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1// SPDX-License-Identifier: GPL-2.0-only2/* Copyright (C) 2020 Red Hat, Inc.3 * Author: Jason Wang <jasowang@redhat.com>4 *5 * IOTLB implementation for vhost.6 */7#include <linux/slab.h>8#include <linux/vhost_iotlb.h>9#include <linux/module.h>10 11#define MOD_VERSION "0.1"12#define MOD_DESC "VHOST IOTLB"13#define MOD_AUTHOR "Jason Wang <jasowang@redhat.com>"14#define MOD_LICENSE "GPL v2"15 16#define START(map) ((map)->start)17#define LAST(map) ((map)->last)18 19INTERVAL_TREE_DEFINE(struct vhost_iotlb_map,20 rb, __u64, __subtree_last,21 START, LAST, static inline, vhost_iotlb_itree);22 23/**24 * vhost_iotlb_map_free - remove a map node and free it25 * @iotlb: the IOTLB26 * @map: the map that want to be remove and freed27 */28void vhost_iotlb_map_free(struct vhost_iotlb *iotlb,29 struct vhost_iotlb_map *map)30{31 vhost_iotlb_itree_remove(map, &iotlb->root);32 list_del(&map->link);33 kfree(map);34 iotlb->nmaps--;35}36EXPORT_SYMBOL_GPL(vhost_iotlb_map_free);37 38/**39 * vhost_iotlb_add_range_ctx - add a new range to vhost IOTLB40 * @iotlb: the IOTLB41 * @start: start of the IOVA range42 * @last: last of IOVA range43 * @addr: the address that is mapped to @start44 * @perm: access permission of this range45 * @opaque: the opaque pointer for the new mapping46 *47 * Returns an error last is smaller than start or memory allocation48 * fails49 */50int vhost_iotlb_add_range_ctx(struct vhost_iotlb *iotlb,51 u64 start, u64 last,52 u64 addr, unsigned int perm,53 void *opaque)54{55 struct vhost_iotlb_map *map;56 57 if (last < start)58 return -EFAULT;59 60 /* If the range being mapped is [0, ULONG_MAX], split it into two entries61 * otherwise its size would overflow u64.62 */63 if (start == 0 && last == ULONG_MAX) {64 u64 mid = last / 2;65 int err = vhost_iotlb_add_range_ctx(iotlb, start, mid, addr,66 perm, opaque);67 68 if (err)69 return err;70 71 addr += mid + 1;72 start = mid + 1;73 }74 75 if (iotlb->limit &&76 iotlb->nmaps == iotlb->limit &&77 iotlb->flags & VHOST_IOTLB_FLAG_RETIRE) {78 map = list_first_entry(&iotlb->list, typeof(*map), link);79 vhost_iotlb_map_free(iotlb, map);80 }81 82 map = kmalloc(sizeof(*map), GFP_ATOMIC);83 if (!map)84 return -ENOMEM;85 86 map->start = start;87 map->size = last - start + 1;88 map->last = last;89 map->addr = addr;90 map->perm = perm;91 map->opaque = opaque;92 93 iotlb->nmaps++;94 vhost_iotlb_itree_insert(map, &iotlb->root);95 96 INIT_LIST_HEAD(&map->link);97 list_add_tail(&map->link, &iotlb->list);98 99 return 0;100}101EXPORT_SYMBOL_GPL(vhost_iotlb_add_range_ctx);102 103int vhost_iotlb_add_range(struct vhost_iotlb *iotlb,104 u64 start, u64 last,105 u64 addr, unsigned int perm)106{107 return vhost_iotlb_add_range_ctx(iotlb, start, last,108 addr, perm, NULL);109}110EXPORT_SYMBOL_GPL(vhost_iotlb_add_range);111 112/**113 * vhost_iotlb_del_range - delete overlapped ranges from vhost IOTLB114 * @iotlb: the IOTLB115 * @start: start of the IOVA range116 * @last: last of IOVA range117 */118void vhost_iotlb_del_range(struct vhost_iotlb *iotlb, u64 start, u64 last)119{120 struct vhost_iotlb_map *map;121 122 while ((map = vhost_iotlb_itree_iter_first(&iotlb->root,123 start, last)))124 vhost_iotlb_map_free(iotlb, map);125}126EXPORT_SYMBOL_GPL(vhost_iotlb_del_range);127 128/**129 * vhost_iotlb_init - initialize a vhost IOTLB130 * @iotlb: the IOTLB that needs to be initialized131 * @limit: maximum number of IOTLB entries132 * @flags: VHOST_IOTLB_FLAG_XXX133 */134void vhost_iotlb_init(struct vhost_iotlb *iotlb, unsigned int limit,135 unsigned int flags)136{137 iotlb->root = RB_ROOT_CACHED;138 iotlb->limit = limit;139 iotlb->nmaps = 0;140 iotlb->flags = flags;141 INIT_LIST_HEAD(&iotlb->list);142}143EXPORT_SYMBOL_GPL(vhost_iotlb_init);144 145/**146 * vhost_iotlb_alloc - add a new vhost IOTLB147 * @limit: maximum number of IOTLB entries148 * @flags: VHOST_IOTLB_FLAG_XXX149 *150 * Returns an error is memory allocation fails151 */152struct vhost_iotlb *vhost_iotlb_alloc(unsigned int limit, unsigned int flags)153{154 struct vhost_iotlb *iotlb = kzalloc(sizeof(*iotlb), GFP_KERNEL);155 156 if (!iotlb)157 return NULL;158 159 vhost_iotlb_init(iotlb, limit, flags);160 161 return iotlb;162}163EXPORT_SYMBOL_GPL(vhost_iotlb_alloc);164 165/**166 * vhost_iotlb_reset - reset vhost IOTLB (free all IOTLB entries)167 * @iotlb: the IOTLB to be reset168 */169void vhost_iotlb_reset(struct vhost_iotlb *iotlb)170{171 vhost_iotlb_del_range(iotlb, 0ULL, 0ULL - 1);172}173EXPORT_SYMBOL_GPL(vhost_iotlb_reset);174 175/**176 * vhost_iotlb_free - reset and free vhost IOTLB177 * @iotlb: the IOTLB to be freed178 */179void vhost_iotlb_free(struct vhost_iotlb *iotlb)180{181 if (iotlb) {182 vhost_iotlb_reset(iotlb);183 kfree(iotlb);184 }185}186EXPORT_SYMBOL_GPL(vhost_iotlb_free);187 188/**189 * vhost_iotlb_itree_first - return the first overlapped range190 * @iotlb: the IOTLB191 * @start: start of IOVA range192 * @last: last byte in IOVA range193 */194struct vhost_iotlb_map *195vhost_iotlb_itree_first(struct vhost_iotlb *iotlb, u64 start, u64 last)196{197 return vhost_iotlb_itree_iter_first(&iotlb->root, start, last);198}199EXPORT_SYMBOL_GPL(vhost_iotlb_itree_first);200 201/**202 * vhost_iotlb_itree_next - return the next overlapped range203 * @map: the starting map node204 * @start: start of IOVA range205 * @last: last byte IOVA range206 */207struct vhost_iotlb_map *208vhost_iotlb_itree_next(struct vhost_iotlb_map *map, u64 start, u64 last)209{210 return vhost_iotlb_itree_iter_next(map, start, last);211}212EXPORT_SYMBOL_GPL(vhost_iotlb_itree_next);213 214MODULE_VERSION(MOD_VERSION);215MODULE_DESCRIPTION(MOD_DESC);216MODULE_AUTHOR(MOD_AUTHOR);217MODULE_LICENSE(MOD_LICENSE);218