Merge tag 'for-linus-20170825' of git://git.infradead.org/linux-mtd

[mirror_ubuntu-artful-kernel.git] / drivers / infiniband / hw / mlx5 / mr.c

/*
 * 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 int clean_mr(struct mlx5_ib_mr *mr);
static int use_umr(struct mlx5_ib_dev *dev, int order);
static int unreg_umr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr);

static int destroy_mkey(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
{
        int err = mlx5_core_destroy_mkey(dev->mdev, &mr->mmkey);

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
        /* Wait until all page fault handlers using the mr complete. */
        synchronize_srcu(&dev->mr_srcu);
#endif

        return err;
}

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));
}

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
static void update_odp_mr(struct mlx5_ib_mr *mr)
{
        if (mr->umem->odp_data) {
                /*
                 * This barrier prevents the compiler from moving the
                 * setting of umem->odp_data->private to point to our
                 * MR, before reg_umr finished, to ensure that the MR
                 * initialization have finished before starting to
                 * handle invalidations.
                 */
                smp_wmb();
                mr->umem->odp_data->private = mr;
                /*
                 * Make sure we will see the new
                 * umem->odp_data->private value in the invalidation
                 * routines, before we can get page faults on the
                 * MR. Page faults can happen once we put the MR in
                 * the tree, below this line. Without the barrier,
                 * there can be a fault handling and an invalidation
                 * before umem->odp_data->private == mr is visible to
                 * the invalidation handler.
                 */
                smp_wmb();
        }
}
#endif

static void reg_mr_callback(int status, void *context)
{
        struct mlx5_ib_mr *mr = context;
        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;
        struct mlx5_mkey_table *table = &dev->mdev->priv.mkey_table;
        int err;

        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);

        write_lock_irqsave(&table->lock, flags);
        err = radix_tree_insert(&table->tree, mlx5_base_mkey(mr->mmkey.key),
                                &mr->mmkey);
        if (err)
                pr_err("Error inserting to mkey tree. 0x%x\n", -err);
        write_unlock_irqrestore(&table->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->umred = 1;
                mr->dev = dev;

                MLX5_SET(mkc, mkc, free, 1);
                MLX5_SET(mkc, mkc, umr_en, 1);
                MLX5_SET(mkc, mkc, access_mode, ent->access_mode);

                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,
                                               in, inlen,
                                               mr->out, sizeof(mr->out),
                                               reg_mr_callback, mr);
                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 *mr;
        int err;
        int i;

        for (i = 0; i < num; i++) {
                spin_lock_irq(&ent->lock);
                if (list_empty(&ent->head)) {
                        spin_unlock_irq(&ent->lock);
                        return;
                }
                mr = list_first_entry(&ent->head, struct mlx5_ib_mr, list);
                list_del(&mr->list);
                ent->cur--;
                ent->size--;
                spin_unlock_irq(&ent->lock);
                err = destroy_mkey(dev, mr);
                if (err)
                        mlx5_ib_warn(dev, "failed destroy mkey\n");
                else
                        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];
        u32 var;
        int err;
        int c;

        if (copy_from_user(lbuf, buf, sizeof(lbuf)))
                return -EFAULT;

        c = order2idx(dev, ent->order);
        lbuf[sizeof(lbuf) - 1] = 0;

        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;

        if (*pos)
                return 0;

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

        if (copy_to_user(buf, lbuf, err))
                return -EFAULT;

        *pos += err;

        return 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];
        u32 var;
        int err;
        int c;

        if (copy_from_user(lbuf, buf, sizeof(lbuf)))
                return -EFAULT;

        c = order2idx(dev, ent->order);
        lbuf[sizeof(lbuf) - 1] = 0;

        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;

        if (*pos)
                return 0;

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

        if (copy_to_user(buf, lbuf, err))
                return -EFAULT;

        *pos += err;

        return 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 NULL;
        }

        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 c;
        int i;

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

        for (i = c; i < MAX_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;

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

        if (unreg_umr(dev, mr))
                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 *mr;
        int err;

        cancel_delayed_work(&ent->dwork);
        while (1) {
                spin_lock_irq(&ent->lock);
                if (list_empty(&ent->head)) {
                        spin_unlock_irq(&ent->lock);
                        return;
                }
                mr = list_first_entry(&ent->head, struct mlx5_ib_mr, list);
                list_del(&mr->list);
                ent->cur--;
                ent->size--;
                spin_unlock_irq(&ent->lock);
                err = destroy_mkey(dev, mr);
                if (err)
                        mlx5_ib_warn(dev, "failed destroy mkey\n");
                else
                        kfree(mr);
        }
}

static void mlx5_mr_cache_debugfs_cleanup(struct mlx5_ib_dev *dev)
{
        if (!mlx5_debugfs_root)
                return;

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

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

        if (!mlx5_debugfs_root)
                return 0;

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

        for (i = 0; i < MAX_MR_CACHE_ENTRIES; i++) {
                ent = &cache->ent[i];
                sprintf(ent->name, "%d", ent->order);
                ent->dir = debugfs_create_dir(ent->name,  cache->root);
                if (!ent->dir)
                        goto err;

                ent->fsize = debugfs_create_file("size", 0600, ent->dir, ent,
                                                 &size_fops);
                if (!ent->fsize)
                        goto err;

                ent->flimit = debugfs_create_file("limit", 0600, ent->dir, ent,
                                                  &limit_fops);
                if (!ent->flimit)
                        goto err;

                ent->fcur = debugfs_create_u32("cur", 0400, ent->dir,
                                               &ent->cur);
                if (!ent->fcur)
                        goto err;

                ent->fmiss = debugfs_create_u32("miss", 0600, ent->dir,
                                                &ent->miss);
                if (!ent->fmiss)
                        goto err;
        }

        return 0;
err:
        mlx5_mr_cache_debugfs_cleanup(dev);

        return -ENOMEM;
}

static void delay_time_func(unsigned long ctx)
{
        struct mlx5_ib_dev *dev = (struct mlx5_ib_dev *)ctx;

        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 err;
        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;
        }

        setup_timer(&dev->delay_timer, delay_time_func, (unsigned long)dev);
        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);
                queue_work(cache->wq, &ent->work);

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

                if (!use_umr(dev, ent->order))
                        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) &&
                    mlx5_core_is_pf(dev->mdev))
                        ent->limit = dev->mdev->profile->mr_cache[i].limit;
                else
                        ent->limit = 0;
        }

        err = mlx5_mr_cache_debugfs_init(dev);
        if (err)
                mlx5_ib_warn(dev, "cache debugfs failure\n");

        /*
         * We don't want to fail driver if debugfs failed to initialize,
         * so we are not forwarding error to the user.
         */

        return 0;
}

static void wait_for_async_commands(struct mlx5_ib_dev *dev)
{
        struct mlx5_mr_cache *cache = &dev->cache;
        struct mlx5_cache_ent *ent;
        int total = 0;
        int i;
        int j;

        for (i = 0; i < MAX_MR_CACHE_ENTRIES; i++) {
                ent = &cache->ent[i];
                for (j = 0 ; j < 1000; j++) {
                        if (!ent->pending)
                                break;
                        msleep(50);
                }
        }
        for (i = 0; i < MAX_MR_CACHE_ENTRIES; i++) {
                ent = &cache->ent[i];
                total += ent->pending;
        }

        if (total)
                mlx5_ib_warn(dev, "aborted while there are %d pending mr requests\n", total);
        else
                mlx5_ib_warn(dev, "done with all pending requests\n");
}

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

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

        mlx5_mr_cache_debugfs_cleanup(dev);

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

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

        return 0;
}

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, MLX5_MKC_ACCESS_MODE_PA);
        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);

        MLX5_SET(mkc, mkc, length64, 1);
        MLX5_SET(mkc, mkc, pd, to_mpd(pd)->pdn);
        MLX5_SET(mkc, mkc, qpn, 0xffffff);
        MLX5_SET64(mkc, mkc, start_addr, 0);

        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_size)
{
        u64 offset;
        int npages;

        offset = addr & (page_size - 1);
        npages = ALIGN(len + offset, page_size) >> ilog2(page_size);
        return (npages + 1) / 2;
}

static int use_umr(struct mlx5_ib_dev *dev, int order)
{
        if (MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset))
                return order <= MAX_UMR_CACHE_ENTRY + 2;
        return order <= MLX5_MAX_UMR_SHIFT;
}

static int mr_umem_get(struct ib_pd *pd, u64 start, u64 length,
                       int access_flags, struct ib_umem **umem,
                       int *npages, int *page_shift, int *ncont,
                       int *order)
{
        struct mlx5_ib_dev *dev = to_mdev(pd->device);
        int err;

        *umem = ib_umem_get(pd->uobject->context, start, length,
                            access_flags, 0);
        err = PTR_ERR_OR_ZERO(*umem);
        if (err < 0) {
                mlx5_ib_err(dev, "umem get failed (%d)\n", err);
                return err;
        }

        mlx5_ib_cont_pages(*umem, start, MLX5_MKEY_PAGE_SHIFT_MASK, npages,
                           page_shift, ncont, order);
        if (!*npages) {
                mlx5_ib_warn(dev, "avoid zero region\n");
                ib_umem_release(*umem);
                return -EINVAL;
        }

        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;
        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 *reg_umr(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;

        err = mlx5_ib_update_xlt(mr, 0, npages, page_shift,
                                 MLX5_IB_UPD_XLT_ENABLE);

        if (err) {
                mlx5_mr_cache_free(dev, mr);
                return ERR_PTR(err);
        }

        mr->live = 1;

        return mr;
}

static inline int populate_xlt(struct mlx5_ib_mr *mr, int idx, int npages,
                               void *xlt, int page_shift, size_t size,
                               int flags)
{
        struct mlx5_ib_dev *dev = mr->dev;
        struct ib_umem *umem = mr->umem;
        if (flags & MLX5_IB_UPD_XLT_INDIRECT) {
                mlx5_odp_populate_klm(xlt, idx, npages, mr, flags);
                return npages;
        }

        npages = min_t(size_t, npages, ib_umem_num_pages(umem) - idx);

        if (!(flags & MLX5_IB_UPD_XLT_ZAP)) {
                __mlx5_ib_populate_pas(dev, umem, page_shift,
                                       idx, npages, xlt,
                                       MLX5_IB_MTT_PRESENT);
                /* Clear padding after the pages
                 * brought from the umem.
                 */
                memset(xlt + (npages * sizeof(struct mlx5_mtt)), 0,
                       size - npages * sizeof(struct mlx5_mtt));
        }

        return npages;
}

#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;
        struct mlx5_ib_ucontext *uctx = NULL;
        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;
        gfp_t gfp;

        /* 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) {
                uctx = to_mucontext(mr->ibmr.pd->uobject->context);
                mlx5_ib_warn(dev, "Using XLT emergency buffer\n");
                size = PAGE_SIZE;
                xlt = (void *)uctx->upd_xlt_page;
                mutex_lock(&uctx->upd_xlt_page_mutex);
                memset(xlt, 0, size);
        }
        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;
        }

        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);
                dma_sync_single_for_cpu(ddev, dma, size, DMA_TO_DEVICE);
                npages = populate_xlt(mr, idx, npages, xlt,
                                      page_shift, size, flags);

                dma_sync_single_for_device(ddev, dma, size, DMA_TO_DEVICE);

                sg.length = ALIGN(npages * desc_size,
                                  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 (uctx)
                mutex_unlock(&uctx->upd_xlt_page_mutex);
        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)
{
        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);

        inlen = MLX5_ST_SZ_BYTES(create_mkey_in) +
                sizeof(*pas) * ((npages + 1) / 2) * 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 (!(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, access_mode, MLX5_MKC_ACCESS_MODE_MTT);
        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_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, 1 << page_shift));
        MLX5_SET(mkc, mkc, log_page_size, page_shift);
        MLX5_SET(mkc, mkc, qpn, 0xffffff);
        MLX5_SET(create_mkey_in, in, translations_octword_actual_size,
                 get_octo_len(virt_addr, length, 1 << 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->umem = umem;
        mr->dev = dev;
        mr->live = 1;
        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_fileds(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;
}

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;
        struct ib_umem *umem;
        int page_shift;
        int npages;
        int ncont;
        int order;
        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);

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
        if (!start && length == U64_MAX) {
                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), access_flags);
                return &mr->ibmr;
        }
#endif

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

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

        if (use_umr(dev, order)) {
                mr = reg_umr(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", order);
                        mr = NULL;
                }
        } else if (access_flags & IB_ACCESS_ON_DEMAND &&
                   !MLX5_CAP_GEN(dev->mdev, umr_extended_translation_offset)) {
                err = -EINVAL;
                pr_err("Got MR registration for ODP MR > 512MB, not supported for Connect-IB");
                goto error;
        }

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

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
        update_odp_mr(mr);
#endif

        return &mr->ibmr;

error:
        ib_umem_release(umem);
        return ERR_PTR(err);
}

static int unreg_umr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
{
        struct mlx5_core_dev *mdev = dev->mdev;
        struct mlx5_umr_wr umrwr = {};

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

        umrwr.wr.send_flags = MLX5_IB_SEND_UMR_DISABLE_MR |
                              MLX5_IB_SEND_UMR_FAIL_IF_FREE;
        umrwr.wr.opcode = MLX5_IB_WR_UMR;
        umrwr.mkey = mr->mmkey.key;

        return mlx5_ib_post_send_wait(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;
        u64 addr = (flags & IB_MR_REREG_TRANS) ? virt_addr : mr->umem->address;
        u64 len = (flags & IB_MR_REREG_TRANS) ? length : mr->umem->length;
        int page_shift = 0;
        int upd_flags = 0;
        int npages = 0;
        int ncont = 0;
        int order = 0;
        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 (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);
                err = mr_umem_get(pd, addr, len, access_flags, &mr->umem,
                                  &npages, &page_shift, &ncont, &order);
                if (err < 0) {
                        clean_mr(mr);
                        return err;
                }
        }

        if (flags & IB_MR_REREG_TRANS && !use_umr_mtt_update(mr, addr, len)) {
                /*
                 * UMR can't be used - MKey needs to be replaced.
                 */
                if (mr->umred) {
                        err = unreg_umr(dev, mr);
                        if (err)
                                mlx5_ib_warn(dev, "Failed to unregister MR\n");
                } else {
                        err = destroy_mkey(dev, mr);
                        if (err)
                                mlx5_ib_warn(dev, "Failed to destroy MKey\n");
                }
                if (err)
                        return err;

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

                if (IS_ERR(mr))
                        return PTR_ERR(mr);

                mr->umred = 0;
        } 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) {
                        mlx5_ib_warn(dev, "Failed to rereg UMR\n");
                        ib_umem_release(mr->umem);
                        clean_mr(mr);
                        return err;
                }
        }

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

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
        update_odp_mr(mr);
#endif
        return 0;
}

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 int clean_mr(struct mlx5_ib_mr *mr)
{
        struct mlx5_ib_dev *dev = to_mdev(mr->ibmr.device);
        int umred = mr->umred;
        int err;

        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);
                kfree(mr->sig);
                mr->sig = NULL;
        }

        mlx5_free_priv_descs(mr);

        if (!umred) {
                err = destroy_mkey(dev, mr);
                if (err) {
                        mlx5_ib_warn(dev, "failed to destroy mkey 0x%x (%d)\n",
                                     mr->mmkey.key, err);
                        return err;
                }
        } else {
                mlx5_mr_cache_free(dev, mr);
        }

        if (!umred)
                kfree(mr);

        return 0;
}

int mlx5_ib_dereg_mr(struct ib_mr *ibmr)
{
        struct mlx5_ib_dev *dev = to_mdev(ibmr->device);
        struct mlx5_ib_mr *mr = to_mmr(ibmr);
        int npages = mr->npages;
        struct ib_umem *umem = mr->umem;

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
        if (umem && umem->odp_data) {
                /* Prevent new page faults from succeeding */
                mr->live = 0;
                /* Wait for all running page-fault handlers to finish. */
                synchronize_srcu(&dev->mr_srcu);
                /* Destroy all page mappings */
                if (umem->odp_data->page_list)
                        mlx5_ib_invalidate_range(umem, ib_umem_start(umem),
                                                 ib_umem_end(umem));
                else
                        mlx5_ib_free_implicit_mr(mr);
                /*
                 * We kill the umem before the MR for ODP,
                 * so that there will not be any invalidations in
                 * flight, looking at the *mr struct.
                 */
                ib_umem_release(umem);
                atomic_sub(npages, &dev->mdev->priv.reg_pages);

                /* Avoid double-freeing the umem. */
                umem = NULL;
        }
#endif

        clean_mr(mr);

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

        return 0;
}

struct ib_mr *mlx5_ib_alloc_mr(struct ib_pd *pd,
                               enum ib_mr_type mr_type,
                               u32 max_num_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;
        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, free, 1);
        MLX5_SET(mkc, mkc, translations_octword_size, ndescs);
        MLX5_SET(mkc, mkc, qpn, 0xffffff);
        MLX5_SET(mkc, mkc, pd, to_mpd(pd)->pdn);

        if (mr_type == IB_MR_TYPE_MEM_REG) {
                mr->access_mode = MLX5_MKC_ACCESS_MODE_MTT;
                MLX5_SET(mkc, mkc, log_page_size, PAGE_SHIFT);
                err = mlx5_alloc_priv_descs(pd->device, mr,
                                            ndescs, sizeof(struct mlx5_mtt));
                if (err)
                        goto err_free_in;

                mr->desc_size = sizeof(struct mlx5_mtt);
                mr->max_descs = ndescs;
        } else if (mr_type == IB_MR_TYPE_SG_GAPS) {
                mr->access_mode = MLX5_MKC_ACCESS_MODE_KLMS;

                err = mlx5_alloc_priv_descs(pd->device, mr,
                                            ndescs, sizeof(struct mlx5_klm));
                if (err)
                        goto err_free_in;
                mr->desc_size = sizeof(struct mlx5_klm);
                mr->max_descs = ndescs;
        } else if (mr_type == IB_MR_TYPE_SIGNATURE) {
                u32 psv_index[2];

                MLX5_SET(mkc, mkc, bsf_en, 1);
                MLX5_SET(mkc, mkc, bsf_octword_size, MLX5_MKEY_BSF_OCTO_SIZE);
                mr->sig = kzalloc(sizeof(*mr->sig), GFP_KERNEL);
                if (!mr->sig) {
                        err = -ENOMEM;
                        goto err_free_in;
                }

                /* 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->access_mode = MLX5_MKC_ACCESS_MODE_KLMS;
                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;
        } else {
                mlx5_ib_warn(dev, "Invalid mr type %d\n", mr_type);
                err = -EINVAL;
                goto err_free_in;
        }

        MLX5_SET(mkc, mkc, access_mode, mr->access_mode);
        MLX5_SET(mkc, mkc, umr_en, 1);

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

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

        return &mr->ibmr;

err_destroy_psv:
        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);
        }
        mlx5_free_priv_descs(mr);
err_free_sig:
        kfree(mr->sig);
err_free_in:
        kfree(in);
err_free:
        kfree(mr);
        return ERR_PTR(err);
}

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, 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;
                }
        }

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

free:
        kfree(mw);
        kfree(in);
        return ERR_PTR(err);
}

int mlx5_ib_dealloc_mw(struct ib_mw *mw)
{
        struct mlx5_ib_mw *mmw = to_mmw(mw);
        int err;

        err =  mlx5_core_destroy_mkey((to_mdev(mw->device))->mdev,
                                      &mmw->mmkey);
        if (!err)
                kfree(mmw);
        return err;
}

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_sg_to_klms(struct mlx5_ib_mr *mr,
                   struct scatterlist *sgl,
                   unsigned short sg_nents,
                   unsigned int *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;

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

        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;

        return i;
}

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;
}

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);
        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;
}