net/xdp/xsk_queue.c

   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 }