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 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 = 1;
		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 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 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)
{
	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, 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, struct ib_udata *udata,
		       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(udata, start, length, access_flags);
		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(udata, start, length, access_flags, 0);
		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;
}

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) {
		if (!umr_can_use_indirect_mkey(dev))
			return -EPERM;
		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;
	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;
	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;
	}

	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 (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);
	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 (!(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, udata, 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);

	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, udata, addr, len, access_flags,
				  &mr->umem, &npages, &page_shift, &ncont,
				  &order);
		if (err)
			goto err;
	}

	if (!mlx5_ib_can_use_umr(dev, true) ||
	    (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 = 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)
			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;
}