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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 924A0C43382 for ; Thu, 27 Sep 2018 14:12:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 418EC216F4 for ; Thu, 27 Sep 2018 14:12:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 418EC216F4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com 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 S1727588AbeI0Ua4 (ORCPT ); Thu, 27 Sep 2018 16:30:56 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:35290 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727262AbeI0Ua4 (ORCPT ); Thu, 27 Sep 2018 16:30:56 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 904BF7A9; Thu, 27 Sep 2018 07:12:28 -0700 (PDT) Received: from [10.4.12.131] (e110467-lin.Emea.Arm.com [10.4.12.131]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 38BD03F5BD; Thu, 27 Sep 2018 07:12:27 -0700 (PDT) Subject: Re: [PATCH 2/5] dma-direct: add an explicit dma_direct_get_required_mask To: Christoph Hellwig , iommu@lists.linux-foundation.org Cc: Marek Szyprowski , Benjamin Herrenschmidt , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org References: <20180920185247.20037-1-hch@lst.de> <20180920185247.20037-3-hch@lst.de> From: Robin Murphy Message-ID: <02ce2ecc-281d-7b7f-6d30-8d246acd1eaa@arm.com> Date: Thu, 27 Sep 2018 15:12:25 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180920185247.20037-3-hch@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20/09/18 19:52, Christoph Hellwig wrote: > This is somewhat modelled after the powerpc version, and differs from > the legacy fallback in use fls64 instead of pointlessly splitting up the > address into low and high dwords and in that it takes (__)phys_to_dma > into account. > > Signed-off-by: Christoph Hellwig > --- > include/linux/dma-direct.h | 1 + > kernel/dma/direct.c | 21 ++++++++++++++++++--- > 2 files changed, 19 insertions(+), 3 deletions(-) > > diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h > index 86a59ba5a7f3..b79496d8c75b 100644 > --- a/include/linux/dma-direct.h > +++ b/include/linux/dma-direct.h > @@ -55,6 +55,7 @@ static inline void dma_mark_clean(void *addr, size_t size) > } > #endif /* CONFIG_ARCH_HAS_DMA_MARK_CLEAN */ > > +u64 dma_direct_get_required_mask(struct device *dev); > void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, > gfp_t gfp, unsigned long attrs); > void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, > diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c > index c954f0a6dc62..81b73a5bba54 100644 > --- a/kernel/dma/direct.c > +++ b/kernel/dma/direct.c > @@ -53,11 +53,25 @@ check_addr(struct device *dev, dma_addr_t dma_addr, size_t size, > return true; > } > > +static inline dma_addr_t phys_to_dma_direct(struct device *dev, > + phys_addr_t phys) > +{ > + if (force_dma_unencrypted()) > + return __phys_to_dma(dev, phys); > + return phys_to_dma(dev, phys); > +} > + > +u64 dma_direct_get_required_mask(struct device *dev) > +{ > + u64 max_dma = phys_to_dma_direct(dev, (max_pfn - 1) << PAGE_SHIFT); > + > + return (1ULL << (fls64(max_dma) - 1)) * 2 - 1; I think that may as well just use __fls64() - it seems reasonable to assume max_dma > 0. Otherwise, Reviewed-by: Robin Murphy > +} > + > static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) > { > - dma_addr_t addr = force_dma_unencrypted() ? > - __phys_to_dma(dev, phys) : phys_to_dma(dev, phys); > - return addr + size - 1 <= dev->coherent_dma_mask; > + return phys_to_dma_direct(dev, phys) + size - 1 <= > + dev->coherent_dma_mask; > } > > void *dma_direct_alloc_pages(struct device *dev, size_t size, > @@ -296,6 +310,7 @@ const struct dma_map_ops dma_direct_ops = { > .unmap_page = dma_direct_unmap_page, > .unmap_sg = dma_direct_unmap_sg, > #endif > + .get_required_mask = dma_direct_get_required_mask, > .dma_supported = dma_direct_supported, > .mapping_error = dma_direct_mapping_error, > .cache_sync = arch_dma_cache_sync, >