text: /*-
   *   BSD LICENSE
   *
   *   Copyright (c) 2017 Red Hat, Inc.
   *
   *   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.
   *     * Neither the name of Intel Corporation nor the names of its
   *       contributors may be used to endorse or promote products derived
   *       from this software without specific prior written permission.
   *
   *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #ifdef RTE_LIBRTE_VHOST_NUMA
  #include <numaif.h>
  #endif
  
  #include <rte_tailq.h>
  
  #include "iotlb.h"
  #include "vhost.h"
  
  struct vhost_iotlb_entry {
  	TAILQ_ENTRY(vhost_iotlb_entry) next;
  
  	uint64_t iova;
  	uint64_t uaddr;
  	uint64_t size;
  	uint8_t perm;
  };
  
  #define IOTLB_CACHE_SIZE 2048
  
  static void
  vhost_user_iotlb_pending_remove_all(struct vhost_virtqueue *vq)
  {
  	struct vhost_iotlb_entry *node, *temp_node;
  
  	rte_rwlock_write_lock(&vq->iotlb_pending_lock);
  
  	TAILQ_FOREACH_SAFE(node, &vq->iotlb_pending_list, next, temp_node) {
  		TAILQ_REMOVE(&vq->iotlb_pending_list, node, next);
  		rte_mempool_put(vq->iotlb_pool, node);
  	}
  
  	rte_rwlock_write_unlock(&vq->iotlb_pending_lock);
  }
  
  bool
  vhost_user_iotlb_pending_miss(struct vhost_virtqueue *vq, uint64_t iova,
  				uint8_t perm)
  {
  	struct vhost_iotlb_entry *node;
  	bool found = false;
  
  	rte_rwlock_read_lock(&vq->iotlb_pending_lock);
  
  	TAILQ_FOREACH(node, &vq->iotlb_pending_list, next) {
  		if ((node->iova == iova) && (node->perm == perm)) {
  			found = true;
  			break;
  		}
  	}
  
  	rte_rwlock_read_unlock(&vq->iotlb_pending_lock);
  
  	return found;
  }
  
  void
  vhost_user_iotlb_pending_insert(struct vhost_virtqueue *vq,
  				uint64_t iova, uint8_t perm)
  {
  	struct vhost_iotlb_entry *node;
  	int ret;
  
  	ret = rte_mempool_get(vq->iotlb_pool, (void **)&node);
  	if (ret) {
  		RTE_LOG(INFO, VHOST_CONFIG,
  				"IOTLB pool empty, clear pending misses\n");
  		vhost_user_iotlb_pending_remove_all(vq);
  		ret = rte_mempool_get(vq->iotlb_pool, (void **)&node);
  		if (ret) {
  			RTE_LOG(ERR, VHOST_CONFIG, "IOTLB pool still empty, failure\n");
  			return;
  		}
  	}
  
  	node->iova = iova;
  	node->perm = perm;
  
  	rte_rwlock_write_lock(&vq->iotlb_pending_lock);
  
  	TAILQ_INSERT_TAIL(&vq->iotlb_pending_list, node, next);
  
  	rte_rwlock_write_unlock(&vq->iotlb_pending_lock);
  }
  
  static void
  vhost_user_iotlb_pending_remove(struct vhost_virtqueue *vq,
  				uint64_t iova, uint64_t size, uint8_t perm)
  {
  	struct vhost_iotlb_entry *node, *temp_node;
  
  	rte_rwlock_write_lock(&vq->iotlb_pending_lock);
  
  	TAILQ_FOREACH_SAFE(node, &vq->iotlb_pending_list, next, temp_node) {
  		if (node->iova < iova)
  			continue;
  		if (node->iova >= iova + size)
  			continue;
  		if ((node->perm & perm) != node->perm)
  			continue;
  		TAILQ_REMOVE(&vq->iotlb_pending_list, node, next);
  		rte_mempool_put(vq->iotlb_pool, node);
  	}
  
  	rte_rwlock_write_unlock(&vq->iotlb_pending_lock);
  }
  
  static void
  vhost_user_iotlb_cache_remove_all(struct vhost_virtqueue *vq)
  {
  	struct vhost_iotlb_entry *node, *temp_node;
  
  	rte_rwlock_write_lock(&vq->iotlb_lock);
  
  	TAILQ_FOREACH_SAFE(node, &vq->iotlb_list, next, temp_node) {
  		TAILQ_REMOVE(&vq->iotlb_list, node, next);
  		rte_mempool_put(vq->iotlb_pool, node);
  	}
  
  	vq->iotlb_cache_nr = 0;
  
  	rte_rwlock_write_unlock(&vq->iotlb_lock);
  }
  
  static void
  vhost_user_iotlb_cache_random_evict(struct vhost_virtqueue *vq)
  {
  	struct vhost_iotlb_entry *node, *temp_node;
  	int entry_idx;
  
  	rte_rwlock_write_lock(&vq->iotlb_lock);
  
  	entry_idx = rte_rand() % vq->iotlb_cache_nr;
  
  	TAILQ_FOREACH_SAFE(node, &vq->iotlb_list, next, temp_node) {
  		if (!entry_idx) {
  			TAILQ_REMOVE(&vq->iotlb_list, node, next);
  			rte_mempool_put(vq->iotlb_pool, node);
  			vq->iotlb_cache_nr--;
  			break;
  		}
  		entry_idx--;
  	}
  
  	rte_rwlock_write_unlock(&vq->iotlb_lock);
  }
  
  void
  vhost_user_iotlb_cache_insert(struct vhost_virtqueue *vq, uint64_t iova,
  				uint64_t uaddr, uint64_t size, uint8_t perm)
  {
  	struct vhost_iotlb_entry *node, *new_node;
  	int ret;
  
  	ret = rte_mempool_get(vq->iotlb_pool, (void **)&new_node);
  	if (ret) {
  		RTE_LOG(DEBUG, VHOST_CONFIG, "IOTLB pool empty, evict one entry\n");
  		vhost_user_iotlb_cache_random_evict(vq);
  		ret = rte_mempool_get(vq->iotlb_pool, (void **)&new_node);
  		if (ret) {
  			RTE_LOG(ERR, VHOST_CONFIG, "IOTLB pool still empty, failure\n");
  			return;
  		}
  	}
  
  	new_node->iova = iova;
  	new_node->uaddr = uaddr;
  	new_node->size = size;
  	new_node->perm = perm;
  
  	rte_rwlock_write_lock(&vq->iotlb_lock);
  
  	TAILQ_FOREACH(node, &vq->iotlb_list, next) {
  		/*
  		 * Entries must be invalidated before being updated.
  		 * So if iova already in list, assume identical.
  		 */
  		if (node->iova == new_node->iova) {
  			rte_mempool_put(vq->iotlb_pool, new_node);
  			goto unlock;
  		} else if (node->iova > new_node->iova) {
  			TAILQ_INSERT_BEFORE(node, new_node, next);
  			vq->iotlb_cache_nr++;
  			goto unlock;
  		}
  	}
  
  	TAILQ_INSERT_TAIL(&vq->iotlb_list, new_node, next);
  	vq->iotlb_cache_nr++;
  
  unlock:
  	vhost_user_iotlb_pending_remove(vq, iova, size, perm);
  
  	rte_rwlock_write_unlock(&vq->iotlb_lock);
  
  }
  
  void
  vhost_user_iotlb_cache_remove(struct vhost_virtqueue *vq,
  					uint64_t iova, uint64_t size)
  {
  	struct vhost_iotlb_entry *node, *temp_node;
  
  	if (unlikely(!size))
  		return;
  
  	rte_rwlock_write_lock(&vq->iotlb_lock);
  
  	TAILQ_FOREACH_SAFE(node, &vq->iotlb_list, next, temp_node) {
  		/* Sorted list */
  		if (unlikely(iova + size < node->iova))
  			break;
  
  		if (iova < node->iova + node->size) {
  			TAILQ_REMOVE(&vq->iotlb_list, node, next);
  			rte_mempool_put(vq->iotlb_pool, node);
  			vq->iotlb_cache_nr--;
  		}
  	}
  
  	rte_rwlock_write_unlock(&vq->iotlb_lock);
  }
  
  uint64_t
  vhost_user_iotlb_cache_find(struct vhost_virtqueue *vq, uint64_t iova,
  						uint64_t *size, uint8_t perm)
  {
  	struct vhost_iotlb_entry *node;
  	uint64_t offset, vva = 0, mapped = 0;
  
  	if (unlikely(!*size))
  		goto out;
  
  	TAILQ_FOREACH(node, &vq->iotlb_list, next) {
  		/* List sorted by iova */
  		if (unlikely(iova < node->iova))
  			break;
  
  		if (iova >= node->iova + node->size)
  			continue;
  
  		if (unlikely((perm & node->perm) != perm)) {
  			vva = 0;
  			break;
  		}
  
  		offset = iova - node->iova;
  		if (!vva)
  			vva = node->uaddr + offset;
  
  		mapped += node->size - offset;
  		iova = node->iova + node->size;
  
  		if (mapped >= *size)
  			break;
  	}
  
  out:
  	/* Only part of the requested chunk is mapped */
  	if (unlikely(mapped < *size))
  		*size = mapped;
  
  	return vva;
  }
  
  int
  vhost_user_iotlb_init(struct virtio_net *dev, int vq_index)
  {
  	char pool_name[RTE_MEMPOOL_NAMESIZE];
  	struct vhost_virtqueue *vq = dev->virtqueue[vq_index];
  	int socket = 0;
  
  	if (vq->iotlb_pool) {
  		/*
  		 * The cache has already been initialized,
  		 * just drop all cached and pending entries.
  		 */
  		vhost_user_iotlb_cache_remove_all(vq);
  		vhost_user_iotlb_pending_remove_all(vq);
  	}
  
  #ifdef RTE_LIBRTE_VHOST_NUMA
  	if (get_mempolicy(&socket, NULL, 0, vq, MPOL_F_NODE | MPOL_F_ADDR) != 0)
  		socket = 0;
  #endif
  
  	rte_rwlock_init(&vq->iotlb_lock);
  	rte_rwlock_init(&vq->iotlb_pending_lock);
  
  	TAILQ_INIT(&vq->iotlb_list);
  	TAILQ_INIT(&vq->iotlb_pending_list);
  
  	snprintf(pool_name, sizeof(pool_name), "iotlb_cache_%d_%d",
  			dev->vid, vq_index);
  
  	/* If already created, free it and recreate */
  	vq->iotlb_pool = rte_mempool_lookup(pool_name);
  	if (vq->iotlb_pool)
  		rte_mempool_free(vq->iotlb_pool);
  
  	vq->iotlb_pool = rte_mempool_create(pool_name,
  			IOTLB_CACHE_SIZE, sizeof(struct vhost_iotlb_entry), 0,
  			0, 0, NULL, NULL, NULL, socket,
  			MEMPOOL_F_NO_CACHE_ALIGN |
  			MEMPOOL_F_SP_PUT |
  			MEMPOOL_F_SC_GET);
  	if (!vq->iotlb_pool) {
  		RTE_LOG(ERR, VHOST_CONFIG,
  				"Failed to create IOTLB cache pool (%s)\n",
  				pool_name);
  		return -1;
  	}
  
  	vq->iotlb_cache_nr = 0;
  
  	return 0;
  }
  
  