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 ECC3CC7EE32 for ; Fri, 3 Mar 2023 21:56:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233142AbjCCV4C (ORCPT ); Fri, 3 Mar 2023 16:56:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48678 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233217AbjCCVzJ (ORCPT ); Fri, 3 Mar 2023 16:55:09 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CE2746F4BA; Fri, 3 Mar 2023 13:48:43 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 3C95F6194C; Fri, 3 Mar 2023 21:46:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 362FDC433A0; Fri, 3 Mar 2023 21:46:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677880016; bh=v6tt9E3aHxxAdKeqDkuuE8e7wq6/1T8rWsMDE3MN5G0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L2KB3cGO4XK7Mh4q9QX6C3KGh32CACDJzOtV0WRP6rOrt1GgSlxDUaNGes5CU2MxV cS2Kozi0ssN9DWKndxtpl9rNn//LvOwkNUYR5cDcJPSnZtq1sZBN124dDrCJ5fG9lt wK9SozNJSNfzR8oZPUxDE2IK7IVD9LrtRakFRWj1qXg0rxHbfX1BT4ho9xL/S8DEK4 mHe93gq2z1Kluk5mGScNj2e1XNUBam+cZQLYGP/Db+BQdlOANfDpmRqMNopwddyoje lKSKMN8Cusu1zve6kmV6qEInuNH5Zuatmy9jT9XErbEzlfL2ZOh+kkcyT3Z7QfpTw0 qE/sRfLSZGETA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Mika Westerberg , Jonathan Cameron , Alexander Motin , Bjorn Helgaas , Sasha Levin , linux-pci@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 38/50] PCI: Take other bus devices into account when distributing resources Date: Fri, 3 Mar 2023 16:45:19 -0500 Message-Id: <20230303214531.1450154-38-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230303214531.1450154-1-sashal@kernel.org> References: <20230303214531.1450154-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mika Westerberg [ Upstream commit 9db0b9b6a14249ef65a5f1e5e3b37762af96f425 ] A PCI bridge may reside on a bus with other devices as well. The resource distribution code does not take this into account and therefore it expands the bridge resource windows too much, not leaving space for the other devices (or functions of a multifunction device). This leads to an issue that Jonathan reported when running QEMU with the following topology (QEMU parameters): -device pcie-root-port,port=0,id=root_port13,chassis=0,slot=2 \ -device x3130-upstream,id=sw1,bus=root_port13,multifunction=on \ -device e1000,bus=root_port13,addr=0.1 \ -device xio3130-downstream,id=fun1,bus=sw1,chassis=0,slot=3 \ -device e1000,bus=fun1 The first e1000 NIC here is another function in the switch upstream port. This leads to following errors: pci 0000:00:04.0: bridge window [mem 0x10200000-0x103fffff] to [bus 02-04] pci 0000:02:00.0: bridge window [mem 0x10200000-0x103fffff] to [bus 03-04] pci 0000:02:00.1: BAR 0: failed to assign [mem size 0x00020000] e1000 0000:02:00.1: can't ioremap BAR 0: [??? 0x00000000 flags 0x0] Fix this by taking into account bridge windows, device BARs and SR-IOV PF BARs on the bus (PF BARs include space for VF BARS so only account PF BARs), including the ones belonging to bridges themselves if it has any. Link: https://lore.kernel.org/linux-pci/20221014124553.0000696f@huawei.com/ Link: https://lore.kernel.org/linux-pci/6053736d-1923-41e7-def9-7585ce1772d9@ixsystems.com/ Link: https://lore.kernel.org/r/20230131092405.29121-3-mika.westerberg@linux.intel.com Reported-by: Jonathan Cameron Reported-by: Alexander Motin Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin --- drivers/pci/setup-bus.c | 176 ++++++++++++++++++++++++---------------- 1 file changed, 106 insertions(+), 70 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 4a6b698b5dd10..16d291e10627b 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1878,12 +1878,67 @@ static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res, add_size = size - new_size; pci_dbg(bridge, "bridge window %pR shrunken by %pa\n", res, &add_size); + } else { + return; } res->end = res->start + new_size - 1; remove_from_list(add_list, res); } +static void remove_dev_resource(struct resource *avail, struct pci_dev *dev, + struct resource *res) +{ + resource_size_t size, align, tmp; + + size = resource_size(res); + if (!size) + return; + + align = pci_resource_alignment(dev, res); + align = align ? ALIGN(avail->start, align) - avail->start : 0; + tmp = align + size; + avail->start = min(avail->start + tmp, avail->end + 1); +} + +static void remove_dev_resources(struct pci_dev *dev, struct resource *io, + struct resource *mmio, + struct resource *mmio_pref) +{ + int i; + + for (i = 0; i < PCI_NUM_RESOURCES; i++) { + struct resource *res = &dev->resource[i]; + + if (resource_type(res) == IORESOURCE_IO) { + remove_dev_resource(io, dev, res); + } else if (resource_type(res) == IORESOURCE_MEM) { + + /* + * Make sure prefetchable memory is reduced from + * the correct resource. Specifically we put 32-bit + * prefetchable memory in non-prefetchable window + * if there is an 64-bit pretchable window. + * + * See comments in __pci_bus_size_bridges() for + * more information. + */ + if ((res->flags & IORESOURCE_PREFETCH) && + ((res->flags & IORESOURCE_MEM_64) == + (mmio_pref->flags & IORESOURCE_MEM_64))) + remove_dev_resource(mmio_pref, dev, res); + else + remove_dev_resource(mmio, dev, res); + } + } +} + +/* + * io, mmio and mmio_pref contain the total amount of bridge window space + * available. This includes the minimal space needed to cover all the + * existing devices on the bus and the possible extra space that can be + * shared with the bridges. + */ static void pci_bus_distribute_available_resources(struct pci_bus *bus, struct list_head *add_list, struct resource io, @@ -1893,7 +1948,7 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, unsigned int normal_bridges = 0, hotplug_bridges = 0; struct resource *io_res, *mmio_res, *mmio_pref_res; struct pci_dev *dev, *bridge = bus->self; - resource_size_t io_per_hp, mmio_per_hp, mmio_pref_per_hp, align; + resource_size_t io_per_b, mmio_per_b, mmio_pref_per_b, align; io_res = &bridge->resource[PCI_BRIDGE_IO_WINDOW]; mmio_res = &bridge->resource[PCI_BRIDGE_MEM_WINDOW]; @@ -1937,100 +1992,81 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus, normal_bridges++; } - /* - * There is only one bridge on the bus so it gets all available - * resources which it can then distribute to the possible hotplug - * bridges below. - */ - if (hotplug_bridges + normal_bridges == 1) { - dev = list_first_entry(&bus->devices, struct pci_dev, bus_list); - if (dev->subordinate) - pci_bus_distribute_available_resources(dev->subordinate, - add_list, io, mmio, mmio_pref); - return; - } - - if (hotplug_bridges == 0) + if (!(hotplug_bridges + normal_bridges)) return; /* - * Calculate the total amount of extra resource space we can - * pass to bridges below this one. This is basically the - * extra space reduced by the minimal required space for the - * non-hotplug bridges. + * Calculate the amount of space we can forward from "bus" to any + * downstream buses, i.e., the space left over after assigning the + * BARs and windows on "bus". */ - for_each_pci_bridge(dev, bus) { - resource_size_t used_size; - struct resource *res; - - if (dev->is_hotplug_bridge) - continue; - - /* - * Reduce the available resource space by what the - * bridge and devices below it occupy. - */ - res = &dev->resource[PCI_BRIDGE_IO_WINDOW]; - align = pci_resource_alignment(dev, res); - align = align ? ALIGN(io.start, align) - io.start : 0; - used_size = align + resource_size(res); - if (!res->parent) - io.start = min(io.start + used_size, io.end + 1); - - res = &dev->resource[PCI_BRIDGE_MEM_WINDOW]; - align = pci_resource_alignment(dev, res); - align = align ? ALIGN(mmio.start, align) - mmio.start : 0; - used_size = align + resource_size(res); - if (!res->parent) - mmio.start = min(mmio.start + used_size, mmio.end + 1); - - res = &dev->resource[PCI_BRIDGE_PREF_MEM_WINDOW]; - align = pci_resource_alignment(dev, res); - align = align ? ALIGN(mmio_pref.start, align) - - mmio_pref.start : 0; - used_size = align + resource_size(res); - if (!res->parent) - mmio_pref.start = min(mmio_pref.start + used_size, - mmio_pref.end + 1); + list_for_each_entry(dev, &bus->devices, bus_list) { + if (!dev->is_virtfn) + remove_dev_resources(dev, &io, &mmio, &mmio_pref); } - io_per_hp = div64_ul(resource_size(&io), hotplug_bridges); - mmio_per_hp = div64_ul(resource_size(&mmio), hotplug_bridges); - mmio_pref_per_hp = div64_ul(resource_size(&mmio_pref), - hotplug_bridges); - /* - * Go over devices on this bus and distribute the remaining - * resource space between hotplug bridges. + * If there is at least one hotplug bridge on this bus it gets all + * the extra resource space that was left after the reductions + * above. + * + * If there are no hotplug bridges the extra resource space is + * split between non-hotplug bridges. This is to allow possible + * hotplug bridges below them to get the extra space as well. */ + if (hotplug_bridges) { + io_per_b = div64_ul(resource_size(&io), hotplug_bridges); + mmio_per_b = div64_ul(resource_size(&mmio), hotplug_bridges); + mmio_pref_per_b = div64_ul(resource_size(&mmio_pref), + hotplug_bridges); + } else { + io_per_b = div64_ul(resource_size(&io), normal_bridges); + mmio_per_b = div64_ul(resource_size(&mmio), normal_bridges); + mmio_pref_per_b = div64_ul(resource_size(&mmio_pref), + normal_bridges); + } + for_each_pci_bridge(dev, bus) { struct resource *res; struct pci_bus *b; b = dev->subordinate; - if (!b || !dev->is_hotplug_bridge) + if (!b) continue; + if (hotplug_bridges && !dev->is_hotplug_bridge) + continue; + + res = &dev->resource[PCI_BRIDGE_IO_WINDOW]; /* - * Distribute available extra resources equally between - * hotplug-capable downstream ports taking alignment into - * account. + * Make sure the split resource space is properly aligned + * for bridge windows (align it down to avoid going above + * what is available). */ - res = &dev->resource[PCI_BRIDGE_IO_WINDOW]; align = pci_resource_alignment(dev, res); - io.end = align ? io.start + ALIGN_DOWN(io_per_hp, align) - 1 - : io.start + io_per_hp - 1; + io.end = align ? io.start + ALIGN_DOWN(io_per_b, align) - 1 + : io.start + io_per_b - 1; + + /* + * The x_per_b holds the extra resource space that can be + * added for each bridge but there is the minimal already + * reserved as well so adjust x.start down accordingly to + * cover the whole space. + */ + io.start -= resource_size(res); res = &dev->resource[PCI_BRIDGE_MEM_WINDOW]; align = pci_resource_alignment(dev, res); - mmio.end = align ? mmio.start + ALIGN_DOWN(mmio_per_hp, align) - 1 - : mmio.start + mmio_per_hp - 1; + mmio.end = align ? mmio.start + ALIGN_DOWN(mmio_per_b, align) - 1 + : mmio.start + mmio_per_b - 1; + mmio.start -= resource_size(res); res = &dev->resource[PCI_BRIDGE_PREF_MEM_WINDOW]; align = pci_resource_alignment(dev, res); mmio_pref.end = align ? mmio_pref.start + - ALIGN_DOWN(mmio_pref_per_hp, align) - 1 - : mmio_pref.start + mmio_pref_per_hp - 1; + ALIGN_DOWN(mmio_pref_per_b, align) - 1 + : mmio_pref.start + mmio_pref_per_b - 1; + mmio_pref.start -= resource_size(res); pci_bus_distribute_available_resources(b, add_list, io, mmio, mmio_pref); -- 2.39.2