From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F78A39934A for ; Wed, 1 Apr 2026 16:39:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775061569; cv=none; b=d7jUdDxioGqCPllJVqmBXvxB46J8amNJsECTgyIQ9Jf9Ni984NGhM0oJZ/DQ+a8Bxj2moto5Ygoq/kVb4qyWHVVvobTiBNA9zYwAt65u9/WkhgZP2IYk8DkJq+iqyJlQLKuELD2XFlw2jPM9cPEM4yrOuSSv1TdV5rA4dO4egqI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775061569; c=relaxed/simple; bh=7dRSTocVVJVHoZ4Ky5tBS1t/O/QyoT1VkCz03gtGhUQ=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=gdYFpcanQniCWzHXpRSwX5VWsNKkDItfXN7G9+2DZMKGiIYIob8VqJaKYCpSPBV4YQyztXH4W0Il7+Bf1rSySbVdY18LPxNZzxRzDkwwpUfWo8pASAzMUq7mjuyc/Pf+0UjBo/hG0b/1r1q+Hw6Cn9bum0EZIEAelKjZ2y/eaUY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=UjPxpB4L; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="UjPxpB4L" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id A0BC64E42897; Wed, 1 Apr 2026 16:39:23 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 73E93602BF; Wed, 1 Apr 2026 16:39:23 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id BFCFF10450306; Wed, 1 Apr 2026 18:39:16 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1775061562; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding; bh=dcM/r2Lb6WVrNr0XnkOMDeChZYJtPlTmLZ5u5BYvidY=; b=UjPxpB4L2kjLznhF4/LNQTRmWQBD2q60zgFYRlPxuWmGmM9+Q1UPywFOiZ/2ZgH6IwMnOl vC2ipFSs8z4UpCfKAX9y1WYLeKm5EMB7N6HiSYH2n53GVlLEnhtEpKO4QMg6xTOYxwnEB7 HGsJeOHVMoQ09r/twrzKCMH0vfgEpyULjZWRkNVCVGwwsne2OitYfmZ93YayzdC3Bwlv2q /9CRl/L93oBt58kixzqzOb9N23wm5f3stASYz11EzdrG2HYNorB9VmCYBNcILh7FvSaYba sk8QI/NSm1GAK6hgYHWdZ+crRT/W1JyKGjoKHL2UZMIituEAVzjIhTSkjNjR6A== From: =?utf-8?q?Th=C3=A9o_Lebrun?= Subject: [PATCH net-next 00/11] net: macb: implement context swapping Date: Wed, 01 Apr 2026 18:39:03 +0200 Message-Id: <20260401-macb-context-v1-0-9590c5ab7272@bootlin.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-B4-Tracking: v=1; b=H4sIAAAAAAAC/yWMQQrDMAwEvxJ0jkA2pod+peRgy0qrQpVguyEQ8 ve67XHYnTmgSlGpcB0OKLJp1cU6uHEAfkS7C2ruDJ78hQI5fEVOyIs12RumTBxnT8GFDF1Zi8y 6/3I3MGlo/QXTf6nv9BRu3xqc5wfwFIMgegAAAA== X-Change-ID: 20260401-macb-context-bd0caf20414d To: Nicolas Ferre , Claudiu Beznea , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Richard Cochran , Russell King Cc: Paolo Valerio , Conor Dooley , Nicolai Buchwitz , Vladimir Kondratiev , Gregory CLEMENT , =?utf-8?q?Beno=C3=AEt_Monin?= , Tawfik Bayouk , Thomas Petazzoni , Maxime Chevallier , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?q?Th=C3=A9o_Lebrun?= X-Mailer: b4 0.15.0 X-Last-TLS-Session-Version: TLSv1.3 MACB has a pretty primitive approach to buffer management. They are all stored in `struct macb *bp`. On operations that require buffer realloc (set_ringparam & change_mtu ATM), the only option is to close the interface, change our global state and re-open the interface. Two issues: - It doesn't fly on memory pressured systems; we free our precious buffers and don't manage to reallocate fully, meaning our machine just lost its network access. - Anecdotally, it is pretty slow because it implies a full PHY reinit. Instead, we shall: - allocate a new context (including buffers) first - if it fails, early return without any impact to the interface - stop interface - update global state (bp, netdev, etc) - pass newly allocated buffer pointers to the hardware - start interface - free old context This is what we implement here. Both .set_ringparam() and .ndo_change_mtu() are covered by this series. In the future, at least .set_channels() [0], XDP [1] and XSK [2] would benefit. The change is super intrusive so conflicts will be major. Sorry! Thanks, Have a nice day, Théo [0]: https://lore.kernel.org/netdev/20260317-macb-set-channels-v4-0-1bd4f4ffcfca@bootlin.com/ [1]: https://lore.kernel.org/netdev/20260323221047.2749577-1-pvalerio@redhat.com/ [2]: https://lore.kernel.org/netdev/20260304-macb-xsk-v1-0-ba2ebe2bdaa3@bootlin.com/ Signed-off-by: Théo Lebrun --- Théo Lebrun (11): net: macb: unify device pointer naming convention net: macb: unify `struct macb *` naming convention net: macb: unify queue index variable naming convention and types net: macb: enforce reverse christmas tree (RCT) convention net: macb: allocate tieoff descriptor once across device lifetime net: macb: introduce macb_context struct for buffer management net: macb: avoid macb_init_rx_buffer_size() modifying state net: macb: make `struct macb` subset reachable from macb_context struct net: macb: introduce macb_context_alloc() helper net: macb: use context swapping in .set_ringparam() net: macb: use context swapping in .ndo_change_mtu() drivers/net/ethernet/cadence/macb.h | 119 +- drivers/net/ethernet/cadence/macb_main.c | 1731 +++++++++++++++++------------- drivers/net/ethernet/cadence/macb_pci.c | 46 +- drivers/net/ethernet/cadence/macb_ptp.c | 26 +- 4 files changed, 1090 insertions(+), 832 deletions(-) --- base-commit: 321d1ee521de1362c22adadbc0ce066050a17783 change-id: 20260401-macb-context-bd0caf20414d Best regards, -- Théo Lebrun