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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB3DCEB64D7 for ; Mon, 26 Jun 2023 18:43:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232600AbjFZSnd (ORCPT ); Mon, 26 Jun 2023 14:43:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56024 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232586AbjFZSn0 (ORCPT ); Mon, 26 Jun 2023 14:43:26 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B94819B0 for ; Mon, 26 Jun 2023 11:43:07 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6ACD160F4B for ; Mon, 26 Jun 2023 18:43:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7077FC433C0; Mon, 26 Jun 2023 18:43:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687804986; bh=sXfJjt87xK5OoaG+7bHlGoMFW+7MV0z8H8DaY6wFbWo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wG6QVz1iE+S7v9PmV+5UqNVL0pRYfY3OoRKL/vOKYqgoI0QrZorcWeuqncym14q4O 6mqnMffEhKVcubCeN+kQho1UbJ8P/VLZ+3a2sQfAvL8qEteEz7jUTChykcbom+BprE C4nyonqT8NcHavQzd191iOSsjtkUDJj2gaCbU45Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dexuan Cui , Michael Kelley , Wei Hu , Wei Liu Subject: [PATCH 5.10 12/81] Revert "PCI: hv: Fix a timing issue which causes kdump to fail occasionally" Date: Mon, 26 Jun 2023 20:11:54 +0200 Message-ID: <20230626180744.962210276@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230626180744.453069285@linuxfoundation.org> References: <20230626180744.453069285@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dexuan Cui commit a847234e24d03d01a9566d1d9dcce018cc018d67 upstream. This reverts commit d6af2ed29c7c1c311b96dac989dcb991e90ee195. The statement "the hv_pci_bus_exit() call releases structures of all its child devices" in commit d6af2ed29c7c is not true: in the path hv_pci_probe() -> hv_pci_enter_d0() -> hv_pci_bus_exit(hdev, true): the parameter "keep_devs" is true, so hv_pci_bus_exit() does *not* release the child "struct hv_pci_dev *hpdev" that is created earlier in pci_devices_present_work() -> new_pcichild_device(). The commit d6af2ed29c7c was originally made in July 2020 for RHEL 7.7, where the old version of hv_pci_bus_exit() was used; when the commit was rebased and merged into the upstream, people didn't notice that it's not really necessary. The commit itself doesn't cause any issue, but it makes hv_pci_probe() more complicated. Revert it to facilitate some upcoming changes to hv_pci_probe(). Signed-off-by: Dexuan Cui Reviewed-by: Michael Kelley Acked-by: Wei Hu Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230615044451.5580-5-decui@microsoft.com Signed-off-by: Wei Liu Signed-off-by: Greg Kroah-Hartman --- drivers/pci/controller/pci-hyperv.c | 71 +++++++++++++++++------------------- 1 file changed, 34 insertions(+), 37 deletions(-) --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -2842,8 +2842,10 @@ static int hv_pci_enter_d0(struct hv_dev struct pci_bus_d0_entry *d0_entry; struct hv_pci_compl comp_pkt; struct pci_packet *pkt; + bool retry = true; int ret; +enter_d0_retry: /* * Tell the host that the bus is ready to use, and moved into the * powered-on state. This includes telling the host which region @@ -2870,6 +2872,38 @@ static int hv_pci_enter_d0(struct hv_dev if (ret) goto exit; + /* + * In certain case (Kdump) the pci device of interest was + * not cleanly shut down and resource is still held on host + * side, the host could return invalid device status. + * We need to explicitly request host to release the resource + * and try to enter D0 again. + */ + if (comp_pkt.completion_status < 0 && retry) { + retry = false; + + dev_err(&hdev->device, "Retrying D0 Entry\n"); + + /* + * Hv_pci_bus_exit() calls hv_send_resource_released() + * to free up resources of its child devices. + * In the kdump kernel we need to set the + * wslot_res_allocated to 255 so it scans all child + * devices to release resources allocated in the + * normal kernel before panic happened. + */ + hbus->wslot_res_allocated = 255; + + ret = hv_pci_bus_exit(hdev, true); + + if (ret == 0) { + kfree(pkt); + goto enter_d0_retry; + } + dev_err(&hdev->device, + "Retrying D0 failed with ret %d\n", ret); + } + if (comp_pkt.completion_status < 0) { dev_err(&hdev->device, "PCI Pass-through VSP failed D0 Entry with status %x\n", @@ -3125,7 +3159,6 @@ static int hv_pci_probe(struct hv_device struct hv_pcibus_device *hbus; u16 dom_req, dom; char *name; - bool enter_d0_retry = true; int ret; /* @@ -3246,47 +3279,11 @@ static int hv_pci_probe(struct hv_device if (ret) goto free_fwnode; -retry: ret = hv_pci_query_relations(hdev); if (ret) goto free_irq_domain; ret = hv_pci_enter_d0(hdev); - /* - * In certain case (Kdump) the pci device of interest was - * not cleanly shut down and resource is still held on host - * side, the host could return invalid device status. - * We need to explicitly request host to release the resource - * and try to enter D0 again. - * Since the hv_pci_bus_exit() call releases structures - * of all its child devices, we need to start the retry from - * hv_pci_query_relations() call, requesting host to send - * the synchronous child device relations message before this - * information is needed in hv_send_resources_allocated() - * call later. - */ - if (ret == -EPROTO && enter_d0_retry) { - enter_d0_retry = false; - - dev_err(&hdev->device, "Retrying D0 Entry\n"); - - /* - * Hv_pci_bus_exit() calls hv_send_resources_released() - * to free up resources of its child devices. - * In the kdump kernel we need to set the - * wslot_res_allocated to 255 so it scans all child - * devices to release resources allocated in the - * normal kernel before panic happened. - */ - hbus->wslot_res_allocated = 255; - ret = hv_pci_bus_exit(hdev, true); - - if (ret == 0) - goto retry; - - dev_err(&hdev->device, - "Retrying D0 failed with ret %d\n", ret); - } if (ret) goto free_irq_domain;