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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable 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 A034BC004D5 for ; Wed, 26 Sep 2018 22:23:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5945021566 for ; Wed, 26 Sep 2018 22:23:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="qsQZJBZ4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5945021566 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726641AbeI0Eic (ORCPT ); Thu, 27 Sep 2018 00:38:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:52722 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726098AbeI0Eib (ORCPT ); Thu, 27 Sep 2018 00:38:31 -0400 Received: from localhost (unknown [69.71.4.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 26D202154B; Wed, 26 Sep 2018 22:23:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1538000604; bh=X7qkjEwP7BOTZakDcYCEWTQ0QopV9gugx0KpKUMMevo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qsQZJBZ4qGpsJuqPGph5PcVwOx1jpEIJuppAaBYuagoMw3ORSsjVYfUKuz0qS4gDA 28BWurpV1p/f0/9y0o7DeP1D9oocGWVlh9yTb8HhngAgR78UUUz594T9cS/iofFb2c JmRhOZqKSutM6thcVZX/XyDNcimLs3LMy378VYmY= Date: Wed, 26 Sep 2018 17:23:22 -0500 From: Bjorn Helgaas To: Jon Derrick Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Lorenzo Pieralisi , Sinan Kaya , Christoph Hellwig , Keith Busch , Matthew Wilcox , Logan Gunthorpe , Mika Westerberg Subject: Re: [PATCH v3] PCI: Equalize hotplug memory and io for non/occupied slots Message-ID: <20180926222322.GL28024@bhelgaas-glaptop.roam.corp.google.com> References: <1537900746-3043-1-git-send-email-jonathan.derrick@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1537900746-3043-1-git-send-email-jonathan.derrick@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 25, 2018 at 12:39:06PM -0600, Jon Derrick wrote: > Currently, a hotplug bridge will be given hpmemsize additional memory > and hpiosize additional io if available, in order to satisfy any future > hotplug allocation requirements. > > These calculations don't consider the current memory/io size of the > hotplug bridge/slot, so hotplug bridges/slots which have downstream > devices will be allocated their current allocation in addition to the > hpmemsize value. > > This makes for possibly undesirable results with a mix of unoccupied and > occupied slots (ex, with hpmemsize=2M): > > 02:03.0 PCI bridge: <-- Occupied > Memory behind bridge: d6200000-d64fffff [size=3M] > 02:04.0 PCI bridge: <-- Unoccupied > Memory behind bridge: d6500000-d66fffff [size=2M] > > This change considers the current allocation size when using the > hpmemsize/hpiosize parameters to make the reservations predictable for > the mix of unoccupied and occupied slots: > > 02:03.0 PCI bridge: <-- Occupied > Memory behind bridge: d6200000-d63fffff [size=2M] > 02:04.0 PCI bridge: <-- Unoccupied > Memory behind bridge: d6400000-d65fffff [size=2M] > > Signed-off-by: Jon Derrick Applied to pci/hotplug for v4.20, thanks! > --- > v2->v3: Made the IO and mem size calculations nearly equivalent > > drivers/pci/setup-bus.c | 28 +++++++++++++++------------- > 1 file changed, 15 insertions(+), 13 deletions(-) > > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index 79b1824..ed96043 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -811,6 +811,8 @@ static struct resource *find_free_bus_resource(struct pci_bus *bus, > static resource_size_t calculate_iosize(resource_size_t size, > resource_size_t min_size, > resource_size_t size1, > + resource_size_t add_size, > + resource_size_t children_add_size, > resource_size_t old_size, > resource_size_t align) > { > @@ -823,15 +825,18 @@ static resource_size_t calculate_iosize(resource_size_t size, > #if defined(CONFIG_ISA) || defined(CONFIG_EISA) > size = (size & 0xff) + ((size & ~0xffUL) << 2); > #endif > - size = ALIGN(size + size1, align); > + size = size + size1; > if (size < old_size) > size = old_size; > + > + size = ALIGN(max(size, add_size) + children_add_size, align); > return size; > } > > static resource_size_t calculate_memsize(resource_size_t size, > resource_size_t min_size, > - resource_size_t size1, > + resource_size_t add_size, > + resource_size_t children_add_size, > resource_size_t old_size, > resource_size_t align) > { > @@ -841,7 +846,8 @@ static resource_size_t calculate_memsize(resource_size_t size, > old_size = 0; > if (size < old_size) > size = old_size; > - size = ALIGN(size + size1, align); > + > + size = ALIGN(max(size, add_size) + children_add_size, align); > return size; > } > > @@ -930,12 +936,10 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, > } > } > > - size0 = calculate_iosize(size, min_size, size1, > + size0 = calculate_iosize(size, min_size, size1, 0, 0, > resource_size(b_res), min_align); > - if (children_add_size > add_size) > - add_size = children_add_size; > - size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 : > - calculate_iosize(size, min_size, add_size + size1, > + size1 = (!realloc_head || (realloc_head && !add_size && !children_add_size)) ? size0 : > + calculate_iosize(size, min_size, size1, add_size, children_add_size, > resource_size(b_res), min_align); > if (!size0 && !size1) { > if (b_res->start || b_res->end) > @@ -1079,12 +1083,10 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, > > min_align = calculate_mem_align(aligns, max_order); > min_align = max(min_align, window_alignment(bus, b_res->flags)); > - size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align); > + size0 = calculate_memsize(size, min_size, 0, 0, resource_size(b_res), min_align); > add_align = max(min_align, add_align); > - if (children_add_size > add_size) > - add_size = children_add_size; > - size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 : > - calculate_memsize(size, min_size, add_size, > + size1 = (!realloc_head || (realloc_head && !add_size && !children_add_size)) ? size0 : > + calculate_memsize(size, min_size, add_size, children_add_size, > resource_size(b_res), add_align); > if (!size0 && !size1) { > if (b_res->start || b_res->end) > -- > 1.8.3.1 >