sg_sw_sec4.h

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/*
 * CAAM/SEC 4.x functions for using scatterlists in caam driver
 *
 * Copyright 2008-2011 Freescale Semiconductor, Inc.
 *
 */

struct sec4_sg_entry;

/*
 * convert single dma address to h/w link table format
 */
static inline void dma_to_sec4_sg_one(struct sec4_sg_entry *sec4_sg_ptr,
                      dma_addr_t dma, u32 len, u32 offset)
{
    sec4_sg_ptr->ptr = dma;
    sec4_sg_ptr->len = len;
    sec4_sg_ptr->reserved = 0;
    sec4_sg_ptr->buf_pool_id = 0;
    sec4_sg_ptr->offset = offset;
#ifdef DEBUG
    print_hex_dump(KERN_ERR, "sec4_sg_ptr@: ",
               DUMP_PREFIX_ADDRESS, 16, 4, sec4_sg_ptr,
               sizeof(struct sec4_sg_entry), 1);
#endif
}

/*
 * convert scatterlist to h/w link table format
 * but does not have final bit; instead, returns last entry
 */
static inline struct sec4_sg_entry *
sg_to_sec4_sg(struct scatterlist *sg, int sg_count,
          struct sec4_sg_entry *sec4_sg_ptr, u32 offset)
{
    while (sg_count) {
        dma_to_sec4_sg_one(sec4_sg_ptr, sg_dma_address(sg),
                   sg_dma_len(sg), offset);
        sec4_sg_ptr++;
        sg = scatterwalk_sg_next(sg);
        sg_count--;
    }
    return sec4_sg_ptr - 1;
}

/*
 * convert scatterlist to h/w link table format
 * scatterlist must have been previously dma mapped
 */
static inline void sg_to_sec4_sg_last(struct scatterlist *sg, int sg_count,
                      struct sec4_sg_entry *sec4_sg_ptr,
                      u32 offset)
{
    sec4_sg_ptr = sg_to_sec4_sg(sg, sg_count, sec4_sg_ptr, offset);
    sec4_sg_ptr->len |= SEC4_SG_LEN_FIN;
}

/* count number of elements in scatterlist */
static inline int __sg_count(struct scatterlist *sg_list, int nbytes,
                 bool *chained)
{
    struct scatterlist *sg = sg_list;
    int sg_nents = 0;

    while (nbytes > 0) {
        sg_nents++;
        nbytes -= sg->length;
        if (!sg_is_last(sg) && (sg + 1)->length == 0)
            *chained = true;
        sg = scatterwalk_sg_next(sg);
    }

    return sg_nents;
}

/* derive number of elements in scatterlist, but return 0 for 1 */
static inline int sg_count(struct scatterlist *sg_list, int nbytes,
                 bool *chained)
{
    int sg_nents = __sg_count(sg_list, nbytes, chained);

    if (likely(sg_nents == 1))
        return 0;

    return sg_nents;
}

static int dma_map_sg_chained(struct device *dev, struct scatterlist *sg,
                  unsigned int nents, enum dma_data_direction dir,
                  bool chained)
{
    if (unlikely(chained)) {
        int i;
        for (i = 0; i < nents; i++) {
            dma_map_sg(dev, sg, 1, dir);
            sg = scatterwalk_sg_next(sg);
        }
    } else {
        dma_map_sg(dev, sg, nents, dir);
    }
    return nents;
}

static int dma_unmap_sg_chained(struct device *dev, struct scatterlist *sg,
                unsigned int nents, enum dma_data_direction dir,
                bool chained)
{
    if (unlikely(chained)) {
        int i;
        for (i = 0; i < nents; i++) {
            dma_unmap_sg(dev, sg, 1, dir);
            sg = scatterwalk_sg_next(sg);
        }
    } else {
        dma_unmap_sg(dev, sg, nents, dir);
    }
    return nents;
}

/* Copy from len bytes of sg to dest, starting from beginning */
static inline void sg_copy(u8 *dest, struct scatterlist *sg, unsigned int len)
{
    struct scatterlist *current_sg = sg;
    int cpy_index = 0, next_cpy_index = current_sg->length;

    while (next_cpy_index < len) {
        memcpy(dest + cpy_index, (u8 *) sg_virt(current_sg),
               current_sg->length);
        current_sg = scatterwalk_sg_next(current_sg);
        cpy_index = next_cpy_index;
        next_cpy_index += current_sg->length;
    }
    if (cpy_index < len)
        memcpy(dest + cpy_index, (u8 *) sg_virt(current_sg),
               len - cpy_index);
}

/* Copy sg data, from to_skip to end, to dest */
static inline void sg_copy_part(u8 *dest, struct scatterlist *sg,
                      int to_skip, unsigned int end)
{
    struct scatterlist *current_sg = sg;
    int sg_index, cpy_index;

    sg_index = current_sg->length;
    while (sg_index <= to_skip) {
        current_sg = scatterwalk_sg_next(current_sg);
        sg_index += current_sg->length;
    }
    cpy_index = sg_index - to_skip;
    memcpy(dest, (u8 *) sg_virt(current_sg) +
           current_sg->length - cpy_index, cpy_index);
    current_sg = scatterwalk_sg_next(current_sg);
    if (end - sg_index)
        sg_copy(dest + cpy_index, current_sg, end - sg_index);
}