From nobody Sun Dec 14 19:54:28 2025 Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BBAFD1FC0ED for ; Thu, 8 May 2025 00:48:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746665326; cv=none; b=KSngtz2tbHE70Vm0nKdXGqYMxhqQnnfZ3jmOKWLHQpEw4+eakQQBZDtbL7nYCKDWDskqxSBFwIlqfh8FZS4Et+c7HI/EB3NqlxvppCp9bVAtr8/0UTONAesy/45mcd7hUGX2RmadT+ay5sIJw3++HjlkqzW5AD4f6gLlOeQ92y4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746665326; c=relaxed/simple; bh=4jUNCNjECA7PPZ4+BZYmFMt31HNjPRlrhkD5S9xqW2c=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Bq+RQQF1ZK2pFN3b3qlztmG5/SOD+k45EObUdPTLP1nazNzkc1c6TudqNWDnhUKHMoUjI+XQ1gSdPBUzSaelgJ5cRyTG1cDy4iQ3BzMN+bFWu+JJEkZmRSKg1sh53AhXTqFWiZfRelqdYXoJhgn5VYjhEKXQhcWEdHXz8x30hyM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--almasrymina.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=GQyE9kYk; arc=none smtp.client-ip=209.85.215.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--almasrymina.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="GQyE9kYk" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-6c8f99fef10so352959a12.3 for ; Wed, 07 May 2025 17:48:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1746665323; x=1747270123; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=GJxPiRsv5mC+aacl3ED/DgmDVvwyw3AKvd/EhyAWZPc=; b=GQyE9kYk34zqNcNbYRcj36kzJUXghYJ36J+c2l2WQkXzf3pMxQBcI2cGeI8XierIGS ThqprV7Lw4qsPiJ7BkSS6CHDnxXwFEsWyd49M6hlK4Xk5hqeFX15C3AcFNB1Idua5MF0 YLHSsrRIFLICQB8N9GanjOv1+sYXOb957HxkbN9d0+Q2QDxrbv1DZxz4oeFjVu0BipuT 7VIKPf6Uf2o4J9Uqvh6r/UnKlL88lcOWIjMMJiqMaNbeaizgMhyM13vR0TcXPIEue901 zQGJIg85ucaqsv3dSRvYR65lHxZ/5/7ixXGD5kJu4qF1RJ7SDF3EDBbTPLYeOjLc4Vy3 6Oew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746665323; x=1747270123; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=GJxPiRsv5mC+aacl3ED/DgmDVvwyw3AKvd/EhyAWZPc=; b=CsFMYz9n65WRVFiFM8p3Ft/THP//yc314IaxHrd5LN9uFSo4PGrFK5dCYL5GKGgTt9 tMzBADvAhFLw37+5I+alTg+wGdkIxzcD5RLyGKa3uSPHWCTXnp0vElyB7rUBpKltq4NR 8TgIq5WEL7YB9t2mwZN5a5Vchbv0i45xAVCN83TznB3oWRJtIrnEkmqwwMAs7jXr+unO E4IFmjIXTdw3M8cYov2MiqkcO9fiph5sUyOwiimRhrTKMO0dkSijkO4M1nwqI5mXKYrj knqpSP9yzrfIYKyJZB6OrJ89QYJB76H+L2su0su4j+R0RCkPg3DbZcIr0JaRW0sbNo/X 7Msg== X-Forwarded-Encrypted: i=1; AJvYcCW52QYlskSU+jnZdg0wvdXzCIctCuCYZ6yho66o1dziUIKu2fvH9Llo/2mxZsmRA3Bne6X8Ml9nKc99Q+Y=@vger.kernel.org X-Gm-Message-State: AOJu0YzGmsH80xsWGt33dzWXJ1rBzEnX31L4nyCj+Z8lTT989X9j0Ypm Uti61g6ivhbh13cMuYxc40mepN+48lPl2IgELqPnidlCSgsq31eE0kI7i9LEbP354HXnImDFygu TqtKVp/svLJcaGZYoSbuklQ== X-Google-Smtp-Source: AGHT+IGmYWzxLwSxhc9NDnVVhx1fBBq1AAFy1tyJQ33YIyq8DB1qbWkBK1FqlOHE8+uWHo9OMasEeZ9R3Hldh8h8uQ== X-Received: from pgix5.prod.google.com ([2002:a63:db45:0:b0:b0d:967f:23de]) (user=almasrymina job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:d04f:b0:1f5:8fe3:4e29 with SMTP id adf61e73a8af0-2148b1133fbmr8296492637.3.1746665322596; Wed, 07 May 2025 17:48:42 -0700 (PDT) Date: Thu, 8 May 2025 00:48:26 +0000 In-Reply-To: <20250508004830.4100853-1-almasrymina@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250508004830.4100853-1-almasrymina@google.com> X-Mailer: git-send-email 2.49.0.987.g0cc8ee98dc-goog Message-ID: <20250508004830.4100853-7-almasrymina@google.com> Subject: [PATCH net-next v14 6/9] net: enable driver support for netmem TX From: Mina Almasry To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, io-uring@vger.kernel.org, virtualization@lists.linux.dev, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Mina Almasry , Donald Hunter , Jakub Kicinski , "David S. Miller" , Eric Dumazet , Paolo Abeni , Simon Horman , Jonathan Corbet , Andrew Lunn , Jeroen de Borst , Harshitha Ramamurthy , Kuniyuki Iwashima , Willem de Bruijn , Jens Axboe , Pavel Begunkov , David Ahern , Neal Cardwell , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , "=?UTF-8?q?Eugenio=20P=C3=A9rez?=" , Stefan Hajnoczi , Stefano Garzarella , Shuah Khan , sdf@fomichev.me, dw@davidwei.uk, Jamal Hadi Salim , Victor Nogueira , Pedro Tammela , Samiullah Khawaja Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Drivers need to make sure not to pass netmem dma-addrs to the dma-mapping API in order to support netmem TX. Add helpers and netmem_dma_*() helpers that enables special handling of netmem dma-addrs that drivers can use. Document in netmem.rst what drivers need to do to support netmem TX. Signed-off-by: Mina Almasry Acked-by: Stanislav Fomichev --- v8: - use spaces instead of tabs (Paolo) v5: - Fix netmet TX documentation (Stan). v4: - New patch --- .../networking/net_cachelines/net_device.rst | 1 + Documentation/networking/netdev-features.rst | 5 ++++ Documentation/networking/netmem.rst | 23 +++++++++++++++++-- include/linux/netdevice.h | 2 ++ include/net/netmem.h | 20 ++++++++++++++++ 5 files changed, 49 insertions(+), 2 deletions(-) diff --git a/Documentation/networking/net_cachelines/net_device.rst b/Docum= entation/networking/net_cachelines/net_device.rst index ca8605eb82ffc..c69cc89c958e0 100644 --- a/Documentation/networking/net_cachelines/net_device.rst +++ b/Documentation/networking/net_cachelines/net_device.rst @@ -10,6 +10,7 @@ Type Name = fastpath_tx_acce =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D unsigned_long:32 priv_flags read_mostl= y __dev_queue_xmit(tx) unsigned_long:1 lltx read_mostl= y HARD_TX_LOCK,HARD_TX_TRYLOCK,HARD_TX_UNLOCK(t= x) +unsigned long:1 netmem_tx:1; read_mostly char name[16] struct netdev_name_node* name_node struct dev_ifalias* ifalias diff --git a/Documentation/networking/netdev-features.rst b/Documentation/n= etworking/netdev-features.rst index 5014f7cc1398b..02bd7536fc0ca 100644 --- a/Documentation/networking/netdev-features.rst +++ b/Documentation/networking/netdev-features.rst @@ -188,3 +188,8 @@ Redundancy) frames from one port to another in hardware. This should be set for devices which duplicate outgoing HSR (High-availabi= lity Seamless Redundancy) or PRP (Parallel Redundancy Protocol) tags automatica= lly frames in hardware. + +* netmem-tx + +This should be set for devices which support netmem TX. See +Documentation/networking/netmem.rst diff --git a/Documentation/networking/netmem.rst b/Documentation/networking= /netmem.rst index 7de21ddb54129..b63aded463370 100644 --- a/Documentation/networking/netmem.rst +++ b/Documentation/networking/netmem.rst @@ -19,8 +19,8 @@ Benefits of Netmem : * Simplified Development: Drivers interact with a consistent API, regardless of the underlying memory implementation. =20 -Driver Requirements -=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D +Driver RX Requirements +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D =20 1. The driver must support page_pool. =20 @@ -77,3 +77,22 @@ Driver Requirements that purpose, but be mindful that some netmem types might have longer circulation times, such as when userspace holds a reference in zerocopy scenarios. + +Driver TX Requirements +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D + +1. The Driver must not pass the netmem dma_addr to any of the dma-mapping = APIs + directly. This is because netmem dma_addrs may come from a source like + dma-buf that is not compatible with the dma-mapping APIs. + + Helpers like netmem_dma_unmap_page_attrs() & netmem_dma_unmap_addr_set() + should be used in lieu of dma_unmap_page[_attrs](), dma_unmap_addr_set(= ). + The netmem variants will handle netmem dma_addrs correctly regardless o= f the + source, delegating to the dma-mapping APIs when appropriate. + + Not all dma-mapping APIs have netmem equivalents at the moment. If your + driver relies on a missing netmem API, feel free to add and propose to + 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 =3D true` diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 0321fd952f708..a661820a26c44 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1772,6 +1772,7 @@ 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. * * @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 @@ -2087,6 +2088,7 @@ struct net_device { struct_group(priv_flags_fast, unsigned long priv_flags:32; unsigned long lltx:1; + unsigned long netmem_tx:1; ); const struct net_device_ops *netdev_ops; const struct header_ops *header_ops; diff --git a/include/net/netmem.h b/include/net/netmem.h index ecb6b29c93f61..386164fb9c185 100644 --- a/include/net/netmem.h +++ b/include/net/netmem.h @@ -8,6 +8,7 @@ #ifndef _NET_NETMEM_H #define _NET_NETMEM_H =20 +#include #include #include =20 @@ -276,4 +277,23 @@ static inline unsigned long netmem_get_dma_addr(netmem= _ref netmem) void get_netmem(netmem_ref netmem); void put_netmem(netmem_ref netmem); =20 +#define netmem_dma_unmap_addr_set(NETMEM, PTR, ADDR_NAME, VAL) \ + do { \ + if (!netmem_is_net_iov(NETMEM)) \ + dma_unmap_addr_set(PTR, ADDR_NAME, VAL); \ + else \ + dma_unmap_addr_set(PTR, ADDR_NAME, 0); \ + } while (0) + +static inline void netmem_dma_unmap_page_attrs(struct device *dev, + dma_addr_t addr, size_t size, + enum dma_data_direction dir, + unsigned long attrs) +{ + if (!addr) + return; + + dma_unmap_page_attrs(dev, addr, size, dir, attrs); +} + #endif /* _NET_NETMEM_H */ --=20 2.49.0.987.g0cc8ee98dc-goog