/*
 * Copyright (c) 2013-2015, 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/kref.h>
#include <linux/random.h>
#include <linux/debugfs.h>
#include <linux/export.h>
#include <linux/delay.h>
#include <rdma/ib_umem.h>
#include <rdma/ib_umem_odp.h>
#include <rdma/ib_verbs.h>
#include "mlx5_ib.h"

enum {
        MAX_PENDING_REG_MR = 8,
};

#define MLX5_UMR_ALIGN 2048

static void clean_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr);
static void dereg_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr);
static int mr_cache_max_order(struct mlx5_ib_dev *dev);

static bool umr_can_use_indirect_mkey(struct mlx5_ib_dev *dev)
{
        return !MLX5_CAP_GEN(dev->mdev, umr_indirect_mkey_disabled);
}

static int destroy_mkey(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
{
        WARN_ON(xa_load(&dev->odp_mkeys, mlx5_base_mkey(mr->mmkey.key)));

        return mlx5_core_destroy_mkey(dev->mdev, &mr->mmkey);
}

static int order2idx(struct mlx5_ib_dev *dev, int order)
{
        struct mlx5_mr_cache *cache = &dev->cache;

        if (order < cache->ent[0].order)
                return 0;
        else
                return order - cache->ent[0].order;
}

static bool use_umr_mtt_update(struct mlx5_ib_mr *mr, u64 start, u64 length)
{
        return ((u64)1 << mr->order) * MLX5_ADAPTER_PAGE_SIZE >=
                length + (start & (MLX5_ADAPTER_PAGE_SIZE - 1));
}

static void reg_mr_callback(int status, struct mlx5_async_work *context)
{
        struct mlx5_ib_mr *mr =
                container_of(context, struct mlx5_ib_mr, cb_work);
        struct mlx5_ib_dev *dev = mr->dev;
        struct mlx5_mr_cache *cache = &dev->cache;
        int c = order2idx(dev, mr->order);
        struct mlx5_cache_ent *ent = &cache->ent[c];
        u8 key;
        unsigned long flags;

        spin_lock_irqsave(&ent->lock, flags);
        ent->pending--;
        spin_unlock_irqrestore(&ent->lock, flags);
        if (status) {
                mlx5_ib_warn(dev, "async reg mr failed. status %d\n", status);
                kfree(mr);
                dev->fill_delay = 1;
                mod_timer(&dev->delay_timer, jiffies + HZ);
                return;
        }

        mr->mmkey.type = MLX5_MKEY_MR;
        spin_lock_irqsave(&dev->mdev->priv.mkey_lock, flags);
        key = dev->mdev->priv.mkey_key++;
        spin_unlock_irqrestore(&dev->mdev->priv.mkey_lock, flags);
        mr->mmkey.key = mlx5_idx_to_mkey(MLX5_GET(create_mkey_out, mr->out, mkey_index)) | key;

        cache->last_add = jiffies;

        spin_lock_irqsave(&ent->lock, flags);
        list_add_tail(&mr->list, &ent->head);
        ent->cur++;
        ent->size++;
        spin_unlock_irqrestore(&ent->lock, flags);

        if (!completion_done(&ent->compl))
                complete(&ent->compl);
}

static int add_keys(struct mlx5_ib_dev *dev, int c, int num)
{
        struct mlx5_mr_cache *cache = &dev->cache;
        struct mlx5_cache_ent *ent = &cache->ent[c];
        int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
        struct mlx5_ib_mr *mr;
        void *mkc;
        u32 *in;
        int err = 0;
        int i;

        in = kzalloc(inlen, GFP_KERNEL);
        if (!in)
                return -ENOMEM;

        mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
        for (i = 0; i < num; i++) {
                if (ent->pending >= MAX_PENDING_REG_MR) {
                        err = -EAGAIN;
                        break;
                }

                mr = kzalloc(sizeof(*mr), GFP_KERNEL);
                if (!mr) {
                        err = -ENOMEM;
                        break;
                }
                mr->order = ent->order;
                mr->allocated_from_cache = true;
                mr->dev = dev;

                MLX5_SET(mkc, mkc, free, 1);
                MLX5_SET(mkc, mkc, umr_en, 1);
                MLX5_SET(mkc, mkc, access_mode_1_0, ent->access_mode & 0x3);
                MLX5_SET(mkc, mkc, access_mode_4_2,
                         (ent->access_mode >> 2) & 0x7);

                MLX5_SET(mkc, mkc, qpn, 0xffffff);
                MLX5_SET(mkc, mkc, translations_octword_size, ent->xlt);
                MLX5_SET(mkc, mkc, log_page_size, ent->page);

                spin_lock_irq(&ent->lock);
                ent->pending++;
                spin_unlock_irq(&ent->lock);
                err = mlx5_core_create_mkey_cb(dev->mdev, &mr->mmkey,
                                               &dev->async_ctx, in, inlen,
                                               mr->out, sizeof(mr->out),
                                               reg_mr_callback, &mr->cb_work);
                if (err) {
                        spin_lock_irq(&ent->lock);
                        ent->pending--;
                        spin_unlock_irq(&ent->lock);
                        mlx5_ib_warn(dev, "create mkey failed %d\n", err);
                        kfree(mr);
                        break;
                }
        }

        kfree(in);
        return err;
}

static void remove_keys(struct mlx5_ib_dev *dev, int c, int num)
{
        struct mlx5_mr_cache *cache = &dev->cache;
        struct mlx5_cache_ent *ent = &cache->ent[c];
        struct mlx5_ib_mr *tmp_mr;
        struct mlx5_ib_mr *mr;
        LIST_HEAD(del_list);
        int i;

        for (i = 0; i < num; i++) {
                spin_lock_irq(&ent->lock);
                if (list_empty(&ent->head)) {
                        spin_unlock_irq(&ent->lock);
                        break;
                }
                mr = list_first_entry(&ent->head, struct mlx5_ib_mr, list);
                list_move(&mr->list, &del_list);
                ent->cur--;
                ent->size--;
                spin_unlock_irq(&ent->lock);
                mlx5_core_destroy_mkey(dev->mdev, &mr->mmkey);
        }

        list_for_each_entry_safe(mr, tmp_mr, &del_list, list) {
                list_del(&mr->list);
                kfree(mr);
        }
}

static ssize_t size_write(struct file *filp, const char __user *buf,
                          size_t count, loff_t *pos)
{
        struct mlx5_cache_ent *ent = filp->private_data;
        struct mlx5_ib_dev *dev = ent->dev;
        char lbuf[20] = {0};
        u32 var;
        int err;
        int c;

        count = min(count, sizeof(lbuf) - 1);
        if (copy_from_user(lbuf, buf, count))
                return -EFAULT;

        c = order2idx(dev, ent->order);

        if (sscanf(lbuf, "%u", &var) != 1)
                return -EINVAL;

        if (var < ent->limit)
                return -EINVAL;

        if (var > ent->size) {
                do {
                        err = add_keys(dev, c, var - ent->size);
                        if (err && err != -EAGAIN)
                                return err;

                        usleep_range(3000, 5000);
                } while (err);
        } else if (var < ent->size) {
                remove_keys(dev, c, ent->size - var);
        }

        return count;
}

static ssize_t size_read(struct file *filp, char __user *buf, size_t count,
                         loff_t *pos)
{
        struct mlx5_cache_ent *ent = filp->private_data;
        char lbuf[20];
        int err;

        err = snprintf(lbuf, sizeof(lbuf), "%d\n", ent->size);
        if (err < 0)
                return err;

        return simple_read_from_buffer(buf, count, pos, lbuf, err);
}

static const struct file_operations size_fops = {
        .owner  = THIS_MODULE,
        .open   = simple_open,
        .write  = size_write,
        .read   = size_read,
};

static ssize_t limit_write(struct file *filp, const char __user *buf,
                           size_t count, loff_t *pos)
{
        struct mlx5_cache_ent *ent = filp->private_data;
        struct mlx5_ib_dev *dev = ent->dev;
        char lbuf[20] = {0};
        u32 var;
        int err;
        int c;

        count = min(count, sizeof(lbuf) - 1);
        if (copy_from_user(lbuf, buf, count))
                return -EFAULT;

        c = order2idx(dev, ent->order);

        if (sscanf(lbuf, "%u", &var) != 1)
                return -EINVAL;

        if (var > ent->size)
                return -EINVAL;

        ent->limit = var;

        if (ent->cur < ent->limit) {
                err = add_keys(dev, c, 2 * ent->limit - ent->cur);
                if (err)
                        return err;
        }

        return count;
}

static ssize_t limit_read(struct file *filp, char __user *buf, size_t count,
                          loff_t *pos)
{
        struct mlx5_cache_ent *ent = filp->private_data;
        char lbuf[20];
        int err;

        err = snprintf(lbuf, sizeof(lbuf), "%d\n", ent->limit);
        if (err < 0)
                return err;

        return simple_read_from_buffer(buf, count, pos, lbuf, err);
}

static const struct file_operations limit_fops = {
        .owner  = THIS_MODULE,
        .open   = simple_open,
        .write  = limit_write,
        .read   = limit_read,
};

static int someone_adding(struct mlx5_mr_cache *cache)
{
        int i;

        for (i = 0; i < MAX_MR_CACHE_ENTRIES; i++) {
                if (cache->ent[i].cur < cache->ent[i].limit)
                        return 1;
        }

        return 0;
}

static void __cache_work_func(struct mlx5_cache_ent *ent)
{
        struct mlx5_ib_dev *dev = ent->dev;
        struct mlx5_mr_cache *cache = &dev->cache;
        int i = order2idx(dev, ent->order);
        int err;

        if (cache->stopped)
                return;

        ent = &dev->cache.ent[i];
        if (ent->cur < 2 * ent->limit && !dev->fill_delay) {
                err = add_keys(dev, i, 1);
                if (ent->cur < 2 * ent->limit) {
                        if (err == -EAGAIN) {
                                mlx5_ib_dbg(dev, "returned eagain, order %d\n",
                                            i + 2);
                                queue_delayed_work(cache->wq, &ent->dwork,
                                                   msecs_to_jiffies(3));
                        } else if (err) {
                                mlx5_ib_warn(dev, "command failed order %d, err %d\n",
                                             i + 2, err);
                                queue_delayed_work(cache->wq, &ent->dwork,
                                                   msecs_to_jiffies(1000));
                        } else {
                                queue_work(cache->wq, &ent->work);
                        }
                }
        } else if (ent->cur > 2 * ent->limit) {
                /*
                 * The remove_keys() logic is performed as garbage collection
                 * task. Such task is intended to be run when no other active
                 * processes are running.
                 *
                 * The need_resched() will return TRUE if there are user tasks
                 * to be activated in near future.
                 *
                 * In such case, we don't execute remove_keys() and postpone
                 * the garbage collection work to try to run in next cycle,
                 * in order to free CPU resources to other tasks.
                 */
                if (!need_resched() && !someone_adding(cache) &&
                    time_after(jiffies, cache->last_add + 300 * HZ)) {
                        remove_keys(dev, i, 1);
                        if (ent->cur > ent->limit)
                                queue_work(cache->wq, &ent->work);
                } else {
                        queue_delayed_work(cache->wq, &ent->dwork, 300 * HZ);
                }
        }
}

static void delayed_cache_work_func(struct work_struct *work)
{
        struct mlx5_cache_ent *ent;

        ent = container_of(work, struct mlx5_cache_ent, dwork.work);
        __cache_work_func(ent);
}

static void cache_work_func(struct work_struct *work)
{
        struct mlx5_cache_ent *ent;

        ent = container_of(work, struct mlx5_cache_ent, work);
        __cache_work_func(ent);
}

struct mlx5_ib_mr *mlx5_mr_cache_alloc(struct mlx5_ib_dev *dev, int entry)
{
        struct mlx5_mr_cache *cache = &dev->cache;
        struct mlx5_cache_ent *ent;
        struct mlx5_ib_mr *mr;
        int err;

        if (entry < 0 || entry >= MAX_MR_CACHE_ENTRIES) {
                mlx5_ib_err(dev, "cache entry %d is out of range\n", entry);
                return ERR_PTR(-EINVAL);
        }

        ent = &cache->ent[entry];
        while (1) {
                spin_lock_irq(&ent->lock);
                if (list_empty(&ent->head)) {
                        spin_unlock_irq(&ent->lock);

                        err = add_keys(dev, entry, 1);
                        if (err && err != -EAGAIN)
                                return ERR_PTR(err);

                        wait_for_completion(&ent->compl);
                } else {
                        mr = list_first_entry(&ent->head, struct mlx5_ib_mr,
                                              list);
                        list_del(&mr->list);
                        ent->cur--;
                        spin_unlock_irq(&ent->lock);
                        if (ent->cur < ent->limit)
                                queue_work(cache->wq, &ent->work);
                        return mr;
                }
        }
}

static struct mlx5_ib_mr *alloc_cached_mr(struct mlx5_ib_dev *dev, int order)
{
        struct mlx5_mr_cache *cache = &dev->cache;
        struct mlx5_ib_mr *mr = NULL;
        struct mlx5_cache_ent *ent;
        int last_umr_cache_entry;
        int c;
        int i;

        c = order2idx(dev, order);
        last_umr_cache_entry = order2idx(dev, mr_cache_max_order(dev));
        if (c < 0 || c > last_umr_cache_entry) {
                mlx5_ib_warn(dev, "order %d, cache index %d\n", order, c);
                return NULL;
        }

        for (i = c; i <= last_umr_cache_entry; i++) {
                ent = &cache->ent[i];

                mlx5_ib_dbg(dev, "order %d, cache index %d\n", ent->order, i);

                spin_lock_irq(&ent->lock);
                if (!list_empty(&ent->head)) {
                        mr = list_first_entry(&ent->head, struct mlx5_ib_mr,
                                              list);
                        list_del(&mr->list);
                        ent->cur--;
                        spin_unlock_irq(&ent->lock);
                        if (ent->cur < ent->limit)
                                queue_work(cache->wq, &ent->work);
                        break;
                }
                spin_unlock_irq(&ent->lock);

                queue_work(cache->wq, &ent->work);
        }

        if (!mr)
                cache->ent[c].miss++;

        return mr;
}

void mlx5_mr_cache_free(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
{
        struct mlx5_mr_cache *cache = &dev->cache;
        struct mlx5_cache_ent *ent;
        int shrink = 0;
        int c;

        if (!mr->allocated_from_cache)
                return;

        c = order2idx(dev, mr->order);
        WARN_ON(c < 0 || c >= MAX_MR_CACHE_ENTRIES);

        if (mlx5_mr_cache_invalidate(mr)) {
                mr->allocated_from_cache = false;
                destroy_mkey(dev, mr);
                ent = &cache->ent[c];
                if (ent->cur < ent->limit)
                        queue_work(cache->wq, &ent->work);
                return;
        }

        ent = &cache->ent[c];
        spin_lock_irq(&ent->lock);
        list_add_tail(&mr->list, &ent->head);
        ent->cur++;
        if (ent->cur > 2 * ent->limit)
                shrink = 1;
        spin_unlock_irq(&ent->lock);

        if (shrink)
                queue_work(cache->wq, &ent->work);
}

static void clean_keys(struct mlx5_ib_dev *dev, int c)
{
        struct mlx5_mr_cache *cache = &dev->cache;
        struct mlx5_cache_ent *ent = &cache->ent[c];
        struct mlx5_ib_mr *tmp_mr;
        struct mlx5_ib_mr *mr;
        LIST_HEAD(del_list);

        cancel_delayed_work(&ent->dwork);
        while (1) {
                spin_lock_irq(&ent->lock);
                if (list_empty(&ent->head)) {
                        spin_unlock_irq(&ent->lock);
                        break;
                }
                mr = list_first_entry(&ent->head, struct mlx5_ib_mr, list);
                list_move(&mr->list, &del_list);
                ent->cur--;
                ent->size--;
                spin_unlock_irq(&ent->lock);
                mlx5_core_destroy_mkey(dev->mdev, &mr->mmkey);
        }

        list_for_each_entry_safe(mr, tmp_mr, &del_list, list) {
                list_del(&mr->list);
                kfree(mr);
        }
}

static void mlx5_mr_cache_debugfs_cleanup(struct mlx5_ib_dev *dev)
{
        if (!mlx5_debugfs_root || dev->is_rep)
                return;

        debugfs_remove_recursive(dev->cache.root);
        dev->cache.root = NULL;
}

static void mlx5_mr_cache_debugfs_init(struct mlx5_ib_dev *dev)
{
        struct mlx5_mr_cache *cache = &dev->cache;
        struct mlx5_cache_ent *ent;
        struct dentry *dir;
        int i;

        if (!mlx5_debugfs_root || dev->is_rep)
                return;

        cache->root = debugfs_create_dir("mr_cache", dev->mdev->priv.dbg_root);

        for (i = 0; i < MAX_MR_CACHE_ENTRIES; i++) {
                ent = &cache->ent[i];
                sprintf(ent->name, "%d", ent->order);
                dir = debugfs_create_dir(ent->name, cache->root);
                debugfs_create_file("size", 0600, dir, ent, &size_fops);
                debugfs_create_file("limit", 0600, dir, ent, &limit_fops);
                debugfs_create_u32("cur", 0400, dir, &ent->cur);
                debugfs_create_u32("miss", 0600, dir, &ent->miss);
        }
}

static void delay_time_func(struct timer_list *t)
{
        struct mlx5_ib_dev *dev = from_timer(dev, t, delay_timer);

        dev->fill_delay = 0;
}

int mlx5_mr_cache_init(struct mlx5_ib_dev *dev)
{
        struct mlx5_mr_cache *cache = &dev->cache;
        struct mlx5_cache_ent *ent;
        int i;

        mutex_init(&dev->slow_path_mutex);
        cache->wq = alloc_ordered_workqueue("mkey_cache", WQ_MEM_RECLAIM);
        if (!cache->wq) {
                mlx5_ib_warn(dev, "failed to create work queue\n");
                return -ENOMEM;
        }

        mlx5_cmd_init_async_ctx(dev->mdev, &dev->async_ctx);
        timer_setup(&dev->delay_timer, delay_time_func, 0);
        for (i = 0; i < MAX_MR_CACHE_ENTRIES; i++) {
                ent = &cache->ent[i];
                INIT_LIST_HEAD(&ent->head);
                spin_lock_init(&ent->lock);
                ent->order = i + 2;
                ent->dev = dev;
                ent->limit = 0;

                init_completion(&ent->compl);
                INIT_WORK(&ent->work, cache_work_func);
                INIT_DELAYED_WORK(&ent->dwork, delayed_cache_work_func);

                if (i > MR_CACHE_LAST_STD_ENTRY) {
                        mlx5_odp_init_mr_cache_entry(ent);
                        continue;
                }

                if (ent->order > mr_cache_max_order(dev))
                        continue;

                ent->page = PAGE_SHIFT;
                ent->xlt = (1 << ent->order) * sizeof(struct mlx5_mtt) /
                           MLX5_IB_UMR_OCTOWORD;
                ent->access_mode = MLX5_MKC_ACCESS_MODE_MTT;
                if ((dev->mdev->profile->mask & MLX5_PROF_MASK_MR_CACHE) &&
                    !dev->is_rep &&
                    mlx5_core_is_pf(dev->mdev))
                        ent->limit = dev->mdev->profile->mr_cache[i].limit;
                else
                        ent->limit = 0;
                queue_work(cache->wq, &ent->work);
        }

        mlx5_mr_cache_debugfs_init(dev);

        return 0;
}

int mlx5_mr_cache_cleanup(struct mlx5_ib_dev *dev)
{
        int i;

        if (!dev->cache.wq)
                return 0;

        dev->cache.stopped = 1;
        flush_workqueue(dev->cache.wq);

        mlx5_mr_cache_debugfs_cleanup(dev);
        mlx5_cmd_cleanup_async_ctx(&dev->async_ctx);

        for (i = 0; i < MAX_MR_CACHE_ENTRIES; i++)
                clean_keys(dev, i);

        destroy_workqueue(dev->cache.wq);
        del_timer_sync(&dev->delay_timer);

        return 0;
}

static void set_mkc_access_pd_addr_fields(void *mkc, int acc, u64 start_addr,
                                          struct ib_pd *pd)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);

        MLX5_SET(mkc, mkc, a, !!(acc & IB_ACCESS_REMOTE_ATOMIC));
        MLX5_SET(mkc, mkc, rw, !!(acc & IB_ACCESS_REMOTE_WRITE));
        MLX5_SET(mkc, mkc, rr, !!(acc & IB_ACCESS_REMOTE_READ));
        MLX5_SET(mkc, mkc, lw, !!(acc & IB_ACCESS_LOCAL_WRITE));
        MLX5_SET(mkc, mkc, lr, 1);

        if (MLX5_CAP_GEN(dev->mdev, relaxed_ordering_write))
                MLX5_SET(mkc, mkc, relaxed_ordering_write,
                         !!(acc & IB_ACCESS_RELAXED_ORDERING));
        if (MLX5_CAP_GEN(dev->mdev, relaxed_ordering_read))
                MLX5_SET(mkc, mkc, relaxed_ordering_read,
                         !!(acc & IB_ACCESS_RELAXED_ORDERING));

        MLX5_SET(mkc, mkc, pd, to_mpd(pd)->pdn);
        MLX5_SET(mkc, mkc, qpn, 0xffffff);
        MLX5_SET64(mkc, mkc, start_addr, start_addr);
}

struct ib_mr *mlx5_ib_get_dma_mr(struct ib_pd *pd, int acc)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
        struct mlx5_core_dev *mdev = dev->mdev;
        struct mlx5_ib_mr *mr;
        void *mkc;
        u32 *in;
        int err;

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

        in = kzalloc(inlen, GFP_KERNEL);
        if (!in) {
                err = -ENOMEM;
                goto err_free;
        }

        mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);

        MLX5_SET(mkc, mkc, access_mode_1_0, MLX5_MKC_ACCESS_MODE_PA);
        MLX5_SET(mkc, mkc, length64, 1);
        set_mkc_access_pd_addr_fields(mkc, acc, 0, pd);

        err = mlx5_core_create_mkey(mdev, &mr->mmkey, in, inlen);
        if (err)
                goto err_in;

        kfree(in);
        mr->mmkey.type = MLX5_MKEY_MR;
        mr->ibmr.lkey = mr->mmkey.key;
        mr->ibmr.rkey = mr->mmkey.key;
        mr->umem = NULL;

        return &mr->ibmr;

err_in:
        kfree(in);

err_free:
        kfree(mr);

        return ERR_PTR(err);
}

static int get_octo_len(u64 addr, u64 len, int page_shift)
{
        u64 page_size = 1ULL << page_shift;
        u64 offset;
        int npages;

        offset = addr & (page_size - 1);
        npages = ALIGN(len + offset, page_size) >> page_shift;
        return (npages + 1) / 2;
}

static int mr_cache_max_order(struct mlx5_ib_dev *dev)
{
        if (MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset))
                return MR_CACHE_LAST_STD_ENTRY + 2;
        return MLX5_MAX_UMR_SHIFT;
}

static int mr_umem_get(struct mlx5_ib_dev *dev, u64 start, u64 length,
                       int access_flags, struct ib_umem **umem, int *npages,
                       int *page_shift, int *ncont, int *order)
{
        struct ib_umem *u;

        *umem = NULL;

        if (access_flags & IB_ACCESS_ON_DEMAND) {
                struct ib_umem_odp *odp;

                odp = ib_umem_odp_get(&dev->ib_dev, start, length, access_flags,
                                      &mlx5_mn_ops);
                if (IS_ERR(odp)) {
                        mlx5_ib_dbg(dev, "umem get failed (%ld)\n",
                                    PTR_ERR(odp));
                        return PTR_ERR(odp);
                }

                u = &odp->umem;

                *page_shift = odp->page_shift;
                *ncont = ib_umem_odp_num_pages(odp);
                *npages = *ncont << (*page_shift - PAGE_SHIFT);
                if (order)
                        *order = ilog2(roundup_pow_of_two(*ncont));
        } else {
                u = ib_umem_get(&dev->ib_dev, start, length, access_flags);
                if (IS_ERR(u)) {
                        mlx5_ib_dbg(dev, "umem get failed (%ld)\n", PTR_ERR(u));
                        return PTR_ERR(u);
                }

                mlx5_ib_cont_pages(u, start, MLX5_MKEY_PAGE_SHIFT_MASK, npages,
                                   page_shift, ncont, order);
        }

        if (!*npages) {
                mlx5_ib_warn(dev, "avoid zero region\n");
                ib_umem_release(u);
                return -EINVAL;
        }

        *umem = u;

        mlx5_ib_dbg(dev, "npages %d, ncont %d, order %d, page_shift %d\n",
                    *npages, *ncont, *order, *page_shift);

        return 0;
}

static void mlx5_ib_umr_done(struct ib_cq *cq, struct ib_wc *wc)
{
        struct mlx5_ib_umr_context *context =
                container_of(wc->wr_cqe, struct mlx5_ib_umr_context, cqe);

        context->status = wc->status;
        complete(&context->done);
}

static inline void mlx5_ib_init_umr_context(struct mlx5_ib_umr_context *context)
{
        context->cqe.done = mlx5_ib_umr_done;
        context->status = -1;
        init_completion(&context->done);
}

static int mlx5_ib_post_send_wait(struct mlx5_ib_dev *dev,
                                  struct mlx5_umr_wr *umrwr)
{
        struct umr_common *umrc = &dev->umrc;
        const struct ib_send_wr *bad;
        int err;
        struct mlx5_ib_umr_context umr_context;

        mlx5_ib_init_umr_context(&umr_context);
        umrwr->wr.wr_cqe = &umr_context.cqe;

        down(&umrc->sem);
        err = ib_post_send(umrc->qp, &umrwr->wr, &bad);
        if (err) {
                mlx5_ib_warn(dev, "UMR post send failed, err %d\n", err);
        } else {
                wait_for_completion(&umr_context.done);
                if (umr_context.status != IB_WC_SUCCESS) {
                        mlx5_ib_warn(dev, "reg umr failed (%u)\n",
                                     umr_context.status);
                        err = -EFAULT;
                }
        }
        up(&umrc->sem);
        return err;
}

static struct mlx5_ib_mr *alloc_mr_from_cache(
                                  struct ib_pd *pd, struct ib_umem *umem,
                                  u64 virt_addr, u64 len, int npages,
                                  int page_shift, int order, int access_flags)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        struct mlx5_ib_mr *mr;
        int err = 0;
        int i;

        for (i = 0; i < 1; i++) {
                mr = alloc_cached_mr(dev, order);
                if (mr)
                        break;

                err = add_keys(dev, order2idx(dev, order), 1);
                if (err && err != -EAGAIN) {
                        mlx5_ib_warn(dev, "add_keys failed, err %d\n", err);
                        break;
                }
        }

        if (!mr)
                return ERR_PTR(-EAGAIN);

        mr->ibmr.pd = pd;
        mr->umem = umem;
        mr->access_flags = access_flags;
        mr->desc_size = sizeof(struct mlx5_mtt);
        mr->mmkey.iova = virt_addr;
        mr->mmkey.size = len;
        mr->mmkey.pd = to_mpd(pd)->pdn;

        return mr;
}

#define MLX5_MAX_UMR_CHUNK ((1 << (MLX5_MAX_UMR_SHIFT + 4)) - \
                            MLX5_UMR_MTT_ALIGNMENT)
#define MLX5_SPARE_UMR_CHUNK 0x10000

int mlx5_ib_update_xlt(struct mlx5_ib_mr *mr, u64 idx, int npages,
                       int page_shift, int flags)
{
        struct mlx5_ib_dev *dev = mr->dev;
        struct device *ddev = dev->ib_dev.dev.parent;
        int size;
        void *xlt;
        dma_addr_t dma;
        struct mlx5_umr_wr wr;
        struct ib_sge sg;
        int err = 0;
        int desc_size = (flags & MLX5_IB_UPD_XLT_INDIRECT)
                               ? sizeof(struct mlx5_klm)
                               : sizeof(struct mlx5_mtt);
        const int page_align = MLX5_UMR_MTT_ALIGNMENT / desc_size;
        const int page_mask = page_align - 1;
        size_t pages_mapped = 0;
        size_t pages_to_map = 0;
        size_t pages_iter = 0;
        size_t size_to_map = 0;
        gfp_t gfp;
        bool use_emergency_page = false;

        if ((flags & MLX5_IB_UPD_XLT_INDIRECT) &&
            !umr_can_use_indirect_mkey(dev))
                return -EPERM;

        /* UMR copies MTTs in units of MLX5_UMR_MTT_ALIGNMENT bytes,
         * so we need to align the offset and length accordingly
         */
        if (idx & page_mask) {
                npages += idx & page_mask;
                idx &= ~page_mask;
        }

        gfp = flags & MLX5_IB_UPD_XLT_ATOMIC ? GFP_ATOMIC : GFP_KERNEL;
        gfp |= __GFP_ZERO | __GFP_NOWARN;

        pages_to_map = ALIGN(npages, page_align);
        size = desc_size * pages_to_map;
        size = min_t(int, size, MLX5_MAX_UMR_CHUNK);

        xlt = (void *)__get_free_pages(gfp, get_order(size));
        if (!xlt && size > MLX5_SPARE_UMR_CHUNK) {
                mlx5_ib_dbg(dev, "Failed to allocate %d bytes of order %d. fallback to spare UMR allocation od %d bytes\n",
                            size, get_order(size), MLX5_SPARE_UMR_CHUNK);

                size = MLX5_SPARE_UMR_CHUNK;
                xlt = (void *)__get_free_pages(gfp, get_order(size));
        }

        if (!xlt) {
                mlx5_ib_warn(dev, "Using XLT emergency buffer\n");
                xlt = (void *)mlx5_ib_get_xlt_emergency_page();
                size = PAGE_SIZE;
                memset(xlt, 0, size);
                use_emergency_page = true;
        }
        pages_iter = size / desc_size;
        dma = dma_map_single(ddev, xlt, size, DMA_TO_DEVICE);
        if (dma_mapping_error(ddev, dma)) {
                mlx5_ib_err(dev, "unable to map DMA during XLT update.\n");
                err = -ENOMEM;
                goto free_xlt;
        }

        if (mr->umem->is_odp) {
                if (!(flags & MLX5_IB_UPD_XLT_INDIRECT)) {
                        struct ib_umem_odp *odp = to_ib_umem_odp(mr->umem);
                        size_t max_pages = ib_umem_odp_num_pages(odp) - idx;

                        pages_to_map = min_t(size_t, pages_to_map, max_pages);
                }
        }

        sg.addr = dma;
        sg.lkey = dev->umrc.pd->local_dma_lkey;

        memset(&wr, 0, sizeof(wr));
        wr.wr.send_flags = MLX5_IB_SEND_UMR_UPDATE_XLT;
        if (!(flags & MLX5_IB_UPD_XLT_ENABLE))
                wr.wr.send_flags |= MLX5_IB_SEND_UMR_FAIL_IF_FREE;
        wr.wr.sg_list = &sg;
        wr.wr.num_sge = 1;
        wr.wr.opcode = MLX5_IB_WR_UMR;

        wr.pd = mr->ibmr.pd;
        wr.mkey = mr->mmkey.key;
        wr.length = mr->mmkey.size;
        wr.virt_addr = mr->mmkey.iova;
        wr.access_flags = mr->access_flags;
        wr.page_shift = page_shift;

        for (pages_mapped = 0;
             pages_mapped < pages_to_map && !err;
             pages_mapped += pages_iter, idx += pages_iter) {
                npages = min_t(int, pages_iter, pages_to_map - pages_mapped);
                size_to_map = npages * desc_size;
                dma_sync_single_for_cpu(ddev, dma, size, DMA_TO_DEVICE);
                if (mr->umem->is_odp) {
                        mlx5_odp_populate_xlt(xlt, idx, npages, mr, flags);
                } else {
                        __mlx5_ib_populate_pas(dev, mr->umem, page_shift, idx,
                                               npages, xlt,
                                               MLX5_IB_MTT_PRESENT);
                        /* Clear padding after the pages
                         * brought from the umem.
                         */
                        memset(xlt + size_to_map, 0, size - size_to_map);
                }
                dma_sync_single_for_device(ddev, dma, size, DMA_TO_DEVICE);

                sg.length = ALIGN(size_to_map, MLX5_UMR_MTT_ALIGNMENT);

                if (pages_mapped + pages_iter >= pages_to_map) {
                        if (flags & MLX5_IB_UPD_XLT_ENABLE)
                                wr.wr.send_flags |=
                                        MLX5_IB_SEND_UMR_ENABLE_MR |

                                        MLX5_IB_SEND_UMR_UPDATE_PD_ACCESS |
                                        MLX5_IB_SEND_UMR_UPDATE_TRANSLATION;
                        if (flags & MLX5_IB_UPD_XLT_PD ||
                            flags & MLX5_IB_UPD_XLT_ACCESS)
                                wr.wr.send_flags |=
                                        MLX5_IB_SEND_UMR_UPDATE_PD_ACCESS;
                        if (flags & MLX5_IB_UPD_XLT_ADDR)
                                wr.wr.send_flags |=
                                        MLX5_IB_SEND_UMR_UPDATE_TRANSLATION;
                }

                wr.offset = idx * desc_size;
                wr.xlt_size = sg.length;

                err = mlx5_ib_post_send_wait(dev, &wr);
        }
        dma_unmap_single(ddev, dma, size, DMA_TO_DEVICE);

free_xlt:
        if (use_emergency_page)
                mlx5_ib_put_xlt_emergency_page();
        else
                free_pages((unsigned long)xlt, get_order(size));

        return err;
}

/*
 * If ibmr is NULL it will be allocated by reg_create.
 * Else, the given ibmr will be used.
 */
static struct mlx5_ib_mr *reg_create(struct ib_mr *ibmr, struct ib_pd *pd,
                                     u64 virt_addr, u64 length,
                                     struct ib_umem *umem, int npages,
                                     int page_shift, int access_flags,
                                     bool populate)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        struct mlx5_ib_mr *mr;
        __be64 *pas;
        void *mkc;
        int inlen;
        u32 *in;
        int err;
        bool pg_cap = !!(MLX5_CAP_GEN(dev->mdev, pg));

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

        mr->ibmr.pd = pd;
        mr->access_flags = access_flags;

        inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
        if (populate)
                inlen += sizeof(*pas) * roundup(npages, 2);
        in = kvzalloc(inlen, GFP_KERNEL);
        if (!in) {
                err = -ENOMEM;
                goto err_1;
        }
        pas = (__be64 *)MLX5_ADDR_OF(create_mkey_in, in, klm_pas_mtt);
        if (populate && !(access_flags & IB_ACCESS_ON_DEMAND))
                mlx5_ib_populate_pas(dev, umem, page_shift, pas,
                                     pg_cap ? MLX5_IB_MTT_PRESENT : 0);

        /* The pg_access bit allows setting the access flags
         * in the page list submitted with the command. */
        MLX5_SET(create_mkey_in, in, pg_access, !!(pg_cap));

        mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
        MLX5_SET(mkc, mkc, free, !populate);
        MLX5_SET(mkc, mkc, access_mode_1_0, MLX5_MKC_ACCESS_MODE_MTT);
        if (MLX5_CAP_GEN(dev->mdev, relaxed_ordering_write))
                MLX5_SET(mkc, mkc, relaxed_ordering_write,
                         !!(access_flags & IB_ACCESS_RELAXED_ORDERING));
        if (MLX5_CAP_GEN(dev->mdev, relaxed_ordering_read))
                MLX5_SET(mkc, mkc, relaxed_ordering_read,
                         !!(access_flags & IB_ACCESS_RELAXED_ORDERING));
        MLX5_SET(mkc, mkc, a, !!(access_flags & IB_ACCESS_REMOTE_ATOMIC));
        MLX5_SET(mkc, mkc, rw, !!(access_flags & IB_ACCESS_REMOTE_WRITE));
        MLX5_SET(mkc, mkc, rr, !!(access_flags & IB_ACCESS_REMOTE_READ));
        MLX5_SET(mkc, mkc, lw, !!(access_flags & IB_ACCESS_LOCAL_WRITE));
        MLX5_SET(mkc, mkc, lr, 1);
        MLX5_SET(mkc, mkc, umr_en, 1);

        MLX5_SET64(mkc, mkc, start_addr, virt_addr);
        MLX5_SET64(mkc, mkc, len, length);
        MLX5_SET(mkc, mkc, pd, to_mpd(pd)->pdn);
        MLX5_SET(mkc, mkc, bsf_octword_size, 0);
        MLX5_SET(mkc, mkc, translations_octword_size,
                 get_octo_len(virt_addr, length, page_shift));
        MLX5_SET(mkc, mkc, log_page_size, page_shift);
        MLX5_SET(mkc, mkc, qpn, 0xffffff);
        if (populate) {
                MLX5_SET(create_mkey_in, in, translations_octword_actual_size,
                         get_octo_len(virt_addr, length, page_shift));
        }

        err = mlx5_core_create_mkey(dev->mdev, &mr->mmkey, in, inlen);
        if (err) {
                mlx5_ib_warn(dev, "create mkey failed\n");
                goto err_2;
        }
        mr->mmkey.type = MLX5_MKEY_MR;
        mr->desc_size = sizeof(struct mlx5_mtt);
        mr->dev = dev;
        kvfree(in);

        mlx5_ib_dbg(dev, "mkey = 0x%x\n", mr->mmkey.key);

        return mr;

err_2:
        kvfree(in);

err_1:
        if (!ibmr)
                kfree(mr);

        return ERR_PTR(err);
}

static void set_mr_fields(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr,
                          int npages, u64 length, int access_flags)
{
        mr->npages = npages;
        atomic_add(npages, &dev->mdev->priv.reg_pages);
        mr->ibmr.lkey = mr->mmkey.key;
        mr->ibmr.rkey = mr->mmkey.key;
        mr->ibmr.length = length;
        mr->access_flags = access_flags;
}

static struct ib_mr *mlx5_ib_get_dm_mr(struct ib_pd *pd, u64 start_addr,
                                       u64 length, int acc, int mode)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
        struct mlx5_core_dev *mdev = dev->mdev;
        struct mlx5_ib_mr *mr;
        void *mkc;
        u32 *in;
        int err;

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

        in = kzalloc(inlen, GFP_KERNEL);
        if (!in) {
                err = -ENOMEM;
                goto err_free;
        }

        mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);

        MLX5_SET(mkc, mkc, access_mode_1_0, mode & 0x3);
        MLX5_SET(mkc, mkc, access_mode_4_2, (mode >> 2) & 0x7);
        MLX5_SET64(mkc, mkc, len, length);
        set_mkc_access_pd_addr_fields(mkc, acc, start_addr, pd);

        err = mlx5_core_create_mkey(mdev, &mr->mmkey, in, inlen);
        if (err)
                goto err_in;

        kfree(in);

        mr->umem = NULL;
        set_mr_fields(dev, mr, 0, length, acc);

        return &mr->ibmr;

err_in:
        kfree(in);

err_free:
        kfree(mr);

        return ERR_PTR(err);
}

int mlx5_ib_advise_mr(struct ib_pd *pd,
                      enum ib_uverbs_advise_mr_advice advice,
                      u32 flags,
                      struct ib_sge *sg_list,
                      u32 num_sge,
                      struct uverbs_attr_bundle *attrs)
{
        if (advice != IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH &&
            advice != IB_UVERBS_ADVISE_MR_ADVICE_PREFETCH_WRITE)
                return -EOPNOTSUPP;

        return mlx5_ib_advise_mr_prefetch(pd, advice, flags,
                                         sg_list, num_sge);
}

struct ib_mr *mlx5_ib_reg_dm_mr(struct ib_pd *pd, struct ib_dm *dm,
                                struct ib_dm_mr_attr *attr,
                                struct uverbs_attr_bundle *attrs)
{
        struct mlx5_ib_dm *mdm = to_mdm(dm);
        struct mlx5_core_dev *dev = to_mdev(dm->device)->mdev;
        u64 start_addr = mdm->dev_addr + attr->offset;
        int mode;

        switch (mdm->type) {
        case MLX5_IB_UAPI_DM_TYPE_MEMIC:
                if (attr->access_flags & ~MLX5_IB_DM_MEMIC_ALLOWED_ACCESS)
                        return ERR_PTR(-EINVAL);

                mode = MLX5_MKC_ACCESS_MODE_MEMIC;
                start_addr -= pci_resource_start(dev->pdev, 0);
                break;
        case MLX5_IB_UAPI_DM_TYPE_STEERING_SW_ICM:
        case MLX5_IB_UAPI_DM_TYPE_HEADER_MODIFY_SW_ICM:
                if (attr->access_flags & ~MLX5_IB_DM_SW_ICM_ALLOWED_ACCESS)
                        return ERR_PTR(-EINVAL);

                mode = MLX5_MKC_ACCESS_MODE_SW_ICM;
                break;
        default:
                return ERR_PTR(-EINVAL);
        }

        return mlx5_ib_get_dm_mr(pd, start_addr, attr->length,
                                 attr->access_flags, mode);
}

struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
                                  u64 virt_addr, int access_flags,
                                  struct ib_udata *udata)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        struct mlx5_ib_mr *mr = NULL;
        bool use_umr;
        struct ib_umem *umem;
        int page_shift;
        int npages;
        int ncont;
        int order;
        int err;

        if (!IS_ENABLED(CONFIG_INFINIBAND_USER_MEM))
                return ERR_PTR(-EOPNOTSUPP);

        mlx5_ib_dbg(dev, "start 0x%llx, virt_addr 0x%llx, length 0x%llx, access_flags 0x%x\n",
                    start, virt_addr, length, access_flags);

        if (IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) && !start &&
            length == U64_MAX) {
                if (virt_addr != start)
                        return ERR_PTR(-EINVAL);
                if (!(access_flags & IB_ACCESS_ON_DEMAND) ||
                    !(dev->odp_caps.general_caps & IB_ODP_SUPPORT_IMPLICIT))
                        return ERR_PTR(-EINVAL);

                mr = mlx5_ib_alloc_implicit_mr(to_mpd(pd), udata, access_flags);
                if (IS_ERR(mr))
                        return ERR_CAST(mr);
                return &mr->ibmr;
        }

        err = mr_umem_get(dev, start, length, access_flags, &umem,
                          &npages, &page_shift, &ncont, &order);

        if (err < 0)
                return ERR_PTR(err);

        use_umr = mlx5_ib_can_use_umr(dev, true, access_flags);

        if (order <= mr_cache_max_order(dev) && use_umr) {
                mr = alloc_mr_from_cache(pd, umem, virt_addr, length, ncont,
                                         page_shift, order, access_flags);
                if (PTR_ERR(mr) == -EAGAIN) {
                        mlx5_ib_dbg(dev, "cache empty for order %d\n", order);
                        mr = NULL;
                }
        } else if (!MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset)) {
                if (access_flags & IB_ACCESS_ON_DEMAND) {
                        err = -EINVAL;
                        pr_err("Got MR registration for ODP MR > 512MB, not supported for Connect-IB\n");
                        goto error;
                }
                use_umr = false;
        }

        if (!mr) {
                mutex_lock(&dev->slow_path_mutex);
                mr = reg_create(NULL, pd, virt_addr, length, umem, ncont,
                                page_shift, access_flags, !use_umr);
                mutex_unlock(&dev->slow_path_mutex);
        }

        if (IS_ERR(mr)) {
                err = PTR_ERR(mr);
                goto error;
        }

        mlx5_ib_dbg(dev, "mkey 0x%x\n", mr->mmkey.key);

        mr->umem = umem;
        set_mr_fields(dev, mr, npages, length, access_flags);

        if (use_umr) {
                int update_xlt_flags = MLX5_IB_UPD_XLT_ENABLE;

                if (access_flags & IB_ACCESS_ON_DEMAND)
                        update_xlt_flags |= MLX5_IB_UPD_XLT_ZAP;

                err = mlx5_ib_update_xlt(mr, 0, ncont, page_shift,
                                         update_xlt_flags);

                if (err) {
                        dereg_mr(dev, mr);
                        return ERR_PTR(err);
                }
        }

        if (is_odp_mr(mr)) {
                to_ib_umem_odp(mr->umem)->private = mr;
                atomic_set(&mr->num_deferred_work, 0);
                err = xa_err(xa_store(&dev->odp_mkeys,
                                      mlx5_base_mkey(mr->mmkey.key), &mr->mmkey,
                                      GFP_KERNEL));
                if (err) {
                        dereg_mr(dev, mr);
                        return ERR_PTR(err);
                }
        }

        return &mr->ibmr;
error:
        ib_umem_release(umem);
        return ERR_PTR(err);
}

/**
 * mlx5_mr_cache_invalidate - Fence all DMA on the MR
 * @mr: The MR to fence
 *
 * Upon return the NIC will not be doing any DMA to the pages under the MR,
 * and any DMA inprogress will be completed. Failure of this function
 * indicates the HW has failed catastrophically.
 */
int mlx5_mr_cache_invalidate(struct mlx5_ib_mr *mr)
{
        struct mlx5_umr_wr umrwr = {};

        if (mr->dev->mdev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR)
                return 0;

        umrwr.wr.send_flags = MLX5_IB_SEND_UMR_DISABLE_MR |
                              MLX5_IB_SEND_UMR_UPDATE_PD_ACCESS;
        umrwr.wr.opcode = MLX5_IB_WR_UMR;
        umrwr.pd = mr->dev->umrc.pd;
        umrwr.mkey = mr->mmkey.key;
        umrwr.ignore_free_state = 1;

        return mlx5_ib_post_send_wait(mr->dev, &umrwr);
}

static int rereg_umr(struct ib_pd *pd, struct mlx5_ib_mr *mr,
                     int access_flags, int flags)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        struct mlx5_umr_wr umrwr = {};
        int err;

        umrwr.wr.send_flags = MLX5_IB_SEND_UMR_FAIL_IF_FREE;

        umrwr.wr.opcode = MLX5_IB_WR_UMR;
        umrwr.mkey = mr->mmkey.key;

        if (flags & IB_MR_REREG_PD || flags & IB_MR_REREG_ACCESS) {
                umrwr.pd = pd;
                umrwr.access_flags = access_flags;
                umrwr.wr.send_flags |= MLX5_IB_SEND_UMR_UPDATE_PD_ACCESS;
        }

        err = mlx5_ib_post_send_wait(dev, &umrwr);

        return err;
}

int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start,
                          u64 length, u64 virt_addr, int new_access_flags,
                          struct ib_pd *new_pd, struct ib_udata *udata)
{
        struct mlx5_ib_dev *dev = to_mdev(ib_mr->device);
        struct mlx5_ib_mr *mr = to_mmr(ib_mr);
        struct ib_pd *pd = (flags & IB_MR_REREG_PD) ? new_pd : ib_mr->pd;
        int access_flags = flags & IB_MR_REREG_ACCESS ?
                            new_access_flags :
                            mr->access_flags;
        int page_shift = 0;
        int upd_flags = 0;
        int npages = 0;
        int ncont = 0;
        int order = 0;
        u64 addr, len;
        int err;

        mlx5_ib_dbg(dev, "start 0x%llx, virt_addr 0x%llx, length 0x%llx, access_flags 0x%x\n",
                    start, virt_addr, length, access_flags);

        atomic_sub(mr->npages, &dev->mdev->priv.reg_pages);

        if (!mr->umem)
                return -EINVAL;

        if (is_odp_mr(mr))
                return -EOPNOTSUPP;

        if (flags & IB_MR_REREG_TRANS) {
                addr = virt_addr;
                len = length;
        } else {
                addr = mr->umem->address;
                len = mr->umem->length;
        }

        if (flags != IB_MR_REREG_PD) {
                /*
                 * Replace umem. This needs to be done whether or not UMR is
                 * used.
                 */
                flags |= IB_MR_REREG_TRANS;
                ib_umem_release(mr->umem);
                mr->umem = NULL;
                err = mr_umem_get(dev, addr, len, access_flags, &mr->umem,
                                  &npages, &page_shift, &ncont, &order);
                if (err)
                        goto err;
        }

        if (!mlx5_ib_can_use_umr(dev, true, access_flags) ||
            (flags & IB_MR_REREG_TRANS && !use_umr_mtt_update(mr, addr, len))) {
                /*
                 * UMR can't be used - MKey needs to be replaced.
                 */
                if (mr->allocated_from_cache)
                        err = mlx5_mr_cache_invalidate(mr);
                else
                        err = destroy_mkey(dev, mr);
                if (err)
                        goto err;

                mr = reg_create(ib_mr, pd, addr, len, mr->umem, ncont,
                                page_shift, access_flags, true);

                if (IS_ERR(mr)) {
                        err = PTR_ERR(mr);
                        mr = to_mmr(ib_mr);
                        goto err;
                }

                mr->allocated_from_cache = false;
        } else {
                /*
                 * Send a UMR WQE
                 */
                mr->ibmr.pd = pd;
                mr->access_flags = access_flags;
                mr->mmkey.iova = addr;
                mr->mmkey.size = len;
                mr->mmkey.pd = to_mpd(pd)->pdn;

                if (flags & IB_MR_REREG_TRANS) {
                        upd_flags = MLX5_IB_UPD_XLT_ADDR;
                        if (flags & IB_MR_REREG_PD)
                                upd_flags |= MLX5_IB_UPD_XLT_PD;
                        if (flags & IB_MR_REREG_ACCESS)
                                upd_flags |= MLX5_IB_UPD_XLT_ACCESS;
                        err = mlx5_ib_update_xlt(mr, 0, npages, page_shift,
                                                 upd_flags);
                } else {
                        err = rereg_umr(pd, mr, access_flags, flags);
                }

                if (err)
                        goto err;
        }

        set_mr_fields(dev, mr, npages, len, access_flags);

        return 0;

err:
        ib_umem_release(mr->umem);
        mr->umem = NULL;

        clean_mr(dev, mr);
        return err;
}

static int
mlx5_alloc_priv_descs(struct ib_device *device,
                      struct mlx5_ib_mr *mr,
                      int ndescs,
                      int desc_size)
{
        int size = ndescs * desc_size;
        int add_size;
        int ret;

        add_size = max_t(int, MLX5_UMR_ALIGN - ARCH_KMALLOC_MINALIGN, 0);

        mr->descs_alloc = kzalloc(size + add_size, GFP_KERNEL);
        if (!mr->descs_alloc)
                return -ENOMEM;

        mr->descs = PTR_ALIGN(mr->descs_alloc, MLX5_UMR_ALIGN);

        mr->desc_map = dma_map_single(device->dev.parent, mr->descs,
                                      size, DMA_TO_DEVICE);
        if (dma_mapping_error(device->dev.parent, mr->desc_map)) {
                ret = -ENOMEM;
                goto err;
        }

        return 0;
err:
        kfree(mr->descs_alloc);

        return ret;
}

static void
mlx5_free_priv_descs(struct mlx5_ib_mr *mr)
{
        if (mr->descs) {
                struct ib_device *device = mr->ibmr.device;
                int size = mr->max_descs * mr->desc_size;

                dma_unmap_single(device->dev.parent, mr->desc_map,
                                 size, DMA_TO_DEVICE);
                kfree(mr->descs_alloc);
                mr->descs = NULL;
        }
}

static void clean_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
{
        int allocated_from_cache = mr->allocated_from_cache;

        if (mr->sig) {
                if (mlx5_core_destroy_psv(dev->mdev,
                                          mr->sig->psv_memory.psv_idx))
                        mlx5_ib_warn(dev, "failed to destroy mem psv %d\n",
                                     mr->sig->psv_memory.psv_idx);
                if (mlx5_core_destroy_psv(dev->mdev,
                                          mr->sig->psv_wire.psv_idx))
                        mlx5_ib_warn(dev, "failed to destroy wire psv %d\n",
                                     mr->sig->psv_wire.psv_idx);
                xa_erase(&dev->sig_mrs, mlx5_base_mkey(mr->mmkey.key));
                kfree(mr->sig);
                mr->sig = NULL;
        }

        if (!allocated_from_cache) {
                destroy_mkey(dev, mr);
                mlx5_free_priv_descs(mr);
        }
}

static void dereg_mr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
{
        int npages = mr->npages;
        struct ib_umem *umem = mr->umem;

        /* Stop all DMA */
        if (is_odp_mr(mr))
                mlx5_ib_fence_odp_mr(mr);
        else
                clean_mr(dev, mr);

        if (mr->allocated_from_cache)
                mlx5_mr_cache_free(dev, mr);
        else
                kfree(mr);

        ib_umem_release(umem);
        atomic_sub(npages, &dev->mdev->priv.reg_pages);

}

int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
{
        struct mlx5_ib_mr *mmr = to_mmr(ibmr);

        if (ibmr->type == IB_MR_TYPE_INTEGRITY) {
                dereg_mr(to_mdev(mmr->mtt_mr->ibmr.device), mmr->mtt_mr);
                dereg_mr(to_mdev(mmr->klm_mr->ibmr.device), mmr->klm_mr);
        }

        if (is_odp_mr(mmr) && to_ib_umem_odp(mmr->umem)->is_implicit_odp) {
                mlx5_ib_free_implicit_mr(mmr);
                return 0;
        }

        dereg_mr(to_mdev(ibmr->device), mmr);

        return 0;
}

static void mlx5_set_umr_free_mkey(struct ib_pd *pd, u32 *in, int ndescs,
                                   int access_mode, int page_shift)
{
        void *mkc;

        mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);

        MLX5_SET(mkc, mkc, free, 1);
        MLX5_SET(mkc, mkc, qpn, 0xffffff);
        MLX5_SET(mkc, mkc, pd, to_mpd(pd)->pdn);
        MLX5_SET(mkc, mkc, translations_octword_size, ndescs);
        MLX5_SET(mkc, mkc, access_mode_1_0, access_mode & 0x3);
        MLX5_SET(mkc, mkc, access_mode_4_2, (access_mode >> 2) & 0x7);
        MLX5_SET(mkc, mkc, umr_en, 1);
        MLX5_SET(mkc, mkc, log_page_size, page_shift);
}

static int _mlx5_alloc_mkey_descs(struct ib_pd *pd, struct mlx5_ib_mr *mr,
                                  int ndescs, int desc_size, int page_shift,
                                  int access_mode, u32 *in, int inlen)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        int err;

        mr->access_mode = access_mode;
        mr->desc_size = desc_size;
        mr->max_descs = ndescs;

        err = mlx5_alloc_priv_descs(pd->device, mr, ndescs, desc_size);
        if (err)
                return err;

        mlx5_set_umr_free_mkey(pd, in, ndescs, access_mode, page_shift);

        err = mlx5_core_create_mkey(dev->mdev, &mr->mmkey, in, inlen);
        if (err)
                goto err_free_descs;

        mr->mmkey.type = MLX5_MKEY_MR;
        mr->ibmr.lkey = mr->mmkey.key;
        mr->ibmr.rkey = mr->mmkey.key;

        return 0;

err_free_descs:
        mlx5_free_priv_descs(mr);
        return err;
}

static struct mlx5_ib_mr *mlx5_ib_alloc_pi_mr(struct ib_pd *pd,
                                u32 max_num_sg, u32 max_num_meta_sg,
                                int desc_size, int access_mode)
{
        int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
        int ndescs = ALIGN(max_num_sg + max_num_meta_sg, 4);
        int page_shift = 0;
        struct mlx5_ib_mr *mr;
        u32 *in;
        int err;

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

        mr->ibmr.pd = pd;
        mr->ibmr.device = pd->device;

        in = kzalloc(inlen, GFP_KERNEL);
        if (!in) {
                err = -ENOMEM;
                goto err_free;
        }

        if (access_mode == MLX5_MKC_ACCESS_MODE_MTT)
                page_shift = PAGE_SHIFT;

        err = _mlx5_alloc_mkey_descs(pd, mr, ndescs, desc_size, page_shift,
                                     access_mode, in, inlen);
        if (err)
                goto err_free_in;

        mr->umem = NULL;
        kfree(in);

        return mr;

err_free_in:
        kfree(in);
err_free:
        kfree(mr);
        return ERR_PTR(err);
}

static int mlx5_alloc_mem_reg_descs(struct ib_pd *pd, struct mlx5_ib_mr *mr,
                                    int ndescs, u32 *in, int inlen)
{
        return _mlx5_alloc_mkey_descs(pd, mr, ndescs, sizeof(struct mlx5_mtt),
                                      PAGE_SHIFT, MLX5_MKC_ACCESS_MODE_MTT, in,
                                      inlen);
}

static int mlx5_alloc_sg_gaps_descs(struct ib_pd *pd, struct mlx5_ib_mr *mr,
                                    int ndescs, u32 *in, int inlen)
{
        return _mlx5_alloc_mkey_descs(pd, mr, ndescs, sizeof(struct mlx5_klm),
                                      0, MLX5_MKC_ACCESS_MODE_KLMS, in, inlen);
}

static int mlx5_alloc_integrity_descs(struct ib_pd *pd, struct mlx5_ib_mr *mr,
                                      int max_num_sg, int max_num_meta_sg,
                                      u32 *in, int inlen)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        u32 psv_index[2];
        void *mkc;
        int err;

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

        /* create mem & wire PSVs */
        err = mlx5_core_create_psv(dev->mdev, to_mpd(pd)->pdn, 2, psv_index);
        if (err)
                goto err_free_sig;

        mr->sig->psv_memory.psv_idx = psv_index[0];
        mr->sig->psv_wire.psv_idx = psv_index[1];

        mr->sig->sig_status_checked = true;
        mr->sig->sig_err_exists = false;
        /* Next UMR, Arm SIGERR */
        ++mr->sig->sigerr_count;
        mr->klm_mr = mlx5_ib_alloc_pi_mr(pd, max_num_sg, max_num_meta_sg,
                                         sizeof(struct mlx5_klm),
                                         MLX5_MKC_ACCESS_MODE_KLMS);
        if (IS_ERR(mr->klm_mr)) {
                err = PTR_ERR(mr->klm_mr);
                goto err_destroy_psv;
        }
        mr->mtt_mr = mlx5_ib_alloc_pi_mr(pd, max_num_sg, max_num_meta_sg,
                                         sizeof(struct mlx5_mtt),
                                         MLX5_MKC_ACCESS_MODE_MTT);
        if (IS_ERR(mr->mtt_mr)) {
                err = PTR_ERR(mr->mtt_mr);
                goto err_free_klm_mr;
        }

        /* Set bsf descriptors for mkey */
        mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
        MLX5_SET(mkc, mkc, bsf_en, 1);
        MLX5_SET(mkc, mkc, bsf_octword_size, MLX5_MKEY_BSF_OCTO_SIZE);

        err = _mlx5_alloc_mkey_descs(pd, mr, 4, sizeof(struct mlx5_klm), 0,
                                     MLX5_MKC_ACCESS_MODE_KLMS, in, inlen);
        if (err)
                goto err_free_mtt_mr;

        err = xa_err(xa_store(&dev->sig_mrs, mlx5_base_mkey(mr->mmkey.key),
                              mr->sig, GFP_KERNEL));
        if (err)
                goto err_free_descs;
        return 0;

err_free_descs:
        destroy_mkey(dev, mr);
        mlx5_free_priv_descs(mr);
err_free_mtt_mr:
        dereg_mr(to_mdev(mr->mtt_mr->ibmr.device), mr->mtt_mr);
        mr->mtt_mr = NULL;
err_free_klm_mr:
        dereg_mr(to_mdev(mr->klm_mr->ibmr.device), mr->klm_mr);
        mr->klm_mr = NULL;
err_destroy_psv:
        if (mlx5_core_destroy_psv(dev->mdev, mr->sig->psv_memory.psv_idx))
                mlx5_ib_warn(dev, "failed to destroy mem psv %d\n",
                             mr->sig->psv_memory.psv_idx);
        if (mlx5_core_destroy_psv(dev->mdev, mr->sig->psv_wire.psv_idx))
                mlx5_ib_warn(dev, "failed to destroy wire psv %d\n",
                             mr->sig->psv_wire.psv_idx);
err_free_sig:
        kfree(mr->sig);

        return err;
}

static struct ib_mr *__mlx5_ib_alloc_mr(struct ib_pd *pd,
                                        enum ib_mr_type mr_type, u32 max_num_sg,
                                        u32 max_num_meta_sg)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
        int ndescs = ALIGN(max_num_sg, 4);
        struct mlx5_ib_mr *mr;
        u32 *in;
        int err;

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

        in = kzalloc(inlen, GFP_KERNEL);
        if (!in) {
                err = -ENOMEM;
                goto err_free;
        }

        mr->ibmr.device = pd->device;
        mr->umem = NULL;

        switch (mr_type) {
        case IB_MR_TYPE_MEM_REG:
                err = mlx5_alloc_mem_reg_descs(pd, mr, ndescs, in, inlen);
                break;
        case IB_MR_TYPE_SG_GAPS:
                err = mlx5_alloc_sg_gaps_descs(pd, mr, ndescs, in, inlen);
                break;
        case IB_MR_TYPE_INTEGRITY:
                err = mlx5_alloc_integrity_descs(pd, mr, max_num_sg,
                                                 max_num_meta_sg, in, inlen);
                break;
        default:
                mlx5_ib_warn(dev, "Invalid mr type %d\n", mr_type);
                err = -EINVAL;
        }

        if (err)
                goto err_free_in;

        kfree(in);

        return &mr->ibmr;

err_free_in:
        kfree(in);
err_free:
        kfree(mr);
        return ERR_PTR(err);
}

struct ib_mr *mlx5_ib_alloc_mr(struct ib_pd *pd, enum ib_mr_type mr_type,
                               u32 max_num_sg, struct ib_udata *udata)
{
        return __mlx5_ib_alloc_mr(pd, mr_type, max_num_sg, 0);
}

struct ib_mr *mlx5_ib_alloc_mr_integrity(struct ib_pd *pd,
                                         u32 max_num_sg, u32 max_num_meta_sg)
{
        return __mlx5_ib_alloc_mr(pd, IB_MR_TYPE_INTEGRITY, max_num_sg,
                                  max_num_meta_sg);
}

struct ib_mw *mlx5_ib_alloc_mw(struct ib_pd *pd, enum ib_mw_type type,
                               struct ib_udata *udata)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
        struct mlx5_ib_mw *mw = NULL;
        u32 *in = NULL;
        void *mkc;
        int ndescs;
        int err;
        struct mlx5_ib_alloc_mw req = {};
        struct {
                __u32   comp_mask;
                __u32   response_length;
        } resp = {};

        err = ib_copy_from_udata(&req, udata, min(udata->inlen, sizeof(req)));
        if (err)
                return ERR_PTR(err);

        if (req.comp_mask || req.reserved1 || req.reserved2)
                return ERR_PTR(-EOPNOTSUPP);

        if (udata->inlen > sizeof(req) &&
            !ib_is_udata_cleared(udata, sizeof(req),
                                 udata->inlen - sizeof(req)))
                return ERR_PTR(-EOPNOTSUPP);

        ndescs = req.num_klms ? roundup(req.num_klms, 4) : roundup(1, 4);

        mw = kzalloc(sizeof(*mw), GFP_KERNEL);
        in = kzalloc(inlen, GFP_KERNEL);
        if (!mw || !in) {
                err = -ENOMEM;
                goto free;
        }

        mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);

        MLX5_SET(mkc, mkc, free, 1);
        MLX5_SET(mkc, mkc, translations_octword_size, ndescs);
        MLX5_SET(mkc, mkc, pd, to_mpd(pd)->pdn);
        MLX5_SET(mkc, mkc, umr_en, 1);
        MLX5_SET(mkc, mkc, lr, 1);
        MLX5_SET(mkc, mkc, access_mode_1_0, MLX5_MKC_ACCESS_MODE_KLMS);
        MLX5_SET(mkc, mkc, en_rinval, !!((type == IB_MW_TYPE_2)));
        MLX5_SET(mkc, mkc, qpn, 0xffffff);

        err = mlx5_core_create_mkey(dev->mdev, &mw->mmkey, in, inlen);
        if (err)
                goto free;

        mw->mmkey.type = MLX5_MKEY_MW;
        mw->ibmw.rkey = mw->mmkey.key;
        mw->ndescs = ndescs;

        resp.response_length = min(offsetof(typeof(resp), response_length) +
                                   sizeof(resp.response_length), udata->outlen);
        if (resp.response_length) {
                err = ib_copy_to_udata(udata, &resp, resp.response_length);
                if (err) {
                        mlx5_core_destroy_mkey(dev->mdev, &mw->mmkey);
                        goto free;
                }
        }

        if (IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING)) {
                err = xa_err(xa_store(&dev->odp_mkeys,
                                      mlx5_base_mkey(mw->mmkey.key), &mw->mmkey,
                                      GFP_KERNEL));
                if (err)
                        goto free_mkey;
        }

        kfree(in);
        return &mw->ibmw;

free_mkey:
        mlx5_core_destroy_mkey(dev->mdev, &mw->mmkey);
free:
        kfree(mw);
        kfree(in);
        return ERR_PTR(err);
}

int mlx5_ib_dealloc_mw(struct ib_mw *mw)
{
        struct mlx5_ib_dev *dev = to_mdev(mw->device);
        struct mlx5_ib_mw *mmw = to_mmw(mw);
        int err;

        if (IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING)) {
                xa_erase(&dev->odp_mkeys, mlx5_base_mkey(mmw->mmkey.key));
                /*
                 * pagefault_single_data_segment() may be accessing mmw under
                 * SRCU if the user bound an ODP MR to this MW.
                 */
                synchronize_srcu(&dev->odp_srcu);
        }

        err = mlx5_core_destroy_mkey(dev->mdev, &mmw->mmkey);
        if (err)
                return err;
        kfree(mmw);
        return 0;
}

int mlx5_ib_check_mr_status(struct ib_mr *ibmr, u32 check_mask,
                            struct ib_mr_status *mr_status)
{
        struct mlx5_ib_mr *mmr = to_mmr(ibmr);
        int ret = 0;

        if (check_mask & ~IB_MR_CHECK_SIG_STATUS) {
                pr_err("Invalid status check mask\n");
                ret = -EINVAL;
                goto done;
        }

        mr_status->fail_status = 0;
        if (check_mask & IB_MR_CHECK_SIG_STATUS) {
                if (!mmr->sig) {
                        ret = -EINVAL;
                        pr_err("signature status check requested on a non-signature enabled MR\n");
                        goto done;
                }

                mmr->sig->sig_status_checked = true;
                if (!mmr->sig->sig_err_exists)
                        goto done;

                if (ibmr->lkey == mmr->sig->err_item.key)
                        memcpy(&mr_status->sig_err, &mmr->sig->err_item,
                               sizeof(mr_status->sig_err));
                else {
                        mr_status->sig_err.err_type = IB_SIG_BAD_GUARD;
                        mr_status->sig_err.sig_err_offset = 0;
                        mr_status->sig_err.key = mmr->sig->err_item.key;
                }

                mmr->sig->sig_err_exists = false;

                mr_status->fail_status |= IB_MR_CHECK_SIG_STATUS;
        }

done:
        return ret;
}

static int
mlx5_ib_map_pa_mr_sg_pi(struct ib_mr *ibmr, struct scatterlist *data_sg,
                        int data_sg_nents, unsigned int *data_sg_offset,
                        struct scatterlist *meta_sg, int meta_sg_nents,
                        unsigned int *meta_sg_offset)
{
        struct mlx5_ib_mr *mr = to_mmr(ibmr);
        unsigned int sg_offset = 0;
        int n = 0;

        mr->meta_length = 0;
        if (data_sg_nents == 1) {
                n++;
                mr->ndescs = 1;
                if (data_sg_offset)
                        sg_offset = *data_sg_offset;
                mr->data_length = sg_dma_len(data_sg) - sg_offset;
                mr->data_iova = sg_dma_address(data_sg) + sg_offset;
                if (meta_sg_nents == 1) {
                        n++;
                        mr->meta_ndescs = 1;
                        if (meta_sg_offset)
                                sg_offset = *meta_sg_offset;
                        else
                                sg_offset = 0;
                        mr->meta_length = sg_dma_len(meta_sg) - sg_offset;
                        mr->pi_iova = sg_dma_address(meta_sg) + sg_offset;
                }
                ibmr->length = mr->data_length + mr->meta_length;
        }

        return n;
}

static int
mlx5_ib_sg_to_klms(struct mlx5_ib_mr *mr,
                   struct scatterlist *sgl,
                   unsigned short sg_nents,
                   unsigned int *sg_offset_p,
                   struct scatterlist *meta_sgl,
                   unsigned short meta_sg_nents,
                   unsigned int *meta_sg_offset_p)
{
        struct scatterlist *sg = sgl;
        struct mlx5_klm *klms = mr->descs;
        unsigned int sg_offset = sg_offset_p ? *sg_offset_p : 0;
        u32 lkey = mr->ibmr.pd->local_dma_lkey;
        int i, j = 0;

        mr->ibmr.iova = sg_dma_address(sg) + sg_offset;
        mr->ibmr.length = 0;

        for_each_sg(sgl, sg, sg_nents, i) {
                if (unlikely(i >= mr->max_descs))
                        break;
                klms[i].va = cpu_to_be64(sg_dma_address(sg) + sg_offset);
                klms[i].bcount = cpu_to_be32(sg_dma_len(sg) - sg_offset);
                klms[i].key = cpu_to_be32(lkey);
                mr->ibmr.length += sg_dma_len(sg) - sg_offset;

                sg_offset = 0;
        }

        if (sg_offset_p)
                *sg_offset_p = sg_offset;

        mr->ndescs = i;
        mr->data_length = mr->ibmr.length;

        if (meta_sg_nents) {
                sg = meta_sgl;
                sg_offset = meta_sg_offset_p ? *meta_sg_offset_p : 0;
                for_each_sg(meta_sgl, sg, meta_sg_nents, j) {
                        if (unlikely(i + j >= mr->max_descs))
                                break;
                        klms[i + j].va = cpu_to_be64(sg_dma_address(sg) +
                                                     sg_offset);
                        klms[i + j].bcount = cpu_to_be32(sg_dma_len(sg) -
                                                         sg_offset);
                        klms[i + j].key = cpu_to_be32(lkey);
                        mr->ibmr.length += sg_dma_len(sg) - sg_offset;

                        sg_offset = 0;
                }
                if (meta_sg_offset_p)
                        *meta_sg_offset_p = sg_offset;

                mr->meta_ndescs = j;
                mr->meta_length = mr->ibmr.length - mr->data_length;
        }

        return i + j;
}

static int mlx5_set_page(struct ib_mr *ibmr, u64 addr)
{
        struct mlx5_ib_mr *mr = to_mmr(ibmr);
        __be64 *descs;

        if (unlikely(mr->ndescs == mr->max_descs))
                return -ENOMEM;

        descs = mr->descs;
        descs[mr->ndescs++] = cpu_to_be64(addr | MLX5_EN_RD | MLX5_EN_WR);

        return 0;
}

static int mlx5_set_page_pi(struct ib_mr *ibmr, u64 addr)
{
        struct mlx5_ib_mr *mr = to_mmr(ibmr);
        __be64 *descs;

        if (unlikely(mr->ndescs + mr->meta_ndescs == mr->max_descs))
                return -ENOMEM;

        descs = mr->descs;
        descs[mr->ndescs + mr->meta_ndescs++] =
                cpu_to_be64(addr | MLX5_EN_RD | MLX5_EN_WR);

        return 0;
}

static int
mlx5_ib_map_mtt_mr_sg_pi(struct ib_mr *ibmr, struct scatterlist *data_sg,
                         int data_sg_nents, unsigned int *data_sg_offset,
                         struct scatterlist *meta_sg, int meta_sg_nents,
                         unsigned int *meta_sg_offset)
{
        struct mlx5_ib_mr *mr = to_mmr(ibmr);
        struct mlx5_ib_mr *pi_mr = mr->mtt_mr;
        int n;

        pi_mr->ndescs = 0;
        pi_mr->meta_ndescs = 0;
        pi_mr->meta_length = 0;

        ib_dma_sync_single_for_cpu(ibmr->device, pi_mr->desc_map,
                                   pi_mr->desc_size * pi_mr->max_descs,
                                   DMA_TO_DEVICE);

        pi_mr->ibmr.page_size = ibmr->page_size;
        n = ib_sg_to_pages(&pi_mr->ibmr, data_sg, data_sg_nents, data_sg_offset,
                           mlx5_set_page);
        if (n != data_sg_nents)
                return n;

        pi_mr->data_iova = pi_mr->ibmr.iova;
        pi_mr->data_length = pi_mr->ibmr.length;
        pi_mr->ibmr.length = pi_mr->data_length;
        ibmr->length = pi_mr->data_length;

        if (meta_sg_nents) {
                u64 page_mask = ~((u64)ibmr->page_size - 1);
                u64 iova = pi_mr->data_iova;

                n += ib_sg_to_pages(&pi_mr->ibmr, meta_sg, meta_sg_nents,
                                    meta_sg_offset, mlx5_set_page_pi);

                pi_mr->meta_length = pi_mr->ibmr.length;
                /*
                 * PI address for the HW is the offset of the metadata address
                 * relative to the first data page address.
                 * It equals to first data page address + size of data pages +
                 * metadata offset at the first metadata page
                 */
                pi_mr->pi_iova = (iova & page_mask) +
                                 pi_mr->ndescs * ibmr->page_size +
                                 (pi_mr->ibmr.iova & ~page_mask);
                /*
                 * In order to use one MTT MR for data and metadata, we register
                 * also the gaps between the end of the data and the start of
                 * the metadata (the sig MR will verify that the HW will access
                 * to right addresses). This mapping is safe because we use
                 * internal mkey for the registration.
                 */
                pi_mr->ibmr.length = pi_mr->pi_iova + pi_mr->meta_length - iova;
                pi_mr->ibmr.iova = iova;
                ibmr->length += pi_mr->meta_length;
        }

        ib_dma_sync_single_for_device(ibmr->device, pi_mr->desc_map,
                                      pi_mr->desc_size * pi_mr->max_descs,
                                      DMA_TO_DEVICE);

        return n;
}

static int
mlx5_ib_map_klm_mr_sg_pi(struct ib_mr *ibmr, struct scatterlist *data_sg,
                         int data_sg_nents, unsigned int *data_sg_offset,
                         struct scatterlist *meta_sg, int meta_sg_nents,
                         unsigned int *meta_sg_offset)
{
        struct mlx5_ib_mr *mr = to_mmr(ibmr);
        struct mlx5_ib_mr *pi_mr = mr->klm_mr;
        int n;

        pi_mr->ndescs = 0;
        pi_mr->meta_ndescs = 0;
        pi_mr->meta_length = 0;

        ib_dma_sync_single_for_cpu(ibmr->device, pi_mr->desc_map,
                                   pi_mr->desc_size * pi_mr->max_descs,
                                   DMA_TO_DEVICE);

        n = mlx5_ib_sg_to_klms(pi_mr, data_sg, data_sg_nents, data_sg_offset,
                               meta_sg, meta_sg_nents, meta_sg_offset);

        ib_dma_sync_single_for_device(ibmr->device, pi_mr->desc_map,
                                      pi_mr->desc_size * pi_mr->max_descs,
                                      DMA_TO_DEVICE);

        /* This is zero-based memory region */
        pi_mr->data_iova = 0;
        pi_mr->ibmr.iova = 0;
        pi_mr->pi_iova = pi_mr->data_length;
        ibmr->length = pi_mr->ibmr.length;

        return n;
}

int mlx5_ib_map_mr_sg_pi(struct ib_mr *ibmr, struct scatterlist *data_sg,
                         int data_sg_nents, unsigned int *data_sg_offset,
                         struct scatterlist *meta_sg, int meta_sg_nents,
                         unsigned int *meta_sg_offset)
{
        struct mlx5_ib_mr *mr = to_mmr(ibmr);
        struct mlx5_ib_mr *pi_mr = NULL;
        int n;

        WARN_ON(ibmr->type != IB_MR_TYPE_INTEGRITY);

        mr->ndescs = 0;
        mr->data_length = 0;
        mr->data_iova = 0;
        mr->meta_ndescs = 0;
        mr->pi_iova = 0;
        /*
         * As a performance optimization, if possible, there is no need to
         * perform UMR operation to register the data/metadata buffers.
         * First try to map the sg lists to PA descriptors with local_dma_lkey.
         * Fallback to UMR only in case of a failure.
         */
        n = mlx5_ib_map_pa_mr_sg_pi(ibmr, data_sg, data_sg_nents,
                                    data_sg_offset, meta_sg, meta_sg_nents,
                                    meta_sg_offset);
        if (n == data_sg_nents + meta_sg_nents)
                goto out;
        /*
         * As a performance optimization, if possible, there is no need to map
         * the sg lists to KLM descriptors. First try to map the sg lists to MTT
         * descriptors and fallback to KLM only in case of a failure.
         * It's more efficient for the HW to work with MTT descriptors
         * (especially in high load).
         * Use KLM (indirect access) only if it's mandatory.
         */
        pi_mr = mr->mtt_mr;
        n = mlx5_ib_map_mtt_mr_sg_pi(ibmr, data_sg, data_sg_nents,
                                     data_sg_offset, meta_sg, meta_sg_nents,
                                     meta_sg_offset);
        if (n == data_sg_nents + meta_sg_nents)
                goto out;

        pi_mr = mr->klm_mr;
        n = mlx5_ib_map_klm_mr_sg_pi(ibmr, data_sg, data_sg_nents,
                                     data_sg_offset, meta_sg, meta_sg_nents,
                                     meta_sg_offset);
        if (unlikely(n != data_sg_nents + meta_sg_nents))
                return -ENOMEM;

out:
        /* This is zero-based memory region */
        ibmr->iova = 0;
        mr->pi_mr = pi_mr;
        if (pi_mr)
                ibmr->sig_attrs->meta_length = pi_mr->meta_length;
        else
                ibmr->sig_attrs->meta_length = mr->meta_length;

        return 0;
}

int mlx5_ib_map_mr_sg(struct ib_mr *ibmr, struct scatterlist *sg, int sg_nents,
                      unsigned int *sg_offset)
{
        struct mlx5_ib_mr *mr = to_mmr(ibmr);
        int n;

        mr->ndescs = 0;

        ib_dma_sync_single_for_cpu(ibmr->device, mr->desc_map,
                                   mr->desc_size * mr->max_descs,
                                   DMA_TO_DEVICE);

        if (mr->access_mode == MLX5_MKC_ACCESS_MODE_KLMS)
                n = mlx5_ib_sg_to_klms(mr, sg, sg_nents, sg_offset, NULL, 0,
                                       NULL);
        else
                n = ib_sg_to_pages(ibmr, sg, sg_nents, sg_offset,
                                mlx5_set_page);

        ib_dma_sync_single_for_device(ibmr->device, mr->desc_map,
                                      mr->desc_size * mr->max_descs,
                                      DMA_TO_DEVICE);

        return n;
}