From patchwork Mon Apr 27 18:23:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sergei Miroshnichenko X-Patchwork-Id: 11513099 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BA85F15E6 for ; Mon, 27 Apr 2020 18:24:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97A0420775 for ; Mon, 27 Apr 2020 18:24:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=yadro.com header.i=@yadro.com header.b="G0yo7inB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726344AbgD0SYP (ORCPT ); Mon, 27 Apr 2020 14:24:15 -0400 Received: from mta-02.yadro.com ([89.207.88.252]:52866 "EHLO mta-01.yadro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725995AbgD0SYP (ORCPT ); Mon, 27 Apr 2020 14:24:15 -0400 Received: from localhost (unknown [127.0.0.1]) by mta-01.yadro.com (Postfix) with ESMTP id DE9C34C845; Mon, 27 Apr 2020 18:24:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yadro.com; h= content-transfer-encoding:content-type:content-type:mime-version :x-mailer:message-id:date:date:subject:subject:from:from :received:received:received; s=mta-01; t=1588011850; x= 1589826251; bh=Z3Pv06L2sM8QP3xtNt0y2Bp/GzEpe1YLDzLuClr3Py8=; b=G 0yo7inBfvUAk2QgjUYOLP+EF1CdTXSOTwBXv7UHj+bOuCTaUFGmhgvu4NKuVyoVg Z0dklQAqq3W79YjB5ivR3QcSyAIjUs2ovpevG4jlN5IA+mzClsi0YeZLfYliMFCr i0ZPJ3JoJ2IasbfbT9h7L0kIktCsyUUWDPXicuiD2M= 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 6l_0w0L2J4FT; Mon, 27 Apr 2020 21:24:10 +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 BF39E499B3; Mon, 27 Apr 2020 21:24:08 +0300 (MSK) Received: from NB-148.yadro.com (172.17.15.136) 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, 27 Apr 2020 21:24:09 +0300 From: Sergei Miroshnichenko To: CC: Bjorn Helgaas , Lukas Wunner , Stefan Roese , Andy Lavr , =?utf-8?q?Chris?= =?utf-8?q?tian_K=C3=B6nig?= , Ard Biesheuvel , David Laight , Rajat Jain , , Sergei Miroshnichenko Subject: [PATCH v8 00/24] PCI: Allow BAR movement during boot and hotplug Date: Mon, 27 Apr 2020 21:23:34 +0300 Message-ID: <20200427182358.2067702-1-s.miroshnichenko@yadro.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 X-Originating-IP: [172.17.15.136] 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 Currently PCI hotplug works on top of resources which are usually reserved not by the kernel, but by BIOS, bootloader, firmware, etc. These resources are gaps in the address space where BARs of new devices may fit, and extra bus number per port, so bridges can be hot-added. This series aim the BARs problem: it shows the kernel how to redistribute them on the run, so the hotplug becomes predictable and cross-platform. A follow-up patchset will propose a solution for bus numbers. To arrange a space for BARs of new hotplugged devices, the kernel can pause the drivers of working PCI devices and reshuffle the assigned BARs. When a driver is un-paused by the kernel, it should ioremap() the new addresses of its BARs. Drivers indicate their support of the feature by implementing the new hooks .rescan_prepare() and .rescan_done() in the struct pci_driver. If a driver doesn't yet support the feature, BARs of its devices will be considered as immovable and handled in the same way as resources with the PCI_FIXED flag: they are guaranteed to remain untouched. Tested on a number of x86_64 machines without any special kernel command line arguments: - PC: i7-5930K + ASUS X99-A; - PC: i5-8500 + ASUS Z370-F; - Supermicro Super Server/H11SSL-i: AMD EPYC 7251; - HP ProLiant DL380 G5: Xeon X5460; - Dell Inspiron N5010: i5 M 480; - Dell Precision M6600: i7-2920XM. Also tested on a Power8 (Vesnin) and Power9 (Nicole) ppc64le machines, but with extra patchset, its next version is to be sent upstream a bit later. First two patches of this series are independent bugfixes, both are not related directly to the movable BARs feature, but without them the rest of this series will not work as expected. Patches 03-15 implement the essentials of the feature. Patches 16-21 are performance improvements for movable BARs and pciehp. Patch 22 enables the feature by default. Patches 23-24 add movable BARs support to nvme and portdrv. This patchset is a part of our work on adding support for hotplugging chains of chassis full of other bridges, NVME drives, SAS HBAs, GPUs, etc. without special requirements such as Hot-Plug Controller, reservation of bus numbers or memory regions by firmware, etc. Added Stefan Roese and Andy Lavr to CC, thank you for trying this on your hardware! Added Christian König and Ard Biesheuvel to CC, because of the recent "PCI: allow pci_resize_resource() to be used on devices on the root bus" thread, which covers a similar problem. Changes since v7: - Added some documentation; - Replaced every occurrence of the word "immovable" with "fixed"; - Don't touch PNP, ACPI resources anymore; - Replaced double rescan with triple rescan: * first try every BAR; * if that failed, retry without BARs which weren't assigned before; * if that failed, retry without BARs of hotplugged devices; - Reassign BARs during boot only if BIOS assigned not all requested BARs; - Fixed up PCIBIOS_MIN_MEM instead of ignoring it; - Now the feature auto-disables in presence of a transparent bridge; - Improved support of runtime PM; - Fixed issues with incorrectly released bridge windows; - Fixed calculating bridge window size. Changes since v6: - Added a fix for hotplug on AMD Epyc + Supermicro H11SSL-i by ignoring PCIBIOS_MIN_MEM; - Fixed a workaround which marks VGA BARs as immovables; - Fixed misleading "can't claim BAR ... no compatible bridge window" error messages; - Refactored the code, reduced the amount of patches; - Exclude PowerPC-specific arch patches, they will be sent separately; - Disabled for PowerNV by default - waiting for the PCIPOCALYPSE patchset. - Fixed reports from the kbuild test robot. Changes since v5: - Simplified the disable flag, now it is "pci=no_movable_buses"; - More deliberate marking the BARs as immovable; - Mark as immovable BARs which are used by unbound drivers; - Ignoring BAR assignment by non-kernel program components, so the kernel is able now to distribute BARs in optimal and predictable way; - Move here PowerNV-specific patches from the older "powerpc/powernv/pci: Make hotplug self-sufficient, independent of FW and DT" series; - Fix EEH cache rebuilding and PE allocation for PowerNV during rescan. Changes since v4: - Feature is enabled by default (turned on by one of the latest patches); - Add pci_dev_movable_bars_supported(dev) instead of marking the immovable BARs with the IORESOURCE_PCI_FIXED flag; - Set up PCIe bridges during rescan via sysfs, so MPS settings are now configured not only during system boot or pcihp events; - Allow movement of switch's BARs if claimed by portdrv; - Update EEH address caches after rescan for powerpc; - Don't disable completely hot-added devices which can't have BARs being fit - just disable their BARs, so they are still visible in lspci etc; - Clearer names: fixed_range_hard -> immovable_range, fixed_range_soft -> realloc_range; - Drop the patch for pci_restore_config_space() - fixed by properly using the runtime PM. Changes since v3: - Rebased to the upstream, so the patches apply cleanly again. Changes since v2: - Fixed double-assignment of bridge windows; - Fixed assignment of fixed prefetched resources; - Fixed releasing of fixed resources; - Fixed a debug message; - Removed auto-enabling the movable BARs for x86 - let's rely on the "pcie_movable_bars=force" option for now; - Reordered the patches - bugfixes first. Changes since v1: - Add a "pcie_movable_bars={ off | force }" command line argument; - Handle the IORESOURCE_PCI_FIXED flag properly; - Don't move BARs of devices which don't support the feature; - Guarantee that new hotplugged devices will not steal memory from working devices by ignoring the failing new devices with the new PCI_DEV_IGNORE flag; - Add rescan_prepare()+rescan_done() to the struct pci_driver instead of using the reset_prepare()+reset_done() from struct pci_error_handlers; - Add a bugfix of a race condition; - Fixed hotplug in a non-pre-enabled (by BIOS/firmware) bridge; - Fix the compatibility of the feature with pm_runtime and D3-state; - Hotplug events from pciehp also can move BARs; - Add support of the feature to the NVME driver. Sergei Miroshnichenko (24): PCI: Fix race condition in pci_enable/disable_device() PCI: Ensure a bridge has I/O and MEM access for hot-added devices PCI: hotplug: Initial support of the movable BARs feature PCI: Add version of release_child_resources() aware of fixed BARs PCI: hotplug: Fix reassigning the released BARs PCI: hotplug: Recalculate every bridge window during rescan PCI: hotplug: Don't allow hot-added devices to steal resources PCI: Reassign BARs if BIOS/bootloader had assigned not all of them PCI: hotplug: Try to reassign movable BARs only once PCI: hotplug: Calculate fixed parts of bridge windows PCI: Include fixed BARs into the bus size calculating PCI: hotplug: movable BARs: Compute limits for relocated bridge windows PCI: Make sure bridge windows include their fixed BARs PCI: hotplug: Add support of fixed BARs to pci_assign_resource() PCI: hotplug: Sort fixed BARs before assignment x86/PCI/ACPI: Fix up PCIBIOS_MIN_MEM if value computed from e820 is invalid PCI: hotplug: Configure MPS after manual bus rescan PCI: hotplug: Don't disable the released bridge windows immediately PCI: pciehp: Trigger a domain rescan on hp events when enabled movable BARs PCI: Don't claim fixed BARs PCI: hotplug: Don't reserve bus space when enabled movable BARs PCI: hotplug: Enable the movable BARs feature by default PCI/portdrv: Declare support of movable BARs nvme-pci: Handle movable BARs Documentation/PCI/pci.rst | 55 +++ .../admin-guide/kernel-parameters.txt | 1 + arch/powerpc/platforms/powernv/pci.c | 2 + arch/powerpc/platforms/pseries/setup.c | 2 + arch/x86/pci/acpi.c | 15 + drivers/nvme/host/pci.c | 21 +- drivers/pci/bus.c | 2 +- drivers/pci/hotplug/pciehp_pci.c | 5 + drivers/pci/iov.c | 2 + drivers/pci/pci.c | 33 +- drivers/pci/pci.h | 33 ++ drivers/pci/pcie/portdrv_pci.c | 11 + drivers/pci/probe.c | 399 +++++++++++++++++- drivers/pci/setup-bus.c | 301 ++++++++++--- drivers/pci/setup-res.c | 75 +++- include/linux/pci.h | 20 + 16 files changed, 905 insertions(+), 72 deletions(-) base-commit: 6a8b55ed4056ea5559ebe4f6a4b247f627870d4c