Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

[cris-mirror.git] / drivers / infiniband / hw / mlx4 / mr.c

/*
 * 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(sizeof(*mr), GFP_KERNEL);
        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);
}

enum {
        MLX4_MAX_MTT_SHIFT = 31
};

static int mlx4_ib_umem_write_mtt_block(struct mlx4_ib_dev *dev,
                                        struct mlx4_mtt *mtt,
                                        u64 mtt_size, u64 mtt_shift, u64 len,
                                        u64 cur_start_addr, u64 *pages,
                                        int *start_index, int *npages)
{
        u64 cur_end_addr = cur_start_addr + len;
        u64 cur_end_addr_aligned = 0;
        u64 mtt_entries;
        int err = 0;
        int k;

        len += (cur_start_addr & (mtt_size - 1ULL));
        cur_end_addr_aligned = round_up(cur_end_addr, mtt_size);
        len += (cur_end_addr_aligned - cur_end_addr);
        if (len & (mtt_size - 1ULL)) {
                pr_warn("write_block: len %llx is not aligned to mtt_size %llx\n",
                        len, mtt_size);
                return -EINVAL;
        }

        mtt_entries = (len >> mtt_shift);

        /*
         * Align the MTT start address to the mtt_size.
         * Required to handle cases when the MR starts in the middle of an MTT
         * record. Was not required in old code since the physical addresses
         * provided by the dma subsystem were page aligned, which was also the
         * MTT size.
         */
        cur_start_addr = round_down(cur_start_addr, mtt_size);
        /* A new block is started ... */
        for (k = 0; k < mtt_entries; ++k) {
                pages[*npages] = cur_start_addr + (mtt_size * k);
                (*npages)++;
                /*
                 * Be friendly to mlx4_write_mtt() and pass it chunks of
                 * appropriate size.
                 */
                if (*npages == PAGE_SIZE / sizeof(u64)) {
                        err = mlx4_write_mtt(dev->dev, mtt, *start_index,
                                             *npages, pages);
                        if (err)
                                return err;

                        (*start_index) += *npages;
                        *npages = 0;
                }
        }

        return 0;
}

static inline u64 alignment_of(u64 ptr)
{
        return ilog2(ptr & (~(ptr - 1)));
}

static int mlx4_ib_umem_calc_block_mtt(u64 next_block_start,
                                       u64 current_block_end,
                                       u64 block_shift)
{
        /* Check whether the alignment of the new block is aligned as well as
         * the previous block.
         * Block address must start with zeros till size of entity_size.
         */
        if ((next_block_start & ((1ULL << block_shift) - 1ULL)) != 0)
                /*
                 * It is not as well aligned as the previous block-reduce the
                 * mtt size accordingly. Here we take the last right bit which
                 * is 1.
                 */
                block_shift = alignment_of(next_block_start);

        /*
         * Check whether the alignment of the end of previous block - is it
         * aligned as well as the start of the block
         */
        if (((current_block_end) & ((1ULL << block_shift) - 1ULL)) != 0)
                /*
                 * It is not as well aligned as the start of the block -
                 * reduce the mtt size accordingly.
                 */
                block_shift = alignment_of(current_block_end);

        return block_shift;
}

int mlx4_ib_umem_write_mtt(struct mlx4_ib_dev *dev, struct mlx4_mtt *mtt,
                           struct ib_umem *umem)
{
        u64 *pages;
        u64 len = 0;
        int err = 0;
        u64 mtt_size;
        u64 cur_start_addr = 0;
        u64 mtt_shift;
        int start_index = 0;
        int npages = 0;
        struct scatterlist *sg;
        int i;

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

        mtt_shift = mtt->page_shift;
        mtt_size = 1ULL << mtt_shift;

        for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) {
                if (cur_start_addr + len == sg_dma_address(sg)) {
                        /* still the same block */
                        len += sg_dma_len(sg);
                        continue;
                }
                /*
                 * A new block is started ...
                 * If len is malaligned, write an extra mtt entry to cover the
                 * misaligned area (round up the division)
                 */
                err = mlx4_ib_umem_write_mtt_block(dev, mtt, mtt_size,
                                                   mtt_shift, len,
                                                   cur_start_addr,
                                                   pages, &start_index,
                                                   &npages);
                if (err)
                        goto out;

                cur_start_addr = sg_dma_address(sg);
                len = sg_dma_len(sg);
        }

        /* Handle the last block */
        if (len > 0) {
                /*
                 * If len is malaligned, write an extra mtt entry to cover
                 * the misaligned area (round up the division)
                 */
                err = mlx4_ib_umem_write_mtt_block(dev, mtt, mtt_size,
                                                   mtt_shift, len,
                                                   cur_start_addr, pages,
                                                   &start_index, &npages);
                if (err)
                        goto out;
        }

        if (npages)
                err = mlx4_write_mtt(dev->dev, mtt, start_index, npages, pages);

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

/*
 * Calculate optimal mtt size based on contiguous pages.
 * Function will return also the number of pages that are not aligned to the
 * calculated mtt_size to be added to total number of pages. For that we should
 * check the first chunk length & last chunk length and if not aligned to
 * mtt_size we should increment the non_aligned_pages number. All chunks in the
 * middle already handled as part of mtt shift calculation for both their start
 * & end addresses.
 */
int mlx4_ib_umem_calc_optimal_mtt_size(struct ib_umem *umem, u64 start_va,
                                       int *num_of_mtts)
{
        u64 block_shift = MLX4_MAX_MTT_SHIFT;
        u64 min_shift = umem->page_shift;
        u64 last_block_aligned_end = 0;
        u64 current_block_start = 0;
        u64 first_block_start = 0;
        u64 current_block_len = 0;
        u64 last_block_end = 0;
        struct scatterlist *sg;
        u64 current_block_end;
        u64 misalignment_bits;
        u64 next_block_start;
        u64 total_len = 0;
        int i;

        for_each_sg(umem->sg_head.sgl, sg, umem->nmap, i) {
                /*
                 * Initialization - save the first chunk start as the
                 * current_block_start - block means contiguous pages.
                 */
                if (current_block_len == 0 && current_block_start == 0) {
                        current_block_start = sg_dma_address(sg);
                        first_block_start = current_block_start;
                        /*
                         * Find the bits that are different between the physical
                         * address and the virtual address for the start of the
                         * MR.
                         * umem_get aligned the start_va to a page boundary.
                         * Therefore, we need to align the start va to the same
                         * boundary.
                         * misalignment_bits is needed to handle the  case of a
                         * single memory region. In this case, the rest of the
                         * logic will not reduce the block size.  If we use a
                         * block size which is bigger than the alignment of the
                         * misalignment bits, we might use the virtual page
                         * number instead of the physical page number, resulting
                         * in access to the wrong data.
                         */
                        misalignment_bits =
                        (start_va & (~(((u64)(BIT(umem->page_shift))) - 1ULL)))
                        ^ current_block_start;
                        block_shift = min(alignment_of(misalignment_bits),
                                          block_shift);
                }

                /*
                 * Go over the scatter entries and check if they continue the
                 * previous scatter entry.
                 */
                next_block_start = sg_dma_address(sg);
                current_block_end = current_block_start + current_block_len;
                /* If we have a split (non-contig.) between two blocks */
                if (current_block_end != next_block_start) {
                        block_shift = mlx4_ib_umem_calc_block_mtt
                                        (next_block_start,
                                         current_block_end,
                                         block_shift);

                        /*
                         * If we reached the minimum shift for 4k page we stop
                         * the loop.
                         */
                        if (block_shift <= min_shift)
                                goto end;

                        /*
                         * If not saved yet we are in first block - we save the
                         * length of first block to calculate the
                         * non_aligned_pages number at the end.
                         */
                        total_len += current_block_len;

                        /* Start a new block */
                        current_block_start = next_block_start;
                        current_block_len = sg_dma_len(sg);
                        continue;
                }
                /* The scatter entry is another part of the current block,
                 * increase the block size.
                 * An entry in the scatter can be larger than 4k (page) as of
                 * dma mapping which merge some blocks together.
                 */
                current_block_len += sg_dma_len(sg);
        }

        /* Account for the last block in the total len */
        total_len += current_block_len;
        /* Add to the first block the misalignment that it suffers from. */
        total_len += (first_block_start & ((1ULL << block_shift) - 1ULL));
        last_block_end = current_block_start + current_block_len;
        last_block_aligned_end = round_up(last_block_end, 1 << block_shift);
        total_len += (last_block_aligned_end - last_block_end);

        if (total_len & ((1ULL << block_shift) - 1ULL))
                pr_warn("misaligned total length detected (%llu, %llu)!",
                        total_len, block_shift);

        *num_of_mtts = total_len >> block_shift;
end:
        if (block_shift < min_shift) {
                /*
                 * If shift is less than the min we set a warning and return the
                 * min shift.
                 */
                pr_warn("umem_calc_optimal_mtt_size - unexpected shift %lld\n", block_shift);

                block_shift = min_shift;
        }
        return block_shift;
}

struct ib_mr *mlx4_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
                                  u64 virt_addr, int access_flags,
                                  struct ib_udata *udata)
{
        struct mlx4_ib_dev *dev = to_mdev(pd->device);
        struct mlx4_ib_mr *mr;
        int shift;
        int err;
        int n;

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

        /* Force registering the memory as writable. */
        /* Used for memory re-registeration. HCA protects the access */
        mr->umem = ib_umem_get(pd->uobject->context, start, length,
                               access_flags | IB_ACCESS_LOCAL_WRITE, 0);
        if (IS_ERR(mr->umem)) {
                err = PTR_ERR(mr->umem);
                goto err_free;
        }

        n = ib_umem_page_count(mr->umem);
        shift = mlx4_ib_umem_calc_optimal_mtt_size(mr->umem, start, &n);

        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;

        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);
}

int 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;

        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) {
                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 = ib_umem_get(mr->uobject->context, start, length,
                                        mr_access_flags |
                                        IB_ACCESS_LOCAL_WRITE,
                                        0);
                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_page_count(mmr->umem);
                shift = mmr->umem->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);

        return err;
}

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 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;
}

struct ib_mw *mlx4_ib_alloc_mw(struct ib_pd *pd, enum ib_mw_type type,
                               struct ib_udata *udata)
{
        struct mlx4_ib_dev *dev = to_mdev(pd->device);
        struct mlx4_ib_mw *mw;
        int err;

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

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

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

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

        return &mw->ibmw;

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

err_free:
        kfree(mw);

        return ERR_PTR(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);
        kfree(mw);

        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(sizeof(*mr), GFP_KERNEL);
        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);
}

struct ib_fmr *mlx4_ib_fmr_alloc(struct ib_pd *pd, int acc,
                                 struct ib_fmr_attr *fmr_attr)
{
        struct mlx4_ib_dev *dev = to_mdev(pd->device);
        struct mlx4_ib_fmr *fmr;
        int err = -ENOMEM;

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

        err = mlx4_fmr_alloc(dev->dev, to_mpd(pd)->pdn, convert_access(acc),
                             fmr_attr->max_pages, fmr_attr->max_maps,
                             fmr_attr->page_shift, &fmr->mfmr);
        if (err)
                goto err_free;

        err = mlx4_fmr_enable(to_mdev(pd->device)->dev, &fmr->mfmr);
        if (err)
                goto err_mr;

        fmr->ibfmr.rkey = fmr->ibfmr.lkey = fmr->mfmr.mr.key;

        return &fmr->ibfmr;

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

err_free:
        kfree(fmr);

        return ERR_PTR(err);
}

int mlx4_ib_map_phys_fmr(struct ib_fmr *ibfmr, u64 *page_list,
                      int npages, u64 iova)
{
        struct mlx4_ib_fmr *ifmr = to_mfmr(ibfmr);
        struct mlx4_ib_dev *dev = to_mdev(ifmr->ibfmr.device);

        return mlx4_map_phys_fmr(dev->dev, &ifmr->mfmr, page_list, npages, iova,
                                 &ifmr->ibfmr.lkey, &ifmr->ibfmr.rkey);
}

int mlx4_ib_unmap_fmr(struct list_head *fmr_list)
{
        struct ib_fmr *ibfmr;
        int err;
        struct mlx4_dev *mdev = NULL;

        list_for_each_entry(ibfmr, fmr_list, list) {
                if (mdev && to_mdev(ibfmr->device)->dev != mdev)
                        return -EINVAL;
                mdev = to_mdev(ibfmr->device)->dev;
        }

        if (!mdev)
                return 0;

        list_for_each_entry(ibfmr, fmr_list, list) {
                struct mlx4_ib_fmr *ifmr = to_mfmr(ibfmr);

                mlx4_fmr_unmap(mdev, &ifmr->mfmr, &ifmr->ibfmr.lkey, &ifmr->ibfmr.rkey);
        }

        /*
         * Make sure all MPT status updates are visible before issuing
         * SYNC_TPT firmware command.
         */
        wmb();

        err = mlx4_SYNC_TPT(mdev);
        if (err)
                pr_warn("SYNC_TPT error %d when "
                       "unmapping FMRs\n", err);

        return 0;
}

int mlx4_ib_fmr_dealloc(struct ib_fmr *ibfmr)
{
        struct mlx4_ib_fmr *ifmr = to_mfmr(ibfmr);
        struct mlx4_ib_dev *dev = to_mdev(ibfmr->device);
        int err;

        err = mlx4_fmr_free(dev->dev, &ifmr->mfmr);

        if (!err)
                kfree(ifmr);

        return 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;
}