/*
 * Copyright (c) 2016 Hisilicon Limited.
 * Copyright (c) 2007, 2008 Mellanox Technologies. 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/vmalloc.h>
#include <linux/count_zeros.h>
#include <rdma/ib_umem.h>
#include <linux/math.h>
#include "hns_roce_device.h"
#include "hns_roce_cmd.h"
#include "hns_roce_hem.h"
#include "hns_roce_trace.h"

static u32 hw_index_to_key(int ind)
{
        return ((u32)ind >> 24) | ((u32)ind << 8);
}

unsigned long key_to_hw_index(u32 key)
{
        return (key << 24) | (key >> 8);
}

static int alloc_mr_key(struct hns_roce_dev *hr_dev, struct hns_roce_mr *mr)
{
        struct hns_roce_ida *mtpt_ida = &hr_dev->mr_table.mtpt_ida;
        struct ib_device *ibdev = &hr_dev->ib_dev;
        int err;
        int id;

        /* Allocate a key for mr from mr_table */
        id = ida_alloc_range(&mtpt_ida->ida, mtpt_ida->min, mtpt_ida->max,
                             GFP_KERNEL);
        if (id < 0) {
                ibdev_err(ibdev, "failed to alloc id for MR key, id(%d)\n", id);
                return -ENOMEM;
        }

        mr->key = hw_index_to_key(id); /* MR key */

        err = hns_roce_table_get(hr_dev, &hr_dev->mr_table.mtpt_table,
                                 (unsigned long)id);
        if (err) {
                ibdev_err(ibdev, "failed to alloc mtpt, ret = %d.\n", err);
                goto err_free_bitmap;
        }

        return 0;
err_free_bitmap:
        ida_free(&mtpt_ida->ida, id);
        return err;
}

static void free_mr_key(struct hns_roce_dev *hr_dev, struct hns_roce_mr *mr)
{
        unsigned long obj = key_to_hw_index(mr->key);

        hns_roce_table_put(hr_dev, &hr_dev->mr_table.mtpt_table, obj);
        ida_free(&hr_dev->mr_table.mtpt_ida.ida, (int)obj);
}

static int alloc_mr_pbl(struct hns_roce_dev *hr_dev, struct hns_roce_mr *mr,
                        struct ib_udata *udata, u64 start)
{
        struct ib_device *ibdev = &hr_dev->ib_dev;
        bool is_fast = mr->type == MR_TYPE_FRMR;
        struct hns_roce_buf_attr buf_attr = {};
        int err;

        mr->pbl_hop_num = is_fast ? 1 : hr_dev->caps.pbl_hop_num;
        buf_attr.page_shift = is_fast ? PAGE_SHIFT :
                              hr_dev->caps.pbl_buf_pg_sz + PAGE_SHIFT;
        buf_attr.region[0].size = mr->size;
        buf_attr.region[0].hopnum = mr->pbl_hop_num;
        buf_attr.region_count = 1;
        buf_attr.user_access = mr->access;
        /* fast MR's buffer is alloced before mapping, not at creation */
        buf_attr.mtt_only = is_fast;
        buf_attr.iova = mr->iova;
        /* pagesize and hopnum is fixed for fast MR */
        buf_attr.adaptive = !is_fast;
        buf_attr.type = MTR_PBL;

        err = hns_roce_mtr_create(hr_dev, &mr->pbl_mtr, &buf_attr,
                                  hr_dev->caps.pbl_ba_pg_sz + PAGE_SHIFT,
                                  udata, start);
        if (err) {
                ibdev_err(ibdev, "failed to alloc pbl mtr, ret = %d.\n", err);
                return err;
        }

        mr->npages = mr->pbl_mtr.hem_cfg.buf_pg_count;
        mr->pbl_hop_num = buf_attr.region[0].hopnum;

        return err;
}

static void free_mr_pbl(struct hns_roce_dev *hr_dev, struct hns_roce_mr *mr)
{
        hns_roce_mtr_destroy(hr_dev, &mr->pbl_mtr);
}

static void hns_roce_mr_free(struct hns_roce_dev *hr_dev, struct hns_roce_mr *mr)
{
        struct ib_device *ibdev = &hr_dev->ib_dev;
        int ret;

        if (mr->enabled) {
                ret = hns_roce_destroy_hw_ctx(hr_dev, HNS_ROCE_CMD_DESTROY_MPT,
                                              key_to_hw_index(mr->key) &
                                              (hr_dev->caps.num_mtpts - 1));
                if (ret)
                        ibdev_warn_ratelimited(ibdev, "failed to destroy mpt, ret = %d.\n",
                                               ret);
        }

        free_mr_pbl(hr_dev, mr);
        free_mr_key(hr_dev, mr);
}

static int hns_roce_mr_enable(struct hns_roce_dev *hr_dev,
                              struct hns_roce_mr *mr)
{
        unsigned long mtpt_idx = key_to_hw_index(mr->key);
        struct hns_roce_cmd_mailbox *mailbox;
        struct device *dev = hr_dev->dev;
        int ret;

        /* Allocate mailbox memory */
        mailbox = hns_roce_alloc_cmd_mailbox(hr_dev);
        if (IS_ERR(mailbox))
                return PTR_ERR(mailbox);

        trace_hns_mr(mr);
        if (mr->type != MR_TYPE_FRMR)
                ret = hr_dev->hw->write_mtpt(hr_dev, mailbox->buf, mr);
        else
                ret = hr_dev->hw->frmr_write_mtpt(mailbox->buf, mr);
        if (ret) {
                dev_err(dev, "failed to write mtpt, ret = %d.\n", ret);
                goto err_page;
        }

        ret = hns_roce_create_hw_ctx(hr_dev, mailbox, HNS_ROCE_CMD_CREATE_MPT,
                                     mtpt_idx & (hr_dev->caps.num_mtpts - 1));
        if (ret) {
                dev_err(dev, "failed to create mpt, ret = %d.\n", ret);
                goto err_page;
        }

        mr->enabled = 1;

err_page:
        hns_roce_free_cmd_mailbox(hr_dev, mailbox);

        return ret;
}

void hns_roce_init_mr_table(struct hns_roce_dev *hr_dev)
{
        struct hns_roce_ida *mtpt_ida = &hr_dev->mr_table.mtpt_ida;

        ida_init(&mtpt_ida->ida);
        mtpt_ida->max = hr_dev->caps.num_mtpts - 1;
        mtpt_ida->min = hr_dev->caps.reserved_mrws;
}

struct ib_mr *hns_roce_get_dma_mr(struct ib_pd *pd, int acc)
{
        struct hns_roce_dev *hr_dev = to_hr_dev(pd->device);
        struct hns_roce_mr *mr;
        int ret;

        mr = kzalloc_obj(*mr);
        if (!mr)
                return  ERR_PTR(-ENOMEM);

        mr->type = MR_TYPE_DMA;
        mr->pd = to_hr_pd(pd)->pdn;
        mr->access = acc;

        /* Allocate memory region key */
        hns_roce_hem_list_init(&mr->pbl_mtr.hem_list);
        ret = alloc_mr_key(hr_dev, mr);
        if (ret)
                goto err_free;

        ret = hns_roce_mr_enable(hr_dev, mr);
        if (ret)
                goto err_mr;

        mr->ibmr.rkey = mr->ibmr.lkey = mr->key;

        return &mr->ibmr;
err_mr:
        free_mr_key(hr_dev, mr);

err_free:
        kfree(mr);
        return ERR_PTR(ret);
}

struct ib_mr *hns_roce_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
                                   u64 virt_addr, int access_flags,
                                   struct ib_dmah *dmah,
                                   struct ib_udata *udata)
{
        struct hns_roce_dev *hr_dev = to_hr_dev(pd->device);
        struct hns_roce_mr *mr;
        int ret;

        if (dmah) {
                ret = -EOPNOTSUPP;
                goto err_out;
        }

        mr = kzalloc_obj(*mr);
        if (!mr) {
                ret = -ENOMEM;
                goto err_out;
        }

        mr->iova = virt_addr;
        mr->size = length;
        mr->pd = to_hr_pd(pd)->pdn;
        mr->access = access_flags;
        mr->type = MR_TYPE_MR;

        ret = alloc_mr_key(hr_dev, mr);
        if (ret)
                goto err_alloc_mr;

        ret = alloc_mr_pbl(hr_dev, mr, udata, start);
        if (ret)
                goto err_alloc_key;

        ret = hns_roce_mr_enable(hr_dev, mr);
        if (ret)
                goto err_alloc_pbl;

        mr->ibmr.rkey = mr->ibmr.lkey = mr->key;

        return &mr->ibmr;

err_alloc_pbl:
        free_mr_pbl(hr_dev, mr);
err_alloc_key:
        free_mr_key(hr_dev, mr);
err_alloc_mr:
        kfree(mr);
err_out:
        atomic64_inc(&hr_dev->dfx_cnt[HNS_ROCE_DFX_MR_REG_ERR_CNT]);

        return ERR_PTR(ret);
}

struct ib_mr *hns_roce_rereg_user_mr(struct ib_mr *ibmr, int flags, u64 start,
                                     u64 length, u64 virt_addr,
                                     int mr_access_flags, struct ib_pd *pd,
                                     struct ib_udata *udata)
{
        struct hns_roce_dev *hr_dev = to_hr_dev(ibmr->device);
        struct ib_device *ib_dev = &hr_dev->ib_dev;
        struct hns_roce_mr *mr = to_hr_mr(ibmr);
        struct hns_roce_cmd_mailbox *mailbox;
        unsigned long mtpt_idx;
        int ret;

        if (!mr->enabled) {
                ret = -EINVAL;
                goto err_out;
        }

        mailbox = hns_roce_alloc_cmd_mailbox(hr_dev);
        ret = PTR_ERR_OR_ZERO(mailbox);
        if (ret)
                goto err_out;

        mtpt_idx = key_to_hw_index(mr->key) & (hr_dev->caps.num_mtpts - 1);

        ret = hns_roce_cmd_mbox(hr_dev, 0, mailbox->dma, HNS_ROCE_CMD_QUERY_MPT,
                                mtpt_idx);
        if (ret)
                goto free_cmd_mbox;

        ret = hns_roce_destroy_hw_ctx(hr_dev, HNS_ROCE_CMD_DESTROY_MPT,
                                      mtpt_idx);
        if (ret)
                ibdev_warn(ib_dev, "failed to destroy MPT, ret = %d.\n", ret);

        mr->enabled = 0;
        mr->iova = virt_addr;
        mr->size = length;

        if (flags & IB_MR_REREG_PD)
                mr->pd = to_hr_pd(pd)->pdn;

        if (flags & IB_MR_REREG_ACCESS)
                mr->access = mr_access_flags;

        if (flags & IB_MR_REREG_TRANS) {
                free_mr_pbl(hr_dev, mr);
                ret = alloc_mr_pbl(hr_dev, mr, udata, start);
                if (ret) {
                        ibdev_err(ib_dev, "failed to alloc mr PBL, ret = %d.\n",
                                  ret);
                        goto free_cmd_mbox;
                }
        }

        ret = hr_dev->hw->rereg_write_mtpt(hr_dev, mr, flags, mailbox->buf);
        if (ret) {
                ibdev_err(ib_dev, "failed to write mtpt, ret = %d.\n", ret);
                goto free_cmd_mbox;
        }

        ret = hns_roce_create_hw_ctx(hr_dev, mailbox, HNS_ROCE_CMD_CREATE_MPT,
                                     mtpt_idx);
        if (ret) {
                ibdev_err(ib_dev, "failed to create MPT, ret = %d.\n", ret);
                goto free_cmd_mbox;
        }

        mr->enabled = 1;

free_cmd_mbox:
        hns_roce_free_cmd_mailbox(hr_dev, mailbox);

err_out:
        if (ret) {
                atomic64_inc(&hr_dev->dfx_cnt[HNS_ROCE_DFX_MR_REREG_ERR_CNT]);
                return ERR_PTR(ret);
        }

        return NULL;
}

int hns_roce_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
{
        struct hns_roce_dev *hr_dev = to_hr_dev(ibmr->device);
        struct hns_roce_mr *mr = to_hr_mr(ibmr);

        if (hr_dev->hw->dereg_mr)
                hr_dev->hw->dereg_mr(hr_dev);

        hns_roce_mr_free(hr_dev, mr);
        kfree(mr);

        return 0;
}

struct ib_mr *hns_roce_alloc_mr(struct ib_pd *pd, enum ib_mr_type mr_type,
                                u32 max_num_sg)
{
        struct hns_roce_dev *hr_dev = to_hr_dev(pd->device);
        struct device *dev = hr_dev->dev;
        struct hns_roce_mr *mr;
        int ret;

        if (mr_type != IB_MR_TYPE_MEM_REG)
                return ERR_PTR(-EINVAL);

        if (max_num_sg > HNS_ROCE_FRMR_MAX_PA) {
                dev_err(dev, "max_num_sg larger than %d\n",
                        HNS_ROCE_FRMR_MAX_PA);
                return ERR_PTR(-EINVAL);
        }

        mr = kzalloc_obj(*mr);
        if (!mr)
                return ERR_PTR(-ENOMEM);

        mr->type = MR_TYPE_FRMR;
        mr->pd = to_hr_pd(pd)->pdn;
        mr->size = max_num_sg * (1 << PAGE_SHIFT);

        /* Allocate memory region key */
        ret = alloc_mr_key(hr_dev, mr);
        if (ret)
                goto err_free;

        ret = alloc_mr_pbl(hr_dev, mr, NULL, 0);
        if (ret)
                goto err_key;

        ret = hns_roce_mr_enable(hr_dev, mr);
        if (ret)
                goto err_pbl;

        mr->ibmr.rkey = mr->ibmr.lkey = mr->key;
        mr->ibmr.length = mr->size;

        return &mr->ibmr;

err_pbl:
        free_mr_pbl(hr_dev, mr);
err_key:
        free_mr_key(hr_dev, mr);
err_free:
        kfree(mr);
        return ERR_PTR(ret);
}

static int hns_roce_set_page(struct ib_mr *ibmr, u64 addr)
{
        struct hns_roce_mr *mr = to_hr_mr(ibmr);

        if (likely(mr->npages < mr->pbl_mtr.hem_cfg.buf_pg_count)) {
                mr->page_list[mr->npages++] = addr;
                return 0;
        }

        return -ENOBUFS;
}

int hns_roce_map_mr_sg(struct ib_mr *ibmr, struct scatterlist *sg, int sg_nents,
                       unsigned int *sg_offset_p)
{
        unsigned int sg_offset = sg_offset_p ? *sg_offset_p : 0;
        struct hns_roce_dev *hr_dev = to_hr_dev(ibmr->device);
        struct ib_device *ibdev = &hr_dev->ib_dev;
        struct hns_roce_mr *mr = to_hr_mr(ibmr);
        struct hns_roce_mtr *mtr = &mr->pbl_mtr;
        int ret, sg_num = 0;

        if (!IS_ALIGNED(sg_offset, HNS_ROCE_FRMR_ALIGN_SIZE) ||
            ibmr->page_size < HNS_HW_PAGE_SIZE ||
            ibmr->page_size > HNS_HW_MAX_PAGE_SIZE)
                return sg_num;

        mr->npages = 0;
        mr->page_list = kvzalloc_objs(dma_addr_t,
                                      mr->pbl_mtr.hem_cfg.buf_pg_count);
        if (!mr->page_list)
                return sg_num;

        sg_num = ib_sg_to_pages(ibmr, sg, sg_nents, sg_offset_p, hns_roce_set_page);
        if (sg_num < 1) {
                ibdev_err(ibdev, "failed to store sg pages %u %u, cnt = %d.\n",
                          mr->npages, mr->pbl_mtr.hem_cfg.buf_pg_count, sg_num);
                goto err_page_list;
        }

        mtr->hem_cfg.region[0].offset = 0;
        mtr->hem_cfg.region[0].count = mr->npages;
        mtr->hem_cfg.region[0].hopnum = mr->pbl_hop_num;
        mtr->hem_cfg.region_count = 1;
        ret = hns_roce_mtr_map(hr_dev, mtr, mr->page_list, mr->npages);
        if (ret) {
                ibdev_err(ibdev, "failed to map sg mtr, ret = %d.\n", ret);
                sg_num = 0;
        } else {
                mr->pbl_mtr.hem_cfg.buf_pg_shift = (u32)ilog2(ibmr->page_size);
        }

err_page_list:
        kvfree(mr->page_list);
        mr->page_list = NULL;

        return sg_num;
}

static int mtr_map_region(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr,
                          struct hns_roce_buf_region *region, dma_addr_t *pages,
                          int max_count)
{
        int count, npage;
        int offset, end;
        __le64 *mtts;
        u64 addr;
        int i;

        offset = region->offset;
        end = offset + region->count;
        npage = 0;
        while (offset < end && npage < max_count) {
                count = 0;
                mtts = hns_roce_hem_list_find_mtt(hr_dev, &mtr->hem_list,
                                                  offset, &count);
                if (!mtts)
                        return -ENOBUFS;

                for (i = 0; i < count && npage < max_count; i++) {
                        addr = pages[npage];

                        mtts[i] = cpu_to_le64(addr);
                        npage++;
                }
                offset += count;
        }

        return npage;
}

static inline bool mtr_has_mtt(struct hns_roce_buf_attr *attr)
{
        int i;

        for (i = 0; i < attr->region_count; i++)
                if (attr->region[i].hopnum != HNS_ROCE_HOP_NUM_0 &&
                    attr->region[i].hopnum > 0)
                        return true;

        /* because the mtr only one root base address, when hopnum is 0 means
         * root base address equals the first buffer address, thus all alloced
         * memory must in a continuous space accessed by direct mode.
         */
        return false;
}

static inline size_t mtr_bufs_size(struct hns_roce_buf_attr *attr)
{
        size_t size = 0;
        int i;

        for (i = 0; i < attr->region_count; i++)
                size += attr->region[i].size;

        return size;
}

/*
 * check the given pages in continuous address space
 * Returns 0 on success, or the error page num.
 */
static inline int mtr_check_direct_pages(dma_addr_t *pages, int page_count,
                                         unsigned int page_shift)
{
        size_t page_size = 1 << page_shift;
        int i;

        for (i = 1; i < page_count; i++)
                if (pages[i] - pages[i - 1] != page_size)
                        return i;

        return 0;
}

static void mtr_free_bufs(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr)
{
        /* release user buffers */
        if (mtr->umem) {
                ib_umem_release(mtr->umem);
                mtr->umem = NULL;
        }

        /* release kernel buffers */
        if (mtr->kmem) {
                hns_roce_buf_free(hr_dev, mtr->kmem);
                mtr->kmem = NULL;
        }
}

static int mtr_alloc_bufs(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr,
                          struct hns_roce_buf_attr *buf_attr,
                          struct ib_udata *udata, unsigned long user_addr)
{
        struct ib_device *ibdev = &hr_dev->ib_dev;
        size_t total_size;

        total_size = mtr_bufs_size(buf_attr);

        if (udata) {
                mtr->kmem = NULL;
                mtr->umem = ib_umem_get(ibdev, user_addr, total_size,
                                        buf_attr->user_access);
                if (IS_ERR(mtr->umem)) {
                        ibdev_err(ibdev, "failed to get umem, ret = %pe.\n",
                                  mtr->umem);
                        return -ENOMEM;
                }
        } else {
                mtr->umem = NULL;
                mtr->kmem = hns_roce_buf_alloc(hr_dev, total_size,
                                               buf_attr->page_shift,
                                               !mtr_has_mtt(buf_attr) ?
                                               HNS_ROCE_BUF_DIRECT : 0);
                if (IS_ERR(mtr->kmem)) {
                        ibdev_err(ibdev, "failed to alloc kmem, ret = %pe.\n",
                                  mtr->kmem);
                        return PTR_ERR(mtr->kmem);
                }
        }

        return 0;
}

static int cal_mtr_pg_cnt(struct hns_roce_mtr *mtr)
{
        struct hns_roce_buf_region *region;
        int page_cnt = 0;
        int i;

        for (i = 0; i < mtr->hem_cfg.region_count; i++) {
                region = &mtr->hem_cfg.region[i];
                page_cnt += region->count;
        }

        return page_cnt;
}

static bool need_split_huge_page(struct hns_roce_mtr *mtr)
{
        /* When HEM buffer uses 0-level addressing, the page size is
         * equal to the whole buffer size. If the current MTR has multiple
         * regions, we split the buffer into small pages(4k, required by hns
         * ROCEE). These pages will be used in multiple regions.
         */
        return mtr->hem_cfg.is_direct && mtr->hem_cfg.region_count > 1;
}

static int mtr_map_bufs(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr)
{
        struct ib_device *ibdev = &hr_dev->ib_dev;
        int page_count = cal_mtr_pg_cnt(mtr);
        unsigned int page_shift;
        dma_addr_t *pages;
        int npage;
        int ret;

        page_shift = need_split_huge_page(mtr) ? HNS_HW_PAGE_SHIFT :
                                                 mtr->hem_cfg.buf_pg_shift;
        /* alloc a tmp array to store buffer's dma address */
        pages = kvzalloc_objs(dma_addr_t, page_count);
        if (!pages)
                return -ENOMEM;

        if (mtr->umem)
                npage = hns_roce_get_umem_bufs(pages, page_count,
                                               mtr->umem, page_shift);
        else
                npage = hns_roce_get_kmem_bufs(hr_dev, pages, page_count,
                                               mtr->kmem, page_shift);

        if (npage != page_count) {
                ibdev_err(ibdev, "failed to get mtr page %d != %d.\n", npage,
                          page_count);
                ret = -ENOBUFS;
                goto err_alloc_list;
        }

        if (need_split_huge_page(mtr) && npage > 1) {
                ret = mtr_check_direct_pages(pages, npage, page_shift);
                if (ret) {
                        ibdev_err(ibdev, "failed to check %s page: %d / %d.\n",
                                  mtr->umem ? "umtr" : "kmtr", ret, npage);
                        ret = -ENOBUFS;
                        goto err_alloc_list;
                }
        }

        ret = hns_roce_mtr_map(hr_dev, mtr, pages, page_count);
        if (ret)
                ibdev_err(ibdev, "failed to map mtr pages, ret = %d.\n", ret);

err_alloc_list:
        kvfree(pages);

        return ret;
}

int hns_roce_mtr_map(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr,
                     dma_addr_t *pages, unsigned int page_cnt)
{
        struct ib_device *ibdev = &hr_dev->ib_dev;
        struct hns_roce_buf_region *r;
        unsigned int i, mapped_cnt;
        int ret = 0;

        /*
         * Only use the first page address as root ba when hopnum is 0, this
         * is because the addresses of all pages are consecutive in this case.
         */
        if (mtr->hem_cfg.is_direct) {
                mtr->hem_cfg.root_ba = pages[0];
                return 0;
        }

        for (i = 0, mapped_cnt = 0; i < mtr->hem_cfg.region_count &&
             mapped_cnt < page_cnt; i++) {
                r = &mtr->hem_cfg.region[i];

                if (r->offset + r->count > page_cnt) {
                        ret = -EINVAL;
                        ibdev_err(ibdev,
                                  "failed to check mtr%u count %u + %u > %u.\n",
                                  i, r->offset, r->count, page_cnt);
                        return ret;
                }

                ret = mtr_map_region(hr_dev, mtr, r, &pages[r->offset],
                                     page_cnt - mapped_cnt);
                if (ret < 0) {
                        ibdev_err(ibdev,
                                  "failed to map mtr%u offset %u, ret = %d.\n",
                                  i, r->offset, ret);
                        return ret;
                }
                mapped_cnt += ret;
                ret = 0;
        }

        if (mapped_cnt < page_cnt) {
                ret = -ENOBUFS;
                ibdev_err(ibdev, "failed to map mtr pages count: %u < %u.\n",
                          mapped_cnt, page_cnt);
        }

        return ret;
}

static int hns_roce_get_direct_addr_mtt(struct hns_roce_hem_cfg *cfg,
                                        u32 start_index, u64 *mtt_buf,
                                        int mtt_cnt)
{
        int mtt_count;
        int total = 0;
        u32 npage;
        u64 addr;

        if (mtt_cnt > cfg->region_count)
                return -EINVAL;

        for (mtt_count = 0; mtt_count < cfg->region_count && total < mtt_cnt;
             mtt_count++) {
                npage = cfg->region[mtt_count].offset;
                if (npage < start_index)
                        continue;

                addr = cfg->root_ba + (npage << HNS_HW_PAGE_SHIFT);
                mtt_buf[total] = addr;

                total++;
        }

        if (!total)
                return -ENOENT;

        return 0;
}

static int hns_roce_get_mhop_mtt(struct hns_roce_dev *hr_dev,
                                 struct hns_roce_mtr *mtr, u32 start_index,
                                 u64 *mtt_buf, int mtt_cnt)
{
        int left = mtt_cnt;
        int total = 0;
        int mtt_count;
        __le64 *mtts;
        u32 npage;

        while (left > 0) {
                mtt_count = 0;
                mtts = hns_roce_hem_list_find_mtt(hr_dev, &mtr->hem_list,
                                                  start_index + total,
                                                  &mtt_count);
                if (!mtts || !mtt_count)
                        break;

                npage = min(mtt_count, left);
                left -= npage;
                for (mtt_count = 0; mtt_count < npage; mtt_count++)
                        mtt_buf[total++] = le64_to_cpu(mtts[mtt_count]);
        }

        if (!total)
                return -ENOENT;

        return 0;
}

int hns_roce_mtr_find(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr,
                      u32 offset, u64 *mtt_buf, int mtt_max)
{
        struct hns_roce_hem_cfg *cfg = &mtr->hem_cfg;
        u32 start_index;
        int ret;

        if (!mtt_buf || mtt_max < 1)
                return -EINVAL;

        /* no mtt memory in direct mode, so just return the buffer address */
        if (cfg->is_direct) {
                start_index = offset >> HNS_HW_PAGE_SHIFT;
                ret = hns_roce_get_direct_addr_mtt(cfg, start_index,
                                                   mtt_buf, mtt_max);
        } else {
                start_index = offset >> cfg->buf_pg_shift;
                ret = hns_roce_get_mhop_mtt(hr_dev, mtr, start_index,
                                            mtt_buf, mtt_max);
        }
        return ret;
}

static int get_best_page_shift(struct hns_roce_dev *hr_dev,
                               struct hns_roce_mtr *mtr,
                               struct hns_roce_buf_attr *buf_attr)
{
        unsigned int page_sz;

        if (!buf_attr->adaptive || buf_attr->type != MTR_PBL || !mtr->umem)
                return 0;

        page_sz = ib_umem_find_best_pgsz(mtr->umem,
                                         hr_dev->caps.page_size_cap,
                                         buf_attr->iova);
        if (!page_sz)
                return -EINVAL;

        buf_attr->page_shift = order_base_2(page_sz);
        return 0;
}

static int get_best_hop_num(struct hns_roce_dev *hr_dev,
                            struct hns_roce_mtr *mtr,
                            struct hns_roce_buf_attr *buf_attr,
                            unsigned int ba_pg_shift)
{
#define INVALID_HOPNUM -1
#define MIN_BA_CNT 1
        size_t buf_pg_sz = 1 << buf_attr->page_shift;
        struct ib_device *ibdev = &hr_dev->ib_dev;
        size_t ba_pg_sz = 1 << ba_pg_shift;
        int hop_num = INVALID_HOPNUM;
        size_t unit = MIN_BA_CNT;
        size_t ba_cnt;
        int j;

        if (!buf_attr->adaptive || buf_attr->type != MTR_PBL)
                return 0;

        /* Caculating the number of buf pages, each buf page need a BA */
        if (mtr->umem)
                ba_cnt = ib_umem_num_dma_blocks(mtr->umem, buf_pg_sz);
        else
                ba_cnt = DIV_ROUND_UP(buf_attr->region[0].size, buf_pg_sz);

        for (j = 0; j <= HNS_ROCE_MAX_HOP_NUM; j++) {
                if (ba_cnt <= unit) {
                        hop_num = j;
                        break;
                }
                /* Number of BAs can be represented at per hop */
                unit *= ba_pg_sz / BA_BYTE_LEN;
        }

        if (hop_num < 0) {
                ibdev_err(ibdev,
                          "failed to calculate a valid hopnum.\n");
                return -EINVAL;
        }

        buf_attr->region[0].hopnum = hop_num;

        return 0;
}

static bool is_buf_attr_valid(struct hns_roce_dev *hr_dev,
                              struct hns_roce_buf_attr *attr)
{
        struct ib_device *ibdev = &hr_dev->ib_dev;

        if (attr->region_count > ARRAY_SIZE(attr->region) ||
            attr->region_count < 1 || attr->page_shift < HNS_HW_PAGE_SHIFT) {
                ibdev_err(ibdev,
                          "invalid buf attr, region count %u, page shift %u.\n",
                          attr->region_count, attr->page_shift);
                return false;
        }

        return true;
}

static int mtr_init_buf_cfg(struct hns_roce_dev *hr_dev,
                            struct hns_roce_mtr *mtr,
                            struct hns_roce_buf_attr *attr)
{
        struct hns_roce_hem_cfg *cfg = &mtr->hem_cfg;
        struct hns_roce_buf_region *r;
        size_t buf_pg_sz;
        size_t buf_size;
        int page_cnt, i;
        u64 pgoff = 0;

        if (!is_buf_attr_valid(hr_dev, attr))
                return -EINVAL;

        /* If mtt is disabled, all pages must be within a continuous range */
        cfg->is_direct = !mtr_has_mtt(attr);
        cfg->region_count = attr->region_count;
        buf_size = mtr_bufs_size(attr);
        if (need_split_huge_page(mtr)) {
                buf_pg_sz = HNS_HW_PAGE_SIZE;
                cfg->buf_pg_count = 1;
                /* The ROCEE requires the page size to be 4K * 2 ^ N. */
                cfg->buf_pg_shift = HNS_HW_PAGE_SHIFT +
                        order_base_2(DIV_ROUND_UP(buf_size, HNS_HW_PAGE_SIZE));
        } else {
                buf_pg_sz = 1 << attr->page_shift;
                cfg->buf_pg_count = mtr->umem ?
                        ib_umem_num_dma_blocks(mtr->umem, buf_pg_sz) :
                        DIV_ROUND_UP(buf_size, buf_pg_sz);
                cfg->buf_pg_shift = attr->page_shift;
                pgoff = mtr->umem ? mtr->umem->address & ~PAGE_MASK : 0;
        }

        /* Convert buffer size to page index and page count for each region and
         * the buffer's offset needs to be appended to the first region.
         */
        for (page_cnt = 0, i = 0; i < attr->region_count; i++) {
                r = &cfg->region[i];
                r->offset = page_cnt;
                buf_size = hr_hw_page_align(attr->region[i].size + pgoff);
                if (attr->type == MTR_PBL && mtr->umem)
                        r->count = ib_umem_num_dma_blocks(mtr->umem, buf_pg_sz);
                else
                        r->count = DIV_ROUND_UP(buf_size, buf_pg_sz);

                pgoff = 0;
                page_cnt += r->count;
                r->hopnum = to_hr_hem_hopnum(attr->region[i].hopnum, r->count);
        }

        return 0;
}

static u64 cal_pages_per_l1ba(unsigned int ba_per_bt, unsigned int hopnum)
{
        return int_pow(ba_per_bt, hopnum - 1);
}

static unsigned int cal_best_bt_pg_sz(struct hns_roce_dev *hr_dev,
                                      struct hns_roce_mtr *mtr,
                                      unsigned int pg_shift)
{
        unsigned long cap = hr_dev->caps.page_size_cap;
        struct hns_roce_buf_region *re;
        unsigned int pgs_per_l1ba;
        unsigned int ba_per_bt;
        unsigned int ba_num;
        int i;

        for_each_set_bit_from(pg_shift, &cap, sizeof(cap) * BITS_PER_BYTE) {
                if (!(BIT(pg_shift) & cap))
                        continue;

                ba_per_bt = BIT(pg_shift) / BA_BYTE_LEN;
                ba_num = 0;
                for (i = 0; i < mtr->hem_cfg.region_count; i++) {
                        re = &mtr->hem_cfg.region[i];
                        if (re->hopnum == 0)
                                continue;

                        pgs_per_l1ba = cal_pages_per_l1ba(ba_per_bt, re->hopnum);
                        ba_num += DIV_ROUND_UP(re->count, pgs_per_l1ba);
                }

                if (ba_num <= ba_per_bt)
                        return pg_shift;
        }

        return 0;
}

static int mtr_alloc_mtt(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr,
                         unsigned int ba_page_shift)
{
        struct hns_roce_hem_cfg *cfg = &mtr->hem_cfg;
        int ret;

        hns_roce_hem_list_init(&mtr->hem_list);
        if (!cfg->is_direct) {
                ba_page_shift = cal_best_bt_pg_sz(hr_dev, mtr, ba_page_shift);
                if (!ba_page_shift)
                        return -ERANGE;

                ret = hns_roce_hem_list_request(hr_dev, &mtr->hem_list,
                                                cfg->region, cfg->region_count,
                                                ba_page_shift);
                if (ret)
                        return ret;
                cfg->root_ba = mtr->hem_list.root_ba;
                cfg->ba_pg_shift = ba_page_shift;
        } else {
                cfg->ba_pg_shift = cfg->buf_pg_shift;
        }

        return 0;
}

static void mtr_free_mtt(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr)
{
        hns_roce_hem_list_release(hr_dev, &mtr->hem_list);
}

/**
 * hns_roce_mtr_create - Create hns memory translate region.
 *
 * @hr_dev: RoCE device struct pointer
 * @mtr: memory translate region
 * @buf_attr: buffer attribute for creating mtr
 * @ba_page_shift: page shift for multi-hop base address table
 * @udata: user space context, if it's NULL, means kernel space
 * @user_addr: userspace virtual address to start at
 */
int hns_roce_mtr_create(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr,
                        struct hns_roce_buf_attr *buf_attr,
                        unsigned int ba_page_shift, struct ib_udata *udata,
                        unsigned long user_addr)
{
        struct ib_device *ibdev = &hr_dev->ib_dev;
        int ret;

        trace_hns_buf_attr(buf_attr);
        /* The caller has its own buffer list and invokes the hns_roce_mtr_map()
         * to finish the MTT configuration.
         */
        if (buf_attr->mtt_only) {
                mtr->umem = NULL;
                mtr->kmem = NULL;
        } else {
                ret = mtr_alloc_bufs(hr_dev, mtr, buf_attr, udata, user_addr);
                if (ret) {
                        ibdev_err(ibdev,
                                  "failed to alloc mtr bufs, ret = %d.\n", ret);
                        return ret;
                }

                ret = get_best_page_shift(hr_dev, mtr, buf_attr);
                if (ret)
                        goto err_init_buf;

                ret = get_best_hop_num(hr_dev, mtr, buf_attr, ba_page_shift);
                if (ret)
                        goto err_init_buf;
        }

        ret = mtr_init_buf_cfg(hr_dev, mtr, buf_attr);
        if (ret)
                goto err_init_buf;

        ret = mtr_alloc_mtt(hr_dev, mtr, ba_page_shift);
        if (ret) {
                ibdev_err(ibdev, "failed to alloc mtr mtt, ret = %d.\n", ret);
                goto err_init_buf;
        }

        if (buf_attr->mtt_only)
                return 0;

        /* Write buffer's dma address to MTT */
        ret = mtr_map_bufs(hr_dev, mtr);
        if (ret) {
                ibdev_err(ibdev, "failed to map mtr bufs, ret = %d.\n", ret);
                goto err_alloc_mtt;
        }

        return 0;

err_alloc_mtt:
        mtr_free_mtt(hr_dev, mtr);
err_init_buf:
        mtr_free_bufs(hr_dev, mtr);

        return ret;
}

void hns_roce_mtr_destroy(struct hns_roce_dev *hr_dev, struct hns_roce_mtr *mtr)
{
        /* release multi-hop addressing resource */
        hns_roce_hem_list_release(hr_dev, &mtr->hem_list);

        /* free buffers */
        mtr_free_bufs(hr_dev, mtr);
}