From 495de55f70199bd7ea09079c484283e58bf75c82 Mon Sep 17 00:00:00 2001 From: Ilias Apalodimas Date: Thu, 14 May 2020 12:49:23 +0200 Subject: net: netsec: Add support for XDP frame size 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. Signed-off-by: Ilias Apalodimas Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Alexei Starovoitov Acked-by: Lorenzo Bianconi Link: https://lore.kernel.org/bpf/158945336295.97035.15034759661036971024.stgit@firesoul --- drivers/net/ethernet/socionext/netsec.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) (limited to 'drivers') diff --git a/drivers/net/ethernet/socionext/netsec.c b/drivers/net/ethernet/socionext/netsec.c index a5a0fb60193a..e1f4be4b3d69 100644 --- a/drivers/net/ethernet/socionext/netsec.c +++ b/drivers/net/ethernet/socionext/netsec.c @@ -884,23 +884,28 @@ static u32 netsec_run_xdp(struct netsec_priv *priv, struct bpf_prog *prog, struct xdp_buff *xdp) { struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_RX]; - unsigned int len = xdp->data_end - xdp->data; + unsigned int sync, len = xdp->data_end - xdp->data; u32 ret = NETSEC_XDP_PASS; + struct page *page; int err; u32 act; 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 - NETSEC_RXBUF_HEADROOM; + sync = max(sync, len); + switch (act) { case XDP_PASS: ret = NETSEC_XDP_PASS; break; case XDP_TX: ret = netsec_xdp_xmit_back(priv, xdp); - if (ret != NETSEC_XDP_TX) - page_pool_put_page(dring->page_pool, - virt_to_head_page(xdp->data), len, - true); + if (ret != NETSEC_XDP_TX) { + page = virt_to_head_page(xdp->data); + page_pool_put_page(dring->page_pool, page, sync, true); + } break; case XDP_REDIRECT: err = xdp_do_redirect(priv->ndev, xdp, prog); @@ -908,9 +913,8 @@ static u32 netsec_run_xdp(struct netsec_priv *priv, struct bpf_prog *prog, ret = NETSEC_XDP_REDIR; } else { ret = NETSEC_XDP_CONSUMED; - page_pool_put_page(dring->page_pool, - virt_to_head_page(xdp->data), len, - true); + page = virt_to_head_page(xdp->data); + page_pool_put_page(dring->page_pool, page, sync, true); } break; default: @@ -921,8 +925,8 @@ static u32 netsec_run_xdp(struct netsec_priv *priv, struct bpf_prog *prog, /* fall through -- handle aborts by dropping packet */ case XDP_DROP: ret = NETSEC_XDP_CONSUMED; - page_pool_put_page(dring->page_pool, - virt_to_head_page(xdp->data), len, true); + page = virt_to_head_page(xdp->data); + page_pool_put_page(dring->page_pool, page, sync, true); break; } @@ -936,10 +940,14 @@ static int netsec_process_rx(struct netsec_priv *priv, int budget) struct netsec_rx_pkt_info rx_info; enum dma_data_direction dma_dir; struct bpf_prog *xdp_prog; + struct xdp_buff xdp; u16 xdp_xmit = 0; u32 xdp_act = 0; int done = 0; + xdp.rxq = &dring->xdp_rxq; + xdp.frame_sz = PAGE_SIZE; + rcu_read_lock(); xdp_prog = READ_ONCE(priv->xdp_prog); dma_dir = page_pool_get_dma_dir(dring->page_pool); @@ -953,7 +961,6 @@ static int netsec_process_rx(struct netsec_priv *priv, int budget) struct sk_buff *skb = NULL; u16 pkt_len, desc_len; dma_addr_t dma_handle; - struct xdp_buff xdp; void *buf_addr; if (de->attr & (1U << NETSEC_RX_PKT_OWN_FIELD)) { @@ -1002,7 +1009,6 @@ static int netsec_process_rx(struct netsec_priv *priv, int budget) xdp.data = desc->addr + NETSEC_RXBUF_HEADROOM; xdp_set_data_meta_invalid(&xdp); xdp.data_end = xdp.data + pkt_len; - xdp.rxq = &dring->xdp_rxq; if (xdp_prog) { xdp_result = netsec_run_xdp(priv, xdp_prog, &xdp); -- cgit v1.2.3