/*
 * 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/platform_device.h>
#include <linux/vmalloc.h>
#include <rdma/ib_umem.h>
#include "hns_roce_device.h"
#include "hns_roce_cmd.h"
#include "hns_roce_hem.h"

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

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

static int hns_roce_sw2hw_mpt(struct hns_roce_dev *hr_dev,
                              struct hns_roce_cmd_mailbox *mailbox,
                              unsigned long mpt_index)
{
        return hns_roce_cmd_mbox(hr_dev, mailbox->dma, 0, mpt_index, 0,
                                 HNS_ROCE_CMD_SW2HW_MPT,
                                 HNS_ROCE_CMD_TIMEOUT_MSECS);
}

int hns_roce_hw2sw_mpt(struct hns_roce_dev *hr_dev,
                              struct hns_roce_cmd_mailbox *mailbox,
                              unsigned long mpt_index)
{
        return hns_roce_cmd_mbox(hr_dev, 0, mailbox ? mailbox->dma : 0,
                                 mpt_index, !mailbox, HNS_ROCE_CMD_HW2SW_MPT,
                                 HNS_ROCE_CMD_TIMEOUT_MSECS);
}

static int hns_roce_buddy_alloc(struct hns_roce_buddy *buddy, int order,
                                unsigned long *seg)
{
        int o;
        u32 m;

        spin_lock(&buddy->lock);

        for (o = order; o <= buddy->max_order; ++o) {
                if (buddy->num_free[o]) {
                        m = 1 << (buddy->max_order - o);
                        *seg = find_first_bit(buddy->bits[o], m);
                        if (*seg < m)
                                goto found;
                }
        }
        spin_unlock(&buddy->lock);
        return -1;

 found:
        clear_bit(*seg, buddy->bits[o]);
        --buddy->num_free[o];

        while (o > order) {
                --o;
                *seg <<= 1;
                set_bit(*seg ^ 1, buddy->bits[o]);
                ++buddy->num_free[o];
        }

        spin_unlock(&buddy->lock);

        *seg <<= order;
        return 0;
}

static void hns_roce_buddy_free(struct hns_roce_buddy *buddy, unsigned long seg,
                                int order)
{
        seg >>= order;

        spin_lock(&buddy->lock);

        while (test_bit(seg ^ 1, buddy->bits[order])) {
                clear_bit(seg ^ 1, buddy->bits[order]);
                --buddy->num_free[order];
                seg >>= 1;
                ++order;
        }

        set_bit(seg, buddy->bits[order]);
        ++buddy->num_free[order];

        spin_unlock(&buddy->lock);
}

static int hns_roce_buddy_init(struct hns_roce_buddy *buddy, int max_order)
{
        int i, s;

        buddy->max_order = max_order;
        spin_lock_init(&buddy->lock);
        buddy->bits = kcalloc(buddy->max_order + 1,
                              sizeof(*buddy->bits),
                              GFP_KERNEL);
        buddy->num_free = kcalloc(buddy->max_order + 1,
                                  sizeof(*buddy->num_free),
                                  GFP_KERNEL);
        if (!buddy->bits || !buddy->num_free)
                goto err_out;

        for (i = 0; i <= buddy->max_order; ++i) {
                s = BITS_TO_LONGS(1 << (buddy->max_order - i));
                buddy->bits[i] = kcalloc(s, sizeof(long), GFP_KERNEL |
                                         __GFP_NOWARN);
                if (!buddy->bits[i]) {
                        buddy->bits[i] = vzalloc(s * sizeof(long));
                        if (!buddy->bits[i])
                                goto err_out_free;
                }
        }

        set_bit(0, buddy->bits[buddy->max_order]);
        buddy->num_free[buddy->max_order] = 1;

        return 0;

err_out_free:
        for (i = 0; i <= buddy->max_order; ++i)
                kvfree(buddy->bits[i]);

err_out:
        kfree(buddy->bits);
        kfree(buddy->num_free);
        return -ENOMEM;
}

static void hns_roce_buddy_cleanup(struct hns_roce_buddy *buddy)
{
        int i;

        for (i = 0; i <= buddy->max_order; ++i)
                kvfree(buddy->bits[i]);

        kfree(buddy->bits);
        kfree(buddy->num_free);
}

static int hns_roce_alloc_mtt_range(struct hns_roce_dev *hr_dev, int order,
                                    unsigned long *seg)
{
        struct hns_roce_mr_table *mr_table = &hr_dev->mr_table;
        int ret = 0;

        ret = hns_roce_buddy_alloc(&mr_table->mtt_buddy, order, seg);
        if (ret == -1)
                return -1;

        if (hns_roce_table_get_range(hr_dev, &mr_table->mtt_table, *seg,
                                     *seg + (1 << order) - 1)) {
                hns_roce_buddy_free(&mr_table->mtt_buddy, *seg, order);
                return -1;
        }

        return 0;
}

int hns_roce_mtt_init(struct hns_roce_dev *hr_dev, int npages, int page_shift,
                      struct hns_roce_mtt *mtt)
{
        int ret = 0;
        int i;

        /* Page num is zero, correspond to DMA memory register */
        if (!npages) {
                mtt->order = -1;
                mtt->page_shift = HNS_ROCE_HEM_PAGE_SHIFT;
                return 0;
        }

        /* Note: if page_shift is zero, FAST memory register */
        mtt->page_shift = page_shift;

        /* Compute MTT entry necessary */
        for (mtt->order = 0, i = HNS_ROCE_MTT_ENTRY_PER_SEG; i < npages;
             i <<= 1)
                ++mtt->order;

        /* Allocate MTT entry */
        ret = hns_roce_alloc_mtt_range(hr_dev, mtt->order, &mtt->first_seg);
        if (ret == -1)
                return -ENOMEM;

        return 0;
}

void hns_roce_mtt_cleanup(struct hns_roce_dev *hr_dev, struct hns_roce_mtt *mtt)
{
        struct hns_roce_mr_table *mr_table = &hr_dev->mr_table;

        if (mtt->order < 0)
                return;

        hns_roce_buddy_free(&mr_table->mtt_buddy, mtt->first_seg, mtt->order);
        hns_roce_table_put_range(hr_dev, &mr_table->mtt_table, mtt->first_seg,
                                 mtt->first_seg + (1 << mtt->order) - 1);
}

static int hns_roce_mr_alloc(struct hns_roce_dev *hr_dev, u32 pd, u64 iova,
                             u64 size, u32 access, int npages,
                             struct hns_roce_mr *mr)
{
        unsigned long index = 0;
        int ret = 0;
        struct device *dev = &hr_dev->pdev->dev;

        /* Allocate a key for mr from mr_table */
        ret = hns_roce_bitmap_alloc(&hr_dev->mr_table.mtpt_bitmap, &index);
        if (ret == -1)
                return -ENOMEM;

        mr->iova = iova;                        /* MR va starting addr */
        mr->size = size;                        /* MR addr range */
        mr->pd = pd;                            /* MR num */
        mr->access = access;                    /* MR access permit */
        mr->enabled = 0;                        /* MR active status */
        mr->key = hw_index_to_key(index);       /* MR key */

        if (size == ~0ull) {
                mr->type = MR_TYPE_DMA;
                mr->pbl_buf = NULL;
                mr->pbl_dma_addr = 0;
        } else {
                mr->type = MR_TYPE_MR;
                mr->pbl_buf = dma_alloc_coherent(dev, npages * 8,
                                                 &(mr->pbl_dma_addr),
                                                 GFP_KERNEL);
                if (!mr->pbl_buf)
                        return -ENOMEM;
        }

        return 0;
}

static void hns_roce_mr_free(struct hns_roce_dev *hr_dev,
                             struct hns_roce_mr *mr)
{
        struct device *dev = &hr_dev->pdev->dev;
        int npages = 0;
        int ret;

        if (mr->enabled) {
                ret = hns_roce_hw2sw_mpt(hr_dev, NULL, key_to_hw_index(mr->key)
                                         & (hr_dev->caps.num_mtpts - 1));
                if (ret)
                        dev_warn(dev, "HW2SW_MPT failed (%d)\n", ret);
        }

        if (mr->size != ~0ULL) {
                npages = ib_umem_page_count(mr->umem);
                dma_free_coherent(dev, (unsigned int)(npages * 8), mr->pbl_buf,
                                  mr->pbl_dma_addr);
        }

        hns_roce_bitmap_free(&hr_dev->mr_table.mtpt_bitmap,
                             key_to_hw_index(mr->key), BITMAP_NO_RR);
}

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

        /* Prepare HEM entry memory */
        ret = hns_roce_table_get(hr_dev, &mr_table->mtpt_table, mtpt_idx);
        if (ret)
                return ret;

        /* Allocate mailbox memory */
        mailbox = hns_roce_alloc_cmd_mailbox(hr_dev);
        if (IS_ERR(mailbox)) {
                ret = PTR_ERR(mailbox);
                goto err_table;
        }

        ret = hr_dev->hw->write_mtpt(mailbox->buf, mr, mtpt_idx);
        if (ret) {
                dev_err(dev, "Write mtpt fail!\n");
                goto err_page;
        }

        ret = hns_roce_sw2hw_mpt(hr_dev, mailbox,
                                 mtpt_idx & (hr_dev->caps.num_mtpts - 1));
        if (ret) {
                dev_err(dev, "SW2HW_MPT failed (%d)\n", ret);
                goto err_page;
        }

        mr->enabled = 1;
        hns_roce_free_cmd_mailbox(hr_dev, mailbox);

        return 0;

err_page:
        hns_roce_free_cmd_mailbox(hr_dev, mailbox);

err_table:
        hns_roce_table_put(hr_dev, &mr_table->mtpt_table, mtpt_idx);
        return ret;
}

static int hns_roce_write_mtt_chunk(struct hns_roce_dev *hr_dev,
                                    struct hns_roce_mtt *mtt, u32 start_index,
                                    u32 npages, u64 *page_list)
{
        u32 i = 0;
        __le64 *mtts = NULL;
        dma_addr_t dma_handle;
        u32 s = start_index * sizeof(u64);

        /* All MTTs must fit in the same page */
        if (start_index / (PAGE_SIZE / sizeof(u64)) !=
                (start_index + npages - 1) / (PAGE_SIZE / sizeof(u64)))
                return -EINVAL;

        if (start_index & (HNS_ROCE_MTT_ENTRY_PER_SEG - 1))
                return -EINVAL;

        mtts = hns_roce_table_find(&hr_dev->mr_table.mtt_table,
                                mtt->first_seg + s / hr_dev->caps.mtt_entry_sz,
                                &dma_handle);
        if (!mtts)
                return -ENOMEM;

        /* Save page addr, low 12 bits : 0 */
        for (i = 0; i < npages; ++i)
                mtts[i] = (cpu_to_le64(page_list[i])) >> PAGE_ADDR_SHIFT;

        return 0;
}

static int hns_roce_write_mtt(struct hns_roce_dev *hr_dev,
                              struct hns_roce_mtt *mtt, u32 start_index,
                              u32 npages, u64 *page_list)
{
        int chunk;
        int ret;

        if (mtt->order < 0)
                return -EINVAL;

        while (npages > 0) {
                chunk = min_t(int, PAGE_SIZE / sizeof(u64), npages);

                ret = hns_roce_write_mtt_chunk(hr_dev, mtt, start_index, chunk,
                                               page_list);
                if (ret)
                        return ret;

                npages -= chunk;
                start_index += chunk;
                page_list += chunk;
        }

        return 0;
}

int hns_roce_buf_write_mtt(struct hns_roce_dev *hr_dev,
                           struct hns_roce_mtt *mtt, struct hns_roce_buf *buf)
{
        u32 i = 0;
        int ret = 0;
        u64 *page_list = NULL;

        page_list = kmalloc_array(buf->npages, sizeof(*page_list), GFP_KERNEL);
        if (!page_list)
                return -ENOMEM;

        for (i = 0; i < buf->npages; ++i) {
                if (buf->nbufs == 1)
                        page_list[i] = buf->direct.map + (i << buf->page_shift);
                else
                        page_list[i] = buf->page_list[i].map;

        }
        ret = hns_roce_write_mtt(hr_dev, mtt, 0, buf->npages, page_list);

        kfree(page_list);

        return ret;
}

int hns_roce_init_mr_table(struct hns_roce_dev *hr_dev)
{
        struct hns_roce_mr_table *mr_table = &hr_dev->mr_table;
        int ret = 0;

        ret = hns_roce_bitmap_init(&mr_table->mtpt_bitmap,
                                   hr_dev->caps.num_mtpts,
                                   hr_dev->caps.num_mtpts - 1,
                                   hr_dev->caps.reserved_mrws, 0);
        if (ret)
                return ret;

        ret = hns_roce_buddy_init(&mr_table->mtt_buddy,
                                  ilog2(hr_dev->caps.num_mtt_segs));
        if (ret)
                goto err_buddy;

        return 0;

err_buddy:
        hns_roce_bitmap_cleanup(&mr_table->mtpt_bitmap);
        return ret;
}

void hns_roce_cleanup_mr_table(struct hns_roce_dev *hr_dev)
{
        struct hns_roce_mr_table *mr_table = &hr_dev->mr_table;

        hns_roce_buddy_cleanup(&mr_table->mtt_buddy);
        hns_roce_bitmap_cleanup(&mr_table->mtpt_bitmap);
}

struct ib_mr *hns_roce_get_dma_mr(struct ib_pd *pd, int acc)
{
        int ret = 0;
        struct hns_roce_mr *mr = NULL;

        mr = kmalloc(sizeof(*mr), GFP_KERNEL);
        if (mr == NULL)
                return  ERR_PTR(-ENOMEM);

        /* Allocate memory region key */
        ret = hns_roce_mr_alloc(to_hr_dev(pd->device), to_hr_pd(pd)->pdn, 0,
                                ~0ULL, acc, 0, mr);
        if (ret)
                goto err_free;

        ret = hns_roce_mr_enable(to_hr_dev(pd->device), mr);
        if (ret)
                goto err_mr;

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

        return &mr->ibmr;

err_mr:
        hns_roce_mr_free(to_hr_dev(pd->device), mr);

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

int hns_roce_ib_umem_write_mtt(struct hns_roce_dev *hr_dev,
                               struct hns_roce_mtt *mtt, struct ib_umem *umem)
{
        struct scatterlist *sg;
        int i, k, entry;
        int ret = 0;
        u64 *pages;
        u32 n;
        int len;

        pages = (u64 *) __get_free_page(GFP_KERNEL);
        if (!pages)
                return -ENOMEM;

        i = n = 0;

        for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
                len = sg_dma_len(sg) >> mtt->page_shift;
                for (k = 0; k < len; ++k) {
                        pages[i++] = sg_dma_address(sg) +
                                (k << umem->page_shift);
                        if (i == PAGE_SIZE / sizeof(u64)) {
                                ret = hns_roce_write_mtt(hr_dev, mtt, n, i,
                                                         pages);
                                if (ret)
                                        goto out;
                                n += i;
                                i = 0;
                        }
                }
        }

        if (i)
                ret = hns_roce_write_mtt(hr_dev, mtt, n, i, pages);

out:
        free_page((unsigned long) pages);
        return ret;
}

static int hns_roce_ib_umem_write_mr(struct hns_roce_mr *mr,
                                     struct ib_umem *umem)
{
        int i = 0;
        int entry;
        struct scatterlist *sg;

        for_each_sg(umem->sg_head.sgl, sg, umem->nmap, entry) {
                mr->pbl_buf[i] = ((u64)sg_dma_address(sg)) >> 12;
                i++;
        }

        /* Memory barrier */
        mb();

        return 0;
}

struct ib_mr *hns_roce_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
                                   u64 virt_addr, int access_flags,
                                   struct ib_udata *udata)
{
        struct hns_roce_dev *hr_dev = to_hr_dev(pd->device);
        struct device *dev = &hr_dev->pdev->dev;
        struct hns_roce_mr *mr = NULL;
        int ret = 0;
        int n = 0;

        mr = kmalloc(sizeof(*mr), GFP_KERNEL);
        if (!mr)
                return ERR_PTR(-ENOMEM);

        mr->umem = ib_umem_get(pd->uobject->context, start, length,
                               access_flags, 0);
        if (IS_ERR(mr->umem)) {
                ret = PTR_ERR(mr->umem);
                goto err_free;
        }

        n = ib_umem_page_count(mr->umem);
        if (mr->umem->page_shift != HNS_ROCE_HEM_PAGE_SHIFT) {
                dev_err(dev, "Just support 4K page size but is 0x%lx now!\n",
                        BIT(mr->umem->page_shift));
                ret = -EINVAL;
                goto err_umem;
        }

        if (n > HNS_ROCE_MAX_MTPT_PBL_NUM) {
                dev_err(dev, " MR len %lld err. MR is limited to 4G at most!\n",
                        length);
                ret = -EINVAL;
                goto err_umem;
        }

        ret = hns_roce_mr_alloc(hr_dev, to_hr_pd(pd)->pdn, virt_addr, length,
                                access_flags, n, mr);
        if (ret)
                goto err_umem;

        ret = hns_roce_ib_umem_write_mr(mr, mr->umem);
        if (ret)
                goto err_mr;

        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:
        hns_roce_mr_free(hr_dev, mr);

err_umem:
        ib_umem_release(mr->umem);

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

int hns_roce_dereg_mr(struct ib_mr *ibmr)
{
        struct hns_roce_dev *hr_dev = to_hr_dev(ibmr->device);
        struct hns_roce_mr *mr = to_hr_mr(ibmr);
        int ret = 0;

        if (hr_dev->hw->dereg_mr) {
                ret = hr_dev->hw->dereg_mr(hr_dev, mr);
        } else {
                hns_roce_mr_free(hr_dev, mr);

                if (mr->umem)
                        ib_umem_release(mr->umem);

                kfree(mr);
        }

        return ret;
}