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=-2.4 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED,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 0795AC4321D for ; Fri, 24 Aug 2018 14:53:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B60942150F for ; Fri, 24 Aug 2018 14:53:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="O8y71oUb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B60942150F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727781AbeHXS2e (ORCPT ); Fri, 24 Aug 2018 14:28:34 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:45332 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727452AbeHXS2d (ORCPT ); Fri, 24 Aug 2018 14:28:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=iGSWkShzxKmp4y9EgSFQrKQYvPJbUEcE97ALgc+NgjM=; b=O8y71oUb7QyMBvM2vzR4DqMYA Oy/Q9vYUuCKsuwVBvOdNnUVyRaXyuPeJavaXEpHqYF4elJE2alsJj2fUj1PfAuzgddE92ql2OxnD6 1cGiQOmS4oupnnvnP4E88yST3xINhzYy+kD2QylcW/ydWDo2HVO1mszNfK5Kqvzs01hOp4TNbw0m7 OL2dScKmm1Nn4uFaD4qkDm4XfwX2QE6CzIx3UxHg/ML6z/aiMlFkC57Kvmb46eqNJ50F5UVi4E9d7 CJDqUJZcb6mnQbgCqpwD692Vx2topt5epMd58/PcV1uTSFPrRsQ6utlG65LPTLJT8UXfgArrW6QSd FUojVSGfQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1ftDSr-0003t7-3n; Fri, 24 Aug 2018 14:53:29 +0000 Date: Fri, 24 Aug 2018 07:53:28 -0700 From: Christoph Hellwig To: murphyt7@tcd.ie Cc: leo.duran@amd.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Changing the AMD IOMMU API path to work in an atomic context which is necessary for any custom drivers using the IOMMU API while holding a spinlock. Message-ID: <20180824145328.GA7996@infradead.org> References: <1535120929-5693-1-git-send-email-murphyt7@tcd.ie> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1535120929-5693-1-git-send-email-murphyt7@tcd.ie> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 24, 2018 at 02:28:49PM +0000, murphyt7@tcd.ie wrote: > From: Tom Murphy > > --- > > This patch allows the IOMMU API path in the AMD driver to be called from an atomic context. > This is useful for anyone building a driver which needs to call the IOMMU API while holding a spinlock. I don't think that is a good idea. Please point to the code in the driver and we can't probably find a better solution.