linux/net/xdp/xsk_queue.c
Magnus Karlsson e4e5aefc11 xsk: Change two variable names for increased clarity
Change two variables names so that it is clearer what they
represent. The first one is xsk_list that in fact only contains the
list of AF_XDP sockets with a Tx component. Change this to xsk_tx_list
for improved clarity. The second variable is size in the ring
structure. One might think that this is the size of the ring, but it
is in fact the size of the umem, copied into the ring structure to
improve performance. Rename this variable umem_size to avoid any
confusion.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1588599232-24897-2-git-send-email-magnus.karlsson@intel.com
2020-05-04 22:56:26 +02:00

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 umem_size, u64 chunk_mask)
{
if (!q)
return;
q->umem_size = umem_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;
}