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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 79F62C43460 for ; Thu, 22 Apr 2021 08:57:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4A48761452 for ; Thu, 22 Apr 2021 08:57:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235590AbhDVI6c (ORCPT ); Thu, 22 Apr 2021 04:58:32 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:56255 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230316AbhDVI63 (ORCPT ); Thu, 22 Apr 2021 04:58:29 -0400 Received: from mail-lf1-f69.google.com ([209.85.167.69]) by youngberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1lZV9l-0005uu-Uy for linux-kernel@vger.kernel.org; Thu, 22 Apr 2021 08:57:54 +0000 Received: by mail-lf1-f69.google.com with SMTP id h3-20020a0565123383b02901ae5c4072deso4733948lfg.5 for ; Thu, 22 Apr 2021 01:57:53 -0700 (PDT) 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=uhKCITlC8z0lLRtKu0vRLYsI5e5s6htEBYCstI+rfV0=; b=pIy6o9UnkeHuJOkXwkJ7XsSdfZ/+rBUeLSLOYs7De5t/G3Yw2UrSDq61R/vEAG7+6n V+GEFtS5ZTZlC1mj5HP9cEx9L3w6mbwCG8ccY4NWOi2JAhr894xG0ClgAqpj/MWE08Hx LzGlOfIC1FCe5XYUga39XjSKBZbmP1wkj+Z8aGcsmpXAxuKNG/F4Wr4uCzozzs2qikph arabYiJKgh7uCs7zrwkLENsJZBluu41XXz/XwilBMRlQF0vWaUeNkQhmUQVEdehJcFzS wpG5kA0X0Kf3vUjUXrSAwEFQUKJt/tF0YwLne2Q+stOWZXe6GsYpWAinl4+mt1DLffgo Y9Yg== X-Gm-Message-State: AOAM532uB7F7gdZZMg0wIlrWAtimPhSTIscy3s2bmLB7JXaNuwekDOVN Rek33zTIak44QrtF9g0Bwz6d1uUPFq1taHO8vdtvS0lOOOyaQRAYefmcm9Ov6M5fj/5OvC2/Ev9 iJa7nPm0wuWrsPY8HO85uTWUmCZ/KHpHPEqUA32lDYmOu6psZcPgptpUnnQ== X-Received: by 2002:a2e:97c6:: with SMTP id m6mr1782295ljj.403.1619081873363; Thu, 22 Apr 2021 01:57:53 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxf1VedjgFvgDyRthjvX0RdF1wlywxyF26kdMlppzEwkoidctA07kTG4IOcwZiQDCy/WaMCHpJ3r4j8aPuJjio= X-Received: by 2002:a2e:97c6:: with SMTP id m6mr1782284ljj.403.1619081873008; Thu, 22 Apr 2021 01:57:53 -0700 (PDT) MIME-Version: 1.0 References: <20210401131252.531935-1-kai.heng.feng@canonical.com> In-Reply-To: <20210401131252.531935-1-kai.heng.feng@canonical.com> From: Kai-Heng Feng Date: Thu, 22 Apr 2021 16:57:41 +0800 Message-ID: Subject: Re: [PATCH v2] PCI: Coalesce contiguous regions for host bridges To: Bjorn Helgaas Cc: "open list:PCI SUBSYSTEM" , open list Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 1, 2021 at 9:12 PM Kai-Heng Feng wrote: > > Built-in graphics on HP EliteDesk 805 G6 doesn't work because graphics > can't get the BAR it needs: > [ 0.611504] pci_bus 0000:00: root bus resource [mem 0x10020200000-0x100303fffff window] > [ 0.611505] pci_bus 0000:00: root bus resource [mem 0x10030400000-0x100401fffff window] > ... > [ 0.638083] pci 0000:00:08.1: bridge window [mem 0xd2000000-0xd23fffff] > [ 0.638086] pci 0000:00:08.1: bridge window [mem 0x10030000000-0x100401fffff 64bit pref] > [ 0.962086] pci 0000:00:08.1: can't claim BAR 15 [mem 0x10030000000-0x100401fffff 64bit pref]: no compatible bridge window > [ 0.962086] pci 0000:00:08.1: [mem 0x10030000000-0x100401fffff 64bit pref] clipped to [mem 0x10030000000-0x100303fffff 64bit pref] > [ 0.962086] pci 0000:00:08.1: bridge window [mem 0x10030000000-0x100303fffff 64bit pref] > [ 0.962086] pci 0000:07:00.0: can't claim BAR 0 [mem 0x10030000000-0x1003fffffff 64bit pref]: no compatible bridge window > [ 0.962086] pci 0000:07:00.0: can't claim BAR 2 [mem 0x10040000000-0x100401fffff 64bit pref]: no compatible bridge window > > However, the root bus has two contiguous regions that can contain the > child resource requested. > > Bjorn Helgaas pointed out that we can simply coalesce contiguous regions > for host bridges, since host bridge don't have _SRS. So do that > accordingly to make child resource can be contained. This change makes > the graphics works on the system in question. > > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212013 > Suggested-by: Bjorn Helgaas > Signed-off-by: Kai-Heng Feng A gentle ping... > --- > v2: > - Coalesce all contiguous regresion in pci_register_host_bridge(), if > conditions are met. > > drivers/pci/probe.c | 49 +++++++++++++++++++++++++++++++++++++++++---- > 1 file changed, 45 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 953f15abc850..3607ce7402b4 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -19,6 +19,7 @@ > #include > #include > #include > +#include > #include "pci.h" > > #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ > @@ -874,14 +875,30 @@ static void pci_set_bus_msi_domain(struct pci_bus *bus) > dev_set_msi_domain(&bus->dev, d); > } > > +static int res_cmp(void *priv, struct list_head *a, struct list_head *b) > +{ > + struct resource_entry *entry1, *entry2; > + > + entry1 = container_of(a, struct resource_entry, node); > + entry2 = container_of(b, struct resource_entry, node); > + > + if (entry1->res->flags != entry2->res->flags) > + return entry1->res->flags > entry2->res->flags; > + > + if (entry1->offset != entry2->offset) > + return entry1->offset > entry2->offset; > + > + return entry1->res->start > entry2->res->start; > +} > + > static int pci_register_host_bridge(struct pci_host_bridge *bridge) > { > struct device *parent = bridge->dev.parent; > - struct resource_entry *window, *n; > + struct resource_entry *window, *next, *n; > struct pci_bus *bus, *b; > - resource_size_t offset; > + resource_size_t offset, next_offset; > LIST_HEAD(resources); > - struct resource *res; > + struct resource *res, *next_res; > char addr[64], *fmt; > const char *name; > int err; > @@ -959,11 +976,35 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) > if (nr_node_ids > 1 && pcibus_to_node(bus) == NUMA_NO_NODE) > dev_warn(&bus->dev, "Unknown NUMA node; performance will be reduced\n"); > > + /* Sort and coalesce contiguous windows */ > + list_sort(NULL, &resources, res_cmp); > + resource_list_for_each_entry_safe(window, n, &resources) { > + if (list_is_last(&window->node, &resources)) > + break; > + > + next = list_next_entry(window, node); > + offset = window->offset; > + res = window->res; > + next_offset = next->offset; > + next_res = next->res; > + > + if (res->flags != next_res->flags || offset != next_offset) > + continue; > + > + if (res->end + 1 == next_res->start) { > + next_res->start = res->start; > + res->flags = res->start = res->end = 0; > + } > + } > + > /* Add initial resources to the bus */ > resource_list_for_each_entry_safe(window, n, &resources) { > - list_move_tail(&window->node, &bridge->windows); > offset = window->offset; > res = window->res; > + if (!res->end) > + continue; > + > + list_move_tail(&window->node, &bridge->windows); > > if (res->flags & IORESOURCE_BUS) > pci_bus_insert_busn_res(bus, bus->number, res->end); > -- > 2.30.2 >