text: /*
   * Copyright (c) 2016 Oracle.  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 "ib_mr.h"
  
  struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev, int npages)
  {
  	struct rds_ib_mr_pool *pool;
  	struct rds_ib_mr *ibmr = NULL;
  	struct rds_ib_fmr *fmr;
  	int err = 0;
  
  	if (npages <= RDS_MR_8K_MSG_SIZE)
  		pool = rds_ibdev->mr_8k_pool;
  	else
  		pool = rds_ibdev->mr_1m_pool;
  
  	if (atomic_read(&pool->dirty_count) >= pool->max_items / 10)
  		queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
  
  	/* Switch pools if one of the pool is reaching upper limit */
  	if (atomic_read(&pool->dirty_count) >=  pool->max_items * 9 / 10) {
  		if (pool->pool_type == RDS_IB_MR_8K_POOL)
  			pool = rds_ibdev->mr_1m_pool;
  		else
  			pool = rds_ibdev->mr_8k_pool;
  	}
  
  	ibmr = rds_ib_try_reuse_ibmr(pool);
  	if (ibmr)
  		return ibmr;
  
  	ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL,
  			    rdsibdev_to_node(rds_ibdev));
  	if (!ibmr) {
  		err = -ENOMEM;
  		goto out_no_cigar;
  	}
  
  	fmr = &ibmr->u.fmr;
  	fmr->fmr = ib_alloc_fmr(rds_ibdev->pd,
  			(IB_ACCESS_LOCAL_WRITE |
  			 IB_ACCESS_REMOTE_READ |
  			 IB_ACCESS_REMOTE_WRITE |
  			 IB_ACCESS_REMOTE_ATOMIC),
  			&pool->fmr_attr);
  	if (IS_ERR(fmr->fmr)) {
  		err = PTR_ERR(fmr->fmr);
  		fmr->fmr = NULL;
  		pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, err);
  		goto out_no_cigar;
  	}
  
  	ibmr->pool = pool;
  	if (pool->pool_type == RDS_IB_MR_8K_POOL)
  		rds_ib_stats_inc(s_ib_rdma_mr_8k_alloc);
  	else
  		rds_ib_stats_inc(s_ib_rdma_mr_1m_alloc);
  
  	return ibmr;
  
  out_no_cigar:
  	kfree(ibmr);
  	atomic_dec(&pool->item_count);
  
  	return ERR_PTR(err);
  }
  
  static int rds_ib_map_fmr(struct rds_ib_device *rds_ibdev,
  			  struct rds_ib_mr *ibmr, struct scatterlist *sg,
  			  unsigned int nents)
  {
  	struct ib_device *dev = rds_ibdev->dev;
  	struct rds_ib_fmr *fmr = &ibmr->u.fmr;
  	struct scatterlist *scat = sg;
  	u64 io_addr = 0;
  	u64 *dma_pages;
  	u32 len;
  	int page_cnt, sg_dma_len;
  	int i, j;
  	int ret;
  
  	sg_dma_len = ib_dma_map_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
  	if (unlikely(!sg_dma_len)) {
  		pr_warn("RDS/IB: %s failed!\n", __func__);
  		return -EBUSY;
  	}
  
  	len = 0;
  	page_cnt = 0;
  
  	for (i = 0; i < sg_dma_len; ++i) {
  		unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
  		u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
  
  		if (dma_addr & ~PAGE_MASK) {
  			if (i > 0) {
  				ib_dma_unmap_sg(dev, sg, nents,
  						DMA_BIDIRECTIONAL);
  				return -EINVAL;
  			} else {
  				++page_cnt;
  			}
  		}
  		if ((dma_addr + dma_len) & ~PAGE_MASK) {
  			if (i < sg_dma_len - 1) {
  				ib_dma_unmap_sg(dev, sg, nents,
  						DMA_BIDIRECTIONAL);
  				return -EINVAL;
  			} else {
  				++page_cnt;
  			}
  		}
  
  		len += dma_len;
  	}
  
  	page_cnt += len >> PAGE_SHIFT;
  	if (page_cnt > ibmr->pool->fmr_attr.max_pages) {
  		ib_dma_unmap_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
  		return -EINVAL;
  	}
  
  	dma_pages = kmalloc_node(sizeof(u64) * page_cnt, GFP_ATOMIC,
  				 rdsibdev_to_node(rds_ibdev));
  	if (!dma_pages) {
  		ib_dma_unmap_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
  		return -ENOMEM;
  	}
  
  	page_cnt = 0;
  	for (i = 0; i < sg_dma_len; ++i) {
  		unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
  		u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
  
  		for (j = 0; j < dma_len; j += PAGE_SIZE)
  			dma_pages[page_cnt++] =
  				(dma_addr & PAGE_MASK) + j;
  	}
  
  	ret = ib_map_phys_fmr(fmr->fmr, dma_pages, page_cnt, io_addr);
  	if (ret) {
  		ib_dma_unmap_sg(dev, sg, nents, DMA_BIDIRECTIONAL);
  		goto out;
  	}
  
  	/* Success - we successfully remapped the MR, so we can
  	 * safely tear down the old mapping.
  	 */
  	rds_ib_teardown_mr(ibmr);
  
  	ibmr->sg = scat;
  	ibmr->sg_len = nents;
  	ibmr->sg_dma_len = sg_dma_len;
  	ibmr->remap_count++;
  
  	if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
  		rds_ib_stats_inc(s_ib_rdma_mr_8k_used);
  	else
  		rds_ib_stats_inc(s_ib_rdma_mr_1m_used);
  	ret = 0;
  
  out:
  	kfree(dma_pages);
  
  	return ret;
  }
  
  struct rds_ib_mr *rds_ib_reg_fmr(struct rds_ib_device *rds_ibdev,
  				 struct scatterlist *sg,
  				 unsigned long nents,
  				 u32 *key)
  {
  	struct rds_ib_mr *ibmr = NULL;
  	struct rds_ib_fmr *fmr;
  	int ret;
  
  	ibmr = rds_ib_alloc_fmr(rds_ibdev, nents);
  	if (IS_ERR(ibmr))
  		return ibmr;
  
  	ibmr->device = rds_ibdev;
  	fmr = &ibmr->u.fmr;
  	ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents);
  	if (ret == 0)
  		*key = fmr->fmr->rkey;
  	else
  		rds_ib_free_mr(ibmr, 0);
  
  	return ibmr;
  }
  
  void rds_ib_unreg_fmr(struct list_head *list, unsigned int *nfreed,
  		      unsigned long *unpinned, unsigned int goal)
  {
  	struct rds_ib_mr *ibmr, *next;
  	struct rds_ib_fmr *fmr;
  	LIST_HEAD(fmr_list);
  	int ret = 0;
  	unsigned int freed = *nfreed;
  
  	/* String all ib_mr's onto one list and hand them to  ib_unmap_fmr */
  	list_for_each_entry(ibmr, list, unmap_list) {
  		fmr = &ibmr->u.fmr;
  		list_add(&fmr->fmr->list, &fmr_list);
  	}
  
  	ret = ib_unmap_fmr(&fmr_list);
  	if (ret)
  		pr_warn("RDS/IB: FMR invalidation failed (err=%d)\n", ret);
  
  	/* Now we can destroy the DMA mapping and unpin any pages */
  	list_for_each_entry_safe(ibmr, next, list, unmap_list) {
  		fmr = &ibmr->u.fmr;
  		*unpinned += ibmr->sg_len;
  		__rds_ib_teardown_mr(ibmr);
  		if (freed < goal ||
  		    ibmr->remap_count >= ibmr->pool->fmr_attr.max_maps) {
  			if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
  				rds_ib_stats_inc(s_ib_rdma_mr_8k_free);
  			else
  				rds_ib_stats_inc(s_ib_rdma_mr_1m_free);
  			list_del(&ibmr->unmap_list);
  			ib_dealloc_fmr(fmr->fmr);
  			kfree(ibmr);
  			freed++;
  		}
  	}
  	*nfreed = freed;
  }
  
  void rds_ib_free_fmr_list(struct rds_ib_mr *ibmr)
  {
  	struct rds_ib_mr_pool *pool = ibmr->pool;
  
  	if (ibmr->remap_count >= pool->fmr_attr.max_maps)
  		llist_add(&ibmr->llnode, &pool->drop_list);
  	else
  		llist_add(&ibmr->llnode, &pool->free_list);
  }
  