/*
 * Copyright (c) 2012, 2013 Intel Corporation.  All rights reserved.
 * Copyright (c) 2006 - 2012 QLogic Corporation.  * All rights reserved.
 * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/err.h>
#include <linux/vmalloc.h>
#include <rdma/rdma_vt.h>
#ifdef CONFIG_DEBUG_FS
#include <linux/seq_file.h>
#endif

#include "qib.h"

/*
 * mask field which was present in now deleted qib_qpn_table
 * is not present in rvt_qpn_table. Defining the same field
 * as qpt_mask here instead of adding the mask field to
 * rvt_qpn_table.
 */
u16 qpt_mask;

static inline unsigned mk_qpn(struct rvt_qpn_table *qpt,
                              struct rvt_qpn_map *map, unsigned off)
{
        return (map - qpt->map) * RVT_BITS_PER_PAGE + off;
}

static inline unsigned find_next_offset(struct rvt_qpn_table *qpt,
                                        struct rvt_qpn_map *map, unsigned off,
                                        unsigned n)
{
        if (qpt_mask) {
                off++;
                if (((off & qpt_mask) >> 1) >= n)
                        off = (off | qpt_mask) + 2;
        } else {
                off = find_next_zero_bit(map->page, RVT_BITS_PER_PAGE, off);
        }
        return off;
}

/*
 * Convert the AETH credit code into the number of credits.
 */
static u32 credit_table[31] = {
        0,                      /* 0 */
        1,                      /* 1 */
        2,                      /* 2 */
        3,                      /* 3 */
        4,                      /* 4 */
        6,                      /* 5 */
        8,                      /* 6 */
        12,                     /* 7 */
        16,                     /* 8 */
        24,                     /* 9 */
        32,                     /* A */
        48,                     /* B */
        64,                     /* C */
        96,                     /* D */
        128,                    /* E */
        192,                    /* F */
        256,                    /* 10 */
        384,                    /* 11 */
        512,                    /* 12 */
        768,                    /* 13 */
        1024,                   /* 14 */
        1536,                   /* 15 */
        2048,                   /* 16 */
        3072,                   /* 17 */
        4096,                   /* 18 */
        6144,                   /* 19 */
        8192,                   /* 1A */
        12288,                  /* 1B */
        16384,                  /* 1C */
        24576,                  /* 1D */
        32768                   /* 1E */
};

static void get_map_page(struct rvt_qpn_table *qpt, struct rvt_qpn_map *map,
                         gfp_t gfp)
{
        unsigned long page = get_zeroed_page(gfp);

        /*
         * Free the page if someone raced with us installing it.
         */

        spin_lock(&qpt->lock);
        if (map->page)
                free_page(page);
        else
                map->page = (void *)page;
        spin_unlock(&qpt->lock);
}

/*
 * Allocate the next available QPN or
 * zero/one for QP type IB_QPT_SMI/IB_QPT_GSI.
 */
int qib_alloc_qpn(struct rvt_dev_info *rdi, struct rvt_qpn_table *qpt,
                  enum ib_qp_type type, u8 port, gfp_t gfp)
{
        u32 i, offset, max_scan, qpn;
        struct rvt_qpn_map *map;
        u32 ret;
        struct qib_ibdev *verbs_dev = container_of(rdi, struct qib_ibdev, rdi);
        struct qib_devdata *dd = container_of(verbs_dev, struct qib_devdata,
                                              verbs_dev);

        if (type == IB_QPT_SMI || type == IB_QPT_GSI) {
                unsigned n;

                ret = type == IB_QPT_GSI;
                n = 1 << (ret + 2 * (port - 1));
                spin_lock(&qpt->lock);
                if (qpt->flags & n)
                        ret = -EINVAL;
                else
                        qpt->flags |= n;
                spin_unlock(&qpt->lock);
                goto bail;
        }

        qpn = qpt->last + 2;
        if (qpn >= RVT_QPN_MAX)
                qpn = 2;
        if (qpt_mask && ((qpn & qpt_mask) >> 1) >= dd->n_krcv_queues)
                qpn = (qpn | qpt_mask) + 2;
        offset = qpn & RVT_BITS_PER_PAGE_MASK;
        map = &qpt->map[qpn / RVT_BITS_PER_PAGE];
        max_scan = qpt->nmaps - !offset;
        for (i = 0;;) {
                if (unlikely(!map->page)) {
                        get_map_page(qpt, map, gfp);
                        if (unlikely(!map->page))
                                break;
                }
                do {
                        if (!test_and_set_bit(offset, map->page)) {
                                qpt->last = qpn;
                                ret = qpn;
                                goto bail;
                        }
                        offset = find_next_offset(qpt, map, offset,
                                dd->n_krcv_queues);
                        qpn = mk_qpn(qpt, map, offset);
                        /*
                         * This test differs from alloc_pidmap().
                         * If find_next_offset() does find a zero
                         * bit, we don't need to check for QPN
                         * wrapping around past our starting QPN.
                         * We just need to be sure we don't loop
                         * forever.
                         */
                } while (offset < RVT_BITS_PER_PAGE && qpn < RVT_QPN_MAX);
                /*
                 * In order to keep the number of pages allocated to a
                 * minimum, we scan the all existing pages before increasing
                 * the size of the bitmap table.
                 */
                if (++i > max_scan) {
                        if (qpt->nmaps == RVT_QPNMAP_ENTRIES)
                                break;
                        map = &qpt->map[qpt->nmaps++];
                        offset = 0;
                } else if (map < &qpt->map[qpt->nmaps]) {
                        ++map;
                        offset = 0;
                } else {
                        map = &qpt->map[0];
                        offset = 2;
                }
                qpn = mk_qpn(qpt, map, offset);
        }

        ret = -ENOMEM;

bail:
        return ret;
}

/**
 * qib_free_all_qps - check for QPs still in use
 */
unsigned qib_free_all_qps(struct rvt_dev_info *rdi)
{
        struct qib_ibdev *verbs_dev = container_of(rdi, struct qib_ibdev, rdi);
        struct qib_devdata *dd = container_of(verbs_dev, struct qib_devdata,
                                              verbs_dev);
        unsigned n, qp_inuse = 0;

        for (n = 0; n < dd->num_pports; n++) {
                struct qib_ibport *ibp = &dd->pport[n].ibport_data;

                rcu_read_lock();
                if (rcu_dereference(ibp->rvp.qp[0]))
                        qp_inuse++;
                if (rcu_dereference(ibp->rvp.qp[1]))
                        qp_inuse++;
                rcu_read_unlock();
        }
        return qp_inuse;
}

void qib_notify_qp_reset(struct rvt_qp *qp)
{
        struct qib_qp_priv *priv = qp->priv;

        atomic_set(&priv->s_dma_busy, 0);
}

void qib_notify_error_qp(struct rvt_qp *qp)
{
        struct qib_qp_priv *priv = qp->priv;
        struct qib_ibdev *dev = to_idev(qp->ibqp.device);

        spin_lock(&dev->rdi.pending_lock);
        if (!list_empty(&priv->iowait) && !(qp->s_flags & RVT_S_BUSY)) {
                qp->s_flags &= ~RVT_S_ANY_WAIT_IO;
                list_del_init(&priv->iowait);
        }
        spin_unlock(&dev->rdi.pending_lock);

        if (!(qp->s_flags & RVT_S_BUSY)) {
                qp->s_hdrwords = 0;
                if (qp->s_rdma_mr) {
                        rvt_put_mr(qp->s_rdma_mr);
                        qp->s_rdma_mr = NULL;
                }
                if (priv->s_tx) {
                        qib_put_txreq(priv->s_tx);
                        priv->s_tx = NULL;
                }
        }
}

static int mtu_to_enum(u32 mtu)
{
        int enum_mtu;

        switch (mtu) {
        case 4096:
                enum_mtu = IB_MTU_4096;
                break;
        case 2048:
                enum_mtu = IB_MTU_2048;
                break;
        case 1024:
                enum_mtu = IB_MTU_1024;
                break;
        case 512:
                enum_mtu = IB_MTU_512;
                break;
        case 256:
                enum_mtu = IB_MTU_256;
                break;
        default:
                enum_mtu = IB_MTU_2048;
        }
        return enum_mtu;
}

int qib_get_pmtu_from_attr(struct rvt_dev_info *rdi, struct rvt_qp *qp,
                           struct ib_qp_attr *attr)
{
        int mtu, pmtu, pidx = qp->port_num - 1;
        struct qib_ibdev *verbs_dev = container_of(rdi, struct qib_ibdev, rdi);
        struct qib_devdata *dd = container_of(verbs_dev, struct qib_devdata,
                                              verbs_dev);
        mtu = ib_mtu_enum_to_int(attr->path_mtu);
        if (mtu == -1)
                return -EINVAL;

        if (mtu > dd->pport[pidx].ibmtu)
                pmtu = mtu_to_enum(dd->pport[pidx].ibmtu);
        else
                pmtu = attr->path_mtu;
        return pmtu;
}

int qib_mtu_to_path_mtu(u32 mtu)
{
        return mtu_to_enum(mtu);
}

u32 qib_mtu_from_qp(struct rvt_dev_info *rdi, struct rvt_qp *qp, u32 pmtu)
{
        return ib_mtu_enum_to_int(pmtu);
}

/**
 * qib_compute_aeth - compute the AETH (syndrome + MSN)
 * @qp: the queue pair to compute the AETH for
 *
 * Returns the AETH.
 */
__be32 qib_compute_aeth(struct rvt_qp *qp)
{
        u32 aeth = qp->r_msn & QIB_MSN_MASK;

        if (qp->ibqp.srq) {
                /*
                 * Shared receive queues don't generate credits.
                 * Set the credit field to the invalid value.
                 */
                aeth |= QIB_AETH_CREDIT_INVAL << QIB_AETH_CREDIT_SHIFT;
        } else {
                u32 min, max, x;
                u32 credits;
                struct rvt_rwq *wq = qp->r_rq.wq;
                u32 head;
                u32 tail;

                /* sanity check pointers before trusting them */
                head = wq->head;
                if (head >= qp->r_rq.size)
                        head = 0;
                tail = wq->tail;
                if (tail >= qp->r_rq.size)
                        tail = 0;
                /*
                 * Compute the number of credits available (RWQEs).
                 * XXX Not holding the r_rq.lock here so there is a small
                 * chance that the pair of reads are not atomic.
                 */
                credits = head - tail;
                if ((int)credits < 0)
                        credits += qp->r_rq.size;
                /*
                 * Binary search the credit table to find the code to
                 * use.
                 */
                min = 0;
                max = 31;
                for (;;) {
                        x = (min + max) / 2;
                        if (credit_table[x] == credits)
                                break;
                        if (credit_table[x] > credits)
                                max = x;
                        else if (min == x)
                                break;
                        else
                                min = x;
                }
                aeth |= x << QIB_AETH_CREDIT_SHIFT;
        }
        return cpu_to_be32(aeth);
}

void *qib_qp_priv_alloc(struct rvt_dev_info *rdi, struct rvt_qp *qp, gfp_t gfp)
{
        struct qib_qp_priv *priv;

        priv = kzalloc(sizeof(*priv), gfp);
        if (!priv)
                return ERR_PTR(-ENOMEM);
        priv->owner = qp;

        priv->s_hdr = kzalloc(sizeof(*priv->s_hdr), gfp);
        if (!priv->s_hdr) {
                kfree(priv);
                return ERR_PTR(-ENOMEM);
        }
        init_waitqueue_head(&priv->wait_dma);
        INIT_WORK(&priv->s_work, _qib_do_send);
        INIT_LIST_HEAD(&priv->iowait);

        return priv;
}

void qib_qp_priv_free(struct rvt_dev_info *rdi, struct rvt_qp *qp)
{
        struct qib_qp_priv *priv = qp->priv;

        kfree(priv->s_hdr);
        kfree(priv);
}

void qib_stop_send_queue(struct rvt_qp *qp)
{
        struct qib_qp_priv *priv = qp->priv;

        cancel_work_sync(&priv->s_work);
        del_timer_sync(&qp->s_timer);
}

void qib_quiesce_qp(struct rvt_qp *qp)
{
        struct qib_qp_priv *priv = qp->priv;

        wait_event(priv->wait_dma, !atomic_read(&priv->s_dma_busy));
        if (priv->s_tx) {
                qib_put_txreq(priv->s_tx);
                priv->s_tx = NULL;
        }
}

void qib_flush_qp_waiters(struct rvt_qp *qp)
{
        struct qib_qp_priv *priv = qp->priv;
        struct qib_ibdev *dev = to_idev(qp->ibqp.device);

        spin_lock(&dev->rdi.pending_lock);
        if (!list_empty(&priv->iowait))
                list_del_init(&priv->iowait);
        spin_unlock(&dev->rdi.pending_lock);
}

/**
 * qib_get_credit - flush the send work queue of a QP
 * @qp: the qp who's send work queue to flush
 * @aeth: the Acknowledge Extended Transport Header
 *
 * The QP s_lock should be held.
 */
void qib_get_credit(struct rvt_qp *qp, u32 aeth)
{
        u32 credit = (aeth >> QIB_AETH_CREDIT_SHIFT) & QIB_AETH_CREDIT_MASK;

        /*
         * If the credit is invalid, we can send
         * as many packets as we like.  Otherwise, we have to
         * honor the credit field.
         */
        if (credit == QIB_AETH_CREDIT_INVAL) {
                if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT)) {
                        qp->s_flags |= RVT_S_UNLIMITED_CREDIT;
                        if (qp->s_flags & RVT_S_WAIT_SSN_CREDIT) {
                                qp->s_flags &= ~RVT_S_WAIT_SSN_CREDIT;
                                qib_schedule_send(qp);
                        }
                }
        } else if (!(qp->s_flags & RVT_S_UNLIMITED_CREDIT)) {
                /* Compute new LSN (i.e., MSN + credit) */
                credit = (aeth + credit_table[credit]) & QIB_MSN_MASK;
                if (qib_cmp24(credit, qp->s_lsn) > 0) {
                        qp->s_lsn = credit;
                        if (qp->s_flags & RVT_S_WAIT_SSN_CREDIT) {
                                qp->s_flags &= ~RVT_S_WAIT_SSN_CREDIT;
                                qib_schedule_send(qp);
                        }
                }
        }
}

/**
 * qib_check_send_wqe - validate wr/wqe
 * @qp - The qp
 * @wqe - The built wqe
 *
 * validate wr/wqe.  This is called
 * prior to inserting the wqe into
 * the ring but after the wqe has been
 * setup.
 *
 * Returns 1 to force direct progress, 0 otherwise, -EINVAL on failure
 */
int qib_check_send_wqe(struct rvt_qp *qp,
                       struct rvt_swqe *wqe)
{
        struct rvt_ah *ah;
        int ret = 0;

        switch (qp->ibqp.qp_type) {
        case IB_QPT_RC:
        case IB_QPT_UC:
                if (wqe->length > 0x80000000U)
                        return -EINVAL;
                break;
        case IB_QPT_SMI:
        case IB_QPT_GSI:
        case IB_QPT_UD:
                ah = ibah_to_rvtah(wqe->ud_wr.ah);
                if (wqe->length > (1 << ah->log_pmtu))
                        return -EINVAL;
                /* progress hint */
                ret = 1;
                break;
        default:
                break;
        }
        return ret;
}

#ifdef CONFIG_DEBUG_FS

struct qib_qp_iter {
        struct qib_ibdev *dev;
        struct rvt_qp *qp;
        int n;
};

struct qib_qp_iter *qib_qp_iter_init(struct qib_ibdev *dev)
{
        struct qib_qp_iter *iter;

        iter = kzalloc(sizeof(*iter), GFP_KERNEL);
        if (!iter)
                return NULL;

        iter->dev = dev;
        if (qib_qp_iter_next(iter)) {
                kfree(iter);
                return NULL;
        }

        return iter;
}

int qib_qp_iter_next(struct qib_qp_iter *iter)
{
        struct qib_ibdev *dev = iter->dev;
        int n = iter->n;
        int ret = 1;
        struct rvt_qp *pqp = iter->qp;
        struct rvt_qp *qp;

        for (; n < dev->rdi.qp_dev->qp_table_size; n++) {
                if (pqp)
                        qp = rcu_dereference(pqp->next);
                else
                        qp = rcu_dereference(dev->rdi.qp_dev->qp_table[n]);
                pqp = qp;
                if (qp) {
                        iter->qp = qp;
                        iter->n = n;
                        return 0;
                }
        }
        return ret;
}

static const char * const qp_type_str[] = {
        "SMI", "GSI", "RC", "UC", "UD",
};

void qib_qp_iter_print(struct seq_file *s, struct qib_qp_iter *iter)
{
        struct rvt_swqe *wqe;
        struct rvt_qp *qp = iter->qp;
        struct qib_qp_priv *priv = qp->priv;

        wqe = rvt_get_swqe_ptr(qp, qp->s_last);
        seq_printf(s,
                   "N %d QP%u %s %u %u %u f=%x %u %u %u %u %u PSN %x %x %x %x %x (%u %u %u %u %u %u) QP%u LID %x\n",
                   iter->n,
                   qp->ibqp.qp_num,
                   qp_type_str[qp->ibqp.qp_type],
                   qp->state,
                   wqe->wr.opcode,
                   qp->s_hdrwords,
                   qp->s_flags,
                   atomic_read(&priv->s_dma_busy),
                   !list_empty(&priv->iowait),
                   qp->timeout,
                   wqe->ssn,
                   qp->s_lsn,
                   qp->s_last_psn,
                   qp->s_psn, qp->s_next_psn,
                   qp->s_sending_psn, qp->s_sending_hpsn,
                   qp->s_last, qp->s_acked, qp->s_cur,
                   qp->s_tail, qp->s_head, qp->s_size,
                   qp->remote_qpn,
                   qp->remote_ah_attr.dlid);
}

#endif