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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 763D2C43381 for ; Thu, 14 Feb 2019 07:47:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 44BAE222A4 for ; Thu, 14 Feb 2019 07:47:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437418AbfBNHrw (ORCPT ); Thu, 14 Feb 2019 02:47:52 -0500 Received: from verein.lst.de ([213.95.11.211]:48531 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437398AbfBNHrt (ORCPT ); Thu, 14 Feb 2019 02:47:49 -0500 Received: by newverein.lst.de (Postfix, from userid 2407) id 94CA068CEB; Thu, 14 Feb 2019 08:47:47 +0100 (CET) Date: Thu, 14 Feb 2019 08:47:47 +0100 From: Christoph Hellwig To: Khalid Aziz Cc: juergh@gmail.com, tycho@tycho.ws, jsteckli@amazon.de, ak@linux.intel.com, torvalds@linux-foundation.org, liran.alon@oracle.com, keescook@google.com, akpm@linux-foundation.org, mhocko@suse.com, catalin.marinas@arm.com, will.deacon@arm.com, jmorris@namei.org, konrad.wilk@oracle.com, Juerg Haefliger , deepa.srinivasan@oracle.com, chris.hyser@oracle.com, tyhicks@canonical.com, dwmw@amazon.co.uk, andrew.cooper3@citrix.com, jcm@redhat.com, boris.ostrovsky@oracle.com, kanth.ghatraju@oracle.com, oao.m.martins@oracle.com, jmattson@google.com, pradeep.vincent@oracle.com, john.haxby@oracle.com, tglx@linutronix.de, kirill.shutemov@linux.intel.com, hch@lst.de, steven.sistare@oracle.com, labbott@redhat.com, luto@kernel.org, dave.hansen@intel.com, peterz@infradead.org, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Tycho Andersen Subject: Re: [RFC PATCH v8 04/14] swiotlb: Map the buffer if it was unmapped by XPFO Message-ID: <20190214074747.GA10666@lst.de> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 13, 2019 at 05:01:27PM -0700, Khalid Aziz wrote: > +++ b/kernel/dma/swiotlb.c > @@ -396,8 +396,9 @@ static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr, > { > unsigned long pfn = PFN_DOWN(orig_addr); > unsigned char *vaddr = phys_to_virt(tlb_addr); > + struct page *page = pfn_to_page(pfn); > > - if (PageHighMem(pfn_to_page(pfn))) { > + if (PageHighMem(page) || xpfo_page_is_unmapped(page)) { I think this just wants a page_unmapped or similar helper instead of needing the xpfo_page_is_unmapped check. We actually have quite a few similar construct in the arch dma mapping code for architectures that require cache flushing. > +bool xpfo_page_is_unmapped(struct page *page) > +{ > + struct xpfo *xpfo; > + > + if (!static_branch_unlikely(&xpfo_inited)) > + return false; > + > + xpfo = lookup_xpfo(page); > + if (unlikely(!xpfo) && !xpfo->inited) > + return false; > + > + return test_bit(XPFO_PAGE_UNMAPPED, &xpfo->flags); > +} > +EXPORT_SYMBOL(xpfo_page_is_unmapped); And at least for swiotlb there is no need to export this helper, as it is always built in.