[PATCH net-next v4 04/33] mvneta: add XDP frame size to driver
flat view
STALE2352d
LANDED: 1 (1M)
From: Jesper Dangaard Brouer <hidden>
Date: 2020-05-14 10:49:33
Also in:
bpf
Subsystem:
marvell mvneta ethernet driver, networking drivers, the rest · Maintainers:
Marcin Wojtas, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Status: Landed in mainline as 494f44d54e25 on 2020-05-15.
Revision v4 (4 revisions archived); 1 review trailer.
Revisions (4)
- v1 re-posted go to this post
- v2 [diff against previous] re-posted go to this post
- v3 [diff against previous]
- v4 current [diff against previous]
This marvell driver mvneta uses PAGE_SIZE frames, which makes it really easy to convert. Driver updates rxq and now frame_sz once per NAPI call. This driver takes advantage of page_pool PP_FLAG_DMA_SYNC_DEV that can help reduce the number of cache-lines that need to be flushed when doing DMA sync for_device. Due to xdp_adjust_tail can grow the area accessible to the by the CPU (can possibly write into), then max sync length *after* bpf_prog_run_xdp() needs to be taken into account. For XDP_TX action the driver is smart and does DMA-sync. When growing tail this is still safe, because page_pool have DMA-mapped the entire page size. Cc: thomas.petazzoni@bootlin.com Acked-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Jesper Dangaard Brouer <redacted> --- drivers/net/ethernet/marvell/mvneta.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 51889770958d..37947949345c 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c@@ -2148,12 +2148,17 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, struct bpf_prog *prog, struct xdp_buff *xdp, struct mvneta_stats *stats) { - unsigned int len; + unsigned int len, sync; + struct page *page; u32 ret, act; len = xdp->data_end - xdp->data_hard_start - pp->rx_offset_correction; act = bpf_prog_run_xdp(prog, xdp); + /* Due xdp_adjust_tail: DMA sync for_device cover max len CPU touch */ + sync = xdp->data_end - xdp->data_hard_start - pp->rx_offset_correction; + sync = max(sync, len); + switch (act) { case XDP_PASS: stats->xdp_pass++;
@@ -2164,9 +2169,8 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, err = xdp_do_redirect(pp->dev, xdp, prog); if (unlikely(err)) { ret = MVNETA_XDP_DROPPED; - page_pool_put_page(rxq->page_pool, - virt_to_head_page(xdp->data), len, - true); + page = virt_to_head_page(xdp->data); + page_pool_put_page(rxq->page_pool, page, sync, true); } else { ret = MVNETA_XDP_REDIR; stats->xdp_redirect++;
@@ -2175,10 +2179,10 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, } case XDP_TX: ret = mvneta_xdp_xmit_back(pp, xdp); - if (ret != MVNETA_XDP_TX) - page_pool_put_page(rxq->page_pool, - virt_to_head_page(xdp->data), len, - true); + if (ret != MVNETA_XDP_TX) { + page = virt_to_head_page(xdp->data); + page_pool_put_page(rxq->page_pool, page, sync, true); + } break; default: bpf_warn_invalid_xdp_action(act);
@@ -2187,8 +2191,8 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, trace_xdp_exception(pp->dev, prog, act); /* fall through */ case XDP_DROP: - page_pool_put_page(rxq->page_pool, - virt_to_head_page(xdp->data), len, true); + page = virt_to_head_page(xdp->data); + page_pool_put_page(rxq->page_pool, page, sync, true); ret = MVNETA_XDP_DROPPED; stats->xdp_drop++; break;
@@ -2320,6 +2324,7 @@ static int mvneta_rx_swbm(struct napi_struct *napi, rcu_read_lock(); xdp_prog = READ_ONCE(pp->xdp_prog); xdp_buf.rxq = &rxq->xdp_rxq; + xdp_buf.frame_sz = PAGE_SIZE; /* Fairness NAPI loop */ while (rx_proc < budget && rx_proc < rx_todo) {