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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 ECF26C28CC3 for ; Thu, 30 May 2019 16:22:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CED1724B81 for ; Thu, 30 May 2019 16:22:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727123AbfE3QW3 (ORCPT ); Thu, 30 May 2019 12:22:29 -0400 Received: from foss.arm.com ([217.140.101.70]:39348 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726045AbfE3QW2 (ORCPT ); Thu, 30 May 2019 12:22:28 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 13CAF341; Thu, 30 May 2019 09:22:28 -0700 (PDT) Received: from redmoon (e121166-lin.cambridge.arm.com [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 23AA43F5AF; Thu, 30 May 2019 09:22:26 -0700 (PDT) Date: Thu, 30 May 2019 17:22:23 +0100 From: Lorenzo Pieralisi To: Alan Mikhak Cc: Kishon Vijay Abraham I , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Palmer Dabbelt , Paul Walmsley , Bjorn Helgaas , gustavo.pimentel@synopsys.com, wen.yang99@zte.com.cn, kjlu@umn.edu Subject: Re: [PATCH v2] PCI: endpoint: Skip odd BAR when skipping 64bit BAR Message-ID: <20190530162223.GG13993@redmoon> References: <1558648540-14239-1-git-send-email-alan.mikhak@sifive.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 24, 2019 at 11:50:41AM -0700, Alan Mikhak wrote: > Hi Kishon, > > Yes. This change is still applicable even when the platform specifies > that it only supports 64-bit BARs by setting the bar_fixed_64bit > member of epc_features. > > The issue being fixed is this: If the 'continue' statement is executed > within the loop, the loop index 'bar' needs to advanced by two, not > one, when the BAR is 64-bit. Otherwise the next loop iteration will be > on an odd BAR which doesn't exist. > > The PCI_BASE_ADDRESS_MEM_TYPE_64 flag in epf_bar->flag reflects the > value set by the platform in the bar_fixed_64bit member of > epc_features. > > This patch moves the checking of PCI_BASE_ADDRESS_MEM_TYPE_64 in > epf_bar->flags to before the 'continue' statement to advance the 'bar' > loop index accordingly. The comment you see about 'pci_epc_set_bar()' > preceding the moved code is the original comment and was also moved > along with the code. @Kishon, I would need your ACK to merge this patch. Thanks, Lorenzo > Regards, > Alan Mikhak > > On Fri, May 24, 2019 at 1:51 AM Kishon Vijay Abraham I wrote: > > > > Hi, > > > > On 24/05/19 5:25 AM, Alan Mikhak wrote: > > > +Bjorn Helgaas, +Gustavo Pimentel, +Wen Yang, +Kangjie Lu > > > > > > On Thu, May 23, 2019 at 2:55 PM Alan Mikhak wrote: > > >> > > >> Always skip odd bar when skipping 64bit BARs in pci_epf_test_set_bar() > > >> and pci_epf_test_alloc_space(). > > >> > > >> Otherwise, pci_epf_test_set_bar() will call pci_epc_set_bar() on odd loop > > >> index when skipping reserved 64bit BAR. Moreover, pci_epf_test_alloc_space() > > >> will call pci_epf_alloc_space() on bind for odd loop index when BAR is 64bit > > >> but leaks on subsequent unbind by not calling pci_epf_free_space(). > > >> > > >> Signed-off-by: Alan Mikhak > > >> Reviewed-by: Paul Walmsley > > >> --- > > >> drivers/pci/endpoint/functions/pci-epf-test.c | 25 ++++++++++++------------- > > >> 1 file changed, 12 insertions(+), 13 deletions(-) > > >> > > >> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c > > >> index 27806987e93b..96156a537922 100644 > > >> --- a/drivers/pci/endpoint/functions/pci-epf-test.c > > >> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c > > >> @@ -389,7 +389,7 @@ static void pci_epf_test_unbind(struct pci_epf *epf) > > >> > > >> static int pci_epf_test_set_bar(struct pci_epf *epf) > > >> { > > >> - int bar; > > >> + int bar, add; > > >> int ret; > > >> struct pci_epf_bar *epf_bar; > > >> struct pci_epc *epc = epf->epc; > > >> @@ -400,8 +400,14 @@ static int pci_epf_test_set_bar(struct pci_epf *epf) > > >> > > >> epc_features = epf_test->epc_features; > > >> > > >> - for (bar = BAR_0; bar <= BAR_5; bar++) { > > >> + for (bar = BAR_0; bar <= BAR_5; bar += add) { > > >> epf_bar = &epf->bar[bar]; > > >> + /* > > >> + * pci_epc_set_bar() sets PCI_BASE_ADDRESS_MEM_TYPE_64 > > >> + * if the specific implementation required a 64-bit BAR, > > >> + * even if we only requested a 32-bit BAR. > > >> + */ > > > > set_bar shouldn't set PCI_BASE_ADDRESS_MEM_TYPE_64. If a platform supports only > > 64-bit BAR, that should be specified in epc_features bar_fixed_64bit member. > > > > Thanks > > Kishon