page_list->base_address & PAGE_MASK)) >> PAGE_SHIFT;
-
-		/* break up copies to not cross page boundary */
-		while (iov[iovec_idx].iov_len) {
-			copy = min_t(int, PAGE_SIZE - iov_byte_offset, len);
-			copy = min_t(int, copy, iov[iovec_idx].iov_len);
-
-			dma_cookie = dma_async_memcpy_buf_to_pg(chan,
-					page_list->pages[page_idx],
-					iov_byte_offset,
-					kdata,
-					copy);
-			/* poll for a descriptor slot */
-			if (unlikely(dma_cookie < 0)) {
-				dma_async_issue_pending(chan);
-				continue;
-			}
-
-			len -= copy;
-			iov[iovec_idx].iov_len -= copy;
-			iov[iovec_idx].iov_base += copy;
-
-			if (!len)
-				return dma_cookie;
-
-			kdata += copy;
-			iov_byte_offset = 0;
-			page_idx++;
-		}
-		iovec_idx++;
-	}
-
-	/* really bad if we ever run out of iovecs */
-	BUG();
-	return -EFAULT;
-}
-
-dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan *chan, struct iovec *iov,
-	struct dma_pinned_list *pinned_list, struct page *page,
-	unsigned int offset, size_t len)
-{
-	int iov_byte_offset;
-	int copy;
-	dma_cookie_t dma_cookie = 0;
-	int iovec_idx;
-	int page_idx;
-	int err;
-
-	/* this needs as-yet-unimplemented buf-to-buff, so punt. */
-	/* TODO: use dma for this */
-	if (!chan || !pinned_list) {
-		u8 *vaddr = kmap(page);
-		err = memcpy_toiovec(iov, vaddr + offset, len);
-		kunmap(page);
-		return err;
-	}
-
-	iovec_idx = 0;
-	while (iovec_idx < pinned_list->nr_iovecs) {
-		struct dma_page_list *page_list;
-
-		/* skip already used-up iovecs */
-		while (!iov[iovec_idx].iov_len)
-			iovec_idx++;
-
-		page_list = &pinned_list->page_list[iovec_idx];
-
-		iov_byte_offset = ((unsigned long)iov[iovec_idx].iov_base & ~PAGE_MASK);
-		page_idx = (((unsigned long)iov[iovec_idx].iov_base & PAGE_MASK)
-			 - ((unsigned long)page_list->base_address & PAGE_MASK)) >> PAGE_SHIFT;
-
-		/* break up copies to not cross page boundary */
-		while (iov[iovec_idx].iov_len) {
-			copy = min_t(int, PAGE_SIZE - iov_byte_offset, len);
-			copy = min_t(int, copy, iov[iovec_idx].iov_len);
-
-			dma_cookie = dma_async_memcpy_pg_to_pg(chan,
-					page_list->pages[page_idx],
-					iov_byte_offset,
-					page,
-					offset,
-					copy);
-			/* poll for a descriptor slot */
-			if (unlikely(dma_cookie < 0)) {
-				dma_async_issue_pending(chan);
-				continue;
-			}
-
-			len -= copy;
-			iov[iovec_idx].iov_len -= copy;
-			iov[iovec_idx].iov_base += copy;
-
-			if (!len)
-				return dma_cookie;
-
-			offset += copy;
-			iov_byte_offset = 0;
-			page_idx++;
-		}
-		iovec_idx++;
-	}
-
-	/* really bad if we ever run out of iovecs */
-	BUG();
-	return -EFAULT;
-}
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index ed6c1f1..acf5c78 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -876,18 +876,6 @@ static inline void dmaengine_put(void)
 }
 #endif

-#ifdef CONFIG_NET_DMA
-#define net_dmaengine_get()	dmaengine_get()
-#define net_dmaengine_put()	dmaengine_put()
-#else
-static inline void net_dmaengine_get(void)
-{
-}
-static inline void net_dmaengine_put(void)
-{
-}
-#endif
-
 #ifdef CONFIG_ASYNC_TX_DMA
 #define async_dmaengine_get()	dmaengine_get()
 #define async_dmaengine_put()	dmaengine_put()
@@ -909,16 +897,8 @@ async_dma_find_channel(enum dma_transaction_type type)
 	return NULL;
 }
 #endif /* CONFIG_ASYNC_TX_DMA */
-
-dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
-	void *dest, void *src, size_t len);
-dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,
-	struct page *page, unsigned int offset, void *kdata, size_t len);
-dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
-	struct page *dest_pg, unsigned int dest_off, struct page *src_pg,
-	unsigned int src_off, size_t len);
 void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
-	struct dma_chan *chan);
+				  struct dma_chan *chan);

 static inline void async_tx_ack(struct dma_async_tx_descriptor *tx)
 {
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 37cb679..1389001 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -28,7 +28,6 @@
 #include <linux/textsearch.h>
 #include <net/checksum.h>
 #include <linux/rcupdate.h>
-#include <linux/dmaengine.h>
 #include <linux/hrtimer.h>
 #include <linux/dma-mapping.h>
 #include <linux/netdev_features.h>
@@ -496,11 +495,8 @@ struct sk_buff {
 	/* 6/8 bit hole (depending on ndisc_nodetype presence) */
 	kmemcheck_bitfield_end(flags2);

-#if defined CONFIG_NET_DMA || defined CONFIG_NET_RX_BUSY_POLL
-	union {
-		unsigned int	napi_id;
-		dma_cookie_t	dma_cookie;
-	};
+#ifdef CONFIG_NET_RX_BUSY_POLL
+	unsigned int	napi_id;
 #endif
 #ifdef CONFIG_NETWORK_SECMARK
 	__u32			secmark;
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index d686334..26f1602 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -19,7 +19,6 @@


 #include <linux/skbuff.h>
-#include <linux/dmaengine.h>
 #include <net/sock.h>
 #include <net/inet_connection_sock.h>
 #include <net/inet_timewait_sock.h>
@@ -169,13 +168,6 @@ struct tcp_sock {
 		struct iovec		*iov;
 		int			memory;
 		int			len;
-#ifdef CONFIG_NET_DMA
-		/* members for async copy */
-		struct dma_chan		*dma_chan;
-		int			wakeup;
-		struct dma_pinned_list	*pinned_list;
-		dma_cookie_t		dma_cookie;
-#endif
 	} ucopy;

 	u32	snd_wl1;	/* Sequence for window update		*/
diff --git a/include/net/netdma.h b/include/net/netdma.h
deleted file mode 100644
index 8ba8ce2..0000000
--- a/include/net/netdma.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * 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
-#ifdef CONFIG_NET_DMA
-#include <linux/dmaengine.h>
-#include <linux/skbuff.h>
-
-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);
-
-#endif /* CONFIG_NET_DMA */
-#endif /* NETDMA_H */
diff --git a/include/net/sock.h b/include/net/sock.h
index 4d64744..749bad5 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -231,7 +231,6 @@ struct cg_proto;
   *	@sk_receive_queue: incoming packets
   *	@sk_wmem_alloc: transmit queue bytes committed
   *	@sk_write_queue: Packet sending queue
-  *	@sk_async_wait_queue: DMA copied packets
   *	@sk_omem_alloc: "o" is "option" or "other"
   *	@sk_wmem_queued: persistent queue size
   *	@sk_forward_alloc: space allocated forward
@@ -354,10 +353,6 @@ struct sock {
 	struct sk_filter __rcu	*sk_filter;
 	struct socket_wq __rcu	*sk_wq;

-#ifdef CONFIG_NET_DMA
-	struct sk_buff_head	sk_async_wait_queue;
-#endif
-
 #ifdef CONFIG_XFRM
 	struct xfrm_policy	*sk_policy[2];
 #endif
@@ -2203,27 +2198,15 @@ void sock_tx_timestamp(struct sock *sk, __u8 *tx_flags);
  * sk_eat_skb - Release a skb if it is no longer needed
  * @sk: socket to eat this skb from
  * @skb: socket buffer to eat
- * @copied_early: flag indicating whether DMA operations copied this data early
  *
  * This routine must be called with interrupts disabled or with the socket
  * locked so that the sk_buff queue operation is ok.
 */
-#ifdef CONFIG_NET_DMA
-static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
-{
-	__skb_unlink(skb, &sk->sk_receive_queue);
-	if (!copied_early)
-		__kfree_skb(skb);
-	else
-		__skb_queue_tail(&sk->sk_async_wait_queue, skb);
-}
-#else
-static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
+static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
 {
 	__skb_unlink(skb, &sk->sk_receive_queue);
 	__kfree_skb(skb);
 }
-#endif

 static inline
 struct net *sock_net(const struct sock *sk)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 197b020..920fc2e 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -27,7 +27,6 @@
 #include <linux/cache.h>
 #include <linux/percpu.h>
 #include <linux/skbuff.h>
-#include <linux/dmaengine.h>
 #include <linux/crypto.h>
 #include <linux/cryptohash.h>
 #include <linux/kref.h>
@@ -267,7 +266,6 @@ extern int sysctl_tcp_adv_win_scale;
 extern int sysctl_tcp_tw_reuse;
 extern int sysctl_tcp_frto;
 extern int sysctl_tcp_low_latency;
-extern int sysctl_tcp_dma_copybreak;
 extern int sysctl_tcp_nometrics_save;
 extern int sysctl_tcp_moderate_rcvbuf;
 extern int sysctl_tcp_tso_win_divisor;
@@ -1033,12 +1031,6 @@ static inline void tcp_prequeue_init(struct tcp_sock *tp)
 	tp->ucopy.len = 0;
 	tp->ucopy.memory = 0;
 	skb_queue_head_init(&tp->ucopy.prequeue);
-#ifdef CONFIG_NET_DMA
-	tp->ucopy.dma_chan = NULL;
-	tp->ucopy.wakeup = 0;
-	tp->ucopy.pinned_list = NULL;
-	tp->ucopy.dma_cookie = 0;
-#endif
 }

 bool tcp_prequeue(struct sock *sk, struct sk_buff *skb);
diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c
index 653cbbd..d457005 100644
--- a/kernel/sysctl_binary.c
+++ b/kernel/sysctl_binary.c
@@ -390,7 +390,6 @@ static const struct bin_table bin_net_ipv4_table[] = {
 	{ CTL_INT,	NET_TCP_MTU_PROBING,			"tcp_mtu_probing" },
 	{ CTL_INT,	NET_TCP_BASE_MSS,			"tcp_base_mss" },
 	{ CTL_INT,	NET_IPV4_TCP_WORKAROUND_SIGNED_WINDOWS,	"tcp_workaround_signed_windows" },
-	{ CTL_INT,	NET_TCP_DMA_COPYBREAK,			"tcp_dma_copybreak" },
 	{ CTL_INT,	NET_TCP_SLOW_START_AFTER_IDLE,		"tcp_slow_start_after_idle" },
 	{ CTL_INT,	NET_CIPSOV4_CACHE_ENABLE,		"cipso_cache_enable" },
 	{ CTL_INT,	NET_CIPSOV4_CACHE_BUCKET_SIZE,		"cipso_cache_bucket_size" },
diff --git a/net/core/Makefile b/net/core/Makefile
index b33b996..5f98e59 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 e61bda3..65c5438 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;
@@ -4375,14 +4373,6 @@ 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 1ed4266..ee847676 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1510,9 +1510,6 @@ 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);
@@ -2341,9 +2338,6 @@ 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 1b5fefd..0000000
--- 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;
-}
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index eb892b4..f9076f2 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -848,7 +848,7 @@ int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		default:
 			dccp_pr_debug("packet_type=%s\n",
 				      dccp_packet_name(dh->dccph_type));
-			sk_eat_skb(sk, skb, false);
+			sk_eat_skb(sk, skb);
 		}
 verify_sock_status:
 		if (sock_flag(sk, SOCK_DONE)) {
@@ -905,7 +905,7 @@ verify_sock_status:
 			len = skb->len;
 	found_fin_ok:
 		if (!(flags & MSG_PEEK))
-			sk_eat_skb(sk, skb, false);
+			sk_eat_skb(sk, skb);
 		break;
 	} while (1);
 out:
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 3d69ec8..79a90b9 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -642,15 +642,6 @@ static struct ctl_table ipv4_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
-#ifdef CONFIG_NET_DMA
-	{
-		.procname	= "tcp_dma_copybreak",
-		.data		= &sysctl_tcp_dma_copybreak,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec
-	},
-#endif
 	{
 		.procname	= "tcp_slow_start_after_idle",
 		.data		= &sysctl_tcp_slow_start_after_idle,
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c200b34..e7a02d8 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -274,7 +274,6 @@
 #include <net/tcp.h>
 #include <net/xfrm.h>
 #include <net/ip.h>
-#include <net/netdma.h>
 #include <net/sock.h>

 #include <asm/uaccess.h>
@@ -1412,39 +1411,6 @@ static void tcp_prequeue_process(struct sock *sk)
 	tp->ucopy.memory = 0;
 }

-#ifdef CONFIG_NET_DMA
-static void tcp_service_net_dma(struct sock *sk, bool wait)
-{
-	dma_cookie_t done, used;
-	dma_cookie_t last_issued;
-	struct tcp_sock *tp = tcp_sk(sk);
-
-	if (!tp->ucopy.dma_chan)
-		return;
-
-	last_issued = tp->ucopy.dma_cookie;
-	dma_async_issue_pending(tp->ucopy.dma_chan);
-
-	do {
-		if (dma_async_is_tx_complete(tp->ucopy.dma_chan,
-					      last_issued, &done,
-					      &used) == DMA_COMPLETE) {
-			/* Safe to free early-copied skbs now */
-			__skb_queue_purge(&sk->sk_async_wait_queue);
-			break;
-		} else {
-			struct sk_buff *skb;
-			while ((skb = skb_peek(&sk->sk_async_wait_queue)) &&
-			       (dma_async_is_complete(skb->dma_cookie, done,
-						      used) == DMA_COMPLETE)) {
-				__skb_dequeue(&sk->sk_async_wait_queue);
-				kfree_skb(skb);
-			}
-		}
-	} while (wait);
-}
-#endif
-
 static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
 {
 	struct sk_buff *skb;
@@ -1462,7 +1428,7 @@ static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
 		 * splitted a fat GRO packet, while we released socket lock
 		 * in skb_splice_bits()
 		 */
-		sk_eat_skb(sk, skb, false);
+		sk_eat_skb(sk, skb);
 	}
 	return NULL;
 }
@@ -1528,11 +1494,11 @@ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
 				continue;
 		}
 		if (tcp_hdr(skb)->fin) {
-			sk_eat_skb(sk, skb, false);
+			sk_eat_skb(sk, skb);
 			++seq;
 			break;
 		}
-		sk_eat_skb(sk, skb, false);
+		sk_eat_skb(sk, skb);
 		if (!desc->count)
 			break;
 		tp->copied_seq = seq;
@@ -1570,7 +1536,6 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	int target;		/* Read at least this many bytes */
 	long timeo;
 	struct task_struct *user_recv = NULL;
-	bool copied_early = false;
 	struct sk_buff *skb;
 	u32 urg_hole = 0;

@@ -1613,28 +1578,6 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,

 	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);

-#ifdef CONFIG_NET_DMA
-	tp->ucopy.dma_chan = NULL;
-	preempt_disable();
-	skb = skb_peek_tail(&sk->sk_receive_queue);
-	{
-		int available = 0;
-
-		if (skb)
-			available = TCP_SKB_CB(skb)->seq + skb->len - (*seq);
-		if ((available < target) &&
-		    (len > sysctl_tcp_dma_copybreak) && !(flags & MSG_PEEK) &&
-		    !sysctl_tcp_low_latency &&
-		    net_dma_find_channel()) {
-			preempt_enable_no_resched();
-			tp->ucopy.pinned_list =
-					dma_pin_iovec_pages(msg->msg_iov, len);
-		} else {
-			preempt_enable_no_resched();
-		}
-	}
-#endif
-
 	do {
 		u32 offset;

@@ -1765,16 +1708,6 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 			/* __ Set realtime policy in scheduler __ */
 		}

-#ifdef CONFIG_NET_DMA
-		if (tp->ucopy.dma_chan) {
-			if (tp->rcv_wnd == 0 &&
-			    !skb_queue_empty(&sk->sk_async_wait_queue)) {
-				tcp_service_net_dma(sk, true);
-				tcp_cleanup_rbuf(sk, copied);
-			} else
-				dma_async_issue_pending(tp->ucopy.dma_chan);
-		}
-#endif
 		if (copied >= target) {
 			/* Do not sleep, just process backlog. */
 			release_sock(sk);
@@ -1782,11 +1715,6 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		} else
 			sk_wait_data(sk, &timeo);

-#ifdef CONFIG_NET_DMA
-		tcp_service_net_dma(sk, false);  /* Don't block */
-		tp->ucopy.wakeup = 0;
-#endif
-
 		if (user_recv) {
 			int chunk;

@@ -1844,43 +1772,13 @@ do_prequeue:
 		}

 		if (!(flags & MSG_TRUNC)) {
-#ifdef CONFIG_NET_DMA
-			if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
-				tp->ucopy.dma_chan = net_dma_find_channel();
-
-			if (tp->ucopy.dma_chan) {
-				tp->ucopy.dma_cookie = dma_skb_copy_datagram_iovec(
-					tp->ucopy.dma_chan, skb, offset,
-					msg->msg_iov, used,
-					tp->ucopy.pinned_list);
-
-				if (tp->ucopy.dma_cookie < 0) {
-
-					pr_alert("%s: dma_cookie < 0\n",
-						 __func__);
-
-					/* Exception. Bailout! */
-					if (!copied)
-						copied = -EFAULT;
-					break;
-				}
-
-				dma_async_issue_pending(tp->ucopy.dma_chan);
-
-				if ((offset + used) == skb->len)
-					copied_early = true;
-
-			} else
-#endif
-			{
-				err = skb_copy_datagram_iovec(skb, offset,
-						msg->msg_iov, used);
-				if (err) {
-					/* Exception. Bailout! */
-					if (!copied)
-						copied = -EFAULT;
-					break;
-				}
+			err = skb_copy_datagram_iovec(skb, offset,
+						      msg->msg_iov, used);
+			if (err) {
+				/* Exception. Bailout! */
+				if (!copied)
+					copied = -EFAULT;
+				break;
 			}
 		}

@@ -1900,19 +1798,15 @@ skip_copy:

 		if (tcp_hdr(skb)->fin)
 			goto found_fin_ok;
-		if (!(flags & MSG_PEEK)) {
-			sk_eat_skb(sk, skb, copied_early);
-			copied_early = false;
-		}
+		if (!(flags & MSG_PEEK))
+			sk_eat_skb(sk, skb);
 		continue;

 	found_fin_ok:
 		/* Process the FIN. */
 		++*seq;
-		if (!(flags & MSG_PEEK)) {
-			sk_eat_skb(sk, skb, copied_early);
-			copied_early = false;
-		}
+		if (!(flags & MSG_PEEK))
+			sk_eat_skb(sk, skb);
 		break;
 	} while (len > 0);

@@ -1935,16 +1829,6 @@ skip_copy:
 		tp->ucopy.len = 0;
 	}

-#ifdef CONFIG_NET_DMA
-	tcp_service_net_dma(sk, true);  /* Wait for queue to drain */
-	tp->ucopy.dma_chan = NULL;
-
-	if (tp->ucopy.pinned_list) {
-		dma_unpin_iovec_pages(tp->ucopy.pinned_list);
-		tp->ucopy.pinned_list = NULL;
-	}
-#endif
-
 	/* According to UNIX98, msg_name/msg_namelen are ignored
 	 * on connected socket. I was just happy when found this 8) --ANK
 	 */
@@ -2288,9 +2172,6 @@ int tcp_disconnect(struct sock *sk, int flags)
 	__skb_queue_purge(&sk->sk_receive_queue);
 	tcp_write_queue_purge(sk);
 	__skb_queue_purge(&tp->out_of_order_queue);
-#ifdef CONFIG_NET_DMA
-	__skb_queue_purge(&sk->sk_async_wait_queue);
-#endif

 	inet->inet_dport = 0;

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 53d60b4..abd367b 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -73,7 +73,6 @@
 #include <net/inet_common.h>
 #include <linux/ipsec.h>
 #include <asm/unaligned.h>
-#include <net/netdma.h>

 int sysctl_tcp_timestamps __read_mostly = 1;
 int sysctl_tcp_window_scaling __read_mostly = 1;
@@ -4966,53 +4965,6 @@ static inline bool tcp_checksum_complete_user(struct sock *sk,
 	       __tcp_checksum_complete_user(sk, skb);
 }

-#ifdef CONFIG_NET_DMA
-static bool tcp_dma_try_early_copy(struct sock *sk, struct sk_buff *skb,
-				  int hlen)
-{
-	struct tcp_sock *tp = tcp_sk(sk);
-	int chunk = skb->len - hlen;
-	int dma_cookie;
-	bool copied_early = false;
-
-	if (tp->ucopy.wakeup)
-		return false;
-
-	if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
-		tp->ucopy.dma_chan = net_dma_find_channel();
-
-	if (tp->ucopy.dma_chan && skb_csum_unnecessary(skb)) {
-
-		dma_cookie = dma_skb_copy_datagram_iovec(tp->ucopy.dma_chan,
-							 skb, hlen,
-							 tp->ucopy.iov, chunk,
-							 tp->ucopy.pinned_list);
-
-		if (dma_cookie < 0)
-			goto out;
-
-		tp->ucopy.dma_cookie = dma_cookie;
-		copied_early = true;
-
-		tp->ucopy.len -= chunk;
-		tp->copied_seq += chunk;
-		tcp_rcv_space_adjust(sk);
-
-		if ((tp->ucopy.len == 0) ||
-		    (tcp_flag_word(tcp_hdr(skb)) & TCP_FLAG_PSH) ||
-		    (atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1))) {
-			tp->ucopy.wakeup = 1;
-			sk->sk_data_ready(sk, 0);
-		}
-	} else if (chunk > 0) {
-		tp->ucopy.wakeup = 1;
-		sk->sk_data_ready(sk, 0);
-	}
-out:
-	return copied_early;
-}
-#endif /* CONFIG_NET_DMA */
-
 /* Does PAWS and seqno based validation of an incoming segment, flags will
  * play significant role here.
  */
@@ -5197,14 +5149,6 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,

 			if (tp->copied_seq == tp->rcv_nxt &&
 			    len - tcp_header_len <= tp->ucopy.len) {
-#ifdef CONFIG_NET_DMA
-				if (tp->ucopy.task == current &&
-				    sock_owned_by_user(sk) &&
-				    tcp_dma_try_early_copy(sk, skb, tcp_header_len)) {
-					copied_early = 1;
-					eaten = 1;
-				}
-#endif
 				if (tp->ucopy.task == current &&
 				    sock_owned_by_user(sk) && !copied_early) {
 					__set_current_state(TASK_RUNNING);
@@ -5270,11 +5214,6 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
 			if (!copied_early || tp->rcv_nxt != tp->rcv_wup)
 				__tcp_ack_snd_check(sk, 0);
 no_ack:
-#ifdef CONFIG_NET_DMA
-			if (copied_early)
-				__skb_queue_tail(&sk->sk_async_wait_queue, skb);
-			else
-#endif
 			if (eaten)
 				kfree_skb_partial(skb, fragstolen);
 			sk->sk_data_ready(sk, 0);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 1d7b9dd..77fe507 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -72,7 +72,6 @@
 #include <net/inet_common.h>
 #include <net/timewait_sock.h>
 #include <net/xfrm.h>
-#include <net/netdma.h>
 #include <net/secure_seq.h>
 #include <net/tcp_memcontrol.h>
 #include <net/busy_poll.h>
@@ -2000,18 +1999,8 @@ process:
 	bh_lock_sock_nested(sk);
 	ret = 0;
 	if (!sock_owned_by_user(sk)) {
-#ifdef CONFIG_NET_DMA
-		struct tcp_sock *tp = tcp_sk(sk);
-		if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
-			tp->ucopy.dma_chan = net_dma_find_channel();
-		if (tp->ucopy.dma_chan)
+		if (!tcp_prequeue(sk, skb))
 			ret = tcp_v4_do_rcv(sk, skb);
-		else
-#endif
-		{
-			if (!tcp_prequeue(sk, skb))
-				ret = tcp_v4_do_rcv(sk, skb);
-		}
 	} else if (unlikely(sk_add_backlog(sk, skb,
 					   sk->sk_rcvbuf + sk->sk_sndbuf))) {
 		bh_unlock_sock(sk);
@@ -2170,11 +2159,6 @@ void tcp_v4_destroy_sock(struct sock *sk)
 	}
 #endif

-#ifdef CONFIG_NET_DMA
-	/* Cleans up our sk_async_wait_queue */
-	__skb_queue_purge(&sk->sk_async_wait_queue);
-#endif
-
 	/* Clean prequeue, it must be empty really */
 	__skb_queue_purge(&tp->ucopy.prequeue);

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index f67033b..282874b 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -59,7 +59,6 @@
 #include <net/snmp.h>
 #include <net/dsfield.h>
 #include <net/timewait_sock.h>
-#include <net/netdma.h>
 #include <net/inet_common.h>
 #include <net/secure_seq.h>
 #include <net/tcp_memcontrol.h>
@@ -1503,18 +1502,8 @@ process:
 	bh_lock_sock_nested(sk);
 	ret = 0;
 	if (!sock_owned_by_user(sk)) {
-#ifdef CONFIG_NET_DMA
-		struct tcp_sock *tp = tcp_sk(sk);
-		if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
-			tp->ucopy.dma_chan = net_dma_find_channel();
-		if (tp->ucopy.dma_chan)
+		if (!tcp_prequeue(sk, skb))
 			ret = tcp_v6_do_rcv(sk, skb);
-		else
-#endif
-		{
-			if (!tcp_prequeue(sk, skb))
-				ret = tcp_v6_do_rcv(sk, skb);
-		}
 	} else if (unlikely(sk_add_backlog(sk, skb,
 					   sk->sk_rcvbuf + sk->sk_sndbuf))) {
 		bh_unlock_sock(sk);
diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index c71b699..78b9734 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -839,7 +839,7 @@ static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,

 		if (!(flags & MSG_PEEK)) {
 			spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
-			sk_eat_skb(sk, skb, false);
+			sk_eat_skb(sk, skb);
 			spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
 			*seq = 0;
 		}
@@ -861,10 +861,10 @@ copy_uaddr:
 		llc_cmsg_rcv(msg, skb);

 	if (!(flags & MSG_PEEK)) {
-			spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
-			sk_eat_skb(sk, skb, false);
-			spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
-			*seq = 0;
+		spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
+		sk_eat_skb(sk, skb);
+		spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
+		*seq = 0;
 	}

 	goto out;
--
1.9.1





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