From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42B80C2D0A8 for ; Mon, 28 Sep 2020 20:11:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E116F20679 for ; Mon, 28 Sep 2020 20:11:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726716AbgI1ULQ (ORCPT ); Mon, 28 Sep 2020 16:11:16 -0400 Received: from dispatch1-us1.ppe-hosted.com ([148.163.129.52]:34194 "EHLO dispatch1-us1.ppe-hosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726310AbgI1ULP (ORCPT ); Mon, 28 Sep 2020 16:11:15 -0400 X-Greylist: delayed 309 seconds by postgrey-1.27 at vger.kernel.org; Mon, 28 Sep 2020 16:11:14 EDT Received: from dispatch1-us1.ppe-hosted.com (localhost.localdomain [127.0.0.1]) by dispatch1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id 0B5642E33C4 for ; Mon, 28 Sep 2020 20:06:05 +0000 (UTC) Received: from mx1-us1.ppe-hosted.com (unknown [10.7.65.61]) by dispatch1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id 17567600CA; Mon, 28 Sep 2020 20:06:05 +0000 (UTC) Received: from us4-mdac16-3.ut7.mdlocal (unknown [10.7.65.71]) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id E7B59800B2; Mon, 28 Sep 2020 20:06:04 +0000 (UTC) X-Virus-Scanned: Proofpoint Essentials engine Received: from mx1-us1.ppe-hosted.com (unknown [10.7.65.174]) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id 670BC8005C; Mon, 28 Sep 2020 20:06:04 +0000 (UTC) Received: from webmail.solarflare.com (uk.solarflare.com [193.34.186.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id EA7851C0089; Mon, 28 Sep 2020 20:06:03 +0000 (UTC) Received: from [10.17.20.203] (10.17.20.203) by ukex01.SolarFlarecom.com (10.17.10.4) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 28 Sep 2020 21:05:56 +0100 From: Edward Cree Subject: [RFC PATCH net-next] sfc: replace in_interrupt() usage To: , CC: , References: <168a1f9e-cba4-69a8-9b29-5c121295e960@solarflare.com> Message-ID: Date: Mon, 28 Sep 2020 21:05:52 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <168a1f9e-cba4-69a8-9b29-5c121295e960@solarflare.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-GB Content-Transfer-Encoding: 7bit X-Originating-IP: [10.17.20.203] X-ClientProxiedBy: ocex03.SolarFlarecom.com (10.20.40.36) To ukex01.SolarFlarecom.com (10.17.10.4) X-TM-AS-Product-Ver: SMEX-12.5.0.1300-8.6.1012-25674.003 X-TM-AS-Result: No-7.745300-8.000000-10 X-TMASE-MatchedRID: vprwuRKvc2lyQSrBguzobEz7FUUjXG1jFfK1en1S7AS04seKBdYiOT6P hj6DfZCEDLYK+Lj1c6690EVVsfrB2Cw76RUR9W5CSJA7ysb1rf5GI9Mwxz8yaQQsw9A3PIlLaLW TWf8lAkvXrd88mu76ZKnehM7bzd9dSwJG7pWPdgoaLqFbxdotGQZyESFXAljfq4++j0vqJoh7po 1bVbK8xJL3k3MJkR/MtSBHmsv2cOHvcjreWe4HbIbV85w+dhNKwJjn8yqLU6JBcCISIacek9ozb eODnXplF7/UMWkFbTaTH1CW/Tkdqu57OgItHYSZJBa5/AMngr00AJe3B5qfBpm3TxN83Lo4akCr XhKzdtntuwW+rpqAYDH23ywzT5a8v5DRh1Wa7JacVWc2a+/ju0tc8DbogbSE31GU/N5W5BCweWt IY1I6Ztr/4Dw+fDLdxGosnG/g3+KtiF+p+9BY6cnUT+eskUQPCqIE7aqEIgZHBAz3YHyS7rhdAR HnUbVtu8XqihW+KQVI3UwDRYAmKaacba0/6+pRB89GKHo03nZ9iuvWn3J8Ksz/SxKo9mJ4uhDcX ba54kdhqzG/Rcar7ZGTpe1iiCJq71zr0FZRMbALbigRnpKlKSPzRlrdFGDwqMbWyNvncxuiOREo j4OYdjqKzoku9SZDvgU+kyqZ4k7JNpPjNk/eQw== X-TM-AS-User-Approved-Sender: Yes X-TM-AS-User-Blocked-Sender: No X-TMASE-Result: 10--7.745300-8.000000 X-TMASE-Version: SMEX-12.5.0.1300-8.6.1012-25674.003 X-MDID: 1601323564-45VpWj7vuF67 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org efx_ef10_try_update_nic_stats_vf() used in_interrupt() to figure out whether it is safe to sleep (for MCDI) or not. The only caller from which it was not is efx_net_stats(), which can be invoked under dev_base_lock from net-sysfs::netstat_show(). So add a new update_stats_atomic() method to struct efx_nic_type, and call it from efx_net_stats(), removing the need for efx_ef10_try_update_nic_stats_vf() to behave differently for this case (which it wasn't doing correctly anyway). For all nic_types other than EF10 VF, this method is NULL and so we call the regular update_stats() methods, which are happy with being called from atomic contexts. Fixes: f00bf2305cab ("sfc: don't update stats on VF when called in atomic context") Reported-by: Sebastian Andrzej Siewior Signed-off-by: Edward Cree --- Only compile-tested so far, because I'm waiting for my kernel to finish rebuilding with CONFIG_DEBUG_ATOMIC_SLEEP which I'm hoping is the right thing to detect the bug in the existing code. I also wasn't quite sure how to give credit to the thorough analysis in the commit message of Sebastian's patch. I don't think we have a Whatever-by: tag to cover that, do we? And this doesn't include your GFP_KERNEL change, which should probably go in separately if you take this. drivers/net/ethernet/sfc/ef10.c | 22 +++++++++++++--------- drivers/net/ethernet/sfc/efx_common.c | 2 +- drivers/net/ethernet/sfc/net_driver.h | 5 +++++ drivers/net/ethernet/sfc/nic_common.h | 7 +++++++ 4 files changed, 26 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c index c9df2e96ebe4..b702ba5986dc 100644 --- a/drivers/net/ethernet/sfc/ef10.c +++ b/drivers/net/ethernet/sfc/ef10.c @@ -1871,15 +1871,6 @@ static int efx_ef10_try_update_nic_stats_vf(struct efx_nic *efx) spin_unlock_bh(&efx->stats_lock); - if (in_interrupt()) { - /* If in atomic context, cannot update stats. Just update the - * software stats and return so the caller can continue. - */ - spin_lock_bh(&efx->stats_lock); - efx_update_sw_stats(efx, stats); - return 0; - } - efx_ef10_get_stat_mask(efx, mask); rc = efx_nic_alloc_buffer(efx, &stats_buf, dma_len, GFP_ATOMIC); @@ -1938,6 +1929,18 @@ static size_t efx_ef10_update_stats_vf(struct efx_nic *efx, u64 *full_stats, return efx_ef10_update_stats_common(efx, full_stats, core_stats); } +static size_t efx_ef10_update_stats_atomic_vf(struct efx_nic *efx, u64 *full_stats, + struct rtnl_link_stats64 *core_stats) +{ + struct efx_ef10_nic_data *nic_data = efx->nic_data; + + /* In atomic context, cannot update HW stats. Just update the + * software stats and return so the caller can continue. + */ + efx_update_sw_stats(efx, nic_data->stats); + return efx_ef10_update_stats_common(efx, full_stats, core_stats); +} + static void efx_ef10_push_irq_moderation(struct efx_channel *channel) { struct efx_nic *efx = channel->efx; @@ -3998,6 +4001,7 @@ const struct efx_nic_type efx_hunt_a0_vf_nic_type = { .finish_flr = efx_port_dummy_op_void, .describe_stats = efx_ef10_describe_stats, .update_stats = efx_ef10_update_stats_vf, + .update_stats_atomic = efx_ef10_update_stats_atomic_vf, .start_stats = efx_port_dummy_op_void, .pull_stats = efx_port_dummy_op_void, .stop_stats = efx_port_dummy_op_void, diff --git a/drivers/net/ethernet/sfc/efx_common.c b/drivers/net/ethernet/sfc/efx_common.c index c256db241570..72a3f0e09f52 100644 --- a/drivers/net/ethernet/sfc/efx_common.c +++ b/drivers/net/ethernet/sfc/efx_common.c @@ -602,7 +602,7 @@ void efx_net_stats(struct net_device *net_dev, struct rtnl_link_stats64 *stats) struct efx_nic *efx = netdev_priv(net_dev); spin_lock_bh(&efx->stats_lock); - efx->type->update_stats(efx, NULL, stats); + efx_nic_update_stats_atomic(efx, NULL, stats); spin_unlock_bh(&efx->stats_lock); } diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h index 47aa753e64bd..9f7dfdf708cf 100644 --- a/drivers/net/ethernet/sfc/net_driver.h +++ b/drivers/net/ethernet/sfc/net_driver.h @@ -1172,6 +1172,9 @@ struct efx_udp_tunnel { * @describe_stats: Describe statistics for ethtool * @update_stats: Update statistics not provided by event handling. * Either argument may be %NULL. + * @update_stats_atomic: Update statistics while in atomic context, if that + * is more limiting than @update_stats. Otherwise, leave %NULL and + * driver core will call @update_stats. * @start_stats: Start the regular fetching of statistics * @pull_stats: Pull stats from the NIC and wait until they arrive. * @stop_stats: Stop the regular fetching of statistics @@ -1316,6 +1319,8 @@ struct efx_nic_type { size_t (*describe_stats)(struct efx_nic *efx, u8 *names); size_t (*update_stats)(struct efx_nic *efx, u64 *full_stats, struct rtnl_link_stats64 *core_stats); + size_t (*update_stats_atomic)(struct efx_nic *efx, u64 *full_stats, + struct rtnl_link_stats64 *core_stats); void (*start_stats)(struct efx_nic *efx); void (*pull_stats)(struct efx_nic *efx); void (*stop_stats)(struct efx_nic *efx); diff --git a/drivers/net/ethernet/sfc/nic_common.h b/drivers/net/ethernet/sfc/nic_common.h index 82271f0b8627..b9cafe9cd568 100644 --- a/drivers/net/ethernet/sfc/nic_common.h +++ b/drivers/net/ethernet/sfc/nic_common.h @@ -244,6 +244,13 @@ void efx_nic_update_stats(const struct efx_hw_stat_desc *desc, size_t count, const unsigned long *mask, u64 *stats, const void *dma_buf, bool accumulate); void efx_nic_fix_nodesc_drop_stat(struct efx_nic *efx, u64 *stat); +static inline size_t efx_nic_update_stats_atomic(struct efx_nic *efx, u64 *full_stats, + struct rtnl_link_stats64 *core_stats) +{ + if (efx->type->update_stats_atomic) + return efx->type->update_stats_atomic(efx, full_stats, core_stats); + return efx->type->update_stats(efx, full_stats, core_stats); +} #define EFX_MAX_FLUSH_TIME 5000