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_ctx - 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 * @opaque: the opaque pointer for the new mapping 46 * 47 * Returns an error last is smaller than start or memory allocation 48 * fails 49 */ 50 int 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 (iotlb->limit && 61 iotlb->nmaps == iotlb->limit && 62 iotlb->flags & VHOST_IOTLB_FLAG_RETIRE) { 63 map = list_first_entry(&iotlb->list, typeof(*map), link); 64 vhost_iotlb_map_free(iotlb, map); 65 } 66 67 map = kmalloc(sizeof(*map), GFP_ATOMIC); 68 if (!map) 69 return -ENOMEM; 70 71 map->start = start; 72 map->size = last - start + 1; 73 map->last = last; 74 map->addr = addr; 75 map->perm = perm; 76 map->opaque = opaque; 77 78 iotlb->nmaps++; 79 vhost_iotlb_itree_insert(map, &iotlb->root); 80 81 INIT_LIST_HEAD(&map->link); 82 list_add_tail(&map->link, &iotlb->list); 83 84 return 0; 85 } 86 EXPORT_SYMBOL_GPL(vhost_iotlb_add_range_ctx); 87 88 int vhost_iotlb_add_range(struct vhost_iotlb *iotlb, 89 u64 start, u64 last, 90 u64 addr, unsigned int perm) 91 { 92 return vhost_iotlb_add_range_ctx(iotlb, start, last, 93 addr, perm, NULL); 94 } 95 EXPORT_SYMBOL_GPL(vhost_iotlb_add_range); 96 97 /** 98 * vhost_iotlb_del_range - delete overlapped ranges from vhost IOTLB 99 * @iotlb: the IOTLB 100 * @start: start of the IOVA range 101 * @last: last of IOVA range 102 */ 103 void vhost_iotlb_del_range(struct vhost_iotlb *iotlb, u64 start, u64 last) 104 { 105 struct vhost_iotlb_map *map; 106 107 while ((map = vhost_iotlb_itree_iter_first(&iotlb->root, 108 start, last))) 109 vhost_iotlb_map_free(iotlb, map); 110 } 111 EXPORT_SYMBOL_GPL(vhost_iotlb_del_range); 112 113 /** 114 * vhost_iotlb_alloc - add a new vhost IOTLB 115 * @limit: maximum number of IOTLB entries 116 * @flags: VHOST_IOTLB_FLAG_XXX 117 * 118 * Returns an error is memory allocation fails 119 */ 120 struct vhost_iotlb *vhost_iotlb_alloc(unsigned int limit, unsigned int flags) 121 { 122 struct vhost_iotlb *iotlb = kzalloc(sizeof(*iotlb), GFP_KERNEL); 123 124 if (!iotlb) 125 return NULL; 126 127 iotlb->root = RB_ROOT_CACHED; 128 iotlb->limit = limit; 129 iotlb->nmaps = 0; 130 iotlb->flags = flags; 131 INIT_LIST_HEAD(&iotlb->list); 132 133 return iotlb; 134 } 135 EXPORT_SYMBOL_GPL(vhost_iotlb_alloc); 136 137 /** 138 * vhost_iotlb_reset - reset vhost IOTLB (free all IOTLB entries) 139 * @iotlb: the IOTLB to be reset 140 */ 141 void vhost_iotlb_reset(struct vhost_iotlb *iotlb) 142 { 143 vhost_iotlb_del_range(iotlb, 0ULL, 0ULL - 1); 144 } 145 EXPORT_SYMBOL_GPL(vhost_iotlb_reset); 146 147 /** 148 * vhost_iotlb_free - reset and free vhost IOTLB 149 * @iotlb: the IOTLB to be freed 150 */ 151 void vhost_iotlb_free(struct vhost_iotlb *iotlb) 152 { 153 if (iotlb) { 154 vhost_iotlb_reset(iotlb); 155 kfree(iotlb); 156 } 157 } 158 EXPORT_SYMBOL_GPL(vhost_iotlb_free); 159 160 /** 161 * vhost_iotlb_itree_first - return the first overlapped range 162 * @iotlb: the IOTLB 163 * @start: start of IOVA range 164 * @last: last byte in IOVA range 165 */ 166 struct vhost_iotlb_map * 167 vhost_iotlb_itree_first(struct vhost_iotlb *iotlb, u64 start, u64 last) 168 { 169 return vhost_iotlb_itree_iter_first(&iotlb->root, start, last); 170 } 171 EXPORT_SYMBOL_GPL(vhost_iotlb_itree_first); 172 173 /** 174 * vhost_iotlb_itree_next - return the next overlapped range 175 * @map: the starting map node 176 * @start: start of IOVA range 177 * @last: last byte IOVA range 178 */ 179 struct vhost_iotlb_map * 180 vhost_iotlb_itree_next(struct vhost_iotlb_map *map, u64 start, u64 last) 181 { 182 return vhost_iotlb_itree_iter_next(map, start, last); 183 } 184 EXPORT_SYMBOL_GPL(vhost_iotlb_itree_next); 185 186 MODULE_VERSION(MOD_VERSION); 187 MODULE_DESCRIPTION(MOD_DESC); 188 MODULE_AUTHOR(MOD_AUTHOR); 189 MODULE_LICENSE(MOD_LICENSE); 190