[S390] qdio: move ACK to newest buffer for devices without QEBSM

[linux-2.6/btrfs-unstable.git] / drivers / s390 / cio / qdio_main.c

/*
 * linux/drivers/s390/cio/qdio_main.c
 *
 * Linux for s390 qdio support, buffer handling, qdio API and module support.
 *
 * Copyright 2000,2008 IBM Corp.
 * Author(s): Utz Bacher <utz.bacher@de.ibm.com>
 *            Jan Glauber <jang@linux.vnet.ibm.com>
 * 2.6 cio integration by Cornelia Huck <cornelia.huck@de.ibm.com>
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/delay.h>
#include <asm/atomic.h>
#include <asm/debug.h>
#include <asm/qdio.h>

#include "cio.h"
#include "css.h"
#include "device.h"
#include "qdio.h"
#include "qdio_debug.h"
#include "qdio_perf.h"

MODULE_AUTHOR("Utz Bacher <utz.bacher@de.ibm.com>,"\
        "Jan Glauber <jang@linux.vnet.ibm.com>");
MODULE_DESCRIPTION("QDIO base support");
MODULE_LICENSE("GPL");

static inline int do_siga_sync(struct subchannel_id schid,
                               unsigned int out_mask, unsigned int in_mask)
{
        register unsigned long __fc asm ("0") = 2;
        register struct subchannel_id __schid asm ("1") = schid;
        register unsigned long out asm ("2") = out_mask;
        register unsigned long in asm ("3") = in_mask;
        int cc;

        asm volatile(
                "       siga    0\n"
                "       ipm     %0\n"
                "       srl     %0,28\n"
                : "=d" (cc)
                : "d" (__fc), "d" (__schid), "d" (out), "d" (in) : "cc");
        return cc;
}

static inline int do_siga_input(struct subchannel_id schid, unsigned int mask)
{
        register unsigned long __fc asm ("0") = 1;
        register struct subchannel_id __schid asm ("1") = schid;
        register unsigned long __mask asm ("2") = mask;
        int cc;

        asm volatile(
                "       siga    0\n"
                "       ipm     %0\n"
                "       srl     %0,28\n"
                : "=d" (cc)
                : "d" (__fc), "d" (__schid), "d" (__mask) : "cc", "memory");
        return cc;
}

/**
 * do_siga_output - perform SIGA-w/wt function
 * @schid: subchannel id or in case of QEBSM the subchannel token
 * @mask: which output queues to process
 * @bb: busy bit indicator, set only if SIGA-w/wt could not access a buffer
 * @fc: function code to perform
 *
 * Returns cc or QDIO_ERROR_SIGA_ACCESS_EXCEPTION.
 * Note: For IQDC unicast queues only the highest priority queue is processed.
 */
static inline int do_siga_output(unsigned long schid, unsigned long mask,
                                 unsigned int *bb, unsigned int fc)
{
        register unsigned long __fc asm("0") = fc;
        register unsigned long __schid asm("1") = schid;
        register unsigned long __mask asm("2") = mask;
        int cc = QDIO_ERROR_SIGA_ACCESS_EXCEPTION;

        asm volatile(
                "       siga    0\n"
                "0:     ipm     %0\n"
                "       srl     %0,28\n"
                "1:\n"
                EX_TABLE(0b, 1b)
                : "+d" (cc), "+d" (__fc), "+d" (__schid), "+d" (__mask)
                : : "cc", "memory");
        *bb = ((unsigned int) __fc) >> 31;
        return cc;
}

static inline int qdio_check_ccq(struct qdio_q *q, unsigned int ccq)
{
        /* all done or next buffer state different */
        if (ccq == 0 || ccq == 32)
                return 0;
        /* not all buffers processed */
        if (ccq == 96 || ccq == 97)
                return 1;
        /* notify devices immediately */
        DBF_ERROR("%4x ccq:%3d", SCH_NO(q), ccq);
        return -EIO;
}

/**
 * qdio_do_eqbs - extract buffer states for QEBSM
 * @q: queue to manipulate
 * @state: state of the extracted buffers
 * @start: buffer number to start at
 * @count: count of buffers to examine
 * @auto_ack: automatically acknowledge buffers
 *
 * Returns the number of successfully extracted equal buffer states.
 * Stops processing if a state is different from the last buffers state.
 */
static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state,
                        int start, int count, int auto_ack)
{
        unsigned int ccq = 0;
        int tmp_count = count, tmp_start = start;
        int nr = q->nr;
        int rc;

        BUG_ON(!q->irq_ptr->sch_token);
        qdio_perf_stat_inc(&perf_stats.debug_eqbs_all);

        if (!q->is_input_q)
                nr += q->irq_ptr->nr_input_qs;
again:
        ccq = do_eqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count,
                      auto_ack);
        rc = qdio_check_ccq(q, ccq);

        /* At least one buffer was processed, return and extract the remaining
         * buffers later.
         */
        if ((ccq == 96) && (count != tmp_count)) {
                qdio_perf_stat_inc(&perf_stats.debug_eqbs_incomplete);
                return (count - tmp_count);
        }

        if (rc == 1) {
                DBF_DEV_EVENT(DBF_WARN, q->irq_ptr, "EQBS again:%2d", ccq);
                goto again;
        }

        if (rc < 0) {
                DBF_ERROR("%4x EQBS ERROR", SCH_NO(q));
                DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);
                q->handler(q->irq_ptr->cdev,
                           QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
                           0, -1, -1, q->irq_ptr->int_parm);
                return 0;
        }
        return count - tmp_count;
}

/**
 * qdio_do_sqbs - set buffer states for QEBSM
 * @q: queue to manipulate
 * @state: new state of the buffers
 * @start: first buffer number to change
 * @count: how many buffers to change
 *
 * Returns the number of successfully changed buffers.
 * Does retrying until the specified count of buffer states is set or an
 * error occurs.
 */
static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start,
                        int count)
{
        unsigned int ccq = 0;
        int tmp_count = count, tmp_start = start;
        int nr = q->nr;
        int rc;

        if (!count)
                return 0;

        BUG_ON(!q->irq_ptr->sch_token);
        qdio_perf_stat_inc(&perf_stats.debug_sqbs_all);

        if (!q->is_input_q)
                nr += q->irq_ptr->nr_input_qs;
again:
        ccq = do_sqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count);
        rc = qdio_check_ccq(q, ccq);
        if (rc == 1) {
                DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "SQBS again:%2d", ccq);
                qdio_perf_stat_inc(&perf_stats.debug_sqbs_incomplete);
                goto again;
        }
        if (rc < 0) {
                DBF_ERROR("%4x SQBS ERROR", SCH_NO(q));
                DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);
                q->handler(q->irq_ptr->cdev,
                           QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
                           0, -1, -1, q->irq_ptr->int_parm);
                return 0;
        }
        WARN_ON(tmp_count);
        return count - tmp_count;
}

/* returns number of examined buffers and their common state in *state */
static inline int get_buf_states(struct qdio_q *q, unsigned int bufnr,
                                 unsigned char *state, unsigned int count,
                                 int auto_ack)
{
        unsigned char __state = 0;
        int i;

        BUG_ON(bufnr > QDIO_MAX_BUFFERS_MASK);
        BUG_ON(count > QDIO_MAX_BUFFERS_PER_Q);

        if (is_qebsm(q))
                return qdio_do_eqbs(q, state, bufnr, count, auto_ack);

        for (i = 0; i < count; i++) {
                if (!__state)
                        __state = q->slsb.val[bufnr];
                else if (q->slsb.val[bufnr] != __state)
                        break;
                bufnr = next_buf(bufnr);
        }
        *state = __state;
        return i;
}

inline int get_buf_state(struct qdio_q *q, unsigned int bufnr,
                  unsigned char *state, int auto_ack)
{
        return get_buf_states(q, bufnr, state, 1, auto_ack);
}

/* wrap-around safe setting of slsb states, returns number of changed buffers */
static inline int set_buf_states(struct qdio_q *q, int bufnr,
                                 unsigned char state, int count)
{
        int i;

        BUG_ON(bufnr > QDIO_MAX_BUFFERS_MASK);
        BUG_ON(count > QDIO_MAX_BUFFERS_PER_Q);

        if (is_qebsm(q))
                return qdio_do_sqbs(q, state, bufnr, count);

        for (i = 0; i < count; i++) {
                xchg(&q->slsb.val[bufnr], state);
                bufnr = next_buf(bufnr);
        }
        return count;
}

static inline int set_buf_state(struct qdio_q *q, int bufnr,
                                unsigned char state)
{
        return set_buf_states(q, bufnr, state, 1);
}

/* set slsb states to initial state */
void qdio_init_buf_states(struct qdio_irq *irq_ptr)
{
        struct qdio_q *q;
        int i;

        for_each_input_queue(irq_ptr, q, i)
                set_buf_states(q, 0, SLSB_P_INPUT_NOT_INIT,
                               QDIO_MAX_BUFFERS_PER_Q);
        for_each_output_queue(irq_ptr, q, i)
                set_buf_states(q, 0, SLSB_P_OUTPUT_NOT_INIT,
                               QDIO_MAX_BUFFERS_PER_Q);
}

static int qdio_siga_sync(struct qdio_q *q, unsigned int output,
                          unsigned int input)
{
        int cc;

        if (!need_siga_sync(q))
                return 0;

        DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "siga-s:%1d", q->nr);
        qdio_perf_stat_inc(&perf_stats.siga_sync);

        cc = do_siga_sync(q->irq_ptr->schid, output, input);
        if (cc)
                DBF_ERROR("%4x SIGA-S:%2d", SCH_NO(q), cc);
        return cc;
}

inline int qdio_siga_sync_q(struct qdio_q *q)
{
        if (q->is_input_q)
                return qdio_siga_sync(q, 0, q->mask);
        else
                return qdio_siga_sync(q, q->mask, 0);
}

static inline int qdio_siga_sync_out(struct qdio_q *q)
{
        return qdio_siga_sync(q, ~0U, 0);
}

static inline int qdio_siga_sync_all(struct qdio_q *q)
{
        return qdio_siga_sync(q, ~0U, ~0U);
}

static int qdio_siga_output(struct qdio_q *q, unsigned int *busy_bit)
{
        unsigned long schid;
        unsigned int fc = 0;
        u64 start_time = 0;
        int cc;

        if (q->u.out.use_enh_siga)
                fc = 3;

        if (is_qebsm(q)) {
                schid = q->irq_ptr->sch_token;
                fc |= 0x80;
        }
        else
                schid = *((u32 *)&q->irq_ptr->schid);

again:
        cc = do_siga_output(schid, q->mask, busy_bit, fc);

        /* hipersocket busy condition */
        if (*busy_bit) {
                WARN_ON(queue_type(q) != QDIO_IQDIO_QFMT || cc != 2);

                if (!start_time) {
                        start_time = get_usecs();
                        goto again;
                }
                if ((get_usecs() - start_time) < QDIO_BUSY_BIT_PATIENCE)
                        goto again;
        }
        return cc;
}

static inline int qdio_siga_input(struct qdio_q *q)
{
        int cc;

        DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "siga-r:%1d", q->nr);
        qdio_perf_stat_inc(&perf_stats.siga_in);

        cc = do_siga_input(q->irq_ptr->schid, q->mask);
        if (cc)
                DBF_ERROR("%4x SIGA-R:%2d", SCH_NO(q), cc);
        return cc;
}

/* called from thinint inbound handler */
void qdio_sync_after_thinint(struct qdio_q *q)
{
        if (pci_out_supported(q)) {
                if (need_siga_sync_thinint(q))
                        qdio_siga_sync_all(q);
                else if (need_siga_sync_out_thinint(q))
                        qdio_siga_sync_out(q);
        } else
                qdio_siga_sync_q(q);
}

inline void qdio_stop_polling(struct qdio_q *q)
{
        if (!q->u.in.polling)
                return;

        q->u.in.polling = 0;
        qdio_perf_stat_inc(&perf_stats.debug_stop_polling);

        /* show the card that we are not polling anymore */
        if (is_qebsm(q)) {
                set_buf_states(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT,
                               q->u.in.ack_count);
                q->u.in.ack_count = 0;
        } else
                set_buf_state(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT);
}

static void announce_buffer_error(struct qdio_q *q, int count)
{
        q->qdio_error |= QDIO_ERROR_SLSB_STATE;

        /* special handling for no target buffer empty */
        if ((!q->is_input_q &&
            (q->sbal[q->first_to_check]->element[15].flags & 0xff) == 0x10)) {
                qdio_perf_stat_inc(&perf_stats.outbound_target_full);
                DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "OUTFULL FTC:%3d",
                              q->first_to_check);
                return;
        }

        DBF_ERROR("%4x BUF ERROR", SCH_NO(q));
        DBF_ERROR((q->is_input_q) ? "IN:%2d" : "OUT:%2d", q->nr);
        DBF_ERROR("FTC:%3d C:%3d", q->first_to_check, count);
        DBF_ERROR("F14:%2x F15:%2x",
                  q->sbal[q->first_to_check]->element[14].flags & 0xff,
                  q->sbal[q->first_to_check]->element[15].flags & 0xff);
}

static inline void inbound_primed(struct qdio_q *q, int count)
{
        int new;

        DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in prim: %3d", count);

        /* for QEBSM the ACK was already set by EQBS */
        if (is_qebsm(q)) {
                if (!q->u.in.polling) {
                        q->u.in.polling = 1;
                        q->u.in.ack_count = count;
                        q->last_move_ftc = q->first_to_check;
                        return;
                }

                /* delete the previous ACK's */
                set_buf_states(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT,
                               q->u.in.ack_count);
                q->u.in.ack_count = count;
                q->last_move_ftc = q->first_to_check;
                return;
        }

        /*
         * ACK the newest buffer. The ACK will be removed in qdio_stop_polling
         * or by the next inbound run.
         */
        new = add_buf(q->first_to_check, count - 1);
        if (q->u.in.polling) {
                /* reset the previous ACK but first set the new one */
                set_buf_state(q, new, SLSB_P_INPUT_ACK);
                set_buf_state(q, q->last_move_ftc, SLSB_P_INPUT_NOT_INIT);
        } else {
                q->u.in.polling = 1;
                set_buf_state(q, new, SLSB_P_INPUT_ACK);
        }

        /*
         * last_move_ftc points to the ACK'ed buffer and not to the last turns
         * first_to_check like for qebsm. Since it is only used to check if
         * the queue front moved in qdio_inbound_q_done this is not a problem.
         */
        q->last_move_ftc = new;
        count--;
        if (!count)
                return;

        /*
         * Need to change all PRIMED buffers to NOT_INIT, otherwise
         * we're loosing initiative in the thinint code.
         */
        set_buf_states(q, q->first_to_check, SLSB_P_INPUT_NOT_INIT,
                       count);
}

static int get_inbound_buffer_frontier(struct qdio_q *q)
{
        int count, stop;
        unsigned char state;

        /*
         * Don't check 128 buffers, as otherwise qdio_inbound_q_moved
         * would return 0.
         */
        count = min(atomic_read(&q->nr_buf_used), QDIO_MAX_BUFFERS_MASK);
        stop = add_buf(q->first_to_check, count);

        /*
         * No siga sync here, as a PCI or we after a thin interrupt
         * will sync the queues.
         */

        /* need to set count to 1 for non-qebsm */
        if (!is_qebsm(q))
                count = 1;

check_next:
        if (q->first_to_check == stop)
                goto out;

        count = get_buf_states(q, q->first_to_check, &state, count, 1);
        if (!count)
                goto out;

        switch (state) {
        case SLSB_P_INPUT_PRIMED:
                inbound_primed(q, count);
                /*
                 * No siga-sync needed for non-qebsm here, as the inbound queue
                 * will be synced on the next siga-r, resp.
                 * tiqdio_is_inbound_q_done will do the siga-sync.
                 */
                q->first_to_check = add_buf(q->first_to_check, count);
                atomic_sub(count, &q->nr_buf_used);
                goto check_next;
        case SLSB_P_INPUT_ERROR:
                announce_buffer_error(q, count);
                /* process the buffer, the upper layer will take care of it */
                q->first_to_check = add_buf(q->first_to_check, count);
                atomic_sub(count, &q->nr_buf_used);
                break;
        case SLSB_CU_INPUT_EMPTY:
        case SLSB_P_INPUT_NOT_INIT:
        case SLSB_P_INPUT_ACK:
                DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in nop");
                break;
        default:
                BUG();
        }
out:
        return q->first_to_check;
}

int qdio_inbound_q_moved(struct qdio_q *q)
{
        int bufnr;

        bufnr = get_inbound_buffer_frontier(q);

        if ((bufnr != q->last_move_ftc) || q->qdio_error) {
                if (!need_siga_sync(q) && !pci_out_supported(q))
                        q->u.in.timestamp = get_usecs();

                DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in moved");
                return 1;
        } else
                return 0;
}

static int qdio_inbound_q_done(struct qdio_q *q)
{
        unsigned char state = 0;

        if (!atomic_read(&q->nr_buf_used))
                return 1;

        /*
         * We need that one for synchronization with the adapter, as it
         * does a kind of PCI avoidance.
         */
        qdio_siga_sync_q(q);

        get_buf_state(q, q->first_to_check, &state, 0);
        if (state == SLSB_P_INPUT_PRIMED)
                /* we got something to do */
                return 0;

        /* on VM, we don't poll, so the q is always done here */
        if (need_siga_sync(q) || pci_out_supported(q))
                return 1;

        /*
         * At this point we know, that inbound first_to_check
         * has (probably) not moved (see qdio_inbound_processing).
         */
        if (get_usecs() > q->u.in.timestamp + QDIO_INPUT_THRESHOLD) {
                DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in done:%3d",
                              q->first_to_check);
                return 1;
        } else {
                DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "in notd:%3d",
                              q->first_to_check);
                return 0;
        }
}

void qdio_kick_inbound_handler(struct qdio_q *q)
{
        int count, start, end;

        qdio_perf_stat_inc(&perf_stats.inbound_handler);

        start = q->first_to_kick;
        end = q->first_to_check;
        if (end >= start)
                count = end - start;
        else
                count = end + QDIO_MAX_BUFFERS_PER_Q - start;

        DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "kih s:%3d c:%3d", start, count);

        if (unlikely(q->irq_ptr->state != QDIO_IRQ_STATE_ACTIVE))
                return;

        q->handler(q->irq_ptr->cdev, q->qdio_error, q->nr,
                   start, count, q->irq_ptr->int_parm);

        /* for the next time */
        q->first_to_kick = q->first_to_check;
        q->qdio_error = 0;
}

static void __qdio_inbound_processing(struct qdio_q *q)
{
        qdio_perf_stat_inc(&perf_stats.tasklet_inbound);
again:
        if (!qdio_inbound_q_moved(q))
                return;

        qdio_kick_inbound_handler(q);

        if (!qdio_inbound_q_done(q))
                /* means poll time is not yet over */
                goto again;

        qdio_stop_polling(q);
        /*
         * We need to check again to not lose initiative after
         * resetting the ACK state.
         */
        if (!qdio_inbound_q_done(q))
                goto again;
}

/* inbound tasklet */
void qdio_inbound_processing(unsigned long data)
{
        struct qdio_q *q = (struct qdio_q *)data;
        __qdio_inbound_processing(q);
}

static int get_outbound_buffer_frontier(struct qdio_q *q)
{
        int count, stop;
        unsigned char state;

        if (((queue_type(q) != QDIO_IQDIO_QFMT) && !pci_out_supported(q)) ||
            (queue_type(q) == QDIO_IQDIO_QFMT && multicast_outbound(q)))
                qdio_siga_sync_q(q);

        /*
         * Don't check 128 buffers, as otherwise qdio_inbound_q_moved
         * would return 0.
         */
        count = min(atomic_read(&q->nr_buf_used), QDIO_MAX_BUFFERS_MASK);
        stop = add_buf(q->first_to_check, count);

        /* need to set count to 1 for non-qebsm */
        if (!is_qebsm(q))
                count = 1;

check_next:
        if (q->first_to_check == stop)
                return q->first_to_check;

        count = get_buf_states(q, q->first_to_check, &state, count, 0);
        if (!count)
                return q->first_to_check;

        switch (state) {
        case SLSB_P_OUTPUT_EMPTY:
                /* the adapter got it */
                DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out empty:%1d %3d", q->nr, count);

                atomic_sub(count, &q->nr_buf_used);
                q->first_to_check = add_buf(q->first_to_check, count);
                /*
                 * We fetch all buffer states at once. get_buf_states may
                 * return count < stop. For QEBSM we do not loop.
                 */
                if (is_qebsm(q))
                        break;
                goto check_next;
        case SLSB_P_OUTPUT_ERROR:
                announce_buffer_error(q, count);
                /* process the buffer, the upper layer will take care of it */
                q->first_to_check = add_buf(q->first_to_check, count);
                atomic_sub(count, &q->nr_buf_used);
                break;
        case SLSB_CU_OUTPUT_PRIMED:
                /* the adapter has not fetched the output yet */
                DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out primed:%1d", q->nr);
                break;
        case SLSB_P_OUTPUT_NOT_INIT:
        case SLSB_P_OUTPUT_HALTED:
                break;
        default:
                BUG();
        }
        return q->first_to_check;
}

/* all buffers processed? */
static inline int qdio_outbound_q_done(struct qdio_q *q)
{
        return atomic_read(&q->nr_buf_used) == 0;
}

static inline int qdio_outbound_q_moved(struct qdio_q *q)
{
        int bufnr;

        bufnr = get_outbound_buffer_frontier(q);

        if ((bufnr != q->last_move_ftc) || q->qdio_error) {
                q->last_move_ftc = bufnr;
                DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out moved:%1d", q->nr);
                return 1;
        } else
                return 0;
}

static void qdio_kick_outbound_q(struct qdio_q *q)
{
        unsigned int busy_bit;
        int cc;

        if (!need_siga_out(q))
                return;

        DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "siga-w:%1d", q->nr);
        qdio_perf_stat_inc(&perf_stats.siga_out);

        cc = qdio_siga_output(q, &busy_bit);
        switch (cc) {
        case 0:
                break;
        case 2:
                if (busy_bit) {
                        DBF_ERROR("%4x cc2 REP:%1d", SCH_NO(q), q->nr);
                        q->qdio_error = cc | QDIO_ERROR_SIGA_BUSY;
                } else {
                        DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "siga-w cc2:%1d",
                                      q->nr);
                        q->qdio_error = cc;
                }
                break;
        case 1:
        case 3:
                DBF_ERROR("%4x SIGA-W:%1d", SCH_NO(q), cc);
                q->qdio_error = cc;
                break;
        }
}

static void qdio_kick_outbound_handler(struct qdio_q *q)
{
        int start, end, count;

        start = q->first_to_kick;
        end = q->last_move_ftc;
        if (end >= start)
                count = end - start;
        else
                count = end + QDIO_MAX_BUFFERS_PER_Q - start;

        DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "kickouth: %1d", q->nr);
        DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "s:%3d c:%3d", start, count);

        if (unlikely(q->irq_ptr->state != QDIO_IRQ_STATE_ACTIVE))
                return;

        q->handler(q->irq_ptr->cdev, q->qdio_error, q->nr, start, count,
                   q->irq_ptr->int_parm);

        /* for the next time: */
        q->first_to_kick = q->last_move_ftc;
        q->qdio_error = 0;
}

static void __qdio_outbound_processing(struct qdio_q *q)
{
        unsigned long flags;

        qdio_perf_stat_inc(&perf_stats.tasklet_outbound);
        spin_lock_irqsave(&q->lock, flags);

        BUG_ON(atomic_read(&q->nr_buf_used) < 0);

        if (qdio_outbound_q_moved(q))
                qdio_kick_outbound_handler(q);

        spin_unlock_irqrestore(&q->lock, flags);

        if (queue_type(q) == QDIO_ZFCP_QFMT)
                if (!pci_out_supported(q) && !qdio_outbound_q_done(q))
                        goto sched;

        /* bail out for HiperSockets unicast queues */
        if (queue_type(q) == QDIO_IQDIO_QFMT && !multicast_outbound(q))
                return;

        if ((queue_type(q) == QDIO_IQDIO_QFMT) &&
            (atomic_read(&q->nr_buf_used)) > QDIO_IQDIO_POLL_LVL)
                goto sched;

        if (q->u.out.pci_out_enabled)
                return;

        /*
         * Now we know that queue type is either qeth without pci enabled
         * or HiperSockets multicast. Make sure buffer switch from PRIMED to
         * EMPTY is noticed and outbound_handler is called after some time.
         */
        if (qdio_outbound_q_done(q))
                del_timer(&q->u.out.timer);
        else {
                if (!timer_pending(&q->u.out.timer)) {
                        mod_timer(&q->u.out.timer, jiffies + 10 * HZ);
                        qdio_perf_stat_inc(&perf_stats.debug_tl_out_timer);
                }
        }
        return;

sched:
        if (unlikely(q->irq_ptr->state == QDIO_IRQ_STATE_STOPPED))
                return;
        tasklet_schedule(&q->tasklet);
}

/* outbound tasklet */
void qdio_outbound_processing(unsigned long data)
{
        struct qdio_q *q = (struct qdio_q *)data;
        __qdio_outbound_processing(q);
}

void qdio_outbound_timer(unsigned long data)
{
        struct qdio_q *q = (struct qdio_q *)data;

        if (unlikely(q->irq_ptr->state == QDIO_IRQ_STATE_STOPPED))
                return;
        tasklet_schedule(&q->tasklet);
}

/* called from thinint inbound tasklet */
void qdio_check_outbound_after_thinint(struct qdio_q *q)
{
        struct qdio_q *out;
        int i;

        if (!pci_out_supported(q))
                return;

        for_each_output_queue(q->irq_ptr, out, i)
                if (!qdio_outbound_q_done(out))
                        tasklet_schedule(&out->tasklet);
}

static inline void qdio_set_state(struct qdio_irq *irq_ptr,
                                  enum qdio_irq_states state)
{
        DBF_DEV_EVENT(DBF_INFO, irq_ptr, "newstate: %1d", state);

        irq_ptr->state = state;
        mb();
}

static void qdio_irq_check_sense(struct qdio_irq *irq_ptr, struct irb *irb)
{
        if (irb->esw.esw0.erw.cons) {
                DBF_ERROR("%4x sense:", irq_ptr->schid.sch_no);
                DBF_ERROR_HEX(irb, 64);
                DBF_ERROR_HEX(irb->ecw, 64);
        }
}

/* PCI interrupt handler */
static void qdio_int_handler_pci(struct qdio_irq *irq_ptr)
{
        int i;
        struct qdio_q *q;

        if (unlikely(irq_ptr->state == QDIO_IRQ_STATE_STOPPED))
                return;

        qdio_perf_stat_inc(&perf_stats.pci_int);

        for_each_input_queue(irq_ptr, q, i)
                tasklet_schedule(&q->tasklet);

        if (!(irq_ptr->qib.ac & QIB_AC_OUTBOUND_PCI_SUPPORTED))
                return;

        for_each_output_queue(irq_ptr, q, i) {
                if (qdio_outbound_q_done(q))
                        continue;

                if (!siga_syncs_out_pci(q))
                        qdio_siga_sync_q(q);

                tasklet_schedule(&q->tasklet);
        }
}

static void qdio_handle_activate_check(struct ccw_device *cdev,
                                unsigned long intparm, int cstat, int dstat)
{
        struct qdio_irq *irq_ptr = cdev->private->qdio_data;
        struct qdio_q *q;

        DBF_ERROR("%4x ACT CHECK", irq_ptr->schid.sch_no);
        DBF_ERROR("intp :%lx", intparm);
        DBF_ERROR("ds: %2x cs:%2x", dstat, cstat);

        if (irq_ptr->nr_input_qs) {
                q = irq_ptr->input_qs[0];
        } else if (irq_ptr->nr_output_qs) {
                q = irq_ptr->output_qs[0];
        } else {
                dump_stack();
                goto no_handler;
        }
        q->handler(q->irq_ptr->cdev, QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
                   0, -1, -1, irq_ptr->int_parm);
no_handler:
        qdio_set_state(irq_ptr, QDIO_IRQ_STATE_STOPPED);
}

static void qdio_call_shutdown(struct work_struct *work)
{
        struct ccw_device_private *priv;
        struct ccw_device *cdev;

        priv = container_of(work, struct ccw_device_private, kick_work);
        cdev = priv->cdev;
        qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
        put_device(&cdev->dev);
}

static void qdio_int_error(struct ccw_device *cdev)
{
        struct qdio_irq *irq_ptr = cdev->private->qdio_data;

        switch (irq_ptr->state) {
        case QDIO_IRQ_STATE_INACTIVE:
        case QDIO_IRQ_STATE_CLEANUP:
                qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ERR);
                break;
        case QDIO_IRQ_STATE_ESTABLISHED:
        case QDIO_IRQ_STATE_ACTIVE:
                qdio_set_state(irq_ptr, QDIO_IRQ_STATE_STOPPED);
                if (get_device(&cdev->dev)) {
                        /* Can't call shutdown from interrupt context. */
                        PREPARE_WORK(&cdev->private->kick_work,
                                     qdio_call_shutdown);
                        queue_work(ccw_device_work, &cdev->private->kick_work);
                }
                break;
        default:
                WARN_ON(1);
        }
        wake_up(&cdev->private->wait_q);
}

static int qdio_establish_check_errors(struct ccw_device *cdev, int cstat,
                                       int dstat)
{
        struct qdio_irq *irq_ptr = cdev->private->qdio_data;

        if (cstat || (dstat & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END))) {
                DBF_ERROR("EQ:ck con");
                goto error;
        }

        if (!(dstat & DEV_STAT_DEV_END)) {
                DBF_ERROR("EQ:no dev");
                goto error;
        }

        if (dstat & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END)) {
                DBF_ERROR("EQ: bad io");
                goto error;
        }
        return 0;
error:
        DBF_ERROR("%4x EQ:error", irq_ptr->schid.sch_no);
        DBF_ERROR("ds: %2x cs:%2x", dstat, cstat);

        qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ERR);
        return 1;
}

static void qdio_establish_handle_irq(struct ccw_device *cdev, int cstat,
                                      int dstat)
{
        struct qdio_irq *irq_ptr = cdev->private->qdio_data;

        DBF_DEV_EVENT(DBF_INFO, irq_ptr, "qest irq");
        if (!qdio_establish_check_errors(cdev, cstat, dstat))
                qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ESTABLISHED);
}

/* qdio interrupt handler */
void qdio_int_handler(struct ccw_device *cdev, unsigned long intparm,
                      struct irb *irb)
{
        struct qdio_irq *irq_ptr = cdev->private->qdio_data;
        int cstat, dstat;

        qdio_perf_stat_inc(&perf_stats.qdio_int);

        if (!intparm || !irq_ptr) {
                DBF_ERROR("qint:%4x", cdev->private->schid.sch_no);
                return;
        }

        if (IS_ERR(irb)) {
                switch (PTR_ERR(irb)) {
                case -EIO:
                        DBF_ERROR("%4x IO error", irq_ptr->schid.sch_no);
                        return;
                case -ETIMEDOUT:
                        DBF_ERROR("%4x IO timeout", irq_ptr->schid.sch_no);
                        qdio_int_error(cdev);
                        return;
                default:
                        WARN_ON(1);
                        return;
                }
        }
        qdio_irq_check_sense(irq_ptr, irb);

        cstat = irb->scsw.cmd.cstat;
        dstat = irb->scsw.cmd.dstat;

        switch (irq_ptr->state) {
        case QDIO_IRQ_STATE_INACTIVE:
                qdio_establish_handle_irq(cdev, cstat, dstat);
                break;

        case QDIO_IRQ_STATE_CLEANUP:
                qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
                break;

        case QDIO_IRQ_STATE_ESTABLISHED:
        case QDIO_IRQ_STATE_ACTIVE:
                if (cstat & SCHN_STAT_PCI) {
                        qdio_int_handler_pci(irq_ptr);
                        /* no state change so no need to wake up wait_q */
                        return;
                }
                if ((cstat & ~SCHN_STAT_PCI) || dstat) {
                        qdio_handle_activate_check(cdev, intparm, cstat,
                                                   dstat);
                        break;
                }
        default:
                WARN_ON(1);
        }
        wake_up(&cdev->private->wait_q);
}

/**
 * qdio_get_ssqd_desc - get qdio subchannel description
 * @cdev: ccw device to get description for
 * @data: where to store the ssqd
 *
 * Returns 0 or an error code. The results of the chsc are stored in the
 * specified structure.
 */
int qdio_get_ssqd_desc(struct ccw_device *cdev,
                       struct qdio_ssqd_desc *data)
{

        if (!cdev || !cdev->private)
                return -EINVAL;

        DBF_EVENT("get ssqd:%4x", cdev->private->schid.sch_no);
        return qdio_setup_get_ssqd(NULL, &cdev->private->schid, data);
}
EXPORT_SYMBOL_GPL(qdio_get_ssqd_desc);

/**
 * qdio_cleanup - shutdown queues and free data structures
 * @cdev: associated ccw device
 * @how: use halt or clear to shutdown
 *
 * This function calls qdio_shutdown() for @cdev with method @how.
 * and qdio_free(). The qdio_free() return value is ignored since
 * !irq_ptr is already checked.
 */
int qdio_cleanup(struct ccw_device *cdev, int how)
{
        struct qdio_irq *irq_ptr = cdev->private->qdio_data;
        int rc;

        if (!irq_ptr)
                return -ENODEV;

        rc = qdio_shutdown(cdev, how);

        qdio_free(cdev);
        return rc;
}
EXPORT_SYMBOL_GPL(qdio_cleanup);

static void qdio_shutdown_queues(struct ccw_device *cdev)
{
        struct qdio_irq *irq_ptr = cdev->private->qdio_data;
        struct qdio_q *q;
        int i;

        for_each_input_queue(irq_ptr, q, i)
                tasklet_kill(&q->tasklet);

        for_each_output_queue(irq_ptr, q, i) {
                del_timer(&q->u.out.timer);
                tasklet_kill(&q->tasklet);
        }
}

/**
 * qdio_shutdown - shut down a qdio subchannel
 * @cdev: associated ccw device
 * @how: use halt or clear to shutdown
 */
int qdio_shutdown(struct ccw_device *cdev, int how)
{
        struct qdio_irq *irq_ptr = cdev->private->qdio_data;
        int rc;
        unsigned long flags;

        if (!irq_ptr)
                return -ENODEV;

        BUG_ON(irqs_disabled());
        DBF_EVENT("qshutdown:%4x", cdev->private->schid.sch_no);

        mutex_lock(&irq_ptr->setup_mutex);
        /*
         * Subchannel was already shot down. We cannot prevent being called
         * twice since cio may trigger a shutdown asynchronously.
         */
        if (irq_ptr->state == QDIO_IRQ_STATE_INACTIVE) {
                mutex_unlock(&irq_ptr->setup_mutex);
                return 0;
        }

        /*
         * Indicate that the device is going down. Scheduling the queue
         * tasklets is forbidden from here on.
         */
        qdio_set_state(irq_ptr, QDIO_IRQ_STATE_STOPPED);

        tiqdio_remove_input_queues(irq_ptr);
        qdio_shutdown_queues(cdev);
        qdio_shutdown_debug_entries(irq_ptr, cdev);

        /* cleanup subchannel */
        spin_lock_irqsave(get_ccwdev_lock(cdev), flags);

        if (how & QDIO_FLAG_CLEANUP_USING_CLEAR)
                rc = ccw_device_clear(cdev, QDIO_DOING_CLEANUP);
        else
                /* default behaviour is halt */
                rc = ccw_device_halt(cdev, QDIO_DOING_CLEANUP);
        if (rc) {
                DBF_ERROR("%4x SHUTD ERR", irq_ptr->schid.sch_no);
                DBF_ERROR("rc:%4d", rc);
                goto no_cleanup;
        }

        qdio_set_state(irq_ptr, QDIO_IRQ_STATE_CLEANUP);
        spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
        wait_event_interruptible_timeout(cdev->private->wait_q,
                irq_ptr->state == QDIO_IRQ_STATE_INACTIVE ||
                irq_ptr->state == QDIO_IRQ_STATE_ERR,
                10 * HZ);
        spin_lock_irqsave(get_ccwdev_lock(cdev), flags);

no_cleanup:
        qdio_shutdown_thinint(irq_ptr);

        /* restore interrupt handler */
        if ((void *)cdev->handler == (void *)qdio_int_handler)
                cdev->handler = irq_ptr->orig_handler;
        spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);

        qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
        mutex_unlock(&irq_ptr->setup_mutex);
        if (rc)
                return rc;
        return 0;
}
EXPORT_SYMBOL_GPL(qdio_shutdown);

/**
 * qdio_free - free data structures for a qdio subchannel
 * @cdev: associated ccw device
 */
int qdio_free(struct ccw_device *cdev)
{
        struct qdio_irq *irq_ptr = cdev->private->qdio_data;

        if (!irq_ptr)
                return -ENODEV;

        DBF_EVENT("qfree:%4x", cdev->private->schid.sch_no);
        mutex_lock(&irq_ptr->setup_mutex);

        if (irq_ptr->debug_area != NULL) {
                debug_unregister(irq_ptr->debug_area);
                irq_ptr->debug_area = NULL;
        }
        cdev->private->qdio_data = NULL;
        mutex_unlock(&irq_ptr->setup_mutex);

        qdio_release_memory(irq_ptr);
        return 0;
}
EXPORT_SYMBOL_GPL(qdio_free);

/**
 * qdio_initialize - allocate and establish queues for a qdio subchannel
 * @init_data: initialization data
 *
 * This function first allocates queues via qdio_allocate() and on success
 * establishes them via qdio_establish().
 */
int qdio_initialize(struct qdio_initialize *init_data)
{
        int rc;

        rc = qdio_allocate(init_data);
        if (rc)
                return rc;

        rc = qdio_establish(init_data);
        if (rc)
                qdio_free(init_data->cdev);
        return rc;
}
EXPORT_SYMBOL_GPL(qdio_initialize);

/**
 * qdio_allocate - allocate qdio queues and associated data
 * @init_data: initialization data
 */
int qdio_allocate(struct qdio_initialize *init_data)
{
        struct qdio_irq *irq_ptr;

        DBF_EVENT("qallocate:%4x", init_data->cdev->private->schid.sch_no);

        if ((init_data->no_input_qs && !init_data->input_handler) ||
            (init_data->no_output_qs && !init_data->output_handler))
                return -EINVAL;

        if ((init_data->no_input_qs > QDIO_MAX_QUEUES_PER_IRQ) ||
            (init_data->no_output_qs > QDIO_MAX_QUEUES_PER_IRQ))
                return -EINVAL;

        if ((!init_data->input_sbal_addr_array) ||
            (!init_data->output_sbal_addr_array))
                return -EINVAL;

        /* irq_ptr must be in GFP_DMA since it contains ccw1.cda */
        irq_ptr = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!irq_ptr)
                goto out_err;

        mutex_init(&irq_ptr->setup_mutex);
        qdio_allocate_dbf(init_data, irq_ptr);

        /*
         * Allocate a page for the chsc calls in qdio_establish.
         * Must be pre-allocated since a zfcp recovery will call
         * qdio_establish. In case of low memory and swap on a zfcp disk
         * we may not be able to allocate memory otherwise.
         */
        irq_ptr->chsc_page = get_zeroed_page(GFP_KERNEL);
        if (!irq_ptr->chsc_page)
                goto out_rel;

        /* qdr is used in ccw1.cda which is u32 */
        irq_ptr->qdr = (struct qdr *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!irq_ptr->qdr)
                goto out_rel;
        WARN_ON((unsigned long)irq_ptr->qdr & 0xfff);

        if (qdio_allocate_qs(irq_ptr, init_data->no_input_qs,
                             init_data->no_output_qs))
                goto out_rel;

        init_data->cdev->private->qdio_data = irq_ptr;
        qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);
        return 0;
out_rel:
        qdio_release_memory(irq_ptr);
out_err:
        return -ENOMEM;
}
EXPORT_SYMBOL_GPL(qdio_allocate);

/**
 * qdio_establish - establish queues on a qdio subchannel
 * @init_data: initialization data
 */
int qdio_establish(struct qdio_initialize *init_data)
{
        struct qdio_irq *irq_ptr;
        struct ccw_device *cdev = init_data->cdev;
        unsigned long saveflags;
        int rc;

        DBF_EVENT("qestablish:%4x", cdev->private->schid.sch_no);

        irq_ptr = cdev->private->qdio_data;
        if (!irq_ptr)
                return -ENODEV;

        if (cdev->private->state != DEV_STATE_ONLINE)
                return -EINVAL;

        mutex_lock(&irq_ptr->setup_mutex);
        qdio_setup_irq(init_data);

        rc = qdio_establish_thinint(irq_ptr);
        if (rc) {
                mutex_unlock(&irq_ptr->setup_mutex);
                qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
                return rc;
        }

        /* establish q */
        irq_ptr->ccw.cmd_code = irq_ptr->equeue.cmd;
        irq_ptr->ccw.flags = CCW_FLAG_SLI;
        irq_ptr->ccw.count = irq_ptr->equeue.count;
        irq_ptr->ccw.cda = (u32)((addr_t)irq_ptr->qdr);

        spin_lock_irqsave(get_ccwdev_lock(cdev), saveflags);
        ccw_device_set_options_mask(cdev, 0);

        rc = ccw_device_start(cdev, &irq_ptr->ccw, QDIO_DOING_ESTABLISH, 0, 0);
        if (rc) {
                DBF_ERROR("%4x est IO ERR", irq_ptr->schid.sch_no);
                DBF_ERROR("rc:%4x", rc);
        }
        spin_unlock_irqrestore(get_ccwdev_lock(cdev), saveflags);

        if (rc) {
                mutex_unlock(&irq_ptr->setup_mutex);
                qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
                return rc;
        }

        wait_event_interruptible_timeout(cdev->private->wait_q,
                irq_ptr->state == QDIO_IRQ_STATE_ESTABLISHED ||
                irq_ptr->state == QDIO_IRQ_STATE_ERR, HZ);

        if (irq_ptr->state != QDIO_IRQ_STATE_ESTABLISHED) {
                mutex_unlock(&irq_ptr->setup_mutex);
                qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR);
                return -EIO;
        }

        qdio_setup_ssqd_info(irq_ptr);
        DBF_EVENT("qDmmwc:%2x", irq_ptr->ssqd_desc.mmwc);
        DBF_EVENT("qib ac:%4x", irq_ptr->qib.ac);

        /* qebsm is now setup if available, initialize buffer states */
        qdio_init_buf_states(irq_ptr);

        mutex_unlock(&irq_ptr->setup_mutex);
        qdio_print_subchannel_info(irq_ptr, cdev);
        qdio_setup_debug_entries(irq_ptr, cdev);
        return 0;
}
EXPORT_SYMBOL_GPL(qdio_establish);

/**
 * qdio_activate - activate queues on a qdio subchannel
 * @cdev: associated cdev
 */
int qdio_activate(struct ccw_device *cdev)
{
        struct qdio_irq *irq_ptr;
        int rc;
        unsigned long saveflags;

        DBF_EVENT("qactivate:%4x", cdev->private->schid.sch_no);

        irq_ptr = cdev->private->qdio_data;
        if (!irq_ptr)
                return -ENODEV;

        if (cdev->private->state != DEV_STATE_ONLINE)
                return -EINVAL;

        mutex_lock(&irq_ptr->setup_mutex);
        if (irq_ptr->state == QDIO_IRQ_STATE_INACTIVE) {
                rc = -EBUSY;
                goto out;
        }

        irq_ptr->ccw.cmd_code = irq_ptr->aqueue.cmd;
        irq_ptr->ccw.flags = CCW_FLAG_SLI;
        irq_ptr->ccw.count = irq_ptr->aqueue.count;
        irq_ptr->ccw.cda = 0;

        spin_lock_irqsave(get_ccwdev_lock(cdev), saveflags);
        ccw_device_set_options(cdev, CCWDEV_REPORT_ALL);

        rc = ccw_device_start(cdev, &irq_ptr->ccw, QDIO_DOING_ACTIVATE,
                              0, DOIO_DENY_PREFETCH);
        if (rc) {
                DBF_ERROR("%4x act IO ERR", irq_ptr->schid.sch_no);
                DBF_ERROR("rc:%4x", rc);
        }
        spin_unlock_irqrestore(get_ccwdev_lock(cdev), saveflags);

        if (rc)
                goto out;

        if (is_thinint_irq(irq_ptr))
                tiqdio_add_input_queues(irq_ptr);

        /* wait for subchannel to become active */
        msleep(5);

        switch (irq_ptr->state) {
        case QDIO_IRQ_STATE_STOPPED:
        case QDIO_IRQ_STATE_ERR:
                rc = -EIO;
                break;
        default:
                qdio_set_state(irq_ptr, QDIO_IRQ_STATE_ACTIVE);
                rc = 0;
        }
out:
        mutex_unlock(&irq_ptr->setup_mutex);
        return rc;
}
EXPORT_SYMBOL_GPL(qdio_activate);

static inline int buf_in_between(int bufnr, int start, int count)
{
        int end = add_buf(start, count);

        if (end > start) {
                if (bufnr >= start && bufnr < end)
                        return 1;
                else
                        return 0;
        }

        /* wrap-around case */
        if ((bufnr >= start && bufnr <= QDIO_MAX_BUFFERS_PER_Q) ||
            (bufnr < end))
                return 1;
        else
                return 0;
}

/**
 * handle_inbound - reset processed input buffers
 * @q: queue containing the buffers
 * @callflags: flags
 * @bufnr: first buffer to process
 * @count: how many buffers are emptied
 */
static void handle_inbound(struct qdio_q *q, unsigned int callflags,
                           int bufnr, int count)
{
        int used, cc, diff;

        if (!q->u.in.polling)
                goto set;

        /* protect against stop polling setting an ACK for an emptied slsb */
        if (count == QDIO_MAX_BUFFERS_PER_Q) {
                /* overwriting everything, just delete polling status */
                q->u.in.polling = 0;
                q->u.in.ack_count = 0;
                goto set;
        } else if (buf_in_between(q->last_move_ftc, bufnr, count)) {
                if (is_qebsm(q)) {
                        /* partial overwrite, just update last_move_ftc */
                        diff = add_buf(bufnr, count);
                        diff = sub_buf(diff, q->last_move_ftc);
                        q->u.in.ack_count -= diff;
                        if (q->u.in.ack_count <= 0) {
                                q->u.in.polling = 0;
                                q->u.in.ack_count = 0;
                                goto set;
                        }
                        q->last_move_ftc = add_buf(q->last_move_ftc, diff);
                }
                else
                        /* the only ACK will be deleted, so stop polling */
                        q->u.in.polling = 0;
        }

set:
        count = set_buf_states(q, bufnr, SLSB_CU_INPUT_EMPTY, count);

        used = atomic_add_return(count, &q->nr_buf_used) - count;
        BUG_ON(used + count > QDIO_MAX_BUFFERS_PER_Q);

        /* no need to signal as long as the adapter had free buffers */
        if (used)
                return;

        if (need_siga_in(q)) {
                cc = qdio_siga_input(q);
                if (cc)
                        q->qdio_error = cc;
        }
}

/**
 * handle_outbound - process filled outbound buffers
 * @q: queue containing the buffers
 * @callflags: flags
 * @bufnr: first buffer to process
 * @count: how many buffers are filled
 */
static void handle_outbound(struct qdio_q *q, unsigned int callflags,
                            int bufnr, int count)
{
        unsigned char state;
        int used;

        qdio_perf_stat_inc(&perf_stats.outbound_handler);

        count = set_buf_states(q, bufnr, SLSB_CU_OUTPUT_PRIMED, count);
        used = atomic_add_return(count, &q->nr_buf_used);
        BUG_ON(used > QDIO_MAX_BUFFERS_PER_Q);

        if (callflags & QDIO_FLAG_PCI_OUT)
                q->u.out.pci_out_enabled = 1;
        else
                q->u.out.pci_out_enabled = 0;

        if (queue_type(q) == QDIO_IQDIO_QFMT) {
                if (multicast_outbound(q))
                        qdio_kick_outbound_q(q);
                else
                        if ((q->irq_ptr->ssqd_desc.mmwc > 1) &&
                            (count > 1) &&
                            (count <= q->irq_ptr->ssqd_desc.mmwc)) {
                                /* exploit enhanced SIGA */
                                q->u.out.use_enh_siga = 1;
                                qdio_kick_outbound_q(q);
                        } else {
                                /*
                                * One siga-w per buffer required for unicast
                                * HiperSockets.
                                */
                                q->u.out.use_enh_siga = 0;
                                while (count--)
                                        qdio_kick_outbound_q(q);
                        }

                /* report CC=2 conditions synchronously */
                if (q->qdio_error)
                        __qdio_outbound_processing(q);
                goto out;
        }

        if (need_siga_sync(q)) {
                qdio_siga_sync_q(q);
                goto out;
        }

        /* try to fast requeue buffers */
        get_buf_state(q, prev_buf(bufnr), &state, 0);
        if (state != SLSB_CU_OUTPUT_PRIMED)
                qdio_kick_outbound_q(q);
        else {
                DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "fast-req");
                qdio_perf_stat_inc(&perf_stats.fast_requeue);
        }
out:
        tasklet_schedule(&q->tasklet);
}

/**
 * do_QDIO - process input or output buffers
 * @cdev: associated ccw_device for the qdio subchannel
 * @callflags: input or output and special flags from the program
 * @q_nr: queue number
 * @bufnr: buffer number
 * @count: how many buffers to process
 */
int do_QDIO(struct ccw_device *cdev, unsigned int callflags,
            int q_nr, int bufnr, int count)
{
        struct qdio_irq *irq_ptr;

        if ((bufnr > QDIO_MAX_BUFFERS_PER_Q) ||
            (count > QDIO_MAX_BUFFERS_PER_Q) ||
            (q_nr > QDIO_MAX_QUEUES_PER_IRQ))
                return -EINVAL;

        if (!count)
                return 0;

        irq_ptr = cdev->private->qdio_data;
        if (!irq_ptr)
                return -ENODEV;

        if (callflags & QDIO_FLAG_SYNC_INPUT)
                DBF_DEV_EVENT(DBF_INFO, irq_ptr, "doQDIO input");
        else
                DBF_DEV_EVENT(DBF_INFO, irq_ptr, "doQDIO output");
        DBF_DEV_EVENT(DBF_INFO, irq_ptr, "q:%1d flag:%4x", q_nr, callflags);
        DBF_DEV_EVENT(DBF_INFO, irq_ptr, "buf:%2d cnt:%3d", bufnr, count);

        if (irq_ptr->state != QDIO_IRQ_STATE_ACTIVE)
                return -EBUSY;

        if (callflags & QDIO_FLAG_SYNC_INPUT)
                handle_inbound(irq_ptr->input_qs[q_nr], callflags, bufnr,
                               count);
        else if (callflags & QDIO_FLAG_SYNC_OUTPUT)
                handle_outbound(irq_ptr->output_qs[q_nr], callflags, bufnr,
                                count);
        else
                return -EINVAL;
        return 0;
}
EXPORT_SYMBOL_GPL(do_QDIO);

static int __init init_QDIO(void)
{
        int rc;

        rc = qdio_setup_init();
        if (rc)
                return rc;
        rc = tiqdio_allocate_memory();
        if (rc)
                goto out_cache;
        rc = qdio_debug_init();
        if (rc)
                goto out_ti;
        rc = qdio_setup_perf_stats();
        if (rc)
                goto out_debug;
        rc = tiqdio_register_thinints();
        if (rc)
                goto out_perf;
        return 0;

out_perf:
        qdio_remove_perf_stats();
out_debug:
        qdio_debug_exit();
out_ti:
        tiqdio_free_memory();
out_cache:
        qdio_setup_exit();
        return rc;
}

static void __exit exit_QDIO(void)
{
        tiqdio_unregister_thinints();
        tiqdio_free_memory();
        qdio_remove_perf_stats();
        qdio_debug_exit();
        qdio_setup_exit();
}

module_init(init_QDIO);
module_exit(exit_QDIO);