From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 AB3122F8E8D; Sat, 9 May 2026 01:46:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778291171; cv=none; b=oBpIjtQdhJ9noICaem9s2lKaZS2QUW9YC21VGzmhfqyWJNSaAHIgM2oJo9nlLJ2+LIsGxfGHcSIjo1ACutRVlpETsj+rpsH6zlHONM6gzAUxVfB2DIdqvbNtq7N4T9X5DJerUb7nhaiYyfZFv4nc5whFIpLMf0H0aBdEwtwkzEI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778291171; c=relaxed/simple; bh=BdduitEx/Iq5i1rUs4QAgBh5C/BbY9EApB51NEx/vLw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JmMMQDQCOPQNoaoAEDZV436uOBwxA/RFCaj3M5OFkavNqjLZWY0C7T13NwJ9uwS/oNir+GY9yth3C3DLuV79ws+pSe/I57nnKqWv1YdFNGy6ZoFdBy1pMqmMFdkUQ1ha4UfhgZpk7b8SmQxL08hKXi3SH4BxSIbfUk8PdM2tgKw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nYWCwI+9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nYWCwI+9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A69CDC2BCB4; Sat, 9 May 2026 01:46:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778291171; bh=BdduitEx/Iq5i1rUs4QAgBh5C/BbY9EApB51NEx/vLw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nYWCwI+94h+mct2TLbTJjnQFISjyiYFHyrKUtGozTDIzANAOJMaOtPVVkreUKD+K9 8WNvMkHjLFyzYUEOC+LVPB9t5tj4hFQKh62vtCnS2z1yiPppl1K/C0jSziA0TkepPx lQgabOvDArnfoCig7Q1reL94Bh+L7djvwE43z6wULkjZr4UR7lF1n952ujk6sPA+Kv VlGwGNnGj/isiYeMo8U/LFFDPgdou8TAMc5UDaGfnUcldMWe3PBPScuapPQAgbKOpw MF1BFrrIZP0qfDeVmsNDUCoXEa+c8+uKJfc9V3OmSdE6LiC3CDu6MTl8otGFIsxEGf xzlGLy1Uo0zTg== From: Jakub Kicinski To: lorenzo@kernel.org Cc: Jakub Kicinski , andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, ansuelsmth@gmail.com, benjamin.larsson@genexis.eu, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, madhur.agrawal@airoha.com Subject: Re: [PATCH net-next v4 05/10] net: airoha: Move qos_sq_bmap in airoha_qdma struct Date: Fri, 8 May 2026 18:46:09 -0700 Message-ID: <20260509014609.3558041-1-kuba@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260507-airoha-eth-multi-serdes-v4-5-af613b61ae02@kernel.org> References: <20260507-airoha-eth-multi-serdes-v4-5-af613b61ae02@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This is an AI-generated review of your patch. The human sending this email has considered the AI review valid, or at least plausible. --- net: airoha: Move qos_sq_bmap in airoha_qdma struct The change moves the HTB-offload channel-allocation bitmap from the per-netdev airoha_gdm_port to the per-QDMA airoha_qdma, so sibling netdevs attached to different QDMA blocks no longer clobber each other's bitmap. > diff --git a/drivers/net/ethernet/airoha/airoha_eth.c b/drivers/net/ethernet/airoha/airoha_eth.c > index 080705e2f58d..69a4c2e0d58b 100644 > --- a/drivers/net/ethernet/airoha/airoha_eth.c > +++ b/drivers/net/ethernet/airoha/airoha_eth.c > @@ -2600,7 +2600,7 @@ static int airoha_tc_htb_alloc_leaf_queue(struct net_device *netdev, > u32 rate = div_u64(opt->rate, 1000) << 3; /* kbps */ > int err, num_tx_queues = netdev->real_num_tx_queues; > struct airoha_gdm_dev *dev = netdev_priv(netdev); > - struct airoha_gdm_port *port = dev->port; > + struct airoha_qdma *qdma = dev->qdma; > > if (opt->parent_classid != TC_HTB_CLASSID_ROOT) { > NL_SET_ERR_MSG_MOD(opt->extack, "invalid parent classid"); > @@ -2627,7 +2627,7 @@ static int airoha_tc_htb_alloc_leaf_queue(struct net_device *netdev, > return err; > } > > - set_bit(channel, port->qos_sq_bmap); > + set_bit(channel, qdma->qos_sq_bmap); > opt->qid = AIROHA_NUM_TX_RING + channel; > > return 0; [High] Now that qos_sq_bmap is per-QDMA, can two sibling netdevs that share the same QDMA block collide on allocation? On EN7581, GDM2/GDM3/GDM4 all select the same qdma pointer via: drivers/net/ethernet/airoha/airoha_eth.c: /* QDMA0 is used for lan ports while QDMA1 is used for WAN ports */ dev->qdma = ð->qdma[!airoha_is_lan_gdm_dev(dev)]; and airoha_is_lan_gdm_dev() returns true only for port->id == 1, so every non-LAN GDM netdev resolves to eth->qdma[1] and shares qdma->qos_sq_bmap. The allocation path does not test the bit before setting it: channel = TC_H_MIN(opt->classid) % AIROHA_NUM_QOS_CHANNELS; ... set_bit(channel, qdma->qos_sq_bmap); opt->qid = AIROHA_NUM_TX_RING + channel; If two sibling netdevs on the same QDMA pick classids whose TC_H_MIN maps to the same channel, both airoha_qdma_set_tx_rate_limit() calls program the same HW TRTCM egress slot, the later caller silently overwrites the earlier configuration, and both netdevs receive the same opt->qid. Should this path use test_and_set_bit() (or similar owner tracking) to reject a channel already owned by a sibling netdev? > @@ -2811,11 +2811,11 @@ static int airoha_dev_setup_tc_block(struct net_device *dev, > static void airoha_tc_remove_htb_queue(struct net_device *netdev, int queue) > { > struct airoha_gdm_dev *dev = netdev_priv(netdev); > - struct airoha_gdm_port *port = dev->port; > + struct airoha_qdma *qdma = dev->qdma; > > netif_set_real_num_tx_queues(netdev, netdev->real_num_tx_queues - 1); > airoha_qdma_set_tx_rate_limit(netdev, queue + 1, 0, 0); > - clear_bit(queue, port->qos_sq_bmap); > + clear_bit(queue, qdma->qos_sq_bmap); > } [High] airoha_tc_remove_htb_queue() operates unconditionally on the caller's netdev but clears a bit that may be owned by a sibling netdev on the same QDMA. The effects that follow look like cross-netdev interference: - netif_set_real_num_tx_queues(netdev, real_num_tx_queues - 1) decrements the caller's tx-queue count for a queue it never allocated, and its return value is discarded (eventually the txq<1 EINVAL guard in netif_set_real_num_tx_queues() will trip silently). - airoha_qdma_set_tx_rate_limit(netdev, queue + 1, 0, 0) zeros the egress TRTCM rate-limit registers for a channel that the sibling netdev still considers active. - clear_bit(queue, qdma->qos_sq_bmap) then hides the channel from the legitimate owner's later test_bit() checks. > @@ -2838,10 +2838,10 @@ static int airoha_tc_htb_delete_leaf_queue(struct net_device *netdev, > static int airoha_tc_htb_destroy(struct net_device *netdev) > { > struct airoha_gdm_dev *dev = netdev_priv(netdev); > - struct airoha_gdm_port *port = dev->port; > + struct airoha_qdma *qdma = dev->qdma; > int q; > > - for_each_set_bit(q, port->qos_sq_bmap, AIROHA_NUM_QOS_CHANNELS) > + for_each_set_bit(q, qdma->qos_sq_bmap, AIROHA_NUM_QOS_CHANNELS) > airoha_tc_remove_htb_queue(netdev, q); > > return 0; > } [High] Does airoha_tc_htb_destroy() now walk bits owned by sibling netdevs? The iteration no longer filters by owning netdev: for_each_set_bit(q, qdma->qos_sq_bmap, AIROHA_NUM_QOS_CHANNELS) airoha_tc_remove_htb_queue(netdev, q); Previously each netdev had a private bitmap, so destroy could only touch its own channels. After this change, tearing down HTB on one GDM netdev appears to remove channels and clear rate-limit HW state belonging to every sibling GDM netdev on the same QDMA. A subsequent tc-htb delete or get on the legitimate owner then hits: if (!test_bit(channel, qdma->qos_sq_bmap)) { NL_SET_ERR_MSG_MOD(opt->extack, "invalid queue id"); return -EINVAL; } Should the bitmap track the owning netdev alongside the bit (for example a per-channel owner pointer, or a per-netdev sub-bitmap inside airoha_qdma), so that destroy/delete can only touch channels owned by the caller? > @@ -2852,9 +2852,9 @@ static int airoha_tc_get_htb_get_leaf_queue(struct net_device *netdev, > { > u32 channel = TC_H_MIN(opt->classid) % AIROHA_NUM_QOS_CHANNELS; > struct airoha_gdm_dev *dev = netdev_priv(netdev); > - struct airoha_gdm_port *port = dev->port; > + struct airoha_qdma *qdma = dev->qdma; > > - if (!test_bit(channel, port->qos_sq_bmap)) { > + if (!test_bit(channel, qdma->qos_sq_bmap)) { > NL_SET_ERR_MSG_MOD(opt->extack, "invalid queue id"); > return -EINVAL; > }