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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 5E8D4C433E0 for ; Sat, 8 Aug 2020 06:34:06 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 47AE620855 for ; Sat, 8 Aug 2020 06:34:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 47AE620855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id EE7F1875F3; Sat, 8 Aug 2020 06:34:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 00vAFPRYiNuV; Sat, 8 Aug 2020 06:34:03 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id DC2B2873DD; Sat, 8 Aug 2020 06:34:03 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id C7BFBC07FF; Sat, 8 Aug 2020 06:34:03 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 87A87C013C for ; Sat, 8 Aug 2020 06:34:02 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 6916088CC4 for ; Sat, 8 Aug 2020 06:34:02 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id g9qrEwcPeRxp for ; Sat, 8 Aug 2020 06:34:00 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by whitealder.osuosl.org (Postfix) with ESMTPS id 9BD1688A47 for ; Sat, 8 Aug 2020 06:34:00 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 3C5AB68C7B; Sat, 8 Aug 2020 08:33:55 +0200 (CEST) Date: Sat, 8 Aug 2020 08:33:54 +0200 From: Christoph Hellwig To: Nicolas Saenz Julienne Subject: Re: [PATCH v3 2/2] dma-pool: Only allocate from CMA when in same memory zone Message-ID: <20200808063354.GA17329@lst.de> References: <20200806184756.32075-1-nsaenzjulienne@suse.de> <20200806184756.32075-3-nsaenzjulienne@suse.de> <20200807052116.GA584@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Cc: amit.pundir@linaro.org, linux-kernel@vger.kernel.org, jeremy.linton@arm.com, iommu@lists.linux-foundation.org, linux-rpi-kernel@lists.infradead.org, rientjes@google.com, Robin Murphy , Christoph Hellwig X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Fri, Aug 07, 2020 at 10:50:19AM +0200, Nicolas Saenz Julienne wrote: > On Fri, 2020-08-07 at 07:21 +0200, Christoph Hellwig wrote: > > On Thu, Aug 06, 2020 at 08:47:55PM +0200, Nicolas Saenz Julienne wrote: > > > There is no guarantee to CMA's placement, so allocating a zone specific > > > atomic pool from CMA might return memory from a completely different > > > memory zone. To get around this double check CMA's placement before > > > allocating from it. > > > > As the builtbot pointed out, memblock_start_of_DRAM can't be used from > > non-__init code. But lookig at it I think throwing that in > > is bogus anyway, as cma_get_base returns a proper physical address > > already. > > It does indeed, but I'm comparing CMA's base with bitmasks that don't take into > account where the memory starts. Say memory starts at 0x80000000, and CMA falls > into ZONE_DMA [0x80000000 0xC0000000], if you want to compare it with > DMA_BIT_MASK(zone_dma_bits) you're forced to unify the memory bases. > > That said, I now realize that this doesn't work for ZONE_DMA32 which has a hard > limit on 32bit addresses reglardless of the memory base. > > That said I still need to call memblock_start_of_DRAM() any suggestions WRT > that? I could save the value in dma_atomic_pool_init(), which is __init code. The pool must be about a 32-bit physical address. The offsets can be different for every device.. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu