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Message-Id: <20220121120011.49316-3-maciej.fijalkowski@intel.com>
Date: Fri, 21 Jan 2022 13:00:06 +0100
From: Maciej Fijalkowski <maciej.fijalkowski@...el.com>
To: bpf@...r.kernel.org, ast@...nel.org, daniel@...earbox.net
Cc: netdev@...r.kernel.org, magnus.karlsson@...el.com,
alexandr.lobakin@...el.com,
Maciej Fijalkowski <maciej.fijalkowski@...el.com>
Subject: [PATCH bpf-next v3 2/7] 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 <magnus.karlsson@...el.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@...el.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..94a46e0e5ed0 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 / 4)
+
#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 2388837d6d6c..0463fc594d08 100644
--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -359,33 +359,28 @@ int ice_xsk_pool_setup(struct ice_vsi *vsi, struct xsk_buff_pool *pool, u16 qid)
}
/**
- * 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;
@@ -394,13 +389,77 @@ 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 = count & ~(rx_thresh - 1);
+ 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);
}
/**
--
2.33.1
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