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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE64BFA373D for ; Thu, 27 Oct 2022 07:11:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234370AbiJ0HLV (ORCPT ); Thu, 27 Oct 2022 03:11:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233506AbiJ0HLT (ORCPT ); Thu, 27 Oct 2022 03:11:19 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF0F1719B7; Thu, 27 Oct 2022 00:11:16 -0700 (PDT) Received: from kwepemi500015.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4MycCv6s1gz15MC0; Thu, 27 Oct 2022 15:06:19 +0800 (CST) Received: from [10.40.188.234] (10.40.188.234) by kwepemi500015.china.huawei.com (7.221.188.92) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Thu, 27 Oct 2022 15:11:13 +0800 Subject: Re: [PATCH v11 3/9] iov_iter: introduce iov_iter_get_pages_[alloc_]flags() To: Logan Gunthorpe , , , , , CC: Christoph Hellwig , Greg Kroah-Hartman , Dan Williams , Jason Gunthorpe , =?UTF-8?Q?Christian_K=c3=b6nig?= , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Martin Oliveira , Chaitanya Kulkarni , Ralph Campbell , Stephen Bates References: <20221021174116.7200-1-logang@deltatee.com> <20221021174116.7200-4-logang@deltatee.com> From: Jay Fang Message-ID: Date: Thu, 27 Oct 2022 15:11:12 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: <20221021174116.7200-4-logang@deltatee.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.40.188.234] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemi500015.china.huawei.com (7.221.188.92) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 2022/10/22 1:41, Logan Gunthorpe wrote: > Add iov_iter_get_pages_flags() and iov_iter_get_pages_alloc_flags() > which take a flags argument that is passed to get_user_pages_fast(). > > This is so that FOLL_PCI_P2PDMA can be passed when appropriate. > > Signed-off-by: Logan Gunthorpe > Reviewed-by: Christoph Hellwig > --- > include/linux/uio.h | 6 ++++++ > lib/iov_iter.c | 32 ++++++++++++++++++++++++-------- > 2 files changed, 30 insertions(+), 8 deletions(-) > > diff --git a/include/linux/uio.h b/include/linux/uio.h > index 2e3134b14ffd..9ede533ce64c 100644 > --- a/include/linux/uio.h > +++ b/include/linux/uio.h > @@ -247,8 +247,14 @@ void iov_iter_pipe(struct iov_iter *i, unsigned int direction, struct pipe_inode > void iov_iter_discard(struct iov_iter *i, unsigned int direction, size_t count); > void iov_iter_xarray(struct iov_iter *i, unsigned int direction, struct xarray *xarray, > loff_t start, size_t count); > +ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, > + size_t maxsize, unsigned maxpages, size_t *start, > + unsigned gup_flags); > ssize_t iov_iter_get_pages2(struct iov_iter *i, struct page **pages, > size_t maxsize, unsigned maxpages, size_t *start); > +ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, > + struct page ***pages, size_t maxsize, size_t *start, > + unsigned gup_flags); > ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, struct page ***pages, > size_t maxsize, size_t *start); > int iov_iter_npages(const struct iov_iter *i, int maxpages); > diff --git a/lib/iov_iter.c b/lib/iov_iter.c > index c3ca28ca68a6..53efad017f3c 100644 > --- a/lib/iov_iter.c > +++ b/lib/iov_iter.c > @@ -1430,7 +1430,8 @@ static struct page *first_bvec_segment(const struct iov_iter *i, > > static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, > struct page ***pages, size_t maxsize, > - unsigned int maxpages, size_t *start) > + unsigned int maxpages, size_t *start, > + unsigned int gup_flags) Hi, found some checkpatch warnings, like this: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' #50: FILE: lib/iov_iter.c:1497: + size_t *start, unsigned gup_flags) > { > unsigned int n; > > @@ -1442,7 +1443,6 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, > maxsize = MAX_RW_COUNT; > > if (likely(user_backed_iter(i))) { > - unsigned int gup_flags = 0; > unsigned long addr; > int res; > > @@ -1492,33 +1492,49 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, > return -EFAULT; > } > > -ssize_t iov_iter_get_pages2(struct iov_iter *i, > +ssize_t iov_iter_get_pages(struct iov_iter *i, > struct page **pages, size_t maxsize, unsigned maxpages, > - size_t *start) > + size_t *start, unsigned gup_flags) > { > if (!maxpages) > return 0; > BUG_ON(!pages); > > - return __iov_iter_get_pages_alloc(i, &pages, maxsize, maxpages, start); > + return __iov_iter_get_pages_alloc(i, &pages, maxsize, maxpages, > + start, gup_flags); > +} > +EXPORT_SYMBOL_GPL(iov_iter_get_pages); > + > +ssize_t iov_iter_get_pages2(struct iov_iter *i, struct page **pages, > + size_t maxsize, unsigned maxpages, size_t *start) > +{ > + return iov_iter_get_pages(i, pages, maxsize, maxpages, start, 0); > } > EXPORT_SYMBOL(iov_iter_get_pages2); > > -ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, > +ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, > struct page ***pages, size_t maxsize, > - size_t *start) > + size_t *start, unsigned gup_flags) > { > ssize_t len; > > *pages = NULL; > > - len = __iov_iter_get_pages_alloc(i, pages, maxsize, ~0U, start); > + len = __iov_iter_get_pages_alloc(i, pages, maxsize, ~0U, start, > + gup_flags); > if (len <= 0) { > kvfree(*pages); > *pages = NULL; > } > return len; > } > +EXPORT_SYMBOL_GPL(iov_iter_get_pages_alloc); > + > +ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, > + struct page ***pages, size_t maxsize, size_t *start) > +{ > + return iov_iter_get_pages_alloc(i, pages, maxsize, start, 0); > +} > EXPORT_SYMBOL(iov_iter_get_pages_alloc2); > > size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, >