1 // SPDX-License-Identifier: GPL-2.0
2 /* XDP user-space ring structure
3 * Copyright(c) 2018 Intel Corporation.
4 */
5
6 #include <linux/log2.h>
7 #include <linux/slab.h>
8 #include <linux/overflow.h>
9 #include <linux/vmalloc.h>
10 #include <net/xdp_sock_drv.h>
11
12 #include "xsk_queue.h"
13
14 static size_t xskq_get_ring_size(struct xsk_queue *q, bool umem_queue)
15 {
16 struct xdp_umem_ring *umem_ring;
17 struct xdp_rxtx_ring *rxtx_ring;
18
19 if (umem_queue)
20 return struct_size(umem_ring, desc, q->nentries);
21 return struct_size(rxtx_ring, desc, q->nentries);
22 }
23
24 struct xsk_queue *xskq_create(u32 nentries, bool umem_queue)
25 {
26 struct xsk_queue *q;
27 size_t size;
28
29 q = kzalloc(sizeof(*q), GFP_KERNEL);
30 if (!q)
31 return NULL;
32
33 q->nentries = nentries;
34 q->ring_mask = nentries - 1;
35
36 size = xskq_get_ring_size(q, umem_queue);
37
38 /* size which is overflowing or close to SIZE_MAX will become 0 in
39 * PAGE_ALIGN(), checking SIZE_MAX is enough due to the previous
40 * is_power_of_2(), the rest will be handled by vmalloc_user()
41 */
42 if (unlikely(size == SIZE_MAX)) {
43 kfree(q);
44 return NULL;
45 }
46
47 size = PAGE_ALIGN(size);
48
49 q->ring = vmalloc_user(size);
50 if (!q->ring) {
51 kfree(q);
52 return NULL;
53 }
54
55 q->ring_vmalloc_size = size;
56 return q;
57 }
58
59 void xskq_destroy(struct xsk_queue *q)
60 {
61 if (!q)
62 return;
63
64 vfree(q->ring);
65 kfree(q);
66 }
67
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