/*
 * Copyright (c) 2007 Cisco Systems, Inc. All rights reserved.
 * 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/slab.h>
#include <rdma/ib_user_verbs.h>

#include "mlx4_ib.h"

static u32 convert_access(int acc)
{
        return (acc & IB_ACCESS_REMOTE_ATOMIC ? MLX4_PERM_ATOMIC       : 0) |
               (acc & IB_ACCESS_REMOTE_WRITE  ? MLX4_PERM_REMOTE_WRITE : 0) |
               (acc & IB_ACCESS_REMOTE_READ   ? MLX4_PERM_REMOTE_READ  : 0) |
               (acc & IB_ACCESS_LOCAL_WRITE   ? MLX4_PERM_LOCAL_WRITE  : 0) |
               (acc & IB_ACCESS_MW_BIND       ? MLX4_PERM_BIND_MW      : 0) |
               MLX4_PERM_LOCAL_READ;
}

static enum mlx4_mw_type to_mlx4_type(enum ib_mw_type type)
{
        switch (type) {
        case IB_MW_TYPE_1:      return MLX4_MW_TYPE_1;
        case IB_MW_TYPE_2:      return MLX4_MW_TYPE_2;
        default:                return -1;
        }
}

struct ib_mr *mlx4_ib_get_dma_mr(struct ib_pd *pd, int acc)
{
        struct mlx4_ib_mr *mr;
        int err;

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

        err = mlx4_mr_alloc(to_mdev(pd->device)->dev, to_mpd(pd)->pdn, 0,
                            ~0ull, convert_access(acc), 0, 0, &mr->mmr);
        if (err)
                goto err_free;

        err = mlx4_mr_enable(to_mdev(pd->device)->dev, &mr->mmr);
        if (err)
                goto err_mr;

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

        return &mr->ibmr;

err_mr:
        (void) mlx4_mr_free(to_mdev(pd->device)->dev, &mr->mmr);

err_free:
        kfree(mr);

        return ERR_PTR(err);
}

int mlx4_ib_umem_write_mtt(struct mlx4_ib_dev *dev, struct mlx4_mtt *mtt,
                           struct ib_umem *umem)
{
        struct ib_block_iter biter;
        int err, i = 0;
        u64 addr;

        rdma_umem_for_each_dma_block(umem, &biter, BIT(mtt->page_shift)) {
                addr = rdma_block_iter_dma_address(&biter);
                err = mlx4_write_mtt(dev->dev, mtt, i++, 1, &addr);
                if (err)
                        return err;
        }
        return 0;
}

static struct ib_umem *mlx4_get_umem_mr(struct ib_device *device, u64 start,
                                        u64 length, int access_flags)
{
        /*
         * Force registering the memory as writable if the underlying pages
         * are writable.  This is so rereg can change the access permissions
         * from readable to writable without having to run through ib_umem_get
         * again
         */
        if (!ib_access_writable(access_flags)) {
                unsigned long untagged_start = untagged_addr(start);
                struct vm_area_struct *vma;

                mmap_read_lock(current->mm);
                /*
                 * FIXME: Ideally this would iterate over all the vmas that
                 * cover the memory, but for now it requires a single vma to
                 * entirely cover the MR to support RO mappings.
                 */
                vma = find_vma(current->mm, untagged_start);
                if (vma && vma->vm_end >= untagged_start + length &&
                    vma->vm_start <= untagged_start) {
                        if (vma->vm_flags & VM_WRITE)
                                access_flags |= IB_ACCESS_LOCAL_WRITE;
                } else {
                        access_flags |= IB_ACCESS_LOCAL_WRITE;
                }

                mmap_read_unlock(current->mm);
        }

        return ib_umem_get(device, start, length, access_flags);
}

struct ib_mr *mlx4_ib_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 mlx4_ib_dev *dev = to_mdev(pd->device);
        struct mlx4_ib_mr *mr;
        int shift;
        int err;
        int n;

        if (dmah)
                return ERR_PTR(-EOPNOTSUPP);

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

        mr->umem = mlx4_get_umem_mr(pd->device, start, length, access_flags);
        if (IS_ERR(mr->umem)) {
                err = PTR_ERR(mr->umem);
                goto err_free;
        }

        shift = mlx4_ib_umem_calc_optimal_mtt_size(mr->umem, start, &n);
        if (shift < 0) {
                err = shift;
                goto err_umem;
        }

        err = mlx4_mr_alloc(dev->dev, to_mpd(pd)->pdn, virt_addr, length,
                            convert_access(access_flags), n, shift, &mr->mmr);
        if (err)
                goto err_umem;

        err = mlx4_ib_umem_write_mtt(dev, &mr->mmr.mtt, mr->umem);
        if (err)
                goto err_mr;

        err = mlx4_mr_enable(dev->dev, &mr->mmr);
        if (err)
                goto err_mr;

        mr->ibmr.rkey = mr->ibmr.lkey = mr->mmr.key;
        mr->ibmr.page_size = 1U << shift;

        return &mr->ibmr;

err_mr:
        (void) mlx4_mr_free(to_mdev(pd->device)->dev, &mr->mmr);

err_umem:
        ib_umem_release(mr->umem);

err_free:
        kfree(mr);

        return ERR_PTR(err);
}

struct ib_mr *mlx4_ib_rereg_user_mr(struct ib_mr *mr, int flags, u64 start,
                                    u64 length, u64 virt_addr,
                                    int mr_access_flags, struct ib_pd *pd,
                                    struct ib_udata *udata)
{
        struct mlx4_ib_dev *dev = to_mdev(mr->device);
        struct mlx4_ib_mr *mmr = to_mmr(mr);
        struct mlx4_mpt_entry *mpt_entry;
        struct mlx4_mpt_entry **pmpt_entry = &mpt_entry;
        int err;

        /* Since we synchronize this call and mlx4_ib_dereg_mr via uverbs,
         * we assume that the calls can't run concurrently. Otherwise, a
         * race exists.
         */
        err =  mlx4_mr_hw_get_mpt(dev->dev, &mmr->mmr, &pmpt_entry);
        if (err)
                return ERR_PTR(err);

        if (flags & IB_MR_REREG_PD) {
                err = mlx4_mr_hw_change_pd(dev->dev, *pmpt_entry,
                                           to_mpd(pd)->pdn);

                if (err)
                        goto release_mpt_entry;
        }

        if (flags & IB_MR_REREG_ACCESS) {
                if (ib_access_writable(mr_access_flags) &&
                    !mmr->umem->writable) {
                        err = -EPERM;
                        goto release_mpt_entry;
                }

                err = mlx4_mr_hw_change_access(dev->dev, *pmpt_entry,
                                               convert_access(mr_access_flags));

                if (err)
                        goto release_mpt_entry;
        }

        if (flags & IB_MR_REREG_TRANS) {
                int shift;
                int n;

                mlx4_mr_rereg_mem_cleanup(dev->dev, &mmr->mmr);
                ib_umem_release(mmr->umem);
                mmr->umem = mlx4_get_umem_mr(mr->device, start, length,
                                             mr_access_flags);
                if (IS_ERR(mmr->umem)) {
                        err = PTR_ERR(mmr->umem);
                        /* Prevent mlx4_ib_dereg_mr from free'ing invalid pointer */
                        mmr->umem = NULL;
                        goto release_mpt_entry;
                }
                n = ib_umem_num_dma_blocks(mmr->umem, PAGE_SIZE);
                shift = PAGE_SHIFT;

                err = mlx4_mr_rereg_mem_write(dev->dev, &mmr->mmr,
                                              virt_addr, length, n, shift,
                                              *pmpt_entry);
                if (err) {
                        ib_umem_release(mmr->umem);
                        goto release_mpt_entry;
                }
                mmr->mmr.iova       = virt_addr;
                mmr->mmr.size       = length;

                err = mlx4_ib_umem_write_mtt(dev, &mmr->mmr.mtt, mmr->umem);
                if (err) {
                        mlx4_mr_rereg_mem_cleanup(dev->dev, &mmr->mmr);
                        ib_umem_release(mmr->umem);
                        goto release_mpt_entry;
                }
        }

        /* If we couldn't transfer the MR to the HCA, just remember to
         * return a failure. But dereg_mr will free the resources.
         */
        err = mlx4_mr_hw_write_mpt(dev->dev, &mmr->mmr, pmpt_entry);
        if (!err && flags & IB_MR_REREG_ACCESS)
                mmr->mmr.access = mr_access_flags;

release_mpt_entry:
        mlx4_mr_hw_put_mpt(dev->dev, pmpt_entry);
        if (err)
                return ERR_PTR(err);
        return NULL;
}

static int
mlx4_alloc_priv_pages(struct ib_device *device,
                      struct mlx4_ib_mr *mr,
                      int max_pages)
{
        int ret;

        /* Ensure that size is aligned to DMA cacheline
         * requirements.
         * max_pages is limited to MLX4_MAX_FAST_REG_PAGES
         * so page_map_size will never cross PAGE_SIZE.
         */
        mr->page_map_size = roundup(max_pages * sizeof(u64),
                                    MLX4_MR_PAGES_ALIGN);

        /* Prevent cross page boundary allocation. */
        mr->pages = (__be64 *)get_zeroed_page(GFP_KERNEL);
        if (!mr->pages)
                return -ENOMEM;

        mr->page_map = dma_map_single(device->dev.parent, mr->pages,
                                      mr->page_map_size, DMA_TO_DEVICE);

        if (dma_mapping_error(device->dev.parent, mr->page_map)) {
                ret = -ENOMEM;
                goto err;
        }

        return 0;

err:
        free_page((unsigned long)mr->pages);
        return ret;
}

static void
mlx4_free_priv_pages(struct mlx4_ib_mr *mr)
{
        if (mr->pages) {
                struct ib_device *device = mr->ibmr.device;

                dma_unmap_single(device->dev.parent, mr->page_map,
                                 mr->page_map_size, DMA_TO_DEVICE);
                free_page((unsigned long)mr->pages);
                mr->pages = NULL;
        }
}

int mlx4_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
{
        struct mlx4_ib_mr *mr = to_mmr(ibmr);
        int ret;

        mlx4_free_priv_pages(mr);

        ret = mlx4_mr_free(to_mdev(ibmr->device)->dev, &mr->mmr);
        if (ret)
                return ret;
        if (mr->umem)
                ib_umem_release(mr->umem);
        kfree(mr);

        return 0;
}

int mlx4_ib_alloc_mw(struct ib_mw *ibmw, struct ib_udata *udata)
{
        struct mlx4_ib_dev *dev = to_mdev(ibmw->device);
        struct mlx4_ib_mw *mw = to_mmw(ibmw);
        int err;

        err = mlx4_mw_alloc(dev->dev, to_mpd(ibmw->pd)->pdn,
                            to_mlx4_type(ibmw->type), &mw->mmw);
        if (err)
                return err;

        err = mlx4_mw_enable(dev->dev, &mw->mmw);
        if (err)
                goto err_mw;

        ibmw->rkey = mw->mmw.key;
        return 0;

err_mw:
        mlx4_mw_free(dev->dev, &mw->mmw);
        return err;
}

int mlx4_ib_dealloc_mw(struct ib_mw *ibmw)
{
        struct mlx4_ib_mw *mw = to_mmw(ibmw);

        mlx4_mw_free(to_mdev(ibmw->device)->dev, &mw->mmw);
        return 0;
}

struct ib_mr *mlx4_ib_alloc_mr(struct ib_pd *pd, enum ib_mr_type mr_type,
                               u32 max_num_sg)
{
        struct mlx4_ib_dev *dev = to_mdev(pd->device);
        struct mlx4_ib_mr *mr;
        int err;

        if (mr_type != IB_MR_TYPE_MEM_REG ||
            max_num_sg > MLX4_MAX_FAST_REG_PAGES)
                return ERR_PTR(-EINVAL);

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

        err = mlx4_mr_alloc(dev->dev, to_mpd(pd)->pdn, 0, 0, 0,
                            max_num_sg, 0, &mr->mmr);
        if (err)
                goto err_free;

        err = mlx4_alloc_priv_pages(pd->device, mr, max_num_sg);
        if (err)
                goto err_free_mr;

        mr->max_pages = max_num_sg;
        err = mlx4_mr_enable(dev->dev, &mr->mmr);
        if (err)
                goto err_free_pl;

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

        return &mr->ibmr;

err_free_pl:
        mr->ibmr.device = pd->device;
        mlx4_free_priv_pages(mr);
err_free_mr:
        (void) mlx4_mr_free(dev->dev, &mr->mmr);
err_free:
        kfree(mr);
        return ERR_PTR(err);
}

static int mlx4_set_page(struct ib_mr *ibmr, u64 addr)
{
        struct mlx4_ib_mr *mr = to_mmr(ibmr);

        if (unlikely(mr->npages == mr->max_pages))
                return -ENOMEM;

        mr->pages[mr->npages++] = cpu_to_be64(addr | MLX4_MTT_FLAG_PRESENT);

        return 0;
}

int mlx4_ib_map_mr_sg(struct ib_mr *ibmr, struct scatterlist *sg, int sg_nents,
                      unsigned int *sg_offset)
{
        struct mlx4_ib_mr *mr = to_mmr(ibmr);
        int rc;

        mr->npages = 0;

        ib_dma_sync_single_for_cpu(ibmr->device, mr->page_map,
                                   mr->page_map_size, DMA_TO_DEVICE);

        rc = ib_sg_to_pages(ibmr, sg, sg_nents, sg_offset, mlx4_set_page);

        ib_dma_sync_single_for_device(ibmr->device, mr->page_map,
                                      mr->page_map_size, DMA_TO_DEVICE);

        return rc;
}