From patchwork Mon Feb 1 10:04:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris Pismenny X-Patchwork-Id: 374534 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, 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 B93F5C433DB for ; Mon, 1 Feb 2021 10:10:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 832C360295 for ; Mon, 1 Feb 2021 10:10:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233035AbhBAKGJ (ORCPT ); Mon, 1 Feb 2021 05:06:09 -0500 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:59720 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S232894AbhBAKGI (ORCPT ); Mon, 1 Feb 2021 05:06:08 -0500 Received: from Internal Mail-Server by MTLPINE1 (envelope-from borisp@mellanox.com) with SMTP; 1 Feb 2021 12:05:13 +0200 Received: from gen-l-vrt-133.mtl.labs.mlnx. (gen-l-vrt-133.mtl.labs.mlnx [10.237.11.160]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id 111A5Cxs029353; Mon, 1 Feb 2021 12:05:12 +0200 From: Boris Pismenny To: dsahern@gmail.com, kuba@kernel.org, davem@davemloft.net, saeedm@nvidia.com, hch@lst.de, sagi@grimberg.me, axboe@fb.com, kbusch@kernel.org, viro@zeniv.linux.org.uk, edumazet@google.com, smalin@marvell.com Cc: boris.pismenny@gmail.com, linux-nvme@lists.infradead.org, netdev@vger.kernel.org, benishay@nvidia.com, ogerlitz@nvidia.com, yorayz@nvidia.com, Ben Ben-Ishay , Or Gerlitz , Yoray Zack Subject: [PATCH v3 net-next 01/21] iov_iter: Introduce new procedures for copy to iter/pages Date: Mon, 1 Feb 2021 12:04:49 +0200 Message-Id: <20210201100509.27351-2-borisp@mellanox.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20210201100509.27351-1-borisp@mellanox.com> References: <20210201100509.27351-1-borisp@mellanox.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When using direct data placement the NIC writes some of the payload directly to the destination buffer, and constructs the SKB such that it points to this data. As a result, the skb_copy datagram_iter call will attempt to copy data when it is not necessary. Introduce new procedures for copy to iter/pages in case that the source of the copy operation might be identical to the destination, in such cases the copy is skipped only for bio_vec, later commits uses those functions to introduce new skb copy(+hash) functions. Signed-off-by: Boris Pismenny Signed-off-by: Ben Ben-Ishay Signed-off-by: Or Gerlitz Signed-off-by: Yoray Zack --- include/linux/uio.h | 12 ++++++++++++ lib/iov_iter.c | 47 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+) diff --git a/include/linux/uio.h b/include/linux/uio.h index 72d88566694e..3c42125a7f24 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -123,6 +123,7 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i); size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i); +size_t _ddp_copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i); size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i); bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i); size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i); @@ -137,6 +138,15 @@ size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) return _copy_to_iter(addr, bytes, i); } +static __always_inline __must_check +size_t ddp_copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) +{ + if (unlikely(!check_copy_size(addr, bytes, true))) + return 0; + else + return _ddp_copy_to_iter(addr, bytes, i); +} + static __always_inline __must_check size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) { @@ -265,6 +275,8 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct io bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i); size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, struct iov_iter *i); +size_t ddp_hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, + struct iov_iter *i); struct iovec *iovec_from_user(const struct iovec __user *uvector, unsigned long nr_segs, unsigned long fast_segs, diff --git a/lib/iov_iter.c b/lib/iov_iter.c index a21e6a5792c5..b8af1d3bbec0 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -473,6 +473,16 @@ static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t kunmap_atomic(from); } +static void ddp_memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) +{ + char *to = kmap_atomic(page); + + if (to + offset != from) + memcpy(to + offset, from, len); + + kunmap_atomic(to); +} + static void memcpy_to_page(struct page *page, size_t offset, const char *from, size_t len) { char *to = kmap_atomic(page); @@ -625,6 +635,24 @@ static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes, return bytes; } +size_t _ddp_copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) +{ + const char *from = addr; + if (unlikely(iov_iter_is_pipe(i))) + return copy_pipe_to_iter(addr, bytes, i); + if (iter_is_iovec(i)) + might_fault(); + iterate_and_advance(i, bytes, v, + copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len), + ddp_memcpy_to_page(v.bv_page, v.bv_offset, + (from += v.bv_len) - v.bv_len, v.bv_len), + memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len) + ) + + return bytes; +} +EXPORT_SYMBOL(_ddp_copy_to_iter); + size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i) { const char *from = addr; @@ -1566,6 +1594,25 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, } EXPORT_SYMBOL(csum_and_copy_to_iter); +size_t ddp_hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, + struct iov_iter *i) +{ +#ifdef CONFIG_CRYPTO_HASH + struct ahash_request *hash = hashp; + struct scatterlist sg; + size_t copied; + + copied = ddp_copy_to_iter(addr, bytes, i); + sg_init_one(&sg, addr, copied); + ahash_request_set_crypt(hash, &sg, NULL, copied); + crypto_ahash_update(hash); + return copied; +#else + return 0; +#endif +} +EXPORT_SYMBOL(ddp_hash_and_copy_to_iter); + size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, struct iov_iter *i) {