From f5bd91388e26557f64ca999e0006038c7a919308 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 7 Sep 2018 10:18:46 +0200 Subject: net: xsk: add a simple buffer reuse queue 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 Tested-by: Andrew Bowers Signed-off-by: Jeff Kirsher --- net/xdp/xsk_queue.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) (limited to 'net/xdp/xsk_queue.c') diff --git a/net/xdp/xsk_queue.c b/net/xdp/xsk_queue.c index 2dc1384d9f27..b66504592d9b 100644 --- a/net/xdp/xsk_queue.c +++ b/net/xdp/xsk_queue.c @@ -3,7 +3,9 @@ * Copyright(c) 2018 Intel Corporation. */ +#include #include +#include #include "xsk_queue.h" @@ -62,3 +64,56 @@ void xskq_destroy(struct xsk_queue *q) 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; +} -- cgit v1.2.3-59-g8ed1b