/*
 * Copyright (c) 2005 Cisco Systems. 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/slab.h>
#include <linux/string.h>
#include <linux/sched.h>

#include <asm/io.h>

#include <rdma/uverbs_ioctl.h>

#include "mthca_dev.h"
#include "mthca_cmd.h"
#include "mthca_memfree.h"
#include "mthca_wqe.h"

enum {
        MTHCA_MAX_DIRECT_SRQ_SIZE = 4 * PAGE_SIZE
};

struct mthca_tavor_srq_context {
        __be64 wqe_base_ds;     /* low 6 bits is descriptor size */
        __be32 state_pd;
        __be32 lkey;
        __be32 uar;
        __be16 limit_watermark;
        __be16 wqe_cnt;
        u32    reserved[2];
};

struct mthca_arbel_srq_context {
        __be32 state_logsize_srqn;
        __be32 lkey;
        __be32 db_index;
        __be32 logstride_usrpage;
        __be64 wqe_base;
        __be32 eq_pd;
        __be16 limit_watermark;
        __be16 wqe_cnt;
        u16    reserved1;
        __be16 wqe_counter;
        u32    reserved2[3];
};

static void *get_wqe(struct mthca_srq *srq, int n)
{
        if (srq->is_direct)
                return srq->queue.direct.buf + (n << srq->wqe_shift);
        else
                return srq->queue.page_list[(n << srq->wqe_shift) >> PAGE_SHIFT].buf +
                        ((n << srq->wqe_shift) & (PAGE_SIZE - 1));
}

/*
 * Return a pointer to the location within a WQE that we're using as a
 * link when the WQE is in the free list.  We use the imm field
 * because in the Tavor case, posting a WQE may overwrite the next
 * segment of the previous WQE, but a receive WQE will never touch the
 * imm field.  This avoids corrupting our free list if the previous
 * WQE has already completed and been put on the free list when we
 * post the next WQE.
 */
static inline int *wqe_to_link(void *wqe)
{
        return (int *) (wqe + offsetof(struct mthca_next_seg, imm));
}

static void mthca_tavor_init_srq_context(struct mthca_dev *dev,
                                         struct mthca_pd *pd,
                                         struct mthca_srq *srq,
                                         struct mthca_tavor_srq_context *context,
                                         struct ib_udata *udata)
{
        struct mthca_ucontext *ucontext = rdma_udata_to_drv_context(
                udata, struct mthca_ucontext, ibucontext);

        memset(context, 0, sizeof *context);

        context->wqe_base_ds = cpu_to_be64(1 << (srq->wqe_shift - 4));
        context->state_pd    = cpu_to_be32(pd->pd_num);
        context->lkey        = cpu_to_be32(srq->mr.ibmr.lkey);

        if (udata)
                context->uar = cpu_to_be32(ucontext->uar.index);
        else
                context->uar = cpu_to_be32(dev->driver_uar.index);
}

static void mthca_arbel_init_srq_context(struct mthca_dev *dev,
                                         struct mthca_pd *pd,
                                         struct mthca_srq *srq,
                                         struct mthca_arbel_srq_context *context,
                                         struct ib_udata *udata)
{
        struct mthca_ucontext *ucontext = rdma_udata_to_drv_context(
                udata, struct mthca_ucontext, ibucontext);
        int logsize, max;

        memset(context, 0, sizeof *context);

        /*
         * Put max in a temporary variable to work around gcc bug
         * triggered by ilog2() on sparc64.
         */
        max = srq->max;
        logsize = ilog2(max);
        context->state_logsize_srqn = cpu_to_be32(logsize << 24 | srq->srqn);
        context->lkey = cpu_to_be32(srq->mr.ibmr.lkey);
        context->db_index = cpu_to_be32(srq->db_index);
        context->logstride_usrpage = cpu_to_be32((srq->wqe_shift - 4) << 29);
        if (udata)
                context->logstride_usrpage |= cpu_to_be32(ucontext->uar.index);
        else
                context->logstride_usrpage |= cpu_to_be32(dev->driver_uar.index);
        context->eq_pd = cpu_to_be32(MTHCA_EQ_ASYNC << 24 | pd->pd_num);
}

static void mthca_free_srq_buf(struct mthca_dev *dev, struct mthca_srq *srq)
{
        mthca_buf_free(dev, srq->max << srq->wqe_shift, &srq->queue,
                       srq->is_direct, &srq->mr);
        kfree(srq->wrid);
}

static int mthca_alloc_srq_buf(struct mthca_dev *dev, struct mthca_pd *pd,
                               struct mthca_srq *srq, struct ib_udata *udata)
{
        struct mthca_data_seg *scatter;
        void *wqe;
        int err;
        int i;

        if (udata)
                return 0;

        srq->wrid = kmalloc_array(srq->max, sizeof(u64), GFP_KERNEL);
        if (!srq->wrid)
                return -ENOMEM;

        err = mthca_buf_alloc(dev, srq->max << srq->wqe_shift,
                              MTHCA_MAX_DIRECT_SRQ_SIZE,
                              &srq->queue, &srq->is_direct, pd, 1, &srq->mr);
        if (err) {
                kfree(srq->wrid);
                return err;
        }

        /*
         * Now initialize the SRQ buffer so that all of the WQEs are
         * linked into the list of free WQEs.  In addition, set the
         * scatter list L_Keys to the sentry value of 0x100.
         */
        for (i = 0; i < srq->max; ++i) {
                struct mthca_next_seg *next;

                next = wqe = get_wqe(srq, i);

                if (i < srq->max - 1) {
                        *wqe_to_link(wqe) = i + 1;
                        next->nda_op = htonl(((i + 1) << srq->wqe_shift) | 1);
                } else {
                        *wqe_to_link(wqe) = -1;
                        next->nda_op = 0;
                }

                for (scatter = wqe + sizeof (struct mthca_next_seg);
                     (void *) scatter < wqe + (1 << srq->wqe_shift);
                     ++scatter)
                        scatter->lkey = cpu_to_be32(MTHCA_INVAL_LKEY);
        }

        srq->last = get_wqe(srq, srq->max - 1);

        return 0;
}

int mthca_alloc_srq(struct mthca_dev *dev, struct mthca_pd *pd,
                    struct ib_srq_attr *attr, struct mthca_srq *srq,
                    struct ib_udata *udata)
{
        struct mthca_mailbox *mailbox;
        int ds;
        int err;

        /* Sanity check SRQ size before proceeding */
        if (attr->max_wr  > dev->limits.max_srq_wqes ||
            attr->max_sge > dev->limits.max_srq_sge)
                return -EINVAL;

        srq->max      = attr->max_wr;
        srq->max_gs   = attr->max_sge;
        srq->counter  = 0;

        if (mthca_is_memfree(dev))
                srq->max = roundup_pow_of_two(srq->max + 1);
        else
                srq->max = srq->max + 1;

        ds = max(64UL,
                 roundup_pow_of_two(sizeof (struct mthca_next_seg) +
                                    srq->max_gs * sizeof (struct mthca_data_seg)));

        if (!mthca_is_memfree(dev) && (ds > dev->limits.max_desc_sz))
                return -EINVAL;

        srq->wqe_shift = ilog2(ds);

        srq->srqn = mthca_alloc(&dev->srq_table.alloc);
        if (srq->srqn == -1)
                return -ENOMEM;

        if (mthca_is_memfree(dev)) {
                err = mthca_table_get(dev, dev->srq_table.table, srq->srqn);
                if (err)
                        goto err_out;

                if (!udata) {
                        srq->db_index = mthca_alloc_db(dev, MTHCA_DB_TYPE_SRQ,
                                                       srq->srqn, &srq->db);
                        if (srq->db_index < 0) {
                                err = -ENOMEM;
                                goto err_out_icm;
                        }
                }
        }

        mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
        if (IS_ERR(mailbox)) {
                err = PTR_ERR(mailbox);
                goto err_out_db;
        }

        err = mthca_alloc_srq_buf(dev, pd, srq, udata);
        if (err)
                goto err_out_mailbox;

        spin_lock_init(&srq->lock);
        srq->refcount = 1;
        init_waitqueue_head(&srq->wait);
        mutex_init(&srq->mutex);

        if (mthca_is_memfree(dev))
                mthca_arbel_init_srq_context(dev, pd, srq, mailbox->buf, udata);
        else
                mthca_tavor_init_srq_context(dev, pd, srq, mailbox->buf, udata);

        err = mthca_SW2HW_SRQ(dev, mailbox, srq->srqn);

        if (err) {
                mthca_warn(dev, "SW2HW_SRQ failed (%d)\n", err);
                goto err_out_free_buf;
        }

        spin_lock_irq(&dev->srq_table.lock);
        if (mthca_array_set(&dev->srq_table.srq,
                            srq->srqn & (dev->limits.num_srqs - 1),
                            srq)) {
                spin_unlock_irq(&dev->srq_table.lock);
                goto err_out_free_srq;
        }
        spin_unlock_irq(&dev->srq_table.lock);

        mthca_free_mailbox(dev, mailbox);

        srq->first_free = 0;
        srq->last_free  = srq->max - 1;

        attr->max_wr    = srq->max - 1;
        attr->max_sge   = srq->max_gs;

        return 0;

err_out_free_srq:
        err = mthca_HW2SW_SRQ(dev, mailbox, srq->srqn);
        if (err)
                mthca_warn(dev, "HW2SW_SRQ failed (%d)\n", err);

err_out_free_buf:
        if (!udata)
                mthca_free_srq_buf(dev, srq);

err_out_mailbox:
        mthca_free_mailbox(dev, mailbox);

err_out_db:
        if (!udata && mthca_is_memfree(dev))
                mthca_free_db(dev, MTHCA_DB_TYPE_SRQ, srq->db_index);

err_out_icm:
        mthca_table_put(dev, dev->srq_table.table, srq->srqn);

err_out:
        mthca_free(&dev->srq_table.alloc, srq->srqn);

        return err;
}

static inline int get_srq_refcount(struct mthca_dev *dev, struct mthca_srq *srq)
{
        int c;

        spin_lock_irq(&dev->srq_table.lock);
        c = srq->refcount;
        spin_unlock_irq(&dev->srq_table.lock);

        return c;
}

void mthca_free_srq(struct mthca_dev *dev, struct mthca_srq *srq)
{
        struct mthca_mailbox *mailbox;
        int err;

        mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
        if (IS_ERR(mailbox)) {
                mthca_warn(dev, "No memory for mailbox to free SRQ.\n");
                return;
        }

        err = mthca_HW2SW_SRQ(dev, mailbox, srq->srqn);
        if (err)
                mthca_warn(dev, "HW2SW_SRQ failed (%d)\n", err);

        spin_lock_irq(&dev->srq_table.lock);
        mthca_array_clear(&dev->srq_table.srq,
                          srq->srqn & (dev->limits.num_srqs - 1));
        --srq->refcount;
        spin_unlock_irq(&dev->srq_table.lock);

        wait_event(srq->wait, !get_srq_refcount(dev, srq));

        if (!srq->ibsrq.uobject) {
                mthca_free_srq_buf(dev, srq);
                if (mthca_is_memfree(dev))
                        mthca_free_db(dev, MTHCA_DB_TYPE_SRQ, srq->db_index);
        }

        mthca_table_put(dev, dev->srq_table.table, srq->srqn);
        mthca_free(&dev->srq_table.alloc, srq->srqn);
        mthca_free_mailbox(dev, mailbox);
}

int mthca_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
                     enum ib_srq_attr_mask attr_mask, struct ib_udata *udata)
{
        struct mthca_dev *dev = to_mdev(ibsrq->device);
        struct mthca_srq *srq = to_msrq(ibsrq);
        int ret = 0;

        /* We don't support resizing SRQs (yet?) */
        if (attr_mask & IB_SRQ_MAX_WR)
                return -EINVAL;

        if (attr_mask & IB_SRQ_LIMIT) {
                u32 max_wr = mthca_is_memfree(dev) ? srq->max - 1 : srq->max;
                if (attr->srq_limit > max_wr)
                        return -EINVAL;

                mutex_lock(&srq->mutex);
                ret = mthca_ARM_SRQ(dev, srq->srqn, attr->srq_limit);
                mutex_unlock(&srq->mutex);
        }

        return ret;
}

int mthca_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *srq_attr)
{
        struct mthca_dev *dev = to_mdev(ibsrq->device);
        struct mthca_srq *srq = to_msrq(ibsrq);
        struct mthca_mailbox *mailbox;
        struct mthca_arbel_srq_context *arbel_ctx;
        struct mthca_tavor_srq_context *tavor_ctx;
        int err;

        mailbox = mthca_alloc_mailbox(dev, GFP_KERNEL);
        if (IS_ERR(mailbox))
                return PTR_ERR(mailbox);

        err = mthca_QUERY_SRQ(dev, srq->srqn, mailbox);
        if (err)
                goto out;

        if (mthca_is_memfree(dev)) {
                arbel_ctx = mailbox->buf;
                srq_attr->srq_limit = be16_to_cpu(arbel_ctx->limit_watermark);
        } else {
                tavor_ctx = mailbox->buf;
                srq_attr->srq_limit = be16_to_cpu(tavor_ctx->limit_watermark);
        }

        srq_attr->max_wr  = srq->max - 1;
        srq_attr->max_sge = srq->max_gs;

out:
        mthca_free_mailbox(dev, mailbox);

        return err;
}

void mthca_srq_event(struct mthca_dev *dev, u32 srqn,
                     enum ib_event_type event_type)
{
        struct mthca_srq *srq;
        struct ib_event event;

        spin_lock(&dev->srq_table.lock);
        srq = mthca_array_get(&dev->srq_table.srq, srqn & (dev->limits.num_srqs - 1));
        if (srq)
                ++srq->refcount;
        spin_unlock(&dev->srq_table.lock);

        if (!srq) {
                mthca_warn(dev, "Async event for bogus SRQ %08x\n", srqn);
                return;
        }

        if (!srq->ibsrq.event_handler)
                goto out;

        event.device      = &dev->ib_dev;
        event.event       = event_type;
        event.element.srq = &srq->ibsrq;
        srq->ibsrq.event_handler(&event, srq->ibsrq.srq_context);

out:
        spin_lock(&dev->srq_table.lock);
        if (!--srq->refcount)
                wake_up(&srq->wait);
        spin_unlock(&dev->srq_table.lock);
}

/*
 * This function must be called with IRQs disabled.
 */
void mthca_free_srq_wqe(struct mthca_srq *srq, u32 wqe_addr)
{
        int ind;
        struct mthca_next_seg *last_free;

        ind = wqe_addr >> srq->wqe_shift;

        spin_lock(&srq->lock);

        last_free = get_wqe(srq, srq->last_free);
        *wqe_to_link(last_free) = ind;
        last_free->nda_op = htonl((ind << srq->wqe_shift) | 1);
        *wqe_to_link(get_wqe(srq, ind)) = -1;
        srq->last_free = ind;

        spin_unlock(&srq->lock);
}

int mthca_tavor_post_srq_recv(struct ib_srq *ibsrq, const struct ib_recv_wr *wr,
                              const struct ib_recv_wr **bad_wr)
{
        struct mthca_dev *dev = to_mdev(ibsrq->device);
        struct mthca_srq *srq = to_msrq(ibsrq);
        unsigned long flags;
        int err = 0;
        int first_ind;
        int ind;
        int next_ind;
        int nreq;
        int i;
        void *wqe;
        void *prev_wqe;

        spin_lock_irqsave(&srq->lock, flags);

        first_ind = srq->first_free;

        for (nreq = 0; wr; wr = wr->next) {
                ind       = srq->first_free;
                wqe       = get_wqe(srq, ind);
                next_ind  = *wqe_to_link(wqe);

                if (unlikely(next_ind < 0)) {
                        mthca_err(dev, "SRQ %06x full\n", srq->srqn);
                        err = -ENOMEM;
                        *bad_wr = wr;
                        break;
                }

                prev_wqe  = srq->last;
                srq->last = wqe;

                ((struct mthca_next_seg *) wqe)->ee_nds = 0;
                /* flags field will always remain 0 */

                wqe += sizeof (struct mthca_next_seg);

                if (unlikely(wr->num_sge > srq->max_gs)) {
                        err = -EINVAL;
                        *bad_wr = wr;
                        srq->last = prev_wqe;
                        break;
                }

                for (i = 0; i < wr->num_sge; ++i) {
                        mthca_set_data_seg(wqe, wr->sg_list + i);
                        wqe += sizeof (struct mthca_data_seg);
                }

                if (i < srq->max_gs)
                        mthca_set_data_seg_inval(wqe);

                ((struct mthca_next_seg *) prev_wqe)->ee_nds =
                        cpu_to_be32(MTHCA_NEXT_DBD);

                srq->wrid[ind]  = wr->wr_id;
                srq->first_free = next_ind;

                ++nreq;
                if (unlikely(nreq == MTHCA_TAVOR_MAX_WQES_PER_RECV_DB)) {
                        nreq = 0;

                        /*
                         * Make sure that descriptors are written
                         * before doorbell is rung.
                         */
                        wmb();

                        mthca_write64(first_ind << srq->wqe_shift, srq->srqn << 8,
                                      dev->kar + MTHCA_RECEIVE_DOORBELL,
                                      MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));

                        first_ind = srq->first_free;
                }
        }

        if (likely(nreq)) {
                /*
                 * Make sure that descriptors are written before
                 * doorbell is rung.
                 */
                wmb();

                mthca_write64(first_ind << srq->wqe_shift, (srq->srqn << 8) | nreq,
                              dev->kar + MTHCA_RECEIVE_DOORBELL,
                              MTHCA_GET_DOORBELL_LOCK(&dev->doorbell_lock));
        }

        spin_unlock_irqrestore(&srq->lock, flags);
        return err;
}

int mthca_arbel_post_srq_recv(struct ib_srq *ibsrq, const struct ib_recv_wr *wr,
                              const struct ib_recv_wr **bad_wr)
{
        struct mthca_dev *dev = to_mdev(ibsrq->device);
        struct mthca_srq *srq = to_msrq(ibsrq);
        unsigned long flags;
        int err = 0;
        int ind;
        int next_ind;
        int nreq;
        int i;
        void *wqe;

        spin_lock_irqsave(&srq->lock, flags);

        for (nreq = 0; wr; ++nreq, wr = wr->next) {
                ind       = srq->first_free;
                wqe       = get_wqe(srq, ind);
                next_ind  = *wqe_to_link(wqe);

                if (unlikely(next_ind < 0)) {
                        mthca_err(dev, "SRQ %06x full\n", srq->srqn);
                        err = -ENOMEM;
                        *bad_wr = wr;
                        break;
                }

                ((struct mthca_next_seg *) wqe)->ee_nds = 0;
                /* flags field will always remain 0 */

                wqe += sizeof (struct mthca_next_seg);

                if (unlikely(wr->num_sge > srq->max_gs)) {
                        err = -EINVAL;
                        *bad_wr = wr;
                        break;
                }

                for (i = 0; i < wr->num_sge; ++i) {
                        mthca_set_data_seg(wqe, wr->sg_list + i);
                        wqe += sizeof (struct mthca_data_seg);
                }

                if (i < srq->max_gs)
                        mthca_set_data_seg_inval(wqe);

                srq->wrid[ind]  = wr->wr_id;
                srq->first_free = next_ind;
        }

        if (likely(nreq)) {
                srq->counter += nreq;

                /*
                 * Make sure that descriptors are written before
                 * we write doorbell record.
                 */
                wmb();
                *srq->db = cpu_to_be32(srq->counter);
        }

        spin_unlock_irqrestore(&srq->lock, flags);
        return err;
}

int mthca_max_srq_sge(struct mthca_dev *dev)
{
        if (mthca_is_memfree(dev))
                return dev->limits.max_sg;

        /*
         * SRQ allocations are based on powers of 2 for Tavor,
         * (although they only need to be multiples of 16 bytes).
         *
         * Therefore, we need to base the max number of sg entries on
         * the largest power of 2 descriptor size that is <= to the
         * actual max WQE descriptor size, rather than return the
         * max_sg value given by the firmware (which is based on WQE
         * sizes as multiples of 16, not powers of 2).
         *
         * If SRQ implementation is changed for Tavor to be based on
         * multiples of 16, the calculation below can be deleted and
         * the FW max_sg value returned.
         */
        return min_t(int, dev->limits.max_sg,
                     ((1 << (fls(dev->limits.max_desc_sz) - 1)) -
                      sizeof (struct mthca_next_seg)) /
                     sizeof (struct mthca_data_seg));
}

int mthca_init_srq_table(struct mthca_dev *dev)
{
        int err;

        if (!(dev->mthca_flags & MTHCA_FLAG_SRQ))
                return 0;

        spin_lock_init(&dev->srq_table.lock);

        err = mthca_alloc_init(&dev->srq_table.alloc,
                               dev->limits.num_srqs,
                               dev->limits.num_srqs - 1,
                               dev->limits.reserved_srqs);
        if (err)
                return err;

        err = mthca_array_init(&dev->srq_table.srq,
                               dev->limits.num_srqs);
        if (err)
                mthca_alloc_cleanup(&dev->srq_table.alloc);

        return err;
}

void mthca_cleanup_srq_table(struct mthca_dev *dev)
{
        if (!(dev->mthca_flags & MTHCA_FLAG_SRQ))
                return;

        mthca_array_cleanup(&dev->srq_table.srq, dev->limits.num_srqs);
        mthca_alloc_cleanup(&dev->srq_table.alloc);
}