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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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
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 it
25 * @iotlb: the IOTLB
26 * @map: the map that want to be remove and freed
27 */
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 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 */
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 (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}
86EXPORT_SYMBOL_GPL(vhost_iotlb_add_range_ctx);
87
88int 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}
95EXPORT_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 */
103void 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}
111EXPORT_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 */
120struct 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}
135EXPORT_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 */
141void vhost_iotlb_reset(struct vhost_iotlb *iotlb)
142{
143 vhost_iotlb_del_range(iotlb, 0ULL, 0ULL - 1);
144}
145EXPORT_SYMBOL_GPL(vhost_iotlb_reset);
146
147/**
148 * vhost_iotlb_free - reset and free vhost IOTLB
149 * @iotlb: the IOTLB to be freed
150 */
151void vhost_iotlb_free(struct vhost_iotlb *iotlb)
152{
153 if (iotlb) {
154 vhost_iotlb_reset(iotlb);
155 kfree(iotlb);
156 }
157}
158EXPORT_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 */
166struct vhost_iotlb_map *
167vhost_iotlb_itree_first(struct vhost_iotlb *iotlb, u64 start, u64 last)
168{
169 return vhost_iotlb_itree_iter_first(&iotlb->root, start, last);
170}
171EXPORT_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 */
179struct vhost_iotlb_map *
180vhost_iotlb_itree_next(struct vhost_iotlb_map *map, u64 start, u64 last)
181{
182 return vhost_iotlb_itree_iter_next(map, start, last);
183}
184EXPORT_SYMBOL_GPL(vhost_iotlb_itree_next);
185
186MODULE_VERSION(MOD_VERSION);
187MODULE_DESCRIPTION(MOD_DESC);
188MODULE_AUTHOR(MOD_AUTHOR);
189MODULE_LICENSE(MOD_LICENSE);