From: Bobby Eshleman Date: Thu, 14 May 2026 17:22:28 +0000 (-0700) Subject: net: convert netmem_tx flag to enum X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7d3ab852dcd853692197a830d20052127754a087;p=thirdparty%2Fkernel%2Flinux.git net: convert netmem_tx flag to enum Devices that support netmem TX previously set dev->netmem_tx = true. This was checked in validate_xmit_unreadable_skb() to drop unreadable skbs (skbs with dmabuf-backed frags) before they reach drivers that would mishandle them or devices that would not have the iommu mappings for them. A subsequent patch will introduce a third state for virtual devices that forward unreadable skbs without ever performing DMA on them. To prepare for that, convert the boolean dev->netmem_tx into an enum: NETMEM_TX_NONE - no netmem TX support (drop unreadable skbs) NETMEM_TX_DMA - full support, device does DMA Update the existing NIC drivers (bnxt, gve, mlx5, fbnic) and the validators in net/core to use the new enum. No functional change. Acked-by: Harshitha Ramamurthy Acked-by: Stanislav Fomichev Signed-off-by: Bobby Eshleman Link: https://patch.msgid.link/20260514-tcp-dm-netkit-v5-1-408c59b91e66@meta.com Signed-off-by: Jakub Kicinski --- diff --git a/Documentation/networking/netmem.rst b/Documentation/networking/netmem.rst index b63aded463370..5ccadba4f373e 100644 --- a/Documentation/networking/netmem.rst +++ b/Documentation/networking/netmem.rst @@ -95,4 +95,7 @@ Driver TX Requirements netdev@, or reach out to the maintainers and/or almasrymina@google.com for help adding the netmem API. -2. Driver should declare support by setting `netdev->netmem_tx = true` +2. Driver should declare support by setting `netdev->netmem_tx` to the + appropriate mode: + + - `NETMEM_TX_DMA`: for physical devices that perform DMA. diff --git a/Documentation/translations/zh_CN/networking/netmem.rst b/Documentation/translations/zh_CN/networking/netmem.rst index fe351a240f021..9c84423b75280 100644 --- a/Documentation/translations/zh_CN/networking/netmem.rst +++ b/Documentation/translations/zh_CN/networking/netmem.rst @@ -89,4 +89,6 @@ dma-mapping API 去处理。 使用某个还不存在的 netmem API，你可以自行添加并提交到 netdev@，也可以联系维护 人员或者发送邮件至 almasrymina@google.com 寻求帮助。 -2. 驱动程序应通过设置 netdev->netmem_tx = true 来表明自身支持 netmem 功能。 +2. 驱动程序应将 `netdev->netmem_tx` 设置为适当的模式： + + - `NETMEM_TX_DMA`：适用于执行 DMA 的物理设备。 diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 945a86696f2f0..d4f93e62f5836 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -17123,7 +17123,7 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) dev->queue_mgmt_ops = &bnxt_queue_mgmt_ops_unsupp; if (BNXT_SUPPORTS_QUEUE_API(bp)) dev->queue_mgmt_ops = &bnxt_queue_mgmt_ops; - dev->netmem_tx = true; + dev->netmem_tx = NETMEM_TX_DMA; rc = register_netdev(dev); if (rc) diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c index 00750643e614f..e4d78ae52dafe 100644 --- a/drivers/net/ethernet/google/gve/gve_main.c +++ b/drivers/net/ethernet/google/gve/gve_main.c @@ -2894,7 +2894,7 @@ static int gve_probe(struct pci_dev *pdev, const struct pci_device_id *ent) goto abort_with_wq; if (!gve_is_gqi(priv) && !gve_is_qpl(priv)) - dev->netmem_tx = true; + dev->netmem_tx = NETMEM_TX_DMA; err = register_netdev(dev); if (err) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c index a904e468c1977..c5d26c6829a0d 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c @@ -5963,7 +5963,7 @@ static void mlx5e_build_nic_netdev(struct net_device *netdev) netdev->priv_flags |= IFF_UNICAST_FLT; - netdev->netmem_tx = true; + netdev->netmem_tx = NETMEM_TX_DMA; netif_set_tso_max_size(netdev, GSO_MAX_SIZE); mlx5e_set_xdp_feature(priv); diff --git a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c index 4dea2bb58d2fc..f99ca551c1ceb 100644 --- a/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c +++ b/drivers/net/ethernet/meta/fbnic/fbnic_netdev.c @@ -752,7 +752,7 @@ struct net_device *fbnic_netdev_alloc(struct fbnic_dev *fbd) netdev->netdev_ops = &fbnic_netdev_ops; netdev->stat_ops = &fbnic_stat_ops; netdev->queue_mgmt_ops = &fbnic_queue_mgmt_ops; - netdev->netmem_tx = true; + netdev->netmem_tx = NETMEM_TX_DMA; fbnic_set_ethtool_ops(netdev); diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index e7af71491a475..b7a4503f7cdb6 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1794,6 +1794,11 @@ enum netdev_stat_type { NETDEV_PCPU_STAT_DSTATS, /* struct pcpu_dstats */ }; +enum netmem_tx_mode { + NETMEM_TX_NONE, /* no netmem TX support */ + NETMEM_TX_DMA, /* DMA-capable netmem TX (real HW) */ +}; + enum netdev_reg_state { NETREG_UNINITIALIZED = 0, NETREG_REGISTERED, /* completed register_netdevice */ @@ -1815,7 +1820,7 @@ enum netdev_reg_state { * @lltx: device supports lockless Tx. Deprecated for real HW * drivers. Mainly used by logical interfaces, such as * bonding and tunnels - * @netmem_tx: device support netmem_tx. + * @netmem_tx: device netmem TX mode * * @name: This is the first field of the "visible" part of this structure * (i.e. as seen by users in the "Space.c" file). It is the name diff --git a/net/core/dev.c b/net/core/dev.c index 267cf3854395f..23c1ad3d393da 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3996,7 +3996,7 @@ static struct sk_buff *validate_xmit_unreadable_skb(struct sk_buff *skb, if (likely(skb_frags_readable(skb))) goto out; - if (!dev->netmem_tx) + if (dev->netmem_tx == NETMEM_TX_NONE) goto out_free; shinfo = skb_shinfo(skb); diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c index b8f6076d80072..4d2c49371cdb4 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -1164,7 +1164,7 @@ int netdev_nl_bind_tx_doit(struct sk_buff *skb, struct genl_info *info) goto err_unlock_netdev; } - if (!netdev->netmem_tx) { + if (netdev->netmem_tx == NETMEM_TX_NONE) { err = -EOPNOTSUPP; NL_SET_ERR_MSG(info->extack, "Driver does not support netmem TX");