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f5bd91388e
XSK UMEM is strongly single producer single consumer so reuse of frames is challenging. Add a simple "stash" of FILL packets to reuse for drivers to optionally make use of. This is useful when driver has to free (ndo_stop) or resize a ring with an active AF_XDP ZC socket. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Tested-by: Andrew Bowers <andrewx.bowers@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
119 lines
2.4 KiB
C
119 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* XDP user-space ring structure
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* Copyright(c) 2018 Intel Corporation.
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*/
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#include <linux/log2.h>
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#include <linux/slab.h>
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#include <linux/overflow.h>
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#include "xsk_queue.h"
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void xskq_set_umem(struct xsk_queue *q, u64 size, u64 chunk_mask)
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{
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if (!q)
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return;
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q->size = size;
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q->chunk_mask = chunk_mask;
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}
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static u32 xskq_umem_get_ring_size(struct xsk_queue *q)
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{
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return sizeof(struct xdp_umem_ring) + q->nentries * sizeof(u64);
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}
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static u32 xskq_rxtx_get_ring_size(struct xsk_queue *q)
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{
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return sizeof(struct xdp_ring) + q->nentries * sizeof(struct xdp_desc);
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}
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struct xsk_queue *xskq_create(u32 nentries, bool umem_queue)
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{
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struct xsk_queue *q;
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gfp_t gfp_flags;
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size_t size;
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q = kzalloc(sizeof(*q), GFP_KERNEL);
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if (!q)
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return NULL;
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q->nentries = nentries;
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q->ring_mask = nentries - 1;
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gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN |
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__GFP_COMP | __GFP_NORETRY;
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size = umem_queue ? xskq_umem_get_ring_size(q) :
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xskq_rxtx_get_ring_size(q);
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q->ring = (struct xdp_ring *)__get_free_pages(gfp_flags,
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get_order(size));
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if (!q->ring) {
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kfree(q);
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return NULL;
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}
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return q;
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}
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void xskq_destroy(struct xsk_queue *q)
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{
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if (!q)
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return;
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page_frag_free(q->ring);
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kfree(q);
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}
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struct xdp_umem_fq_reuse *xsk_reuseq_prepare(u32 nentries)
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{
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struct xdp_umem_fq_reuse *newq;
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/* Check for overflow */
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if (nentries > (u32)roundup_pow_of_two(nentries))
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return NULL;
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nentries = roundup_pow_of_two(nentries);
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newq = kvmalloc(struct_size(newq, handles, nentries), GFP_KERNEL);
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if (!newq)
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return NULL;
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memset(newq, 0, offsetof(typeof(*newq), handles));
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newq->nentries = nentries;
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return newq;
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}
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EXPORT_SYMBOL_GPL(xsk_reuseq_prepare);
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struct xdp_umem_fq_reuse *xsk_reuseq_swap(struct xdp_umem *umem,
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struct xdp_umem_fq_reuse *newq)
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{
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struct xdp_umem_fq_reuse *oldq = umem->fq_reuse;
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if (!oldq) {
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umem->fq_reuse = newq;
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return NULL;
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}
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if (newq->nentries < oldq->length)
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return newq;
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memcpy(newq->handles, oldq->handles,
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array_size(oldq->length, sizeof(u64)));
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newq->length = oldq->length;
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umem->fq_reuse = newq;
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return oldq;
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}
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EXPORT_SYMBOL_GPL(xsk_reuseq_swap);
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void xsk_reuseq_free(struct xdp_umem_fq_reuse *rq)
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{
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kvfree(rq);
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}
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EXPORT_SYMBOL_GPL(xsk_reuseq_free);
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void xsk_reuseq_destroy(struct xdp_umem *umem)
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{
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xsk_reuseq_free(umem->fq_reuse);
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umem->fq_reuse = NULL;
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}
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