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/slab.h>
   7
   8 #include "xsk_queue.h"
   9
  10 void xskq_set_umem(struct xsk_queue *q, struct xdp_umem_props *umem_props)
  11 {
  12         if (!q)
  13                 return;
  14
  15         q->umem_props = *umem_props;
  16 }
  17
  18 static u32 xskq_umem_get_ring_size(struct xsk_queue *q)
  19 {
  20         return sizeof(struct xdp_umem_ring) + q->nentries * sizeof(u64);
  21 }
  22
  23 static u32 xskq_rxtx_get_ring_size(struct xsk_queue *q)
  24 {
  25         return sizeof(struct xdp_ring) + q->nentries * sizeof(struct xdp_desc);
  26 }
  27
  28 struct xsk_queue *xskq_create(u32 nentries, bool umem_queue)
  29 {
  30         struct xsk_queue *q;
  31         gfp_t gfp_flags;
  32         size_t size;
  33
  34         q = kzalloc(sizeof(*q), GFP_KERNEL);
  35         if (!q)
  36                 return NULL;
  37
  38         q->nentries = nentries;
  39         q->ring_mask = nentries - 1;
  40
  41         gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN |
  42                     __GFP_COMP  | __GFP_NORETRY;
  43         size = umem_queue ? xskq_umem_get_ring_size(q) :
  44                xskq_rxtx_get_ring_size(q);
  45
  46         q->ring = (struct xdp_ring *)__get_free_pages(gfp_flags,
  47                                                       get_order(size));
  48         if (!q->ring) {
  49                 kfree(q);
  50                 return NULL;
  51         }
  52
  53         return q;
  54 }
  55
  56 void xskq_destroy(struct xsk_queue *q)
  57 {
  58         if (!q)
  59                 return;
  60
  61         page_frag_free(q->ring);
  62         kfree(q);
  63 }