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net/mlx5e: XDP, Consider large muti-buffer packets in Striding RQ params calculations

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Function mlx5e_rx_get_linear_stride_sz() returns PAGE_SIZE immediately
in case an XDP program is attached. The more accurate formula is
ALIGN(sz, PAGE_SIZE), to prevent two packets from residing on the same
page.

The assumption behind the current code is that sz <= PAGE_SIZE holds for
all cases with XDP program set.

This is true because it is being called from:
- 3 times from Striding RQ flows, in which XDP is not supported for such
  large packets.
- 1 time from Legacy RQ flow, under the condition
  mlx5e_rx_is_linear_skb().

No functional change here, just removing the implied assumption in
preparation for supporting XDP multi-buffer in Striding RQ.

Reviewed-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tariq Toukan 2023-04-17 15:18:57 +03:00 committed by David S. Miller
parent abd3f84eca
commit 20409abe52
1 changed files with 7 additions and 4 deletions
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11
drivers/net/ethernet/mellanox/mlx5/core/en/params.c
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@ -253,17 +253,20 @@ static u32 mlx5e_rx_get_linear_stride_sz(struct mlx5_core_dev *mdev,
struct mlx5e_xsk_param *xsk,
bool mpwqe)
{
u32 sz;
/* XSK frames are mapped as individual pages, because frames may come in
* an arbitrary order from random locations in the UMEM.
*/
if (xsk)
return mpwqe ? 1 << mlx5e_mpwrq_page_shift(mdev, xsk) : PAGE_SIZE;
/* XDP in mlx5e doesn't support multiple packets per page. */
if (params->xdp_prog)
return PAGE_SIZE;
sz = roundup_pow_of_two(mlx5e_rx_get_linear_sz_skb(params, false));
return roundup_pow_of_two(mlx5e_rx_get_linear_sz_skb(params, false));
/* XDP in mlx5e doesn't support multiple packets per page.
* Do not assume sz <= PAGE_SIZE if params->xdp_prog is set.
*/
return params->xdp_prog && sz < PAGE_SIZE ? PAGE_SIZE : sz;
}
static u8 mlx5e_mpwqe_log_pkts_per_wqe(struct mlx5_core_dev *mdev,