linux-imx

/*

 * Copyright 2016 Broadcom

 *

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

 * it under the terms of the GNU General Public License, version 2, as

 * published by the Free Software Foundation (the "GPL").

 *

 * 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 version 2 (GPLv2) for more details.

 *

 * You should have received a copy of the GNU General Public License

 * version 2 (GPLv2) along with this source code.

 */

​

#include <linux/debugfs.h>

​

#include "cipher.h"

#include "util.h"

​

/* offset of SPU_OFIFO_CTRL register */

#define SPU_OFIFO_CTRL      0x40

#define SPU_FIFO_WATERMARK  0x1FF

​

/**

 * spu_sg_at_offset() - Find the scatterlist entry at a given distance from the

 * start of a scatterlist.

 * @sg:         [in]  Start of a scatterlist

 * @skip:       [in]  Distance from the start of the scatterlist, in bytes

 * @sge:        [out] Scatterlist entry at skip bytes from start

 * @sge_offset: [out] Number of bytes from start of sge buffer to get to

 *                    requested distance.

 *

 * Return: 0 if entry found at requested distance

 *         < 0 otherwise

 */

int spu_sg_at_offset(struct scatterlist *sg, unsigned int skip,

             struct scatterlist **sge, unsigned int *sge_offset)

{

    /* byte index from start of sg to the end of the previous entry */

    unsigned int index = 0;

    /* byte index from start of sg to the end of the current entry */

    unsigned int next_index;

​

    next_index = sg->length;

    while (next_index <= skip) {

        sg = sg_next(sg);

        index = next_index;

        if (!sg)

            return -EINVAL;

        next_index += sg->length;

    }

​

    *sge_offset = skip - index;

    *sge = sg;

    return 0;

}

​

/* Copy len bytes of sg data, starting at offset skip, to a dest buffer */

void sg_copy_part_to_buf(struct scatterlist *src, u8 *dest,

             unsigned int len, unsigned int skip)

{

    size_t copied;

    unsigned int nents = sg_nents(src);

​

    copied = sg_pcopy_to_buffer(src, nents, dest, len, skip);

    if (copied != len) {

        flow_log("%s copied %u bytes of %u requested. ",

             __func__, (u32)copied, len);

        flow_log("sg with %u entries and skip %u\n", nents, skip);

    }

}

​

/*

 * Copy data into a scatterlist starting at a specified offset in the

 * scatterlist. Specifically, copy len bytes of data in the buffer src

 * into the scatterlist dest, starting skip bytes into the scatterlist.

 */

void sg_copy_part_from_buf(struct scatterlist *dest, u8 *src,

               unsigned int len, unsigned int skip)

{

    size_t copied;

    unsigned int nents = sg_nents(dest);

​

    copied = sg_pcopy_from_buffer(dest, nents, src, len, skip);

    if (copied != len) {

        flow_log("%s copied %u bytes of %u requested. ",

             __func__, (u32)copied, len);

        flow_log("sg with %u entries and skip %u\n", nents, skip);

    }

}