From patchwork Thu Oct 24 17:12:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergei Miroshnichenko X-Patchwork-Id: 11210437 X-Patchwork-Delegate: bhelgaas@google.com 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 08422112C for ; Thu, 24 Oct 2019 17:12:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB4A221929 for ; Thu, 24 Oct 2019 17:12:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=yadro.com header.i=@yadro.com header.b="GNC1o+1P" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436863AbfJXRMu (ORCPT ); Thu, 24 Oct 2019 13:12:50 -0400 Received: from mta-02.yadro.com ([89.207.88.252]:48808 "EHLO mta-01.yadro.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2436801AbfJXRMu (ORCPT ); Thu, 24 Oct 2019 13:12:50 -0400 Received: from localhost (unknown [127.0.0.1]) by mta-01.yadro.com (Postfix) with ESMTP id 76E9A42F15; Thu, 24 Oct 2019 17:12:48 +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= 1571937167; x=1573751568; bh=dEtonO9WGVanX91lx4CEaG6vqwfmZCpSHvc P/eimQVM=; b=GNC1o+1PVFrShivoThk3yWRC/OSQCwMVc7QEIRUYlbyTP66iOh8 cc+mRyvYyMGPFrT2kBOz8f4PZSj25H549+b22cmVBCP5NMOtEEAQz+tMMFkGvLmo by3QJ1DOee63CqgOo/OUTzm1nc6SwQF2BMBRQXmRmdUYm3CO5aCiHvIs= 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 LVn_oPmCl1r7; Thu, 24 Oct 2019 20:12:47 +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 A0E9E43130; Thu, 24 Oct 2019 20:12:41 +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; Thu, 24 Oct 2019 20:12:41 +0300 From: Sergey Miroshnichenko To: , CC: Bjorn Helgaas , , Sergey Miroshnichenko Subject: [PATCH v6 13/30] PCI: hotplug: movable BARs: Compute limits for relocated bridge windows Date: Thu, 24 Oct 2019 20:12:11 +0300 Message-ID: <20191024171228.877974-14-s.miroshnichenko@yadro.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191024171228.877974-1-s.miroshnichenko@yadro.com> References: <20191024171228.877974-1-s.miroshnichenko@yadro.com> 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 With enabled movable BARs, bridge windows are recalculated during each pci rescan. Some of the BARs below the bridge may be fixed/immovable: these areas are represented by the .immovable_range field in struct pci_bus. If a bridge window size is equal to its immovable range, it can only be assigned to the start of this range. But if a bridge window size is larger, and this difference in size is denoted as "delta", the window can start from (immovable_range.start - delta) to (immovable_range.start), and it can end from (immovable_range.end) to (immovable_range.end + delta). This range (the new .realloc_range field in struct pci_bus) must then be compared with immovable ranges of neighbouring bridges to guarantee no intersections. This patch only calculates valid ranges for reallocated bridges during pci rescan, and the next one will make use of these values during allocation. Signed-off-by: Sergey Miroshnichenko --- drivers/pci/setup-bus.c | 67 +++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 6 ++++ 2 files changed, 73 insertions(+) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index a7546e02ea7c..653ba4d5f191 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1819,6 +1819,72 @@ static enum enable_type pci_realloc_detect(struct pci_bus *bus, } #endif +/* + * Calculate the address margins where the bridge windows may be allocated to fit all + * the fixed and immovable BARs beneath. + */ +static void pci_bus_update_realloc_range(struct pci_bus *bus) +{ + struct pci_dev *dev; + struct pci_bus *parent = bus->parent; + int idx; + + list_for_each_entry(dev, &bus->devices, bus_list) + if (dev->subordinate) + pci_bus_update_realloc_range(dev->subordinate); + + if (!parent || !bus->self) + return; + + for (idx = 0; idx < PCI_BRIDGE_RESOURCE_NUM; ++idx) { + struct resource *immovable_range = &bus->immovable_range[idx]; + resource_size_t window_size = resource_size(bus->resource[idx]); + resource_size_t realloc_start, realloc_end; + + bus->realloc_range[idx].start = 0; + bus->realloc_range[idx].end = 0; + + /* Check if there any immovable BARs under the bridge */ + if (immovable_range->start >= immovable_range->end) + continue; + + /* The lowest possible address where the bridge window can start */ + realloc_start = immovable_range->end - window_size + 1; + /* The highest possible address where the bridge window can end */ + realloc_end = immovable_range->start + window_size - 1; + + if (realloc_start > immovable_range->start) + realloc_start = immovable_range->start; + + if (realloc_end < immovable_range->end) + realloc_end = immovable_range->end; + + /* + * Check that realloc range doesn't intersect with hard fixed ranges + * of neighboring bridges + */ + list_for_each_entry(dev, &parent->devices, bus_list) { + struct pci_bus *neighbor = dev->subordinate; + struct resource *n_imm_range; + + if (!neighbor || neighbor == bus) + continue; + + n_imm_range = &neighbor->immovable_range[idx]; + + if (n_imm_range->start >= n_imm_range->end) + continue; + + if (n_imm_range->end < immovable_range->start && + n_imm_range->end > realloc_start) + realloc_start = n_imm_range->end; + } + + bus->realloc_range[idx].start = realloc_start; + bus->realloc_range[idx].end = realloc_end; + } +} + /* * First try will not touch PCI bridge res. * Second and later try will clear small leaf bridge res. @@ -1838,6 +1904,7 @@ void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus) if (pci_can_move_bars) { __pci_bus_size_bridges(bus, NULL); + pci_bus_update_realloc_range(bus); __pci_bus_assign_resources(bus, NULL, NULL); goto dump; diff --git a/include/linux/pci.h b/include/linux/pci.h index ef41be0ce082..e1edcb3fad31 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -587,6 +587,12 @@ struct pci_bus { */ struct resource immovable_range[PCI_BRIDGE_RESOURCE_NUM]; + /* + * Acceptable address range, where the bridge window may reside, considering its + * size, so it will cover all the fixed and immovable BARs below. + */ + struct resource realloc_range[PCI_BRIDGE_RESOURCE_NUM]; + struct pci_ops *ops; /* Configuration access functions */ struct msi_controller *msi; /* MSI controller */ void *sysdata; /* Hook for sys-specific extension */