From patchwork Fri Nov 6 17:00:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 11887533 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=-12.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 680E0C388F2 for ; Fri, 6 Nov 2020 17:00:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDCB622202 for ; Fri, 6 Nov 2020 17:00:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=deltatee.com header.i=@deltatee.com header.b="soNcve2w" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726075AbgKFRAx (ORCPT ); Fri, 6 Nov 2020 12:00:53 -0500 Received: from ale.deltatee.com ([204.191.154.188]:57604 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725868AbgKFRAx (ORCPT ); Fri, 6 Nov 2020 12:00:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Cc:To:From:Sender:Reply-To: Content-Type: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=zgGEpEC881xygcChLUzP5MM+TPIgCL+RooeJy/MEFvk=; b=soNcve2wKJLNlkdIcwhFKrP00x UXFJJhudsSkX2SoBn5CzMojAj0uyR2/WZqlCmQ/roDA/tjn6xVSzQu+640oHm0jxA9uJO+KPDZB2G Oq2rKjg3PcmQ6QJuv02gmSnlDR6+W0FJ6I7CDF1vKR8DUcOpumtVWqKYU3Q/xYP3DNgg/KR7V8uUp Sjtqu2gdb19JzmLSGzPhptvO846Ick13R0oTl58IwEn9Oipv/GhF9Np9hw63jsKDkQlT4dpJYLiPQ 3KZ01uvW3ys592KHNx+H/xFfQw/zHmxKjSRmJL0sZrzTcbmwZJDE7aGagChRGvl6uO9r0hehlSsVR mhF6EdYw==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kb56Z-0002Pa-5l; Fri, 06 Nov 2020 10:00:52 -0700 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.92) (envelope-from ) id 1kb56U-0004sz-Hw; Fri, 06 Nov 2020 10:00:46 -0700 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org Cc: Stephen Bates , Christoph Hellwig , Dan Williams , Jason Gunthorpe , =?utf-8?q?Christian_K=C3=B6nig?= , Ira Weiny , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Logan Gunthorpe Date: Fri, 6 Nov 2020 10:00:25 -0700 Message-Id: <20201106170036.18713-5-logang@deltatee.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201106170036.18713-1-logang@deltatee.com> References: <20201106170036.18713-1-logang@deltatee.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, sbates@raithlin.com, hch@lst.de, jgg@ziepe.ca, christian.koenig@amd.com, dan.j.williams@intel.com, iweiny@intel.com, jhubbard@nvidia.com, ddutile@redhat.com, willy@infradead.org, daniel.vetter@ffwll.ch, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [RFC PATCH 04/15] lib/scatterlist: Add flag for indicating P2PDMA segments in an SGL X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org We make use of the top bit of the dma_length to indicate a P2PDMA segment. Code that uses this will need to use sg_dma_p2pdma_len() to get the length and ensure no lengths exceed 2GB. An sg_dma_is_p2pdma() helper is included to check if a particular segment is p2pdma(). Signed-off-by: Logan Gunthorpe --- include/linux/scatterlist.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 36c47e7e66a2..e738159d56f9 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -39,6 +39,10 @@ struct scatterlist { #define sg_dma_len(sg) ((sg)->length) #endif +#define SG_P2PDMA_FLAG (1U << 31) +#define sg_dma_p2pdma_len(sg) (sg_dma_len(sg) & ~SG_P2PDMA_FLAG) +#define sg_dma_is_p2pdma(sg) (sg_dma_len(sg) & SG_P2PDMA_FLAG) + struct sg_table { struct scatterlist *sgl; /* the list */ unsigned int nents; /* number of mapped entries */