diff options
Diffstat (limited to 'net/core/user_dma.c')
-rw-r--r-- | net/core/user_dma.c | 131 |
1 files changed, 0 insertions, 131 deletions
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; -} |