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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 46A96C2B9F4 for ; Mon, 28 Jun 2021 13:40:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24EB361883 for ; Mon, 28 Jun 2021 13:40:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230086AbhF1NnE (ORCPT ); Mon, 28 Jun 2021 09:43:04 -0400 Received: from foss.arm.com ([217.140.110.172]:59592 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230154AbhF1NnE (ORCPT ); Mon, 28 Jun 2021 09:43:04 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 982E01042; Mon, 28 Jun 2021 06:40:38 -0700 (PDT) Received: from [10.57.8.89] (unknown [10.57.8.89]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 649B63F718; Mon, 28 Jun 2021 06:40:36 -0700 (PDT) Subject: Re: [PATCH RFC 1/2] scatterlist: add I/O variant of sg_pcopy & sg_copy To: Neil Armstrong , jgg@ziepe.ca, leon@kernel.org, m.szyprowski@samsung.com, ulf.hansson@linaro.org Cc: torvalds@linux-foundation.org, khilman@baylibre.com, jbrunet@baylibre.com, linux-mmc@vger.kernel.org, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20210628123411.119778-1-narmstrong@baylibre.com> <20210628123411.119778-2-narmstrong@baylibre.com> From: Robin Murphy Message-ID: Date: Mon, 28 Jun 2021 14:40:29 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210628123411.119778-2-narmstrong@baylibre.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org On 2021-06-28 13:34, Neil Armstrong wrote: > When copying from/to an iomem mapped memory, the current sg_copy & sg_pcopy can't > be used and lead to local variants in drivers like in [1] & [2]. > > This introduces an I/O variant to be used instead of the local variants. > > [1] mv_cesa_sg_copy in drivers/crypto/marvell/cesa/tdma.c > [2] meson_mmc_copy_buffer in drivers/mmc/host/meson-gx-mmc.c Other than one apparent typo below, this looks like what I imagined, thanks for putting it together! > Cc: Robin Murphy > Signed-off-by: Neil Armstrong > --- > include/linux/scatterlist.h | 14 +++++ > lib/scatterlist.c | 119 ++++++++++++++++++++++++++++++++++++ > 2 files changed, 133 insertions(+) > > diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h > index 6f70572b2938..6ef339ba5290 100644 > --- a/include/linux/scatterlist.h > +++ b/include/linux/scatterlist.h > @@ -308,15 +308,29 @@ void sgl_free(struct scatterlist *sgl); > size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf, > size_t buflen, off_t skip, bool to_buffer); > > +size_t sg_copy_io(struct scatterlist *sgl, unsigned int nents, void __iomem *buf, > + size_t buflen, off_t skip, bool to_buffer); > + > size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents, > const void *buf, size_t buflen); > size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents, > void *buf, size_t buflen); > > +size_t sg_copy_from_io(struct scatterlist *sgl, unsigned int nents, > + const void __iomem *buf, size_t buflen); > +size_t sg_copy_to_io(struct scatterlist *sgl, unsigned int nents, > + void __iomem *buf, size_t buflen); > + > size_t sg_pcopy_from_buffer(struct scatterlist *sgl, unsigned int nents, > const void *buf, size_t buflen, off_t skip); > size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents, > void *buf, size_t buflen, off_t skip); > + > +size_t sg_pcopy_from_io(struct scatterlist *sgl, unsigned int nents, > + const void __iomem *buf, size_t buflen, off_t skip); > +size_t sg_pcopy_to_io(struct scatterlist *sgl, unsigned int nents, > + void __iomem *buf, size_t buflen, off_t skip); > + > size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents, > size_t buflen, off_t skip); > > diff --git a/lib/scatterlist.c b/lib/scatterlist.c > index a59778946404..e52f37b181fa 100644 > --- a/lib/scatterlist.c > +++ b/lib/scatterlist.c > @@ -954,6 +954,55 @@ size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf, > } > EXPORT_SYMBOL(sg_copy_buffer); > > +/** > + * sg_copy_io - Copy data between an I/O mapped buffer and an SG list > + * @sgl: The SG list > + * @nents: Number of SG entries > + * @buf: Where to copy from > + * @buflen: The number of bytes to copy > + * @skip: Number of bytes to skip before copying > + * @to_buffer: transfer direction (true == from an sg list to a > + * buffer, false == from a buffer to an sg list) > + * > + * Returns the number of copied bytes. > + * > + **/ > +size_t sg_copy_io(struct scatterlist *sgl, unsigned int nents, void __iomem *buf, > + size_t buflen, off_t skip, bool to_buffer) > +{ > + unsigned int offset = 0; > + struct sg_mapping_iter miter; > + unsigned int sg_flags = SG_MITER_ATOMIC; > + > + if (to_buffer) > + sg_flags |= SG_MITER_FROM_SG; > + else > + sg_flags |= SG_MITER_TO_SG; > + > + sg_miter_start(&miter, sgl, nents, sg_flags); > + > + if (!sg_miter_skip(&miter, skip)) > + return 0; > + > + while ((offset < buflen) && sg_miter_next(&miter)) { > + unsigned int len; > + > + len = min(miter.length, buflen - offset); > + > + if (to_buffer) > + memcpy_toio(buf + offset, miter.addr, len); > + else > + memcpy_fromio(miter.addr, buf + offset, len); > + > + offset += len; > + } > + > + sg_miter_stop(&miter); > + > + return offset; > +} > +EXPORT_SYMBOL(sg_copy_io); > + > /** > * sg_copy_from_buffer - Copy from a linear buffer to an SG list > * @sgl: The SG list > @@ -988,6 +1037,40 @@ size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents, > } > EXPORT_SYMBOL(sg_copy_to_buffer); > > +/** > + * sg_copy_from_io - Copy from an I/O mapped buffer to an SG list > + * @sgl: The SG list > + * @nents: Number of SG entries > + * @buf: Where to copy from > + * @buflen: The number of bytes to copy > + * > + * Returns the number of copied bytes. > + * > + **/ > +size_t sg_copy_from_io(struct scatterlist *sgl, unsigned int nents, > + const void *buf, size_t buflen) The __iomem annotation wants to be on buf here raher than cast in below, to match the prototype (and everything else). Cheers, Robin. > +{ > + return sg_copy_io(sgl, nents, (void __iomem *)buf, buflen, 0, false); > +} > +EXPORT_SYMBOL(sg_copy_from_io); > + > +/** > + * sg_copy_to_io - Copy from an SG list to an I/O mapped buffer > + * @sgl: The SG list > + * @nents: Number of SG entries > + * @buf: Where to copy to > + * @buflen: The number of bytes to copy > + * > + * Returns the number of copied bytes. > + * > + **/ > +size_t sg_copy_to_io(struct scatterlist *sgl, unsigned int nents, > + void __iomem *buf, size_t buflen) > +{ > + return sg_copy_io(sgl, nents, buf, buflen, 0, true); > +} > +EXPORT_SYMBOL(sg_copy_to_io); > + > /** > * sg_pcopy_from_buffer - Copy from a linear buffer to an SG list > * @sgl: The SG list > @@ -1024,6 +1107,42 @@ size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents, > } > EXPORT_SYMBOL(sg_pcopy_to_buffer); > > +/** > + * sg_pcopy_from_io - Copy from an I/O mapped buffer to an SG list > + * @sgl: The SG list > + * @nents: Number of SG entries > + * @buf: Where to copy from > + * @buflen: The number of bytes to copy > + * @skip: Number of bytes to skip before copying > + * > + * Returns the number of copied bytes. > + * > + **/ > +size_t sg_pcopy_from_io(struct scatterlist *sgl, unsigned int nents, > + const void __iomem *buf, size_t buflen, off_t skip) > +{ > + return sg_copy_io(sgl, nents, (void __iomem *)buf, buflen, skip, false); > +} > +EXPORT_SYMBOL(sg_pcopy_from_io); > + > +/** > + * sg_pcopy_to_io - Copy from an SG list to an I/O mapped buffer > + * @sgl: The SG list > + * @nents: Number of SG entries > + * @buf: Where to copy to > + * @buflen: The number of bytes to copy > + * @skip: Number of bytes to skip before copying > + * > + * Returns the number of copied bytes. > + * > + **/ > +size_t sg_pcopy_to_io(struct scatterlist *sgl, unsigned int nents, > + void __iomem *buf, size_t buflen, off_t skip) > +{ > + return sg_copy_io(sgl, nents, buf, buflen, skip, true); > +} > +EXPORT_SYMBOL(sg_pcopy_to_io); > + > /** > * sg_zero_buffer - Zero-out a part of a SG list > * @sgl: The SG list >