From bc4db83470034b4644a8bf164a984bdb68b61622 Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Fri, 10 Feb 2023 18:06:13 +0100 Subject: [PATCH] ice: fix ice_tx_ring:: Xdp_tx_active underflow xdp_tx_active is used to indicate whether an XDP ring has any %XDP_TX frames queued to shortcut processing Tx cleaning for XSk-enabled queues. When !XSk, it simply indicates whether the ring has any queued frames in general. It gets increased on each frame placed onto the ring and counts the whole frame, not each frag. However, currently it gets decremented in ice_clean_xdp_tx_buf(), which is called per each buffer, i.e. per each frag. Thus, on completing multi-frag frames, an underflow happens. Move the decrement to the outer function and do it once per frame, not buf. Also, do that on the stack and update the ring counter after the loop is done to save several cycles. XSk rings are fine since there are no frags at the moment. Fixes: 3246a10752a7 ("ice: Add support for XDP multi-buffer on Tx side") Signed-off-by: Alexander Lobakin Signed-off-by: Daniel Borkmann Acked-by: Maciej Fijalkowski Link: https://lore.kernel.org/bpf/20230210170618.1973430-2-alexandr.lobakin@intel.com --- drivers/net/ethernet/intel/ice/ice_txrx_lib.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c index 9bbed3f14e427..d1a7171e618ba 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx_lib.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx_lib.c @@ -231,7 +231,6 @@ ice_clean_xdp_tx_buf(struct ice_tx_ring *xdp_ring, struct ice_tx_buf *tx_buf) dma_unmap_single(xdp_ring->dev, dma_unmap_addr(tx_buf, dma), dma_unmap_len(tx_buf, len), DMA_TO_DEVICE); dma_unmap_len_set(tx_buf, len, 0); - xdp_ring->xdp_tx_active--; page_frag_free(tx_buf->raw_buf); tx_buf->raw_buf = NULL; } @@ -246,8 +245,8 @@ static u32 ice_clean_xdp_irq(struct ice_tx_ring *xdp_ring) u32 ntc = xdp_ring->next_to_clean; struct ice_tx_desc *tx_desc; u32 cnt = xdp_ring->count; + u32 frags, xdp_tx = 0; u32 ready_frames = 0; - u32 frags; u32 idx; u32 ret; @@ -274,6 +273,7 @@ static u32 ice_clean_xdp_irq(struct ice_tx_ring *xdp_ring) total_pkts++; /* count head + frags */ ready_frames -= frags + 1; + xdp_tx++; if (xdp_ring->xsk_pool) xsk_buff_free(tx_buf->xdp); @@ -295,6 +295,7 @@ static u32 ice_clean_xdp_irq(struct ice_tx_ring *xdp_ring) tx_desc->cmd_type_offset_bsz = 0; xdp_ring->next_to_clean = ntc; + xdp_ring->xdp_tx_active -= xdp_tx; ice_update_tx_ring_stats(xdp_ring, total_pkts, total_bytes); return ret; -- 2.30.2