From patchwork Fri Jan 11 15:36:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergei Miroshnichenko X-Patchwork-Id: 10758281 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6AF34746 for ; Fri, 11 Jan 2019 15:43:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5A41A2848B for ; Fri, 11 Jan 2019 15:43:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4C06728574; Fri, 11 Jan 2019 15:43:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D6DC52848B for ; Fri, 11 Jan 2019 15:43:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731970AbfAKPnz (ORCPT ); Fri, 11 Jan 2019 10:43:55 -0500 Received: from mta-01.yadro.com ([89.207.88.251]:40066 "EHLO mta-01.yadro.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731088AbfAKPny (ORCPT ); Fri, 11 Jan 2019 10:43:54 -0500 Received: from localhost (unknown [127.0.0.1]) by mta-01.yadro.com (Postfix) with ESMTP id C06FD419B9 for ; Fri, 11 Jan 2019 15:37:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=yadro.com; h= content-type:content-type:content-transfer-encoding:mime-version :references:in-reply-to:x-mailer:message-id:date:date:subject :subject:from:from:received:received:received; s=mta-01; t= 1547221042; x=1549035443; bh=hCcqWUEOeHKpsKqTX40npQA0JC4L81ub3lt tuK53l5M=; b=Xh5HaAgdTGsANecJOtbq6xfVGK0xwDm7zkROkpJVD2cJ6Z04lY4 8N1z7u6TE1b/u0GDdslMyD2m0Cl7GyFacqLDzdWVrKkvFO8smGLHWe2nuVAyOrgc Z4jU8a3lCs8AvB+HBtTS4j4MuQuGDWGhZ0DeC86zy+fyDZUxryBtZqbQ= 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 vaKQgf0lTJwT for ; Fri, 11 Jan 2019 18:37:22 +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 2B52741994 for ; Fri, 11 Jan 2019 18:37:22 +0300 (MSK) Received: from NB-148.yadro.com (172.17.15.60) 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; Fri, 11 Jan 2019 18:37:21 +0300 From: Sergey Miroshnichenko To: CC: , Sergey Miroshnichenko Subject: [PATCH RFC v2 03/21] PCI: hotplug: Add a flag for the movable BARs feature Date: Fri, 11 Jan 2019 18:36:49 +0300 Message-ID: <20190111153707.10140-4-s.miroshnichenko@yadro.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190111153707.10140-1-s.miroshnichenko@yadro.com> References: <20190111153707.10140-1-s.miroshnichenko@yadro.com> MIME-Version: 1.0 X-Originating-IP: [172.17.15.60] 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 X-Virus-Scanned: ClamAV using ClamSMTP If a new PCIe device has been hot-plugged between the two active ones without big enough gap between their BARs, these BARs should be moved if their drivers support this feature. The drivers should be notified and paused during the procedure: 1) dev 8 (new) | v .. | dev 3 | dev 3 | dev 5 | dev 7 | .. | BAR 0 | BAR 1 | BAR 0 | BAR 0 | 2) dev 8 | v .. | dev 3 | dev 3 | --> --> | dev 5 | dev 7 | .. | BAR 0 | BAR 1 | --> --> | BAR 0 | BAR 0 | 3) .. | dev 3 | dev 3 | dev 8 | dev 8 | dev 5 | dev 7 | .. | BAR 0 | BAR 1 | BAR 0 | BAR 1 | BAR 0 | BAR 0 | Thus, prior reservation of memory regions by BIOS/bootloader/firmware is not required anymore for the PCIe hotplug. The PCI_MOVABLE_BARS flag is set by the platform is this feature is supported and tested, but can be overridden by the following command line option: pcie_movable_bars={ off | force } Signed-off-by: Sergey Miroshnichenko --- .../admin-guide/kernel-parameters.txt | 7 ++++++ drivers/pci/pci.c | 24 +++++++++++++++++++ include/linux/pci.h | 2 ++ 3 files changed, 33 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b799bcf67d7b..2165c4b5aea6 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3387,6 +3387,13 @@ nomsi Do not use MSI for native PCIe PME signaling (this makes all PCIe root ports use INTx for all services). + pcie_movable_bars=[PCIE] + Override the movable BARs support detection: + off + Disable even if supported by the platform + force + Enable even if not explicitly declared as supported + pcmv= [HW,PCMCIA] BadgePAD 4 pd_ignore_unused diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 5580ddc5b9b1..71e056771e67 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -139,6 +139,30 @@ static int __init pcie_port_pm_setup(char *str) } __setup("pcie_port_pm=", pcie_port_pm_setup); +static bool pcie_movable_bars_off; +static bool pcie_movable_bars_force; +static int __init pcie_movable_bars_setup(char *str) +{ + if (!strcmp(str, "off")) + pcie_movable_bars_off = true; + else if (!strcmp(str, "force")) + pcie_movable_bars_force = true; + return 1; +} +__setup("pcie_movable_bars=", pcie_movable_bars_setup); + +bool pci_movable_bars_enabled(void) +{ + if (pcie_movable_bars_off) + return false; + + if (pcie_movable_bars_force) + return true; + + return pci_has_flag(PCI_MOVABLE_BARS); +} +EXPORT_SYMBOL(pci_movable_bars_enabled); + /* Time to wait after a reset for device to become responsive */ #define PCIE_RESET_READY_POLL_MS 60000 diff --git a/include/linux/pci.h b/include/linux/pci.h index 65f1d8c2f082..84751f0931cd 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -862,6 +862,7 @@ enum { PCI_ENABLE_PROC_DOMAINS = 0x00000010, /* Enable domains in /proc */ PCI_COMPAT_DOMAIN_0 = 0x00000020, /* ... except domain 0 */ PCI_SCAN_ALL_PCIE_DEVS = 0x00000040, /* Scan all, not just dev 0 */ + PCI_MOVABLE_BARS = 0x00000080, /* Runtime BAR reassign after hotplug */ }; /* These external functions are only available when PCI support is enabled */ @@ -1341,6 +1342,7 @@ unsigned char pci_bus_max_busnr(struct pci_bus *bus); void pci_setup_bridge(struct pci_bus *bus); resource_size_t pcibios_window_alignment(struct pci_bus *bus, unsigned long type); +bool pci_movable_bars_enabled(void); #define PCI_VGA_STATE_CHANGE_BRIDGE (1 << 0) #define PCI_VGA_STATE_CHANGE_DECODES (1 << 1)