| // SPDX-License-Identifier: GPL-2.0-only |
| /* Copyright (C) 2020 Red Hat, Inc. |
| * Author: Jason Wang <jasowang@redhat.com> |
| * |
| * IOTLB implementation for vhost. |
| */ |
| #include <linux/slab.h> |
| #include <linux/vhost_iotlb.h> |
| #include <linux/module.h> |
| |
| #define MOD_VERSION "0.1" |
| #define MOD_DESC "VHOST IOTLB" |
| #define MOD_AUTHOR "Jason Wang <jasowang@redhat.com>" |
| #define MOD_LICENSE "GPL v2" |
| |
| #define START(map) ((map)->start) |
| #define LAST(map) ((map)->last) |
| |
| INTERVAL_TREE_DEFINE(struct vhost_iotlb_map, |
| rb, __u64, __subtree_last, |
| START, LAST, static inline, vhost_iotlb_itree); |
| |
| /** |
| * vhost_iotlb_map_free - remove a map node and free it |
| * @iotlb: the IOTLB |
| * @map: the map that want to be remove and freed |
| */ |
| void vhost_iotlb_map_free(struct vhost_iotlb *iotlb, |
| struct vhost_iotlb_map *map) |
| { |
| vhost_iotlb_itree_remove(map, &iotlb->root); |
| list_del(&map->link); |
| kfree(map); |
| iotlb->nmaps--; |
| } |
| EXPORT_SYMBOL_GPL(vhost_iotlb_map_free); |
| |
| /** |
| * vhost_iotlb_add_range_ctx - add a new range to vhost IOTLB |
| * @iotlb: the IOTLB |
| * @start: start of the IOVA range |
| * @last: last of IOVA range |
| * @addr: the address that is mapped to @start |
| * @perm: access permission of this range |
| * @opaque: the opaque pointer for the new mapping |
| * |
| * Returns an error last is smaller than start or memory allocation |
| * fails |
| */ |
| int vhost_iotlb_add_range_ctx(struct vhost_iotlb *iotlb, |
| u64 start, u64 last, |
| u64 addr, unsigned int perm, |
| void *opaque) |
| { |
| struct vhost_iotlb_map *map; |
| |
| if (last < start) |
| return -EFAULT; |
| |
| /* If the range being mapped is [0, ULONG_MAX], split it into two entries |
| * otherwise its size would overflow u64. |
| */ |
| if (start == 0 && last == ULONG_MAX) { |
| u64 mid = last / 2; |
| int err = vhost_iotlb_add_range_ctx(iotlb, start, mid, addr, |
| perm, opaque); |
| |
| if (err) |
| return err; |
| |
| addr += mid + 1; |
| start = mid + 1; |
| } |
| |
| if (iotlb->limit && |
| iotlb->nmaps == iotlb->limit && |
| iotlb->flags & VHOST_IOTLB_FLAG_RETIRE) { |
| map = list_first_entry(&iotlb->list, typeof(*map), link); |
| vhost_iotlb_map_free(iotlb, map); |
| } |
| |
| map = kmalloc(sizeof(*map), GFP_ATOMIC); |
| if (!map) |
| return -ENOMEM; |
| |
| map->start = start; |
| map->size = last - start + 1; |
| map->last = last; |
| map->addr = addr; |
| map->perm = perm; |
| map->opaque = opaque; |
| |
| iotlb->nmaps++; |
| vhost_iotlb_itree_insert(map, &iotlb->root); |
| |
| INIT_LIST_HEAD(&map->link); |
| list_add_tail(&map->link, &iotlb->list); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(vhost_iotlb_add_range_ctx); |
| |
| int vhost_iotlb_add_range(struct vhost_iotlb *iotlb, |
| u64 start, u64 last, |
| u64 addr, unsigned int perm) |
| { |
| return vhost_iotlb_add_range_ctx(iotlb, start, last, |
| addr, perm, NULL); |
| } |
| EXPORT_SYMBOL_GPL(vhost_iotlb_add_range); |
| |
| /** |
| * vhost_iotlb_del_range - delete overlapped ranges from vhost IOTLB |
| * @iotlb: the IOTLB |
| * @start: start of the IOVA range |
| * @last: last of IOVA range |
| */ |
| void vhost_iotlb_del_range(struct vhost_iotlb *iotlb, u64 start, u64 last) |
| { |
| struct vhost_iotlb_map *map; |
| |
| while ((map = vhost_iotlb_itree_iter_first(&iotlb->root, |
| start, last))) |
| vhost_iotlb_map_free(iotlb, map); |
| } |
| EXPORT_SYMBOL_GPL(vhost_iotlb_del_range); |
| |
| /** |
| * vhost_iotlb_alloc - add a new vhost IOTLB |
| * @limit: maximum number of IOTLB entries |
| * @flags: VHOST_IOTLB_FLAG_XXX |
| * |
| * Returns an error is memory allocation fails |
| */ |
| struct vhost_iotlb *vhost_iotlb_alloc(unsigned int limit, unsigned int flags) |
| { |
| struct vhost_iotlb *iotlb = kzalloc(sizeof(*iotlb), GFP_KERNEL); |
| |
| if (!iotlb) |
| return NULL; |
| |
| iotlb->root = RB_ROOT_CACHED; |
| iotlb->limit = limit; |
| iotlb->nmaps = 0; |
| iotlb->flags = flags; |
| INIT_LIST_HEAD(&iotlb->list); |
| |
| return iotlb; |
| } |
| EXPORT_SYMBOL_GPL(vhost_iotlb_alloc); |
| |
| /** |
| * vhost_iotlb_reset - reset vhost IOTLB (free all IOTLB entries) |
| * @iotlb: the IOTLB to be reset |
| */ |
| void vhost_iotlb_reset(struct vhost_iotlb *iotlb) |
| { |
| vhost_iotlb_del_range(iotlb, 0ULL, 0ULL - 1); |
| } |
| EXPORT_SYMBOL_GPL(vhost_iotlb_reset); |
| |
| /** |
| * vhost_iotlb_free - reset and free vhost IOTLB |
| * @iotlb: the IOTLB to be freed |
| */ |
| void vhost_iotlb_free(struct vhost_iotlb *iotlb) |
| { |
| if (iotlb) { |
| vhost_iotlb_reset(iotlb); |
| kfree(iotlb); |
| } |
| } |
| EXPORT_SYMBOL_GPL(vhost_iotlb_free); |
| |
| /** |
| * vhost_iotlb_itree_first - return the first overlapped range |
| * @iotlb: the IOTLB |
| * @start: start of IOVA range |
| * @last: last byte in IOVA range |
| */ |
| struct vhost_iotlb_map * |
| vhost_iotlb_itree_first(struct vhost_iotlb *iotlb, u64 start, u64 last) |
| { |
| return vhost_iotlb_itree_iter_first(&iotlb->root, start, last); |
| } |
| EXPORT_SYMBOL_GPL(vhost_iotlb_itree_first); |
| |
| /** |
| * vhost_iotlb_itree_next - return the next overlapped range |
| * @map: the starting map node |
| * @start: start of IOVA range |
| * @last: last byte IOVA range |
| */ |
| struct vhost_iotlb_map * |
| vhost_iotlb_itree_next(struct vhost_iotlb_map *map, u64 start, u64 last) |
| { |
| return vhost_iotlb_itree_iter_next(map, start, last); |
| } |
| EXPORT_SYMBOL_GPL(vhost_iotlb_itree_next); |
| |
| MODULE_VERSION(MOD_VERSION); |
| MODULE_DESCRIPTION(MOD_DESC); |
| MODULE_AUTHOR(MOD_AUTHOR); |
| MODULE_LICENSE(MOD_LICENSE); |