From patchwork Mon Mar 11 13:31:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergei Miroshnichenko X-Patchwork-Id: 10847467 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E485518A6 for ; Mon, 11 Mar 2019 13:32:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 303C0292FC for ; Mon, 11 Mar 2019 13:31:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2DB6529489; Mon, 11 Mar 2019 13:31:43 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 17985292FC for ; Mon, 11 Mar 2019 13:31:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727667AbfCKNbk (ORCPT ); Mon, 11 Mar 2019 09:31:40 -0400 Received: from mta-01.yadro.com ([89.207.88.251]:50956 "EHLO mta-01.yadro.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727320AbfCKNbk (ORCPT ); Mon, 11 Mar 2019 09:31:40 -0400 Received: from localhost (unknown [127.0.0.1]) by mta-01.yadro.com (Postfix) with ESMTP id 1F285419D8; Mon, 11 Mar 2019 13:31:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yadro.com; h= content-type:content-type:content-transfer-encoding:mime-version :references:in-reply-to:x-mailer:message-id:date:date:subject :subject:from:from:received:received:received; s=mta-01; t= 1552311096; x=1554125497; bh=/9KIMo8tGFGsSavddHdVGWehEBkzqeWWLDq mnnymnno=; b=CIecb3sld/QncDrstpQzACVN4VFypvS9//JFArcQVUpxByywJ6S 1hym/Xaifynl5kTbB7pYQLLGAk21UGJhc2U0jrW/dcdyefr+TTkrxLLJdl5pGkEi 3Ws/zX/W4IEjasbjvNab/XFLdhupE89uPDNd3B1VVufU7b/yIa0La09Q= X-Virus-Scanned: amavisd-new at yadro.com Received: from mta-01.yadro.com ([127.0.0.1]) by localhost (mta-01.yadro.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id d1xed_7j1Bn8; Mon, 11 Mar 2019 16:31:36 +0300 (MSK) Received: from T-EXCH-02.corp.yadro.com (t-exch-02.corp.yadro.com [172.17.10.102]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mta-01.yadro.com (Postfix) with ESMTPS id CF4D14193F; Mon, 11 Mar 2019 16:31:32 +0300 (MSK) Received: from NB-148.yadro.com (172.17.15.60) by T-EXCH-02.corp.yadro.com (172.17.10.102) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P384) id 15.1.669.32; Mon, 11 Mar 2019 16:31:32 +0300 From: Sergey Miroshnichenko To: , CC: Bjorn Helgaas , , Sergey Miroshnichenko Subject: [PATCH RFC v4 12/21] PCI: Don't allow hotplugged devices to steal resources Date: Mon, 11 Mar 2019 16:31:13 +0300 Message-ID: <20190311133122.11417-13-s.miroshnichenko@yadro.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190311133122.11417-1-s.miroshnichenko@yadro.com> References: <20190311133122.11417-1-s.miroshnichenko@yadro.com> MIME-Version: 1.0 X-Originating-IP: [172.17.15.60] X-ClientProxiedBy: T-EXCH-01.corp.yadro.com (172.17.10.101) To T-EXCH-02.corp.yadro.com (172.17.10.102) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When movable BARs are enabled, the PCI subsystem at first releases all the bridge windows and then performs an attempt to assign new requested resources and re-assign the existing ones. If a hotplugged device gets its resources first, there could be no space left to re-assign resources of already working devices, which is unacceptable. If this happens, this patch marks one of the new devices with the new introduced flag PCI_DEV_IGNORE and retries the resource assignment. This patch adds a new res_mask bitmask to the struct pci_dev for storing the indices of assigned resources. Signed-off-by: Sergey Miroshnichenko --- drivers/pci/bus.c | 5 ++ drivers/pci/pci.h | 11 +++++ drivers/pci/probe.c | 100 +++++++++++++++++++++++++++++++++++++++- drivers/pci/setup-bus.c | 15 ++++++ include/linux/pci.h | 1 + 5 files changed, 130 insertions(+), 2 deletions(-) diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 5cb40b2518f9..a9784144d6f2 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -311,6 +311,11 @@ void pci_bus_add_device(struct pci_dev *dev) { int retval; + if (pci_dev_is_ignored(dev)) { + pci_warn(dev, "%s: don't enable the ignored device\n", __func__); + return; + } + /* * Can not put in pci_device_add yet because resources * are not assigned yet for some devices. diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index e06e8692a7b1..56b905068ac5 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -366,6 +366,7 @@ static inline bool pci_dev_is_disconnected(const struct pci_dev *dev) /* pci_dev priv_flags */ #define PCI_DEV_ADDED 0 +#define PCI_DEV_IGNORE 1 static inline void pci_dev_assign_added(struct pci_dev *dev, bool added) { @@ -377,6 +378,16 @@ static inline bool pci_dev_is_added(const struct pci_dev *dev) return test_bit(PCI_DEV_ADDED, &dev->priv_flags); } +static inline void pci_dev_ignore(struct pci_dev *dev, bool ignore) +{ + assign_bit(PCI_DEV_IGNORE, &dev->priv_flags, ignore); +} + +static inline bool pci_dev_is_ignored(const struct pci_dev *dev) +{ + return test_bit(PCI_DEV_IGNORE, &dev->priv_flags); +} + #ifdef CONFIG_PCIEAER #include diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 692752c71f71..62f4058a001f 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -3248,6 +3248,23 @@ unsigned int pci_rescan_bus_bridge_resize(struct pci_dev *bridge) return max; } +static unsigned int pci_dev_res_mask(struct pci_dev *dev) +{ + unsigned int res_mask = 0; + int i; + + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) { + struct resource *r = &dev->resource[i]; + + if (!r->flags || (r->flags & IORESOURCE_UNSET) || !r->parent) + continue; + + res_mask |= (1 << i); + } + + return res_mask; +} + static void pci_bus_rescan_prepare(struct pci_bus *bus) { struct pci_dev *dev; @@ -3257,6 +3274,8 @@ static void pci_bus_rescan_prepare(struct pci_bus *bus) list_for_each_entry(dev, &bus->devices, bus_list) { struct pci_bus *child = dev->subordinate; + dev->res_mask = pci_dev_res_mask(dev); + if (child) { pci_bus_rescan_prepare(child); } else if (dev->driver && @@ -3318,6 +3337,84 @@ static void pci_setup_bridges(struct pci_bus *bus) pci_setup_bridge(bus); } +static struct pci_dev *pci_find_next_new_device(struct pci_bus *bus) +{ + struct pci_dev *dev; + + if (!bus) + return NULL; + + list_for_each_entry(dev, &bus->devices, bus_list) { + struct pci_bus *child_bus = dev->subordinate; + + if (!pci_dev_is_added(dev) && !pci_dev_is_ignored(dev)) + return dev; + + if (child_bus) { + struct pci_dev *next_new_dev; + + next_new_dev = pci_find_next_new_device(child_bus); + if (next_new_dev) + return next_new_dev; + } + } + + return NULL; +} + +static bool pci_bus_validate_resources(struct pci_bus *bus) +{ + struct pci_dev *dev; + bool ret = true; + + if (!bus) + return false; + + list_for_each_entry(dev, &bus->devices, bus_list) { + struct pci_bus *child = dev->subordinate; + unsigned int res_mask = pci_dev_res_mask(dev); + + if (pci_dev_is_ignored(dev)) + continue; + + if (dev->res_mask & ~res_mask) { + pci_err(dev, "%s: Non-re-enabled resources found: 0x%x -> 0x%x\n", + __func__, dev->res_mask, res_mask); + ret = false; + } + + if (child && !pci_bus_validate_resources(child)) + ret = false; + } + + return ret; +} + +static void pci_reassign_root_bus_resources(struct pci_bus *root) +{ + do { + struct pci_dev *next_new_dev; + + pci_bus_release_root_bridge_resources(root); + pci_assign_unassigned_root_bus_resources(root); + + if (pci_bus_validate_resources(root)) + break; + + next_new_dev = pci_find_next_new_device(root); + if (!next_new_dev) { + dev_err(&root->dev, "%s: failed to re-assign resources even after ignoring all the hotplugged devices\n", + __func__); + break; + } + + dev_warn(&root->dev, "%s: failed to re-assign resources, disable the next hotplugged device %s and retry\n", + __func__, dev_name(&next_new_dev->dev)); + + pci_dev_ignore(next_new_dev, true); + } while (true); +} + /** * pci_rescan_bus - Scan a PCI bus for devices * @bus: PCI bus to scan @@ -3341,8 +3438,7 @@ unsigned int pci_rescan_bus(struct pci_bus *bus) max = pci_scan_child_bus(root); - pci_bus_release_root_bridge_resources(root); - pci_assign_unassigned_root_bus_resources(root); + pci_reassign_root_bus_resources(root); pci_setup_bridges(root); pci_bus_rescan_done(root); diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 36a1907d9509..551108f48df7 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -131,6 +131,9 @@ static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head) { int i; + if (pci_dev_is_ignored(dev)) + return; + for (i = 0; i < PCI_NUM_RESOURCES; i++) { struct resource *r; struct pci_dev_resource *dev_res, *tmp; @@ -181,6 +184,9 @@ static void __dev_sort_resources(struct pci_dev *dev, { u16 class = dev->class >> 8; + if (pci_dev_is_ignored(dev)) + return; + /* Don't touch classless devices or host bridges or ioapics. */ if (class == PCI_CLASS_NOT_DEFINED || class == PCI_CLASS_BRIDGE_HOST) return; @@ -284,6 +290,9 @@ static void assign_requested_resources_sorted(struct list_head *head, int idx; list_for_each_entry(dev_res, head, list) { + if (pci_dev_is_ignored(dev_res->dev)) + continue; + res = dev_res->res; idx = res - &dev_res->dev->resource[0]; if (resource_size(res) && @@ -991,6 +1000,9 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, list_for_each_entry(dev, &bus->devices, bus_list) { int i; + if (pci_dev_is_ignored(dev)) + continue; + for (i = 0; i < PCI_NUM_RESOURCES; i++) { struct resource *r = &dev->resource[i]; resource_size_t r_size; @@ -1353,6 +1365,9 @@ void __pci_bus_assign_resources(const struct pci_bus *bus, pbus_assign_resources_sorted(bus, realloc_head, fail_head); list_for_each_entry(dev, &bus->devices, bus_list) { + if (pci_dev_is_ignored(dev)) + continue; + pdev_assign_fixed_resources(dev); b = dev->subordinate; diff --git a/include/linux/pci.h b/include/linux/pci.h index 3d52f5538282..26aa59cb6220 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -369,6 +369,7 @@ struct pci_dev { */ unsigned int irq; struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory regions + expansion ROMs */ + unsigned int res_mask; /* Bitmask of assigned resources */ bool match_driver; /* Skip attaching driver */