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 */ vhost_iotlb_map_free(struct vhost_iotlb * iotlb,struct vhost_iotlb_map * map)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 */ vhost_iotlb_add_range_ctx(struct vhost_iotlb * iotlb,u64 start,u64 last,u64 addr,unsigned int perm,void * opaque)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 the range being mapped is [0, ULONG_MAX], split it into two entries 61 * 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 } 101 EXPORT_SYMBOL_GPL(vhost_iotlb_add_range_ctx); 102 vhost_iotlb_add_range(struct vhost_iotlb * iotlb,u64 start,u64 last,u64 addr,unsigned int perm)103 int 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 } 110 EXPORT_SYMBOL_GPL(vhost_iotlb_add_range); 111 112 /** 113 * vhost_iotlb_del_range - delete overlapped ranges from vhost IOTLB 114 * @iotlb: the IOTLB 115 * @start: start of the IOVA range 116 * @last: last of IOVA range 117 */ vhost_iotlb_del_range(struct vhost_iotlb * iotlb,u64 start,u64 last)118 void 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 } 126 EXPORT_SYMBOL_GPL(vhost_iotlb_del_range); 127 128 /** 129 * vhost_iotlb_init - initialize a vhost IOTLB 130 * @iotlb: the IOTLB that needs to be initialized 131 * @limit: maximum number of IOTLB entries 132 * @flags: VHOST_IOTLB_FLAG_XXX 133 */ vhost_iotlb_init(struct vhost_iotlb * iotlb,unsigned int limit,unsigned int flags)134 void 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 } 143 EXPORT_SYMBOL_GPL(vhost_iotlb_init); 144 145 /** 146 * vhost_iotlb_alloc - add a new vhost IOTLB 147 * @limit: maximum number of IOTLB entries 148 * @flags: VHOST_IOTLB_FLAG_XXX 149 * 150 * Returns an error is memory allocation fails 151 */ vhost_iotlb_alloc(unsigned int limit,unsigned int flags)152 struct 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 } 163 EXPORT_SYMBOL_GPL(vhost_iotlb_alloc); 164 165 /** 166 * vhost_iotlb_reset - reset vhost IOTLB (free all IOTLB entries) 167 * @iotlb: the IOTLB to be reset 168 */ vhost_iotlb_reset(struct vhost_iotlb * iotlb)169 void vhost_iotlb_reset(struct vhost_iotlb *iotlb) 170 { 171 vhost_iotlb_del_range(iotlb, 0ULL, 0ULL - 1); 172 } 173 EXPORT_SYMBOL_GPL(vhost_iotlb_reset); 174 175 /** 176 * vhost_iotlb_free - reset and free vhost IOTLB 177 * @iotlb: the IOTLB to be freed 178 */ vhost_iotlb_free(struct vhost_iotlb * iotlb)179 void vhost_iotlb_free(struct vhost_iotlb *iotlb) 180 { 181 if (iotlb) { 182 vhost_iotlb_reset(iotlb); 183 kfree(iotlb); 184 } 185 } 186 EXPORT_SYMBOL_GPL(vhost_iotlb_free); 187 188 /** 189 * vhost_iotlb_itree_first - return the first overlapped range 190 * @iotlb: the IOTLB 191 * @start: start of IOVA range 192 * @last: last byte in IOVA range 193 */ 194 struct vhost_iotlb_map * vhost_iotlb_itree_first(struct vhost_iotlb * iotlb,u64 start,u64 last)195 vhost_iotlb_itree_first(struct vhost_iotlb *iotlb, u64 start, u64 last) 196 { 197 return vhost_iotlb_itree_iter_first(&iotlb->root, start, last); 198 } 199 EXPORT_SYMBOL_GPL(vhost_iotlb_itree_first); 200 201 /** 202 * vhost_iotlb_itree_next - return the next overlapped range 203 * @map: the starting map node 204 * @start: start of IOVA range 205 * @last: last byte IOVA range 206 */ 207 struct vhost_iotlb_map * vhost_iotlb_itree_next(struct vhost_iotlb_map * map,u64 start,u64 last)208 vhost_iotlb_itree_next(struct vhost_iotlb_map *map, u64 start, u64 last) 209 { 210 return vhost_iotlb_itree_iter_next(map, start, last); 211 } 212 EXPORT_SYMBOL_GPL(vhost_iotlb_itree_next); 213 214 MODULE_VERSION(MOD_VERSION); 215 MODULE_DESCRIPTION(MOD_DESC); 216 MODULE_AUTHOR(MOD_AUTHOR); 217 MODULE_LICENSE(MOD_LICENSE); 218