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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 4E023C3F2D2 for ; Mon, 2 Mar 2020 14:15:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B9342173E for ; Mon, 2 Mar 2020 14:15:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727306AbgCBOPD (ORCPT ); Mon, 2 Mar 2020 09:15:03 -0500 Received: from mga14.intel.com ([192.55.52.115]:1513 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726884AbgCBOPC (ORCPT ); Mon, 2 Mar 2020 09:15:02 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Mar 2020 06:14:55 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,507,1574150400"; d="scan'208";a="257963379" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga002.jf.intel.com with ESMTP; 02 Mar 2020 06:14:52 -0800 Received: by black.fi.intel.com (Postfix, from userid 1001) id 8C7B724E; Mon, 2 Mar 2020 16:14:51 +0200 (EET) From: Mika Westerberg To: Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Bjorn Helgaas Cc: Borislav Petkov , x86@kernel.org, =?UTF-8?q?Benoit=20Gr=C3=A9goire?= , Mika Westerberg , juhapekka.heikkila@gmail.com, linux-kernel@vger.kernel.org Subject: [PATCH] x86/resource: Do not exclude regions that are marked as MMIO in EFI memmap Date: Mon, 2 Mar 2020 17:14:51 +0300 Message-Id: <20200302141451.18983-1-mika.westerberg@linux.intel.com> X-Mailer: git-send-email 2.25.0 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 4dc2287c1805 ("x86: avoid E820 regions when allocating address space") made the resource allocation code to avoid all regions that are in E820 table. This prevents the kernel to assign MMIO resources to regions that may be real RAM for example. However, at least with Lenovo Yoca C940 and S740 this causes problems when allocating resources for PCIe devices behind Thunderbolt port(s). On Yoga S740 the E820 table contains an entry like this: BIOS-e820: [mem 0x000000002bc50000-0x00000000cfffffff] reserved and ACPI _CRS method for the host bridge returns these windows: pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7 window] pci_bus 0000:00: root bus resource [io 0x0d00-0xffff window] pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff window] pci_bus 0000:00: root bus resource [mem 0x45400000-0xbfffffff window] pci_bus 0000:00: root bus resource [mem 0x4000000000-0x7fffffffff window] Note that the 0x45400000-0xbfffffff entry is also included in the E820 table and marked as "reserved". When Thunderbolt device is connected and the PCIe gets tunneled PCI core tries to allocate memory for the new devices but it fails because all the resources are inside this reserved region so arch_remove_reservations() clips them which makes the resource assignment fail as in below log: pci 0000:00:07.0: PCI bridge to [bus 01-2a] pci 0000:00:07.0: bridge window [mem 0x46000000-0x521fffff] pci 0000:00:07.0: bridge window [mem 0x6000000000-0x601bffffff 64bit pref] ... pci 0000:02:04.0: bridge window [mem 0x00100000-0x001fffff 64bit pref] to [bus 07-2a] add_size 100000 add_align 100000 pci 0000:02:04.0: bridge window [mem 0x00100000-0x001fffff] to [bus 07-2a] add_size 100000 add_align 100000 pci 0000:01:00.0: bridge window [mem 0x00100000-0x005fffff 64bit pref] to [bus 02-2a] add_size 100000 add_align 100000 pci 0000:01:00.0: bridge window [mem 0x00100000-0x005fffff] to [bus 02-2a] add_size 100000 add_align 100000 pci 0000:01:00.0: bridge window [io 0x1000-0x5fff] shrunken by 0x0000000000004000 pci 0000:01:00.0: bridge window [mem 0x00100000-0x005fffff] extended by 0x000000000bd00000 pci 0000:01:00.0: bridge window [mem 0x00100000-0x005fffff 64bit pref] extended by 0x000000001bb00000 pci 0000:02:04.0: bridge window [mem 0x00100000-0x001fffff] extended by 0x000000000bd00000 pci 0000:02:04.0: bridge window [mem 0x00100000-0x001fffff 64bit pref] extended by 0x000000001bb00000 pci 0000:01:00.0: BAR 8: no space for [mem size 0x0c200000] pci 0000:01:00.0: BAR 8: failed to assign [mem size 0x0c200000] pci 0000:01:00.0: BAR 9: assigned [mem 0x6000000000-0x601bffffff 64bit pref] pci 0000:01:00.0: BAR 7: assigned [io 0x4000-0x4fff] The 01:00.0 is the upstream port of the PCIe switch that is connected to the PCIe root port (00:07.1) over Thunderbolt link. If I add "efi=debug" to the command line I can see that the EFI memory map actually contains several entries: [Reserved | | | | | | | | | |WB|WT|WC|UC] range=[0x000000002bc50000-0x000000003fffffff] (323MB) [Reserved | | | | | | | | | |WB| | |UC] range=[0x0000000040000000-0x0000000040ffffff] (16MB) [Reserved | | | | | | | | | | | | | ] range=[0x0000000041000000-0x00000000453fffff] (68MB) [Memory Mapped I/O |RUN| | | | | | | | | | | |UC] range=[0x0000000045400000-0x00000000cfffffff] (2220MB) I think the EFI stub merges these consecutive entries into that single E820 entry showed above. The last region marked as EFI_MEMORY_MAPPED_IO actually covers the PCI host bridge window entirely. However, since there is corresponding E820 type for this it is simply marked as E820_TYPE_RESERVED. All in all, I think we can fix this by modifying arch_remove_reservations() to check the EFI type as well and if it is EFI_MEMORY_MAPPED_IO skip the clipping in that case. Reported-by: Benoit Grégoire Link: https://bugzilla.kernel.org/show_bug.cgi?id=206459 Signed-off-by: Mika Westerberg --- arch/x86/kernel/resource.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/resource.c b/arch/x86/kernel/resource.c index 9b9fb7882c20..c0bc9117dd7d 100644 --- a/arch/x86/kernel/resource.c +++ b/arch/x86/kernel/resource.c @@ -1,4 +1,5 @@ // SPDX-License-Identifier: GPL-2.0 +#include #include #include @@ -36,6 +37,36 @@ static void remove_e820_regions(struct resource *avail) } } +#ifdef CONFIG_EFI +static bool efi_mmio_mem(const struct resource *avail) +{ + resource_size_t start, end; + efi_memory_desc_t desc; + + if (!efi_enabled(EFI_MEMMAP) || + efi_mem_desc_lookup(avail->start, &desc)) + return false; + + start = desc.phys_addr; + end = desc.phys_addr + (desc.num_pages << EFI_PAGE_SHIFT) - 1; + + /* + * No need to clip the resource if it is fully contained in an + * EFI memory mapped region. + */ + if (avail->start >= start && avail->end <= end && + desc.type == EFI_MEMORY_MAPPED_IO) + return true; + + return false; +} +#else +static inline bool efi_mmio_mem(const struct resource *avail) +{ + return false; +} +#endif + void arch_remove_reservations(struct resource *avail) { /* @@ -46,6 +77,7 @@ void arch_remove_reservations(struct resource *avail) if (avail->flags & IORESOURCE_MEM) { resource_clip(avail, BIOS_ROM_BASE, BIOS_ROM_END); - remove_e820_regions(avail); + if (!efi_mmio_mem(avail)) + remove_e820_regions(avail); } } -- 2.25.0