From: Dragos Tatulea Date: Wed, 27 Aug 2025 14:39:58 +0000 (+0300) Subject: net/mlx5e: add op for getting netdev DMA device X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f1debf1a2ef44ca1baa15a0cc088cb2be1f95449;p=users%2Fhch%2Fmisc.git net/mlx5e: add op for getting netdev DMA device For zero-copy (devmem, io_uring), the netdev DMA device used is the parent device of the net device. However that is not always accurate for mlx5 devices: - SFs: The parent device is an auxdev. - Multi-PF netdevs: The DMA device should be determined by the queue. This change implements the DMA device queue API that returns the DMA device appropriately for all cases. Signed-off-by: Dragos Tatulea Reviewed-by: Mina Almasry Link: https://patch.msgid.link/20250827144017.1529208-6-dtatulea@nvidia.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index 21bb88c5d3dc..0e48065a46eb 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -5625,12 +5625,36 @@ static int mlx5e_queue_start(struct net_device *dev, void *newq, return 0; } +static struct device *mlx5e_queue_get_dma_dev(struct net_device *dev, + int queue_index) +{ + struct mlx5e_priv *priv = netdev_priv(dev); + struct mlx5e_channels *channels; + struct device *pdev = NULL; + struct mlx5e_channel *ch; + + channels = &priv->channels; + + mutex_lock(&priv->state_lock); + + if (queue_index >= channels->num) + goto out; + + ch = channels->c[queue_index]; + pdev = ch->pdev; +out: + mutex_unlock(&priv->state_lock); + + return pdev; +} + static const struct netdev_queue_mgmt_ops mlx5e_queue_mgmt_ops = { .ndo_queue_mem_size = sizeof(struct mlx5_qmgmt_data), .ndo_queue_mem_alloc = mlx5e_queue_mem_alloc, .ndo_queue_mem_free = mlx5e_queue_mem_free, .ndo_queue_start = mlx5e_queue_start, .ndo_queue_stop = mlx5e_queue_stop, + .ndo_queue_get_dma_dev = mlx5e_queue_get_dma_dev, }; static void mlx5e_build_nic_netdev(struct net_device *netdev)