diff options
Diffstat (limited to 'drivers/dma/iovlock.c')
-rw-r--r-- | drivers/dma/iovlock.c | 280 |
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(¤t->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(¤t->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; -} |