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=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 B8C80C433E0 for ; Tue, 4 Aug 2020 10:14:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77FD722CA1 for ; Tue, 4 Aug 2020 10:14:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="Li8yWgFg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726351AbgHDKOG (ORCPT ); Tue, 4 Aug 2020 06:14:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726041AbgHDKOF (ORCPT ); Tue, 4 Aug 2020 06:14:05 -0400 Received: from mail-lf1-x143.google.com (mail-lf1-x143.google.com [IPv6:2a00:1450:4864:20::143]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5630AC061756 for ; Tue, 4 Aug 2020 03:14:05 -0700 (PDT) Received: by mail-lf1-x143.google.com with SMTP id j22so16167349lfm.2 for ; Tue, 04 Aug 2020 03:14:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=LktSD0GDAmnkBmBwptIgps9F92P71iAP/NC7BG6uhsw=; b=Li8yWgFgXSfBF5hINl+KxWV+Orl1QmxwKDUgyXW2Im9OvkncU8s0Se8k1lgzBNnNH4 +U6GBYpDgWBqYIWOgfqCBb4bDMOcsh2k4oRBcpAj3YhsIW7bFGZ6HOk/qqab6ei352Hh b8vYTpBNyC/irtMdq7omLR9P/9Z4S0TJLdy/I= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=LktSD0GDAmnkBmBwptIgps9F92P71iAP/NC7BG6uhsw=; b=qZbpzDmafyctj7aZfXPUlWVD3bt9pyCTnbBcooxT3lCDswvkFv/UvRd+yKa485+BnH NdhK1fZbJNsQwQNViIWc3mC2V8xkNKTYfrxchTN9fcE7z3HeZ8CX6KEEsUerVy7zmGy3 JTLjjI+cD5tFL5G21k2E8JuIPu6h8cS/5szk8BZQBgMsF67WhpluGnsiHEjjhzjOUuky DVGMIoLG6EKciVaEN49NR+Z8LfSlnO7XQg6oVBeq2iBCcLOvRXcSO88/lehJRr6pkL/J CJOiMMfdeGcRBVPc5F8g9Tlj5lcT7UIG2ax82jKramFIULnawnceaPl1T7yFUc4P97FI MscA== X-Gm-Message-State: AOAM531/tTD9QHwDukmFyZqTs1dlbt0pNYHPCBMoNBcq3jlYysiu+agv hAJHrOcywIREDcZ8JVh9efNiDXtfchUl1ulZ5Vnpqg== X-Google-Smtp-Source: ABdhPJyW+uYQRJhhgXAVBvh6Tu9btpAQM4uWbOhrNdM2FOnO8dZkjhsRmorOBZCbjSH5c6gF4bRQND7acKgtweih4OY= X-Received: by 2002:a19:4c57:: with SMTP id z84mr10945520lfa.92.1596536043506; Tue, 04 Aug 2020 03:14:03 -0700 (PDT) MIME-Version: 1.0 References: <1595847753-2234-1-git-send-email-moshe@mellanox.com> <7a9c315f-fa29-7bd5-31be-3748b8841b29@mellanox.com> <7fd63d16-f9fa-9d55-0b30-fe190d0fb1cb@mellanox.com> In-Reply-To: <7fd63d16-f9fa-9d55-0b30-fe190d0fb1cb@mellanox.com> From: Vasundhara Volam Date: Tue, 4 Aug 2020 15:43:52 +0530 Message-ID: Subject: Re: [PATCH net-next RFC 00/13] Add devlink reload level option To: Moshe Shemesh Cc: Jacob Keller , "David S. Miller" , Jiri Pirko , Netdev , open list Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 3, 2020 at 7:23 PM Moshe Shemesh wrote: > > > On 8/3/2020 3:47 PM, Vasundhara Volam wrote: > > On Mon, Aug 3, 2020 at 5:47 PM Moshe Shemesh wrote: > >> > >> On 8/3/2020 1:24 PM, Vasundhara Volam wrote: > >>> On Tue, Jul 28, 2020 at 10:13 PM Jacob Keller wrote: > >>>> > >>>> On 7/27/2020 10:25 PM, Vasundhara Volam wrote: > >>>>> On Mon, Jul 27, 2020 at 4:36 PM Moshe Shemesh wrote: > >>>>>> Introduce new option on devlink reload API to enable the user to select the > >>>>>> reload level required. Complete support for all levels in mlx5. > >>>>>> The following reload levels are supported: > >>>>>> driver: Driver entities re-instantiation only. > >>>>>> fw_reset: Firmware reset and driver entities re-instantiation. > >>>>> The Name is a little confusing. I think it should be renamed to > >>>>> fw_live_reset (in which both firmware and driver entities are > >>>>> re-instantiated). For only fw_reset, the driver should not undergo > >>>>> reset (it requires a driver reload for firmware to undergo reset). > >>>>> > >>>> So, I think the differentiation here is that "live_patch" doesn't reset > >>>> anything. > >>> This seems similar to flashing the firmware and does not reset anything. > >> > >> The live patch is activating fw change without reset. > >> > >> It is not suitable for any fw change but fw gaps which don't require reset. > >> > >> I can query the fw to check if the pending image change is suitable or > >> require fw reset. > > Okay. > >>>>>> fw_live_patch: Firmware live patching only. > >>>>> This level is not clear. Is this similar to flashing?? > >>>>> > >>>>> Also I have a basic query. The reload command is split into > >>>>> reload_up/reload_down handlers (Please correct me if this behaviour is > >>>>> changed with this patchset). What if the vendor specific driver does > >>>>> not support up/down and needs only a single handler to fire a firmware > >>>>> reset or firmware live reset command? > >>>> In the "reload_down" handler, they would trigger the appropriate reset, > >>>> and quiesce anything that needs to be done. Then on reload up, it would > >>>> restore and bring up anything quiesced in the first stage. > >>> Yes, I got the "reload_down" and "reload_up". Similar to the device > >>> "remove" and "re-probe" respectively. > >>> > >>> But our requirement is a similar "ethtool reset" command, where > >>> ethtool calls a single callback in driver and driver just sends a > >>> firmware command for doing the reset. Once firmware receives the > >>> command, it will initiate the reset of driver and firmware entities > >>> asynchronously. > >> > >> It is similar to mlx5 case here for fw_reset. The driver triggers the fw > >> command to reset and all PFs drivers gets events to handle and do > >> re-initialization. To fit it to the devlink reload_down and reload_up, > >> I wait for the event handler to complete and it stops at driver unload > >> to have the driver up by devlink reload_up. See patch 8 in this patchset. > >> > > Yes, I see reload_down is triggering the reset. In our driver, after > > triggering the reset through a firmware command, reset is done in > > another context as the driver initiates the reset only after receiving > > an ASYNC event from the firmware. > > > Same here. > > > > > Probably, we have to use reload_down() to send firmware command to > > trigger reset and do nothing in reload_up. > I had that in previous version, but its wrong to use devlink reload this > way, so I added wait with timeout for the event handling to complete > before unload_down function ends. See mlx5_fw_wait_fw_reset_done(). Also > the event handler stops before load back to have that done by devlink > reload_up. But "devlink dev reload" will be invoked by the user only on a single dev handler and all function drivers will be re-instantiated upon the ASYNC event. reload_down and reload_up are invoked only the function which the user invoked. Take an example of a 2-port (PF0 and PF1) adapter on a single host and with some VFs loaded on the device. User invokes "devlink dev reload" on PF0, ASYNC event is received on 2 PFs and VFs for reset. All the function drivers will be re-instantiated including PF0. If we wait for some time in reload_down() of PF0 and then call load in reload_up(), this code will be different from other function drivers. > > And returning from reload > > does not mean that reset is complete as it is done in another context > > and the driver notifies the health reporter once the reset is > > complete. devlink framework may have to allow drivers to implement > > reload_down only to look more clean or call reload_up only if the > > driver notifies the devlink once reset is completed from another > > context. Please suggest.