From patchwork Tue Aug 1 12:29:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Souradeep Chakrabarti X-Patchwork-Id: 13336638 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 852E81F952 for ; Tue, 1 Aug 2023 12:29:57 +0000 (UTC) Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 399961FC6; Tue, 1 Aug 2023 05:29:56 -0700 (PDT) Received: by linux.microsoft.com (Postfix, from userid 1099) id 87B5A238AF50; Tue, 1 Aug 2023 05:29:55 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 87B5A238AF50 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1690892995; bh=Le5IWUlV+SOiU8nvbAjGXFDnfuBjbT8nhrykMj0k14k=; h=From:To:Cc:Subject:Date:From; b=QbxCkPlXOL/LLmKwjN3yXH6ja2Lg3P8hNezx5avxJmSJyLmBcOP9KapwTglQPrWgI rRV1trxCqelfaklwj2dNcuOWZSeI38r8SfjIGl+2JI/8e3XBUHCvdcdwhMbb5c0Oaf TOxfJApD/w9ureNlZ3mTBBTnR8k+zD5B2SV+Tp7M= From: Souradeep Chakrabarti To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, longli@microsoft.com, sharmaajay@microsoft.com, leon@kernel.org, cai.huoqing@linux.dev, ssengar@linux.microsoft.com, vkuznets@redhat.com, tglx@linutronix.de, linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org Cc: schakrabarti@microsoft.com, Souradeep Chakrabarti , stable@vger.kernel.org Subject: [PATCH V7 net] net: mana: Fix MANA VF unload when hardware is Date: Tue, 1 Aug 2023 05:29:13 -0700 Message-Id: <1690892953-25201-1-git-send-email-schakrabarti@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 X-Spam-Status: No, score=-17.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,ENV_AND_HDR_SPF_MATCH,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_PASS,SPF_PASS,T_SCC_BODY_TEXT_LINE,USER_IN_DEF_DKIM_WL, USER_IN_DEF_SPF_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: X-Patchwork-Delegate: kuba@kernel.org When unloading the MANA driver, mana_dealloc_queues() waits for the MANA hardware to complete any inflight packets and set the pending send count to zero. But if the hardware has failed, mana_dealloc_queues() could wait forever. Fix this by adding a timeout to the wait. Set the timeout to 120 seconds, which is a somewhat arbitrary value that is more than long enough for functional hardware to complete any sends. Cc: stable@vger.kernel.org Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network Adapter (MANA)") Signed-off-by: Souradeep Chakrabarti --- V6 -> V7: * Optimized the while loop for freeing skb. V5 -> V6: * Added pcie_flr to reset the pci after timeout. * Fixed the position of changelog. * Removed unused variable like cq. V4 -> V5: * Added fixes tag * Changed the usleep_range from static to incremental value. * Initialized timeout in the begining. V3 -> V4: * Removed the unnecessary braces from mana_dealloc_queues(). V2 -> V3: * Removed the unnecessary braces from mana_dealloc_queues(). V1 -> V2: * Added net branch * Removed the typecasting to (struct mana_context*) of void pointer * Repositioned timeout variable in mana_dealloc_queues() * Repositioned vf_unload_timeout in mana_context struct, to utilise the 6 bytes hole --- drivers/net/ethernet/microsoft/mana/mana_en.c | 37 +++++++++++++++++-- 1 file changed, 33 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index a499e460594b..3c5552a176d0 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -8,6 +8,7 @@ #include #include #include +#include #include #include @@ -2345,9 +2346,12 @@ int mana_attach(struct net_device *ndev) static int mana_dealloc_queues(struct net_device *ndev) { struct mana_port_context *apc = netdev_priv(ndev); + unsigned long timeout = jiffies + 120 * HZ; struct gdma_dev *gd = apc->ac->gdma_dev; struct mana_txq *txq; + struct sk_buff *skb; int i, err; + u32 tsleep; if (apc->port_is_up) return -EINVAL; @@ -2363,15 +2367,40 @@ static int mana_dealloc_queues(struct net_device *ndev) * to false, but it doesn't matter since mana_start_xmit() drops any * new packets due to apc->port_is_up being false. * - * Drain all the in-flight TX packets + * Drain all the in-flight TX packets. + * A timeout of 120 seconds for all the queues is used. + * This will break the while loop when h/w is not responding. + * This value of 120 has been decided here considering max + * number of queues. */ + for (i = 0; i < apc->num_queues; i++) { txq = &apc->tx_qp[i].txq; - - while (atomic_read(&txq->pending_sends) > 0) - usleep_range(1000, 2000); + tsleep = 1000; + while (atomic_read(&txq->pending_sends) > 0 && + time_before(jiffies, timeout)) { + usleep_range(tsleep, tsleep + 1000); + tsleep <<= 1; + } + if (atomic_read(&txq->pending_sends)) { + err = pcie_flr(to_pci_dev(gd->gdma_context->dev)); + if (err) { + netdev_err(ndev, "flr failed %d with %d pkts pending in txq %u\n", + err, atomic_read(&txq->pending_sends), + txq->gdma_txq_id); + } + break; + } } + for (i = 0; i < apc->num_queues; i++) { + txq = &apc->tx_qp[i].txq; + while (skb = skb_dequeue(&txq->pending_skbs)) { + mana_unmap_skb(skb, apc); + dev_consume_skb_any(skb); + } + atomic_set(&txq->pending_sends, 0); + } /* We're 100% sure the queues can no longer be woken up, because * we're sure now mana_poll_tx_cq() can't be running. */