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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96F54C433FE for ; Wed, 12 Oct 2022 09:21:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229892AbiJLJVO (ORCPT ); Wed, 12 Oct 2022 05:21:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229633AbiJLJUp (ORCPT ); Wed, 12 Oct 2022 05:20:45 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D361F2251A for ; Wed, 12 Oct 2022 02:20:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1665566442; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=I3P7oPtImaphFMRrVE6g+ZColp81HMQz95/EX453FiI=; b=dTRhgFruesKIZeQQnQWSu2h6jr6RSX8TKPvrdQq8evWKOlC4bCMtTgHarW07RXWmO8mIbC gm9Iyi3ETZFVuf9xYMk1dUEex/VXcPRVyRwYwSQm9NJXsnMJK+aRrK5vnhP7w6OCPmSzXW L2GRiySX86DvHGzSdwIhUlJ5N2z3No4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-612-FJzsnLBlMJqrL_Twqn-zXg-1; Wed, 12 Oct 2022 05:20:35 -0400 X-MC-Unique: FJzsnLBlMJqrL_Twqn-zXg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2891185A583; Wed, 12 Oct 2022 09:20:35 +0000 (UTC) Received: from localhost (ovpn-12-34.pek2.redhat.com [10.72.12.34]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4874C1121325; Wed, 12 Oct 2022 09:20:32 +0000 (UTC) Date: Wed, 12 Oct 2022 17:20:29 +0800 From: Baoquan He To: Niklas Schnelle Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, hch@infradead.org, agordeev@linux.ibm.com, wangkefeng.wang@huawei.com, christophe.leroy@csgroup.eu, David.Laight@aculab.com, shorne@gmail.com, Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , linux-s390@vger.kernel.org Subject: Re: [PATCH v3 09/11] s390: mm: Convert to GENERIC_IOREMAP Message-ID: References: <20221009103114.149036-1-bhe@redhat.com> <20221009103114.149036-10-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/12/22 at 09:37am, Niklas Schnelle wrote: > On Wed, 2022-10-12 at 13:52 +0800, Baoquan He wrote: > > On 10/11/22 at 05:16pm, Niklas Schnelle wrote: > > > On Sun, 2022-10-09 at 18:31 +0800, Baoquan He wrote: > > > > By taking GENERIC_IOREMAP method, the generic ioremap_prot() and > > > > iounmap() are visible and available to arch. Arch only needs to > > > > provide implementation of arch_ioremap() or arch_iounmap() if there's > > > > arch specific handling needed in its ioremap() or iounmap(). This > > > > change will simplify implementation by removing duplicated codes with > > > > generic ioremap() and iounmap(), and has the equivalent functioality > > > > as before. > > > > > > > > For s390, add hooks arch_ioremap() and arch_iounmap() for s390's special > > > > operation when ioremap() and iounmap(), then ioremap_[wc|wt]() are > > > > converted to use ioremap_prot() from GENERIC_IOREMAP. > > > > > > > > Signed-off-by: Baoquan He > > > > Cc: Niklas Schnelle > > > > Cc: Gerald Schaefer > > > > Cc: Heiko Carstens > > > > Cc: Vasily Gorbik > > > > Cc: Alexander Gordeev > > > > Cc: Christian Borntraeger > > > > Cc: Sven Schnelle > > > > Cc: linux-s390@vger.kernel.org > > > > --- > > > > v2->v3: > > > > - Add code comment inside arch_ioremap() to help uderstand the > > > > obsucre code. Christoph suggested this, Niklas provided the > > > > paragraph of text. > > > > > > > > arch/s390/Kconfig | 1 + > > > > arch/s390/include/asm/io.h | 25 +++++++++------ > > > > arch/s390/pci/pci.c | 65 ++++++++------------------------------ > > > > 3 files changed, 30 insertions(+), 61 deletions(-) > > > > > > > > diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig > > > > index 318fce77601d..c59e1b25f59d 100644 > > > > --- a/arch/s390/Kconfig > > > > +++ b/arch/s390/Kconfig > > > > @@ -135,6 +135,7 @@ config S390 > > > > select GENERIC_SMP_IDLE_THREAD > > > > select GENERIC_TIME_VSYSCALL > > > > select GENERIC_VDSO_TIME_NS > > > > + select GENERIC_IOREMAP > > > > > > I think you should add the "if PCI" from the diff in your last mail to > > > this patch. > > > > That's reasonable, will do. > > > > The code change in driver should be posted separately to get reviewing > > from the relevant drvier maintainers. I may wrap it into this series in > > next post so that people know its background. > > I agree about doing the driver change separately. Since the problem > already exists one could send it separately. If you want I can take of > that too. Both is fine to me, since you suggested the fix. > > > > > > > select HAVE_ALIGNED_STRUCT_PAGE if SLUB > > > > select HAVE_ARCH_AUDITSYSCALL > > > > select HAVE_ARCH_JUMP_LABEL > > ...... > > > > diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c > > > > index 73cdc5539384..3c00dc7d79bc 100644 > > > > --- a/arch/s390/pci/pci.c > > > > +++ b/arch/s390/pci/pci.c > > > > @@ -244,64 +244,25 @@ void __iowrite64_copy(void __iomem *to, const void *from, size_t count) > > > > zpci_memcpy_toio(to, from, count); > > > > } > > > > > > > > -static void __iomem *__ioremap(phys_addr_t addr, size_t size, pgprot_t prot) > > > > +void __iomem * > > > > +arch_ioremap(phys_addr_t *paddr, size_t size, unsigned long *prot_val) > > > > { > > > > - unsigned long offset, vaddr; > > > > - struct vm_struct *area; > > > > - phys_addr_t last_addr; > > > > - > > > > - last_addr = addr + size - 1; > > > > - if (!size || last_addr < addr) > > > > - return NULL; > > > > - > > > > + /* > > > > + * When PCI MIO instructions are unavailable the "physical" address > > > > + * encodes a hint for accessing the PCI memory space it represents. > > > > + * Just pass it unchanged such that ioread/iowrite can decode it. > > > > + */ > > > > if (!static_branch_unlikely(&have_mio)) > > > > - return (void __iomem *) addr; > > > > - > > > > - offset = addr & ~PAGE_MASK; > > > > - addr &= PAGE_MASK; > > > > - size = PAGE_ALIGN(size + offset); > > > > - area = get_vm_area(size, VM_IOREMAP); > > > > - if (!area) > > > > - return NULL; > > > > - > > > > - vaddr = (unsigned long) area->addr; > > > > - if (ioremap_page_range(vaddr, vaddr + size, addr, prot)) { > > > > - free_vm_area(area); > > > > - return NULL; > > > > - } > > > > - return (void __iomem *) ((unsigned long) area->addr + offset); > > > > + return (void __iomem *) *paddr; > > > > > > nit: no space after the cast > > > > Sorry, remember you pointed this out in v2, while I didn't get what > > it is. Could you be more specific or give the right line of code? > > > > Are you suggesting below line? > > > > - return (void __iomem *) ((unsigned long) area->addr + offset); > > + return (void __iomem *)*paddr; > > Yes, though I did just check and somehow checkpatch doesn't complain, > maybe because of the dereference. I do think I remember it complaining > but I guess if it doesn't you might as well keep it this way. OK, I will keep it unless checkpatch complaim about it. Thanks.