net/xdp/xsk_queue.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /* XDP user-space ring structure
0003  * Copyright(c) 2018 Intel Corporation.
0004  */
0005
0006 #include <linux/log2.h>
0007 #include <linux/slab.h>
0008 #include <linux/overflow.h>
0009 #include <net/xdp_sock_drv.h>
0010
0011 #include "xsk_queue.h"
0012
0013 static size_t xskq_get_ring_size(struct xsk_queue *q, bool umem_queue)
0014 {
0015     struct xdp_umem_ring *umem_ring;
0016     struct xdp_rxtx_ring *rxtx_ring;
0017
0018     if (umem_queue)
0019         return struct_size(umem_ring, desc, q->nentries);
0020     return struct_size(rxtx_ring, desc, q->nentries);
0021 }
0022
0023 struct xsk_queue *xskq_create(u32 nentries, bool umem_queue)
0024 {
0025     struct xsk_queue *q;
0026     gfp_t gfp_flags;
0027     size_t size;
0028
0029     q = kzalloc(sizeof(*q), GFP_KERNEL);
0030     if (!q)
0031         return NULL;
0032
0033     q->nentries = nentries;
0034     q->ring_mask = nentries - 1;
0035
0036     gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN |
0037             __GFP_COMP  | __GFP_NORETRY;
0038     size = xskq_get_ring_size(q, umem_queue);
0039
0040     q->ring = (struct xdp_ring *)__get_free_pages(gfp_flags,
0041                               get_order(size));
0042     if (!q->ring) {
0043         kfree(q);
0044         return NULL;
0045     }
0046
0047     return q;
0048 }
0049
0050 void xskq_destroy(struct xsk_queue *q)
0051 {
0052     if (!q)
0053         return;
0054
0055     page_frag_free(q->ring);
0056     kfree(q);
0057 }