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[144.49.247.2]) by smtp-relay.gmail.com with ESMTPS id d9443c01a7336-2a79e174f39sm2097425ad.27.2026.01.20.23.36.04 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 20 Jan 2026 23:36:04 -0800 (PST) X-Relaying-Domain: broadcom.com X-CFilter-Loop: Reflected Received: by mail-qv1-f72.google.com with SMTP id 6a1803df08f44-8946448adbdso40586046d6.1 for ; Tue, 20 Jan 2026 23:36:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; t=1768980963; x=1769585763; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=IPRVbPwF+wXnXIym+qvc8QVBDwbNyNX7SjLMFiSMDaA=; b=ZrWDQfs4mx3KruX54fLgv0qIZKL4h8LrHqMvrmC/BVDEZHc065oEYm6raK0I3O8Jq7 7z6n3s4ll6LY0XZjdEFVwtxDQopMAePgpQLSarqQw3ZKkRd97Lnk2KWT3Pk3xGr4AX76 PPXzmYiLtdMM5Q6Nwd2Xmbgg8eQ2IqhMJWugg= X-Forwarded-Encrypted: i=1; AJvYcCVD7bEjPGjOs+DuodMv+d74QJtzPyC6Hy7CKDYaIq/YfDNhpnGqXSA1C/Qy09fSxmnBGE46a8oVDZIUCLs=@vger.kernel.org X-Received: by 2002:a05:6214:29c2:b0:893:348e:4126 with SMTP id 6a1803df08f44-8942e52179fmr267876956d6.61.1768980963172; Tue, 20 Jan 2026 23:36:03 -0800 (PST) X-Received: by 2002:a05:6214:29c2:b0:893:348e:4126 with SMTP id 6a1803df08f44-8942e52179fmr267876746d6.61.1768980962761; Tue, 20 Jan 2026 23:36:02 -0800 (PST) Received: from lvnvda4076.lvn.broadcom.net ([192.19.161.250]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-894592ba642sm51439736d6.57.2026.01.20.23.36.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Jan 2026 23:36:02 -0800 (PST) From: Kiran Kella To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jayakrishnan.udayavarma@broadcom.com, ajit.khaparde@broadcom.com, akhilesh.samineni@broadcom.com, Kiran Kella Subject: [net-next 1/2] psp: Support for transmit on logical device when the underlying transport device supports PSP. Date: Tue, 20 Jan 2026 23:35:16 -0800 Message-ID: <20260121073517.3323332-2-kiran.kella@broadcom.com> X-Mailer: git-send-email 2.45.4 In-Reply-To: <20260121073517.3323332-1-kiran.kella@broadcom.com> References: <20260121073517.3323332-1-kiran.kella@broadcom.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-DetectorID-Processed: b00c1d49-9d2e-4205-b15f-d015386d3d5e Content-Type: text/plain; charset="utf-8" This is achieved by propagating the psp_dev from the lower device to the upper devices in the device stack via a netdevice notifier. The lowest device owns the psp_dev pointer while the upper devices just borrow the pointer. When the lower device is unlinked, the borrowed pointer is cleared in the upper device. Assumption being that psp_dev is set on the lowest device before any upper devices stack are linked on that lowest device at a later point of time. In case of bond devices: - If an upper device has multiple lower devices, the psp_dev is not propogated as it would be ambiguous which slave will be used for transmission. - If a bond device transitions from having one slave device to multiple slaves, any previously borrowed psp_dev pointer is cleared to avoid ambiguity. Signed-off-by: Kiran Kella Reviewed-by: Ajit Kumar Khaparde Reviewed-by: Akhilesh Samineni --- net/psp/psp_main.c | 114 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) diff --git a/net/psp/psp_main.c b/net/psp/psp_main.c index a8534124f626..0bff50c9314d 100644 --- a/net/psp/psp_main.c +++ b/net/psp/psp_main.c @@ -313,10 +313,124 @@ int psp_dev_rcv(struct sk_buff *skb, u16 dev_id, u8 = generation, bool strip_icv) } EXPORT_SYMBOL(psp_dev_rcv); =20 +/** + * psp_netdevice_event() - Handle netdevice events for PSP device propagat= ion + * @nb: notifier block + * @event: netdevice event + * @ptr: netdevice notifier info + * + * Propagates psp_dev pointer from lower devices to upper devices when + * upper devices are created (e.g., VLAN subinterfaces). + */ +static int psp_netdevice_event(struct notifier_block *nb, + unsigned long event, void *ptr) +{ + struct netdev_notifier_changeupper_info *info; + struct net_device *dev, *upper_dev; + struct psp_dev *psd; + + if (event !=3D NETDEV_CHANGEUPPER) + return NOTIFY_DONE; + + info =3D ptr; + dev =3D netdev_notifier_info_to_dev(ptr); + upper_dev =3D info->upper_dev; + + if (info->linking) { + bool has_multiple_lowers =3D false; + struct list_head *iter; + + /* Lower device is being linked to an upper device. + * Propagate psp_dev from the immediate lower device to the + * upper device. The immediate lower device would have already + * got the psp_dev pointer set in a previous notification (or + * owns it if it's the lowest device), + * Upper devices just borrow the pointer. + * + * However, if the upper device has multiple lower devices, + * don't propagate psp_dev as it would be ambiguous + * which slave will be used for transmission (eg., bond device). + * If the upper device already has psp_dev set and is getting + * a second lower device, clear the psp_dev. + */ + + rcu_read_lock(); + iter =3D &upper_dev->adj_list.lower; + /* Check if there's a second lower device */ + if (netdev_next_lower_dev_rcu(upper_dev, &iter)) + if (netdev_next_lower_dev_rcu(upper_dev, &iter)) + has_multiple_lowers =3D true; + + /* If upper device now has multiple lower devices, clear psp_dev + * if it was previously set (from when it had only one slave). + */ + if (has_multiple_lowers) { + psd =3D rcu_dereference(upper_dev->psp_dev); + rcu_read_unlock(); + if (psd) + rcu_assign_pointer(upper_dev->psp_dev, NULL); + + return NOTIFY_DONE; + } + + /* Get psp_dev from the immediate lower device */ + psd =3D rcu_dereference(dev->psp_dev); + rcu_read_unlock(); + + /* Propagate psp_dev to upper device if found */ + if (psd) + rcu_assign_pointer(upper_dev->psp_dev, psd); + } else { + struct net_device *remaining_lower =3D NULL; + bool has_single_lower =3D false; + struct list_head *iter; + + /* Lower device is being unlinked from an upper device. + * After unlinking, check if the upper device now has exactly + * one lower device remaining. If so, propagate psp_dev from + * that remaining lower device to the upper device. + */ + + rcu_read_lock(); + iter =3D &upper_dev->adj_list.lower; + remaining_lower =3D netdev_next_lower_dev_rcu(upper_dev, &iter); + /* Check if there's a second lower device */ + if (remaining_lower) + if (!netdev_next_lower_dev_rcu(upper_dev, &iter)) + has_single_lower =3D true; + + if (has_single_lower) { + /* Upper device now has exactly one lower device. + * Propagate psp_dev from the remaining lower device. + */ + psd =3D rcu_dereference(remaining_lower->psp_dev); + rcu_read_unlock(); + if (psd) + rcu_assign_pointer(upper_dev->psp_dev, psd); + } else { + /* Upper device has zero or multiple lower devices. + * Clear psp_dev if it was previously set. + */ + psd =3D rcu_dereference(upper_dev->psp_dev); + rcu_read_unlock(); + if (psd) + rcu_assign_pointer(upper_dev->psp_dev, NULL); + } + } + + return NOTIFY_DONE; +} + +static struct notifier_block psp_netdevice_notifier =3D { + .notifier_call =3D psp_netdevice_event, +}; + static int __init psp_init(void) { mutex_init(&psp_devs_lock); =20 + register_netdevice_notifier(&psp_netdevice_notifier); + return genl_register_family(&psp_nl_family); } =20 --=20 2.45.4