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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6B4FC433F5 for ; Thu, 4 Nov 2021 08:54:11 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 87BED610FC for ; Thu, 4 Nov 2021 08:54:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 87BED610FC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=uwAh17oaL6WXGcP58piURDVBLKnHiUXM+MaAK3OgO00=; b=oIwKfn1CbJ8UZ1 ZwDBFCXjNN3eNii29t5ksEiSRmO9Hju61dAIxWfTzwWwJBJ1Ioy3qxXThDtIq4KDb81qNsJdfvA7Q HyEDbF9f8FWDij/lO4xEonbIwdfKrkHKazaA5V3LTh7dTU3yo0DY9SwRh8UcuGH4T9s2yGZMz+fR+ ITJeZJra4/PsAWh9EfZ7zwuPBPxJokkP1vnsHyPinZW76nLbb1j9BtO9B6/ut6gVrOiNFcLPX2Imj l55RxkNLDAPK4JCA7O3PQWNvAVW4RCv4xunTtwKvyhca6EW70xXgbiNjjwXNoqBa4tig1KoaGY5oW +ot3iqyvlegDdydjWNTQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1miYVU-008NFM-Df; Thu, 04 Nov 2021 08:54:00 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1miYVI-008NBx-Ey; Thu, 04 Nov 2021 08:53:49 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 89EB968AA6; Thu, 4 Nov 2021 09:53:36 +0100 (CET) Date: Thu, 4 Nov 2021 09:53:36 +0100 From: Christoph Hellwig To: Walter Wu Cc: Christoph Hellwig , Marek Szyprowski , Robin Murphy , Matthias Brugger , Ard Biesheuvel , Andrew Morton , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, wsd_upstream , linux-mediatek@lists.infradead.org Subject: Re: [PATCH v2] dma-direct: improve DMA_ATTR_NO_KERNEL_MAPPING Message-ID: <20211104085336.GA24260@lst.de> References: <20211104023221.16391-1-walter-zh.wu@mediatek.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20211104023221.16391-1-walter-zh.wu@mediatek.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211104_015348_694930_E4A49BC0 X-CRM114-Status: GOOD ( 18.70 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Thu, Nov 04, 2021 at 10:32:21AM +0800, Walter Wu wrote: > diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h > index f36be5166c19..6c7d1683339c 100644 > --- a/include/linux/set_memory.h > +++ b/include/linux/set_memory.h > @@ -7,11 +7,16 @@ > > #ifdef CONFIG_ARCH_HAS_SET_MEMORY > #include > + > +#ifndef CONFIG_RODATA_FULL_DEFAULT_ENABLED This is an arm64-specific symbol, and one that only controls a default. I don't think it is suitable to key off stubs in common code. > +static inline int set_memory_valid(unsigned long addr, int numpages, int enable) { return 0; } Pleae avoid overly long lines. > + if (IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED)) { > + kaddr = (unsigned long)phys_to_virt(dma_to_phys(dev, *dma_handle)); This can just use page_address. > + /* page remove kernel mapping for arm64 */ > + set_memory_valid(kaddr, size >> PAGE_SHIFT, 0); > + } But more importantly: set_memory_valid only exists on arm64, this will break compile everywhere else. And this API is complete crap. Passing kernel virtual addresses as unsigned long just sucks, and passing an integer argument for valid/non-valid also is a horrible API. Not to mention the overly long line. Same on the free side. _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek