xref: /openbmc/linux/net/xdp/xsk_queue.c (revision 1a2bd3bd)
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 	size = PAGE_ALIGN(size);
38 
39 	q->ring = vmalloc_user(size);
40 	if (!q->ring) {
41 		kfree(q);
42 		return NULL;
43 	}
44 
45 	q->ring_vmalloc_size = size;
46 	return q;
47 }
48 
49 void xskq_destroy(struct xsk_queue *q)
50 {
51 	if (!q)
52 		return;
53 
54 	vfree(q->ring);
55 	kfree(q);
56 }
57