zfcp_qdio.h

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/*
 * zfcp device driver
 *
 * Header file for zfcp qdio interface
 *
 * Copyright IBM Corp. 2010
 */

#ifndef ZFCP_QDIO_H
#define ZFCP_QDIO_H

#include <asm/qdio.h>

#define ZFCP_QDIO_SBALE_LEN PAGE_SIZE

/* Max SBALS for chaining */
#define ZFCP_QDIO_MAX_SBALS_PER_REQ 36

struct zfcp_qdio {
    struct qdio_buffer  *res_q[QDIO_MAX_BUFFERS_PER_Q];
    struct qdio_buffer  *req_q[QDIO_MAX_BUFFERS_PER_Q];
    u8          req_q_idx;
    atomic_t        req_q_free;
    spinlock_t      stat_lock;
    spinlock_t      req_q_lock;
    unsigned long long  req_q_time;
    u64         req_q_util;
    atomic_t        req_q_full;
    wait_queue_head_t   req_q_wq;
    struct zfcp_adapter *adapter;
    u16         max_sbale_per_sbal;
    u16         max_sbale_per_req;
};

struct zfcp_qdio_req {
    u8  sbtype;
    u8  sbal_number;
    u8  sbal_first;
    u8  sbal_last;
    u8  sbal_limit;
    u8  sbale_curr;
    u8  sbal_response;
    u16 qdio_outb_usage;
};

static inline struct qdio_buffer_element *
zfcp_qdio_sbale_req(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
    return &qdio->req_q[q_req->sbal_last]->element[0];
}

static inline struct qdio_buffer_element *
zfcp_qdio_sbale_curr(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
    return &qdio->req_q[q_req->sbal_last]->element[q_req->sbale_curr];
}

static inline
void zfcp_qdio_req_init(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
            unsigned long req_id, u8 sbtype, void *data, u32 len)
{
    struct qdio_buffer_element *sbale;
    int count = min(atomic_read(&qdio->req_q_free),
            ZFCP_QDIO_MAX_SBALS_PER_REQ);

    q_req->sbal_first = q_req->sbal_last = qdio->req_q_idx;
    q_req->sbal_number = 1;
    q_req->sbtype = sbtype;
    q_req->sbale_curr = 1;
    q_req->sbal_limit = (q_req->sbal_first + count - 1)
                    % QDIO_MAX_BUFFERS_PER_Q;

    sbale = zfcp_qdio_sbale_req(qdio, q_req);
    sbale->addr = (void *) req_id;
    sbale->eflags = 0;
    sbale->sflags = SBAL_SFLAGS0_COMMAND | sbtype;

    if (unlikely(!data))
        return;
    sbale++;
    sbale->addr = data;
    sbale->length = len;
}

static inline
void zfcp_qdio_fill_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req,
             void *data, u32 len)
{
    struct qdio_buffer_element *sbale;

    BUG_ON(q_req->sbale_curr == qdio->max_sbale_per_sbal - 1);
    q_req->sbale_curr++;
    sbale = zfcp_qdio_sbale_curr(qdio, q_req);
    sbale->addr = data;
    sbale->length = len;
}

static inline
void zfcp_qdio_set_sbale_last(struct zfcp_qdio *qdio,
                  struct zfcp_qdio_req *q_req)
{
    struct qdio_buffer_element *sbale;

    sbale = zfcp_qdio_sbale_curr(qdio, q_req);
    sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY;
}

static inline
int zfcp_qdio_sg_one_sbale(struct scatterlist *sg)
{
    return sg_is_last(sg) && sg->length <= ZFCP_QDIO_SBALE_LEN;
}

static inline
void zfcp_qdio_skip_to_last_sbale(struct zfcp_qdio *qdio,
                  struct zfcp_qdio_req *q_req)
{
    q_req->sbale_curr = qdio->max_sbale_per_sbal - 1;
}

static inline
void zfcp_qdio_sbal_limit(struct zfcp_qdio *qdio,
              struct zfcp_qdio_req *q_req, int max_sbals)
{
    int count = min(atomic_read(&qdio->req_q_free), max_sbals);

    q_req->sbal_limit = (q_req->sbal_first + count - 1) %
                QDIO_MAX_BUFFERS_PER_Q;
}

static inline
void zfcp_qdio_set_data_div(struct zfcp_qdio *qdio,
                struct zfcp_qdio_req *q_req, u32 count)
{
    struct qdio_buffer_element *sbale;

    sbale = qdio->req_q[q_req->sbal_first]->element;
    sbale->length = count;
}

static inline
unsigned int zfcp_qdio_sbale_count(struct scatterlist *sg)
{
    unsigned int count = 0;

    for (; sg; sg = sg_next(sg))
        count++;

    return count;
}

static inline
unsigned int zfcp_qdio_real_bytes(struct scatterlist *sg)
{
    unsigned int real_bytes = 0;

    for (; sg; sg = sg_next(sg))
        real_bytes += sg->length;

    return real_bytes;
}

static inline
void zfcp_qdio_set_scount(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req)
{
    struct qdio_buffer_element *sbale;

    sbale = qdio->req_q[q_req->sbal_first]->element;
    sbale->scount = q_req->sbal_number - 1;
}

#endif /* ZFCP_QDIO_H */