xref: /openbmc/linux/net/xdp/xsk_queue.c (revision 842ed298)
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 <net/xdp_sock_drv.h>
10 
11 #include "xsk_queue.h"
12 
13 static size_t xskq_get_ring_size(struct xsk_queue *q, bool umem_queue)
14 {
15 	struct xdp_umem_ring *umem_ring;
16 	struct xdp_rxtx_ring *rxtx_ring;
17 
18 	if (umem_queue)
19 		return struct_size(umem_ring, desc, q->nentries);
20 	return struct_size(rxtx_ring, desc, q->nentries);
21 }
22 
23 struct xsk_queue *xskq_create(u32 nentries, bool umem_queue)
24 {
25 	struct xsk_queue *q;
26 	gfp_t gfp_flags;
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 	gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN |
37 		    __GFP_COMP  | __GFP_NORETRY;
38 	size = xskq_get_ring_size(q, umem_queue);
39 
40 	q->ring = (struct xdp_ring *)__get_free_pages(gfp_flags,
41 						      get_order(size));
42 	if (!q->ring) {
43 		kfree(q);
44 		return NULL;
45 	}
46 
47 	return q;
48 }
49 
50 void xskq_destroy(struct xsk_queue *q)
51 {
52 	if (!q)
53 		return;
54 
55 	page_frag_free(q->ring);
56 	kfree(q);
57 }
58