Commit 665a7e13 authored by Dragos Tatulea's avatar Dragos Tatulea Committed by Jakub Kicinski
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net/mlx5e: SHAMPO, Fix header mapping for 64K pages



HW-GRO is broken on mlx5 for 64K page sizes. The patch in the fixes tag
didn't take into account larger page sizes when doing an align down
of max_ksm_entries. For 64K page size, max_ksm_entries is 0 which will skip
mapping header pages via WQE UMR. This breaks header-data split
and will result in the following syndrome:

mlx5_core 0000:00:08.0 eth2: Error cqe on cqn 0x4c9, ci 0x0, qn 0x1133, opcode 0xe, syndrome 0x4, vendor syndrome 0x32
00000000: 00 00 00 00 04 4a 00 00 00 00 00 00 20 00 93 32
00000010: 55 00 00 00 fb cc 00 00 00 00 00 00 07 18 00 00
00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 4a
00000030: 00 00 3b c7 93 01 32 04 00 00 00 00 00 00 bf e0
mlx5_core 0000:00:08.0 eth2: ERR CQE on RQ: 0x1133

Furthermore, the function that fills in WQE UMRs for the headers
(mlx5e_build_shampo_hd_umr()) only supports mapping page sizes that
fit in a single UMR WQE.

This patch goes back to the old non-aligned max_ksm_entries value and it
changes mlx5e_build_shampo_hd_umr() to support mapping a large page over
multiple UMR WQEs.

This means that mlx5e_build_shampo_hd_umr() can now leave a page only
partially mapped. The caller, mlx5e_alloc_rx_hd_mpwqe(), ensures that
there are enough UMR WQEs to cover complete pages by working on
ksm_entries that are multiples of MLX5E_SHAMPO_WQ_HEADER_PER_PAGE.

Fixes: 8a0ee540 ("net/mlx5e: SHAMPO, Simplify UMR allocation for headers")
Signed-off-by: default avatarDragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: default avatarTariq Toukan <tariqt@nvidia.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/1762238915-1027590-2-git-send-email-tariqt@nvidia.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent ae4789af
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+17 −19
Original line number Diff line number Diff line
@@ -671,7 +671,7 @@ static int mlx5e_build_shampo_hd_umr(struct mlx5e_rq *rq,
	u16 pi, header_offset, err, wqe_bbs;
	u32 lkey = rq->mdev->mlx5e_res.hw_objs.mkey;
	struct mlx5e_umr_wqe *umr_wqe;
	int headroom, i = 0;
	int headroom, i;

	headroom = rq->buff.headroom;
	wqe_bbs = MLX5E_KSM_UMR_WQEBBS(ksm_entries);
@@ -679,26 +679,25 @@ static int mlx5e_build_shampo_hd_umr(struct mlx5e_rq *rq,
	umr_wqe = mlx5_wq_cyc_get_wqe(&sq->wq, pi);
	build_ksm_umr(sq, umr_wqe, shampo->mkey_be, index, ksm_entries);

	WARN_ON_ONCE(ksm_entries & (MLX5E_SHAMPO_WQ_HEADER_PER_PAGE - 1));
	while (i < ksm_entries) {
		struct mlx5e_frag_page *frag_page = mlx5e_shampo_hd_to_frag_page(rq, index);
	for (i = 0; i < ksm_entries; i++, index++) {
		struct mlx5e_frag_page *frag_page;
		u64 addr;

		err = mlx5e_page_alloc_fragmented(rq->hd_page_pool, frag_page);
		if (unlikely(err))
		frag_page = mlx5e_shampo_hd_to_frag_page(rq, index);
		header_offset = mlx5e_shampo_hd_offset(index);
		if (!header_offset) {
			err = mlx5e_page_alloc_fragmented(rq->hd_page_pool,
							  frag_page);
			if (err)
				goto err_unmap;
		}

		addr = page_pool_get_dma_addr_netmem(frag_page->netmem);

		for (int j = 0; j < MLX5E_SHAMPO_WQ_HEADER_PER_PAGE; j++) {
			header_offset = mlx5e_shampo_hd_offset(index++);

			umr_wqe->inline_ksms[i++] = (struct mlx5_ksm) {
		umr_wqe->inline_ksms[i] = (struct mlx5_ksm) {
			.key = cpu_to_be32(lkey),
			.va  = cpu_to_be64(addr + header_offset + headroom),
		};
	}
	}

	sq->db.wqe_info[pi] = (struct mlx5e_icosq_wqe_info) {
		.wqe_type	= MLX5E_ICOSQ_WQE_SHAMPO_HD_UMR,
@@ -713,7 +712,7 @@ static int mlx5e_build_shampo_hd_umr(struct mlx5e_rq *rq,
	return 0;

err_unmap:
	while (--i) {
	while (--i >= 0) {
		--index;
		header_offset = mlx5e_shampo_hd_offset(index);
		if (!header_offset) {
@@ -735,8 +734,7 @@ static int mlx5e_alloc_rx_hd_mpwqe(struct mlx5e_rq *rq)
	struct mlx5e_icosq *sq = rq->icosq;
	int i, err, max_ksm_entries, len;

	max_ksm_entries = ALIGN_DOWN(MLX5E_MAX_KSM_PER_WQE(rq->mdev),
				     MLX5E_SHAMPO_WQ_HEADER_PER_PAGE);
	max_ksm_entries = MLX5E_MAX_KSM_PER_WQE(rq->mdev);
	ksm_entries = bitmap_find_window(shampo->bitmap,
					 shampo->hd_per_wqe,
					 shampo->hd_per_wq, shampo->pi);