1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 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 19 INTERVAL_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 it 25 * @iotlb: the IOTLB 26 * @map: the map that want to be remove and freed 27 */ 28 void 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 } 36 EXPORT_SYMBOL_GPL(vhost_iotlb_map_free); 37 38 /** 39 * vhost_iotlb_add_range - add a new range to vhost IOTLB 40 * @iotlb: the IOTLB 41 * @start: start of the IOVA range 42 * @last: last of IOVA range 43 * @addr: the address that is mapped to @start 44 * @perm: access permission of this range 45 * 46 * Returns an error last is smaller than start or memory allocation 47 * fails 48 */ 49 int vhost_iotlb_add_range(struct vhost_iotlb *iotlb, 50 u64 start, u64 last, 51 u64 addr, unsigned int perm) 52 { 53 struct vhost_iotlb_map *map; 54 55 if (last < start) 56 return -EFAULT; 57 58 if (iotlb->limit && 59 iotlb->nmaps == iotlb->limit && 60 iotlb->flags & VHOST_IOTLB_FLAG_RETIRE) { 61 map = list_first_entry(&iotlb->list, typeof(*map), link); 62 vhost_iotlb_map_free(iotlb, map); 63 } 64 65 map = kmalloc(sizeof(*map), GFP_ATOMIC); 66 if (!map) 67 return -ENOMEM; 68 69 map->start = start; 70 map->size = last - start + 1; 71 map->last = last; 72 map->addr = addr; 73 map->perm = perm; 74 75 iotlb->nmaps++; 76 vhost_iotlb_itree_insert(map, &iotlb->root); 77 78 INIT_LIST_HEAD(&map->link); 79 list_add_tail(&map->link, &iotlb->list); 80 81 return 0; 82 } 83 EXPORT_SYMBOL_GPL(vhost_iotlb_add_range); 84 85 /** 86 * vhost_iotlb_del_range - delete overlapped ranges from vhost IOTLB 87 * @iotlb: the IOTLB 88 * @start: start of the IOVA range 89 * @last: last of IOVA range 90 */ 91 void vhost_iotlb_del_range(struct vhost_iotlb *iotlb, u64 start, u64 last) 92 { 93 struct vhost_iotlb_map *map; 94 95 while ((map = vhost_iotlb_itree_iter_first(&iotlb->root, 96 start, last))) 97 vhost_iotlb_map_free(iotlb, map); 98 } 99 EXPORT_SYMBOL_GPL(vhost_iotlb_del_range); 100 101 /** 102 * vhost_iotlb_alloc - add a new vhost IOTLB 103 * @limit: maximum number of IOTLB entries 104 * @flags: VHOST_IOTLB_FLAG_XXX 105 * 106 * Returns an error is memory allocation fails 107 */ 108 struct vhost_iotlb *vhost_iotlb_alloc(unsigned int limit, unsigned int flags) 109 { 110 struct vhost_iotlb *iotlb = kzalloc(sizeof(*iotlb), GFP_KERNEL); 111 112 if (!iotlb) 113 return NULL; 114 115 iotlb->root = RB_ROOT_CACHED; 116 iotlb->limit = limit; 117 iotlb->nmaps = 0; 118 iotlb->flags = flags; 119 INIT_LIST_HEAD(&iotlb->list); 120 121 return iotlb; 122 } 123 EXPORT_SYMBOL_GPL(vhost_iotlb_alloc); 124 125 /** 126 * vhost_iotlb_reset - reset vhost IOTLB (free all IOTLB entries) 127 * @iotlb: the IOTLB to be reset 128 */ 129 void vhost_iotlb_reset(struct vhost_iotlb *iotlb) 130 { 131 vhost_iotlb_del_range(iotlb, 0ULL, 0ULL - 1); 132 } 133 EXPORT_SYMBOL_GPL(vhost_iotlb_reset); 134 135 /** 136 * vhost_iotlb_free - reset and free vhost IOTLB 137 * @iotlb: the IOTLB to be freed 138 */ 139 void vhost_iotlb_free(struct vhost_iotlb *iotlb) 140 { 141 if (iotlb) { 142 vhost_iotlb_reset(iotlb); 143 kfree(iotlb); 144 } 145 } 146 EXPORT_SYMBOL_GPL(vhost_iotlb_free); 147 148 /** 149 * vhost_iotlb_itree_first - return the first overlapped range 150 * @iotlb: the IOTLB 151 * @start: start of IOVA range 152 * @last: last byte in IOVA range 153 */ 154 struct vhost_iotlb_map * 155 vhost_iotlb_itree_first(struct vhost_iotlb *iotlb, u64 start, u64 last) 156 { 157 return vhost_iotlb_itree_iter_first(&iotlb->root, start, last); 158 } 159 EXPORT_SYMBOL_GPL(vhost_iotlb_itree_first); 160 161 /** 162 * vhost_iotlb_itree_next - return the next overlapped range 163 * @map: the starting map node 164 * @start: start of IOVA range 165 * @last: last byte IOVA range 166 */ 167 struct vhost_iotlb_map * 168 vhost_iotlb_itree_next(struct vhost_iotlb_map *map, u64 start, u64 last) 169 { 170 return vhost_iotlb_itree_iter_next(map, start, last); 171 } 172 EXPORT_SYMBOL_GPL(vhost_iotlb_itree_next); 173 174 MODULE_VERSION(MOD_VERSION); 175 MODULE_DESCRIPTION(MOD_DESC); 176 MODULE_AUTHOR(MOD_AUTHOR); 177 MODULE_LICENSE(MOD_LICENSE); 178