[PATCH 6.18.y 1/2] net/mlx5e: SHAMPO, Always calculate page size

[Sasha Levin <sashal@kernel.org>]

From: Dragos Tatulea <dtatulea@nvidia.com>

[ Upstream commit dff1c3164a69284ac9fedb1c25d4c008139e9fb8 ]

Adapt the rx path in SHAMPO mode to calculate page size based on
configured page_shift when dealing with payload data.

This is necessary as an upcoming patch will add support for using
different page sizes.

This change has no functional changes.

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260223204155.1783580-9-tariqt@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Backport to 6.18: preserve the XDP fragment accounting fix from
7d7342a18fadc ("net/mlx5e: RX, Fix XDP multi-buf frag counting for
striding RQ"). Keep new_nr_frags and the original frag_page endpoint;
only replace PAGE_SIZE with page_size in the truesize adjustment.
Reintroducing the old frag_page rewind would break page reference
accounting for fragments consumed by XDP.

Retain the page-size calculations and SHAMPO space-check changes so
e2466392a0b8496000e12181cb1ee1535eb0da25 ("net/mlx5e: do not HW-GRO
coalesce small frames") applies without modification. No functions
are added.

Stable-dep-of: e2466392a0b8 ("net/mlx5e: do not HW-GRO coalesce small frames")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   | 34 ++++++++++++-------
 1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 2ffa4e6b8c373..8a61c958c5679 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -2014,11 +2014,14 @@ mlx5e_shampo_fill_skb_data(struct sk_buff *skb, struct mlx5e_rq *rq,
 			   struct mlx5e_frag_page *frag_page,
 			   u32 data_bcnt, u32 data_offset)
 {
+	u32 page_size = BIT(rq->mpwqe.page_shift);
+
 	net_prefetchw(skb->data);
 
 	do {
 		/* Non-linear mode, hence non-XSK, which always uses PAGE_SIZE. */
-		u32 pg_consumed_bytes = min_t(u32, PAGE_SIZE - data_offset, data_bcnt);
+		u32 pg_consumed_bytes = min_t(u32, page_size - data_offset,
+					      data_bcnt);
 		unsigned int truesize = pg_consumed_bytes;
 
 		mlx5e_add_skb_frag(rq, skb, frag_page, data_offset,
@@ -2039,6 +2042,7 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
 	u16 headlen = min_t(u16, MLX5E_RX_MAX_HEAD, cqe_bcnt);
 	struct mlx5e_frag_page *head_page = frag_page;
 	struct mlx5e_xdp_buff *mxbuf = &rq->mxbuf;
+	u32 page_size = BIT(rq->mpwqe.page_shift);
 	u32 frag_offset    = head_offset;
 	u32 byte_cnt       = cqe_bcnt;
 	struct skb_shared_info *sinfo;
@@ -2084,9 +2088,9 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
 		linear_hr = skb_headroom(skb);
 		linear_data_len = headlen;
 		linear_frame_sz = MLX5_SKB_FRAG_SZ(skb_end_offset(skb));
-		if (unlikely(frag_offset >= PAGE_SIZE)) {
+		if (unlikely(frag_offset >= page_size)) {
 			frag_page++;
-			frag_offset -= PAGE_SIZE;
+			frag_offset -= page_size;
 		}
 	}
 
@@ -2098,7 +2102,7 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
 	while (byte_cnt) {
 		/* Non-linear mode, hence non-XSK, which always uses PAGE_SIZE. */
 		pg_consumed_bytes =
-			min_t(u32, PAGE_SIZE - frag_offset, byte_cnt);
+			min_t(u32, page_size - frag_offset, byte_cnt);
 
 		if (test_bit(MLX5E_RQ_STATE_SHAMPO, &rq->state))
 			truesize += pg_consumed_bytes;
@@ -2135,7 +2139,7 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w
 		new_nr_frags = sinfo->nr_frags;
 		nr_frags_free = old_nr_frags - new_nr_frags;
 		if (unlikely(nr_frags_free))
-			truesize -= (nr_frags_free - 1) * PAGE_SIZE +
+			truesize -= (nr_frags_free - 1) * page_size +
 				ALIGN(pg_consumed_bytes,
 				      BIT(rq->mpwqe.log_stride_sz));
 
@@ -2349,15 +2353,16 @@ mlx5e_shampo_flush_skb(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe, bool match)
 	rq->hw_gro_data->skb = NULL;
 }
 
-static bool
-mlx5e_hw_gro_skb_has_enough_space(struct sk_buff *skb, u16 data_bcnt)
+static bool mlx5e_hw_gro_skb_has_enough_space(struct sk_buff *skb,
+					      u16 data_bcnt,
+					      u32 page_size)
 {
 	int nr_frags = skb_shinfo(skb)->nr_frags;
 
-	if (PAGE_SIZE >= GRO_LEGACY_MAX_SIZE)
+	if (page_size >= GRO_LEGACY_MAX_SIZE)
 		return skb->len + data_bcnt <= GRO_LEGACY_MAX_SIZE;
 	else
-		return PAGE_SIZE * nr_frags + data_bcnt <= GRO_LEGACY_MAX_SIZE;
+		return page_size * nr_frags + data_bcnt <= GRO_LEGACY_MAX_SIZE;
 }
 
 static void mlx5e_handle_rx_cqe_mpwrq_shampo(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe)
@@ -2366,18 +2371,19 @@ static void mlx5e_handle_rx_cqe_mpwrq_shampo(struct mlx5e_rq *rq, struct mlx5_cq
 	u16 header_index	= mlx5e_shampo_get_cqe_header_index(rq, cqe);
 	u32 wqe_offset		= be32_to_cpu(cqe->shampo.data_offset);
 	u16 cstrides		= mpwrq_get_cqe_consumed_strides(cqe);
-	u32 data_offset		= wqe_offset & (PAGE_SIZE - 1);
 	u32 cqe_bcnt		= mpwrq_get_cqe_byte_cnt(cqe);
 	u16 wqe_id		= be16_to_cpu(cqe->wqe_id);
-	u32 page_idx		= wqe_offset >> PAGE_SHIFT;
 	u16 head_size		= cqe->shampo.header_size;
 	struct sk_buff **skb	= &rq->hw_gro_data->skb;
 	bool flush		= cqe->shampo.flush;
 	bool match		= cqe->shampo.match;
+	u32 page_size = BIT(rq->mpwqe.page_shift);
 	struct mlx5e_rq_stats *stats = rq->stats;
 	struct mlx5e_rx_wqe_ll *wqe;
 	struct mlx5e_mpw_info *wi;
 	struct mlx5_wq_ll *wq;
+	u32 data_offset;
+	u32 page_idx;
 
 	wi = mlx5e_get_mpw_info(rq, wqe_id);
 	wi->consumed_strides += cstrides;
@@ -2393,7 +2399,11 @@ static void mlx5e_handle_rx_cqe_mpwrq_shampo(struct mlx5e_rq *rq, struct mlx5_cq
 		goto mpwrq_cqe_out;
 	}
 
-	if (*skb && (!match || !(mlx5e_hw_gro_skb_has_enough_space(*skb, data_bcnt)))) {
+	data_offset = wqe_offset & (page_size - 1);
+	page_idx = wqe_offset >> rq->mpwqe.page_shift;
+	if (*skb &&
+	    !(match && mlx5e_hw_gro_skb_has_enough_space(*skb, data_bcnt,
+							 page_size))) {
 		match = false;
 		mlx5e_shampo_flush_skb(rq, cqe, match);
 	}
-- 
2.53.0