/*
 * Copyright (c) 2016 Oracle.  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 "ib_mr.h"

struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev, int npages)
{
        struct rds_ib_mr_pool *pool;
        struct rds_ib_mr *ibmr = NULL;
        struct rds_ib_fmr *fmr;
        int err = 0;

        if (npages <= RDS_MR_8K_MSG_SIZE)
                pool = rds_ibdev->mr_8k_pool;
        else
                pool = rds_ibdev->mr_1m_pool;

        if (atomic_read(&pool->dirty_count) >= pool->max_items / 10)
                queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);

        /* Switch pools if one of the pool is reaching upper limit */
        if (atomic_read(&pool->dirty_count) >=  pool->max_items * 9 / 10) {
                if (pool->pool_type == RDS_IB_MR_8K_POOL)
                        pool = rds_ibdev->mr_1m_pool;
                else
                        pool = rds_ibdev->mr_8k_pool;
        }

        ibmr = rds_ib_try_reuse_ibmr(pool);
        if (ibmr)
                return ibmr;

        ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL,
                            rdsibdev_to_node(rds_ibdev));
        if (!ibmr) {
                err = -ENOMEM;
                goto out_no_cigar;
        }

        fmr = &ibmr->u.fmr;
        fmr->fmr = ib_alloc_fmr(rds_ibdev->pd,
                        (IB_ACCESS_LOCAL_WRITE |
                         IB_ACCESS_REMOTE_READ |
                         IB_ACCESS_REMOTE_WRITE |
                         IB_ACCESS_REMOTE_ATOMIC),
                        &pool->fmr_attr);
        if (IS_ERR(fmr->fmr)) {
                err = PTR_ERR(fmr->fmr);
                fmr->fmr = NULL;
                pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, err);
                goto out_no_cigar;
        }

        ibmr->pool = pool;
        if (pool->pool_type == RDS_IB_MR_8K_POOL)
                rds_ib_stats_inc(s_ib_rdma_mr_8k_alloc);
        else
                rds_ib_stats_inc(s_ib_rdma_mr_1m_alloc);

        return ibmr;

out_no_cigar:
        kfree(ibmr);
        atomic_dec(&pool->item_count);

        return ERR_PTR(err);
}

static int rds_ib_map_fmr(struct rds_ib_device *rds_ibdev,
                          struct rds_ib_mr *ibmr, struct scatterlist *sg,
                          unsigned int nents)
{
        struct ib_device *dev = rds_ibdev->dev;
        struct rds_ib_fmr *fmr = &ibmr->u.fmr;
        struct scatterlist *scat = sg;
        u64 io_addr = 0;
        u64 *dma_pages;
        u32 len;
        int page_cnt, sg_dma_len;
        int i, j;
        int ret;

        sg_dma_len = ib_dma_map_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
        if (unlikely(!sg_dma_len)) {
                pr_warn("RDS/IB: %s failed!\n", __func__);
                return -EBUSY;
        }

        len = 0;
        page_cnt = 0;

        for (i = 0; i < sg_dma_len; ++i) {
                unsigned int dma_len = sg_dma_len(&scat[i]);
                u64 dma_addr = sg_dma_address(&scat[i]);

                if (dma_addr & ~PAGE_MASK) {
                        if (i > 0) {
                                ib_dma_unmap_sg(dev, sg, nents,
                                                DMA_BIDIRECTIONAL);
                                return -EINVAL;
                        } else {
                                ++page_cnt;
                        }
                }
                if ((dma_addr + dma_len) & ~PAGE_MASK) {
                        if (i < sg_dma_len - 1) {
                                ib_dma_unmap_sg(dev, sg, nents,
                                                DMA_BIDIRECTIONAL);
                                return -EINVAL;
                        } else {
                                ++page_cnt;
                        }
                }

                len += dma_len;
        }

        page_cnt += len >> PAGE_SHIFT;
        if (page_cnt > ibmr->pool->fmr_attr.max_pages) {
                ib_dma_unmap_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
                return -EINVAL;
        }

        dma_pages = kmalloc_array_node(sizeof(u64), page_cnt, GFP_ATOMIC,
                                       rdsibdev_to_node(rds_ibdev));
        if (!dma_pages) {
                ib_dma_unmap_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
                return -ENOMEM;
        }

        page_cnt = 0;
        for (i = 0; i < sg_dma_len; ++i) {
                unsigned int dma_len = sg_dma_len(&scat[i]);
                u64 dma_addr = sg_dma_address(&scat[i]);

                for (j = 0; j < dma_len; j += PAGE_SIZE)
                        dma_pages[page_cnt++] =
                                (dma_addr & PAGE_MASK) + j;
        }

        ret = ib_map_phys_fmr(fmr->fmr, dma_pages, page_cnt, io_addr);
        if (ret) {
                ib_dma_unmap_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
                goto out;
        }

        /* Success - we successfully remapped the MR, so we can
         * safely tear down the old mapping.
         */
        rds_ib_teardown_mr(ibmr);

        ibmr->sg = scat;
        ibmr->sg_len = nents;
        ibmr->sg_dma_len = sg_dma_len;
        ibmr->remap_count++;

        if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
                rds_ib_stats_inc(s_ib_rdma_mr_8k_used);
        else
                rds_ib_stats_inc(s_ib_rdma_mr_1m_used);
        ret = 0;

out:
        kfree(dma_pages);

        return ret;
}

struct rds_ib_mr *rds_ib_reg_fmr(struct rds_ib_device *rds_ibdev,
                                 struct scatterlist *sg,
                                 unsigned long nents,
                                 u32 *key)
{
        struct rds_ib_mr *ibmr = NULL;
        struct rds_ib_fmr *fmr;
        int ret;

        ibmr = rds_ib_alloc_fmr(rds_ibdev, nents);
        if (IS_ERR(ibmr))
                return ibmr;

        ibmr->device = rds_ibdev;
        fmr = &ibmr->u.fmr;
        ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents);
        if (ret == 0)
                *key = fmr->fmr->rkey;
        else
                rds_ib_free_mr(ibmr, 0);

        return ibmr;
}

void rds_ib_unreg_fmr(struct list_head *list, unsigned int *nfreed,
                      unsigned long *unpinned, unsigned int goal)
{
        struct rds_ib_mr *ibmr, *next;
        struct rds_ib_fmr *fmr;
        LIST_HEAD(fmr_list);
        int ret = 0;
        unsigned int freed = *nfreed;

        /* String all ib_mr's onto one list and hand them to  ib_unmap_fmr */
        list_for_each_entry(ibmr, list, unmap_list) {
                fmr = &ibmr->u.fmr;
                list_add(&fmr->fmr->list, &fmr_list);
        }

        ret = ib_unmap_fmr(&fmr_list);
        if (ret)
                pr_warn("RDS/IB: FMR invalidation failed (err=%d)\n", ret);

        /* Now we can destroy the DMA mapping and unpin any pages */
        list_for_each_entry_safe(ibmr, next, list, unmap_list) {
                fmr = &ibmr->u.fmr;
                *unpinned += ibmr->sg_len;
                __rds_ib_teardown_mr(ibmr);
                if (freed < goal ||
                    ibmr->remap_count >= ibmr->pool->fmr_attr.max_maps) {
                        if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
                                rds_ib_stats_inc(s_ib_rdma_mr_8k_free);
                        else
                                rds_ib_stats_inc(s_ib_rdma_mr_1m_free);
                        list_del(&ibmr->unmap_list);
                        ib_dealloc_fmr(fmr->fmr);
                        kfree(ibmr);
                        freed++;
                }
        }
        *nfreed = freed;
}

void rds_ib_free_fmr_list(struct rds_ib_mr *ibmr)
{
        struct rds_ib_mr_pool *pool = ibmr->pool;

        if (ibmr->remap_count >= pool->fmr_attr.max_maps)
                llist_add(&ibmr->llnode, &pool->drop_list);
        else
                llist_add(&ibmr->llnode, &pool->free_list);
}