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,URIBL_BLOCKED autolearn=ham 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 3A875C433B4 for ; Tue, 11 May 2021 03:33:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D10C61585 for ; Tue, 11 May 2021 03:33:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230183AbhEKDez (ORCPT ); Mon, 10 May 2021 23:34:55 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:36529 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229736AbhEKDey (ORCPT ); Mon, 10 May 2021 23:34:54 -0400 Received: from mail-lj1-f197.google.com ([209.85.208.197]) by youngberry.canonical.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1lgJ9X-0006Il-PW for linux-pci@vger.kernel.org; Tue, 11 May 2021 03:33:47 +0000 Received: by mail-lj1-f197.google.com with SMTP id g6-20020a05651c0446b02900dee525f111so10169102ljg.19 for ; Mon, 10 May 2021 20:33:47 -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=fSs6wGkqCeP3e2X7oXR6Znw5oiB9jcI2Zxhz3FUpuYs=; b=GsIgcwWgDCCJesKZORYQasEiKSg+JM25RALxOJ00edmAj0z6ECibd0RcCTY7S7XKtw vkUY2iZ5/gm3F1FJd3iY4mbvNsb0Tb7wCWSvW0i0xO9bdLIsASe9Vl5Owu8SdGFm+puT kht1rAGylKIAQZREQ2qzEu+PN2G+VgmLokQvBm3x+dPyYyl1xN+Iat1oMTpnju/Ya4we i+OWwxted9wZgxjpg5JnuFCXUtcOamjfcXJsldYCqrrkC4HPjvr0Ah3A14INzjflDp5t hDwENs6+hmSB2hETHhmFWBNDypWHnhs9PGnf5gWe9731D5cNFELc5tmiMYPc7gHJhVcJ g/nw== X-Gm-Message-State: AOAM532BkA0yN+ta59t+9A+WAf+KB6zABCE+tKQ4UWOi6KtsrIjQTTDq TKgllSBu7w0yRTgtvIPhaAoAKTHivrZTvxPNSRPRFY+IauXRjHKnGuoPdzZlI6DaV+NfoAp+qOA 6PbxbwXw85qk62mgKWv9kWAq7o2gpHz+7qP39QkZQWq4TxHkD9PbFjw== X-Received: by 2002:ac2:5fc9:: with SMTP id q9mr19797837lfg.290.1620704027217; Mon, 10 May 2021 20:33:47 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwP91Z8IW8EkWCaYE8EiEizLo10auyoxnofDLFvVJpbYoM/pbeICOSGgXCP8irVnTkBCxZQjTKfX4gt3OIYbS8= X-Received: by 2002:ac2:5fc9:: with SMTP id q9mr19797820lfg.290.1620704026948; Mon, 10 May 2021 20:33:46 -0700 (PDT) MIME-Version: 1.0 References: <20210401131252.531935-1-kai.heng.feng@canonical.com> In-Reply-To: From: Kai-Heng Feng Date: Tue, 11 May 2021 11:33:34 +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-pci@vger.kernel.org On Thu, Apr 22, 2021 at 4:57 PM Kai-Heng Feng wrote: > > 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... Another 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 > >