linux/net/xdp/xsk_queue.c
Magnus Karlsson 1d9cb1f381 xsk: Use struct_size() helper
Improve readability and maintainability by using the struct_size()
helper when allocating the AF_XDP rings.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/1576759171-28550-13-git-send-email-magnus.karlsson@intel.com
2019-12-20 16:00:09 -08:00

119 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* XDP user-space ring structure
* Copyright(c) 2018 Intel Corporation.
*/
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/overflow.h>
#include "xsk_queue.h"
void xskq_set_umem(struct xsk_queue *q, u64 size, u64 chunk_mask)
{
if (!q)
return;
q->size = size;
q->chunk_mask = chunk_mask;
}
static size_t xskq_get_ring_size(struct xsk_queue *q, bool umem_queue)
{
struct xdp_umem_ring *umem_ring;
struct xdp_rxtx_ring *rxtx_ring;
if (umem_queue)
return struct_size(umem_ring, desc, q->nentries);
return struct_size(rxtx_ring, desc, q->nentries);
}
struct xsk_queue *xskq_create(u32 nentries, bool umem_queue)
{
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_get_ring_size(q, umem_queue);
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);
}
struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries)
{
struct xdp_umem_fq_reuse *newq;
/* Check for overflow */
if (nentries > (u32)roundup_pow_of_two(nentries))
return NULL;
nentries = roundup_pow_of_two(nentries);
newq = kvmalloc(struct_size(newq, handles, nentries), GFP_KERNEL);
if (!newq)
return NULL;
memset(newq, 0, offsetof(typeof(*newq), handles));
newq->nentries = nentries;
return newq;
}
EXPORT_SYMBOL_GPL(xsk_reuseq_prepare);
struct xdp_umem_fq_reuse *xsk_reuseq_swap(struct xdp_umem *umem,
struct xdp_umem_fq_reuse *newq)
{
struct xdp_umem_fq_reuse *oldq = umem->fq_reuse;
if (!oldq) {
umem->fq_reuse = newq;
return NULL;
}
if (newq->nentries < oldq->length)
return newq;
memcpy(newq->handles, oldq->handles,
array_size(oldq->length, sizeof(u64)));
newq->length = oldq->length;
umem->fq_reuse = newq;
return oldq;
}
EXPORT_SYMBOL_GPL(xsk_reuseq_swap);
void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq)
{
kvfree(rq);
}
EXPORT_SYMBOL_GPL(xsk_reuseq_free);
void xsk_reuseq_destroy(struct xdp_umem *umem)
{
xsk_reuseq_free(umem->fq_reuse);
umem->fq_reuse = NULL;
}