linux-imx

/*

 * asynchronous raid6 recovery self test

 * Copyright (c) 2009, Intel Corporation.

 *

 * based on drivers/md/raid6test/test.c:

 *  Copyright 2002-2007 H. Peter Anvin

 *

 * 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/async_tx.h>

#include <linux/gfp.h>

#include <linux/mm.h>

#include <linux/random.h>

#include <linux/module.h>

​

#undef pr

#define pr(fmt, args...) pr_info("raid6test: " fmt, ##args)

​

#define NDISKS 64 /* Including P and Q */

​

static struct page *dataptrs[NDISKS];

static addr_conv_t addr_conv[NDISKS];

static struct page *data[NDISKS+3];

static struct page *spare;

static struct page *recovi;

static struct page *recovj;

​

static void callback(void *param)

{

    struct completion *cmp = param;

​

    complete(cmp);

}

​

static void makedata(int disks)

{

    int i;

​

    for (i = 0; i < disks; i++) {

        prandom_bytes(page_address(data[i]), PAGE_SIZE);

        dataptrs[i] = data[i];

    }

}

​

static char disk_type(int d, int disks)

{

    if (d == disks - 2)

        return 'P';

    else if (d == disks - 1)

        return 'Q';

    else

        return 'D';

}

​

/* Recover two failed blocks. */

static void raid6_dual_recov(int disks, size_t bytes, int faila, int failb, struct page **ptrs)

{

    struct async_submit_ctl submit;

    struct completion cmp;

    struct dma_async_tx_descriptor *tx = NULL;

    enum sum_check_flags result = ~0;

​

    if (faila > failb)

        swap(faila, failb);

​

    if (failb == disks-1) {

        if (faila == disks-2) {

            /* P+Q failure.  Just rebuild the syndrome. */

            init_async_submit(&submit, 0, NULL, NULL, NULL, addr_conv);

            tx = async_gen_syndrome(ptrs, 0, disks, bytes, &submit);

        } else {

            struct page *blocks[NDISKS];

            struct page *dest;

            int count = 0;

            int i;

​

            BUG_ON(disks > NDISKS);

​

            /* data+Q failure.  Reconstruct data from P,

             * then rebuild syndrome