From 3876ff525de70ae850f3aa9b7c295e9cf7253b0e Mon Sep 17 00:00:00 2001 From: Maciej Fijalkowski Date: Tue, 25 Jan 2022 17:04:41 +0100 Subject: [PATCH] ice: xsk: Handle SW XDP ring wrap and bump tail more often Currently, if ice_clean_rx_irq_zc() processed the whole ring and next_to_use != 0, then ice_alloc_rx_buf_zc() would not refill the whole ring even if the XSK buffer pool would have enough free entries (either from fill ring or the internal recycle mechanism) - it is because ring wrap is not handled. Improve the logic in ice_alloc_rx_buf_zc() to address the problem above. Do not clamp the count of buffers that is passed to xsk_buff_alloc_batch() in case when next_to_use + buffer count >= rx_ring->count, but rather split it and have two calls to the mentioned function - one for the part up until the wrap and one for the part after the wrap. Signed-off-by: Magnus Karlsson Signed-off-by: Maciej Fijalkowski Signed-off-by: Daniel Borkmann Reviewed-by: Alexander Lobakin Link: https://lore.kernel.org/bpf/20220125160446.78976-4-maciej.fijalkowski@intel.com --- drivers/net/ethernet/intel/ice/ice_txrx.h | 2 + drivers/net/ethernet/intel/ice/ice_xsk.c | 99 ++++++++++++++++++----- 2 files changed, 81 insertions(+), 20 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.h b/drivers/net/ethernet/intel/ice/ice_txrx.h index b7b3bd4816f0..f70a5eb74839 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.h +++ b/drivers/net/ethernet/intel/ice/ice_txrx.h @@ -111,6 +111,8 @@ static inline int ice_skb_pad(void) (u16)((((R)->next_to_clean > (R)->next_to_use) ? 0 : (R)->count) + \ (R)->next_to_clean - (R)->next_to_use - 1) +#define ICE_RING_QUARTER(R) ((R)->count >> 2) + #define ICE_TX_FLAGS_TSO BIT(0) #define ICE_TX_FLAGS_HW_VLAN BIT(1) #define ICE_TX_FLAGS_SW_VLAN BIT(2) diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c index 27b087808313..b12079a7ef8a 100644 --- a/drivers/net/ethernet/intel/ice/ice_xsk.c +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c @@ -367,33 +367,28 @@ failure: } /** - * ice_alloc_rx_bufs_zc - allocate a number of Rx buffers - * @rx_ring: Rx ring + * ice_fill_rx_descs - pick buffers from XSK buffer pool and use it + * @pool: XSK Buffer pool to pull the buffers from + * @xdp: SW ring of xdp_buff that will hold the buffers + * @rx_desc: Pointer to Rx descriptors that will be filled * @count: The number of buffers to allocate * * This function allocates a number of Rx buffers from the fill ring * or the internal recycle mechanism and places them on the Rx ring. * - * Returns true if all allocations were successful, false if any fail. + * Note that ring wrap should be handled by caller of this function. + * + * Returns the amount of allocated Rx descriptors */ -bool ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count) +static u16 ice_fill_rx_descs(struct xsk_buff_pool *pool, struct xdp_buff **xdp, + union ice_32b_rx_flex_desc *rx_desc, u16 count) { - union ice_32b_rx_flex_desc *rx_desc; - u16 ntu = rx_ring->next_to_use; - struct xdp_buff **xdp; - u32 nb_buffs, i; dma_addr_t dma; + u16 buffs; + int i; - rx_desc = ICE_RX_DESC(rx_ring, ntu); - xdp = ice_xdp_buf(rx_ring, ntu); - - nb_buffs = min_t(u16, count, rx_ring->count - ntu); - nb_buffs = xsk_buff_alloc_batch(rx_ring->xsk_pool, xdp, nb_buffs); - if (!nb_buffs) - return false; - - i = nb_buffs; - while (i--) { + buffs = xsk_buff_alloc_batch(pool, xdp, count); + for (i = 0; i < buffs; i++) { dma = xsk_buff_xdp_get_dma(*xdp); rx_desc->read.pkt_addr = cpu_to_le64(dma); rx_desc->wb.status_error0 = 0; @@ -402,13 +397,77 @@ bool ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count) xdp++; } + return buffs; +} + +/** + * __ice_alloc_rx_bufs_zc - allocate a number of Rx buffers + * @rx_ring: Rx ring + * @count: The number of buffers to allocate + * + * Place the @count of descriptors onto Rx ring. Handle the ring wrap + * for case where space from next_to_use up to the end of ring is less + * than @count. Finally do a tail bump. + * + * Returns true if all allocations were successful, false if any fail. + */ +static bool __ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count) +{ + union ice_32b_rx_flex_desc *rx_desc; + u32 nb_buffs_extra = 0, nb_buffs; + u16 ntu = rx_ring->next_to_use; + u16 total_count = count; + struct xdp_buff **xdp; + + rx_desc = ICE_RX_DESC(rx_ring, ntu); + xdp = ice_xdp_buf(rx_ring, ntu); + + if (ntu + count >= rx_ring->count) { + nb_buffs_extra = ice_fill_rx_descs(rx_ring->xsk_pool, xdp, + rx_desc, + rx_ring->count - ntu); + rx_desc = ICE_RX_DESC(rx_ring, 0); + xdp = ice_xdp_buf(rx_ring, 0); + ntu = 0; + count -= nb_buffs_extra; + ice_release_rx_desc(rx_ring, 0); + } + + nb_buffs = ice_fill_rx_descs(rx_ring->xsk_pool, xdp, rx_desc, count); + ntu += nb_buffs; if (ntu == rx_ring->count) ntu = 0; - ice_release_rx_desc(rx_ring, ntu); + if (rx_ring->next_to_use != ntu) + ice_release_rx_desc(rx_ring, ntu); + + return total_count == (nb_buffs_extra + nb_buffs); +} + +/** + * ice_alloc_rx_bufs_zc - allocate a number of Rx buffers + * @rx_ring: Rx ring + * @count: The number of buffers to allocate + * + * Wrapper for internal allocation routine; figure out how many tail + * bumps should take place based on the given threshold + * + * Returns true if all calls to internal alloc routine succeeded + */ +bool ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count) +{ + u16 rx_thresh = ICE_RING_QUARTER(rx_ring); + u16 batched, leftover, i, tail_bumps; + + batched = ALIGN_DOWN(count, rx_thresh); + tail_bumps = batched / rx_thresh; + leftover = count & (rx_thresh - 1); - return count == nb_buffs; + for (i = 0; i < tail_bumps; i++) + if (!__ice_alloc_rx_bufs_zc(rx_ring, rx_thresh)) + return false; + return __ice_alloc_rx_bufs_zc(rx_ring, leftover); } /** -- 2.39.5