summaryrefslogtreecommitdiff
path: root/drivers/dma/iovlock.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/dma/iovlock.c')
-rw-r--r--drivers/dma/iovlock.c280
1 files changed, 0 insertions, 280 deletions
diff --git a/drivers/dma/iovlock.c b/drivers/dma/iovlock.c
deleted file mode 100644
index bb48a57c2fc1..000000000000
--- 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;
-}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-18 15:16:31 +0000