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>

1 files changed, 0 insertions, 280 deletions

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;
-}