linux-imx

/*

 * xor offload engine api

 *

 * Copyright © 2006, Intel Corporation.

 *

 *      Dan Williams <dan.j.williams@intel.com>

 *

 *      with architecture considerations by:

 *      Neil Brown <neilb@suse.de>

 *      Jeff Garzik <jeff@garzik.org>

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope 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.,

 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */

#include <linux/kernel.h>

#include <linux/interrupt.h>

#include <linux/module.h>

#include <linux/mm.h>

#include <linux/dma-mapping.h>

#include <linux/raid/xor.h>

#include <linux/async_tx.h>

​

/* do_async_xor - dma map the pages and perform the xor with an engine */

static __async_inline struct dma_async_tx_descriptor *

do_async_xor(struct dma_chan *chan, struct dmaengine_unmap_data *unmap,

         struct async_submit_ctl *submit)

{

    struct dma_device *dma = chan->device;

    struct dma_async_tx_descriptor *tx = NULL;

    dma_async_tx_callback cb_fn_orig = submit->cb_fn;

    void *cb_param_orig = submit->cb_param;

    enum async_tx_flags flags_orig = submit->flags;

    enum dma_ctrl_flags dma_flags = 0;

    int src_cnt = unmap->to_cnt;

    int xor_src_cnt;

    dma_addr_t dma_dest = unmap->addr[unmap->to_cnt];

    dma_addr_t *src_list = unmap->addr;

​

    while (src_cnt) {

        dma_addr_t tmp;

​

        submit->flags = flags_orig;

        xor_src_cnt = min(src_cnt, (int)dma->max_xor);

        /* if we are submitting additional xors, leave the chain open

         * and clear the callback parameters

         */

        if (src_cnt > xor_src_cnt) {

            submit->flags &= ~ASYNC_TX_ACK;

            submit->flags |= ASYNC_TX_FENCE;

            submit->cb_fn = NULL;

            submit->cb_param = NULL;

        } else {