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
14static 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
24struct 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
59void xskq_destroy(struct xsk_queue *q)
60{
61	if (!q)
62		return;
63
64	vfree(q->ring);
65	kfree(q);
66}
67