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=-12.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 AC2A5C4707F for ; Thu, 27 May 2021 13:09:45 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 6416D613AB for ; Thu, 27 May 2021 13:09:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6416D613AB Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.133337.248561 (Exim 4.92) (envelope-from ) id 1lmFlO-0001B1-8L; Thu, 27 May 2021 13:09:26 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 133337.248561; Thu, 27 May 2021 13:09:26 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lmFlO-0001Au-56; Thu, 27 May 2021 13:09:26 +0000 Received: by outflank-mailman (input) for mailman id 133337; Thu, 27 May 2021 13:09:24 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lmFlM-0001Am-M4 for xen-devel@lists.xenproject.org; Thu, 27 May 2021 13:09:24 +0000 Received: from smtp-out1.suse.de (unknown [195.135.220.28]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 5d77f7bb-cd7e-4b05-8793-c849af92b23e; Thu, 27 May 2021 13:09:23 +0000 (UTC) Received: from imap.suse.de (imap-alt.suse-dmz.suse.de [192.168.254.47]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id A78C8218DD; Thu, 27 May 2021 13:09:22 +0000 (UTC) Received: from director2.suse.de (director2.suse-dmz.suse.de [192.168.254.72]) by imap.suse.de (Postfix) with ESMTPSA id 7DBDC11A98; Thu, 27 May 2021 13:09:22 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 5d77f7bb-cd7e-4b05-8793-c849af92b23e DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1622120962; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=trLBAOWe0MCleefC+wGsBbKvDk54IBj1+8SrsR29cGI=; b=CZ73lC6l7m/6kpFXnBwSHC2Qi05l5z0GwPVV4EO6ELMcTDS9Vc1IwsRqYXBLD6U6Pl9Wj1 f1B7/ckbSSIaZUd2m6+WYYygivdYwJbGPSIOEwo5yk2O1ubA6S8vvHaNf+ZdETPpcei2vv RgzcSbMzOchK1cuQfQPUSGDeRSrhp1o= Subject: Re: [PATCH v2 01/12] x86: introduce ioremap_wc() To: Julien Grall Cc: Andrew Cooper , Wei Liu , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , "xen-devel@lists.xenproject.org" References: <8f56a8f4-0482-932f-96a9-c791bebb4610@suse.com> <20abac99-609c-f4f6-1242-c79919f4c317@suse.com> From: Jan Beulich Message-ID: Date: Thu, 27 May 2021 15:09:18 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 27.05.2021 14:48, Julien Grall wrote: > On 27/05/2021 13:30, Jan Beulich wrote: >> --- a/xen/arch/x86/mm.c >> +++ b/xen/arch/x86/mm.c >> @@ -5881,6 +5881,20 @@ void __iomem *ioremap(paddr_t pa, size_t >> return (void __force __iomem *)va; >> } >> >> +void __iomem *__init ioremap_wc(paddr_t pa, size_t len) >> +{ >> + mfn_t mfn = _mfn(PFN_DOWN(pa)); >> + unsigned int offs = pa & (PAGE_SIZE - 1); >> + unsigned int nr = PFN_UP(offs + len); >> + void *va; >> + >> + WARN_ON(page_is_ram_type(mfn_x(mfn), RAM_TYPE_CONVENTIONAL)); >> + >> + va = __vmap(&mfn, nr, 1, 1, PAGE_HYPERVISOR_WC, VMAP_DEFAULT); >> + >> + return (void __force __iomem *)(va + offs); >> +} > > Arm is already providing ioremap_wc() which is a wrapper to > ioremap_attr(). I did notice this, yes. > Can this be moved to the common code to avoid duplication? If by "this" you mean ioremap_attr(), then I wasn't convinced we want a function of this name on x86. In particular you may note that x86'es ioremap() is sort of the equivalent of Arm's ioremap_nocache(), but is different from the new ioremap_wc() by more than just the different PTE attributes. Also I was specifically asked to make ioremap_wc() __init; ioremap() cannot be, because of at least the use from pci_vtd_quirk(). Plus I'd need to clean up Arm's lack of __iomem if I wanted to fold things. Or wait - it's declaration and definition which are out of sync there, i.e. a pre-existing issue. Bottom line - while I did consider folding, I don't think that's feasible at this point in time. Jan