linux/net/xdp/xsk_queue.c
Magnus Karlsson 423f38329d xsk: add umem fill queue support and mmap
Here, we add another setsockopt for registered user memory (umem)
called XDP_UMEM_FILL_QUEUE. Using this socket option, the process can
ask the kernel to allocate a queue (ring buffer) and also mmap it
(XDP_UMEM_PGOFF_FILL_QUEUE) into the process.

The queue is used to explicitly pass ownership of umem frames from the
user process to the kernel. These frames will in a later patch be
filled in with Rx packet data by the kernel.

v2: Fixed potential crash in xsk_mmap.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-03 15:55:23 -07:00

59 lines
1.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* XDP user-space ring structure
* Copyright(c) 2018 Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <linux/slab.h>
#include "xsk_queue.h"
static u32 xskq_umem_get_ring_size(struct xsk_queue *q)
{
return sizeof(struct xdp_umem_ring) + q->nentries * sizeof(u32);
}
struct xsk_queue *xskq_create(u32 nentries)
{
struct xsk_queue *q;
gfp_t gfp_flags;
size_t size;
q = kzalloc(sizeof(*q), GFP_KERNEL);
if (!q)
return NULL;
q->nentries = nentries;
q->ring_mask = nentries - 1;
gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN |
__GFP_COMP | __GFP_NORETRY;
size = xskq_umem_get_ring_size(q);
q->ring = (struct xdp_ring *)__get_free_pages(gfp_flags,
get_order(size));
if (!q->ring) {
kfree(q);
return NULL;
}
return q;
}
void xskq_destroy(struct xsk_queue *q)
{
if (!q)
return;
page_frag_free(q->ring);
kfree(q);
}