From 423f38329d267969130fb6f2c685f73d72687558 Mon Sep 17 00:00:00 2001 From: Magnus Karlsson Date: Wed, 2 May 2018 13:01:24 +0200 Subject: 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 Signed-off-by: Alexei Starovoitov --- net/xdp/xsk_queue.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 net/xdp/xsk_queue.c (limited to 'net/xdp/xsk_queue.c') diff --git a/net/xdp/xsk_queue.c b/net/xdp/xsk_queue.c new file mode 100644 index 000000000000..23da4f29d3fb --- /dev/null +++ b/net/xdp/xsk_queue.c @@ -0,0 +1,58 @@ +// 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 + +#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); +} -- cgit