From patchwork Mon Oct 24 01:02:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Gilbert X-Patchwork-Id: 13016477 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 4C22EC3A59D for ; Mon, 24 Oct 2022 01:12:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229915AbiJXBMC (ORCPT ); Sun, 23 Oct 2022 21:12:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229875AbiJXBMA (ORCPT ); Sun, 23 Oct 2022 21:12:00 -0400 Received: from smtp.infotech.no (smtp.infotech.no [82.134.31.41]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id F38AE63D0B for ; Sun, 23 Oct 2022 18:11:57 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by smtp.infotech.no (Postfix) with ESMTP id 0C7112041BD; Mon, 24 Oct 2022 03:02:55 +0200 (CEST) X-Virus-Scanned: by amavisd-new-2.6.6 (20110518) (Debian) at infotech.no Received: from smtp.infotech.no ([127.0.0.1]) by localhost (smtp.infotech.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id SqhNeNPHYkpc; Mon, 24 Oct 2022 03:02:53 +0200 (CEST) Received: from treten.bingwo.ca (host-45-78-203-98.dyn.295.ca [45.78.203.98]) by smtp.infotech.no (Postfix) with ESMTPA id 3EE492041AF; Mon, 24 Oct 2022 03:02:51 +0200 (CEST) From: Douglas Gilbert To: linux-scsi@vger.kernel.org Cc: martin.petersen@oracle.com, jejb@linux.vnet.ibm.com, hare@suse.de, bvanassche@acm.org, Bodo Stroesser Subject: [PATCH 4/5] scatterlist: add sgl_memset() Date: Sun, 23 Oct 2022 21:02:43 -0400 Message-Id: <20221024010244.9522-5-dgilbert@interlog.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221024010244.9522-1-dgilbert@interlog.com> References: <20221024010244.9522-1-dgilbert@interlog.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org The existing sg_zero_buffer() function is a bit restrictive. For example protection information (PI) blocks are usually initialized to 0xff bytes. As its name suggests sgl_memset() is modelled on memset(). One difference is the type of the val argument which is u8 rather than int. Plus it returns the number of bytes (over)written. Change implementation of sg_zero_buffer() to call this new function. Reviewed-by: Bodo Stroesser Signed-off-by: Douglas Gilbert --- include/linux/scatterlist.h | 20 +++++++++- lib/scatterlist.c | 78 ++++++++++++++++++++----------------- 2 files changed, 61 insertions(+), 37 deletions(-) diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index e1552a3e9e13..dbcf0f6fd8d9 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -442,8 +442,6 @@ 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_zero_buffer(struct scatterlist *sgl, unsigned int nents, - size_t buflen, off_t skip); size_t sgl_copy_sgl(struct scatterlist *d_sgl, unsigned int d_nents, off_t d_skip, struct scatterlist *s_sgl, unsigned int s_nents, off_t s_skip, @@ -457,6 +455,24 @@ bool sgl_equal_sgl_idx(struct scatterlist *x_sgl, unsigned int x_nents, off_t x_ struct scatterlist *y_sgl, unsigned int y_nents, off_t y_skip, size_t n_bytes, size_t *miscompare_idx); +size_t sgl_memset(struct scatterlist *sgl, unsigned int nents, off_t skip, + u8 val, size_t n_bytes); + +/** + * sg_zero_buffer - Zero-out a part of a SG list + * @sgl: The SG list + * @nents: Number of SG entries + * @buflen: The number of bytes to zero out + * @skip: Number of bytes to skip before zeroing + * + * Returns the number of bytes zeroed. + **/ +static inline size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents, + size_t buflen, off_t skip) +{ + return sgl_memset(sgl, nents, skip, 0, buflen); +} + /* * Maximum number of entries that will be allocated in one piece, if * a list larger than this is required then chaining will be utilized. diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 426d73ba464a..2694aeedf6e2 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -1054,41 +1054,6 @@ size_t sg_pcopy_to_buffer(struct scatterlist *sgl, unsigned int nents, } EXPORT_SYMBOL(sg_pcopy_to_buffer); -/** - * sg_zero_buffer - Zero-out a part of a SG list - * @sgl: The SG list - * @nents: Number of SG entries - * @buflen: The number of bytes to zero out - * @skip: Number of bytes to skip before zeroing - * - * Returns the number of bytes zeroed. - **/ -size_t sg_zero_buffer(struct scatterlist *sgl, unsigned int nents, - size_t buflen, off_t skip) -{ - unsigned int offset = 0; - struct sg_mapping_iter miter; - unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG; - - sg_miter_start(&miter, sgl, nents, sg_flags); - - if (!sg_miter_skip(&miter, skip)) - return false; - - while (offset < buflen && sg_miter_next(&miter)) { - unsigned int len; - - len = min(miter.length, buflen - offset); - memset(miter.addr, 0, len); - - offset += len; - } - - sg_miter_stop(&miter); - return offset; -} -EXPORT_SYMBOL(sg_zero_buffer); - /** * sgl_copy_sgl - Copy over a destination sgl from a source sgl * @d_sgl: Destination sgl @@ -1272,3 +1237,46 @@ bool sgl_equal_sgl(struct scatterlist *x_sgl, unsigned int x_nents, off_t x_skip return sgl_equal_sgl_idx(x_sgl, x_nents, x_skip, y_sgl, y_nents, y_skip, n_bytes, NULL); } EXPORT_SYMBOL(sgl_equal_sgl); + +/** + * sgl_memset - set byte 'val' up to n_bytes times on SG list + * @sgl: The SG list + * @nents: Number of SG entries in sgl + * @skip: Number of bytes to skip before starting + * @val: byte value to write to sgl + * @n_bytes: The (maximum) number of bytes to modify + * + * Returns: + * The number of bytes written. + * + * Notes: + * Stops writing if either sgl or n_bytes is exhausted. If n_bytes is + * set SIZE_MAX then val will be written to each byte until the end + * of sgl. + * + * The notes in sgl_copy_sgl() about large sgl_s _applies here as well. + * + **/ +size_t sgl_memset(struct scatterlist *sgl, unsigned int nents, off_t skip, + u8 val, size_t n_bytes) +{ + size_t offset = 0; + size_t len; + struct sg_mapping_iter miter; + + if (n_bytes == 0) + return 0; + sg_miter_start(&miter, sgl, nents, SG_MITER_ATOMIC | SG_MITER_TO_SG); + if (!sg_miter_skip(&miter, skip)) + goto fini; + + while ((offset < n_bytes) && sg_miter_next(&miter)) { + len = min(miter.length, n_bytes - offset); + memset(miter.addr, val, len); + offset += len; + } +fini: + sg_miter_stop(&miter); + return offset; +} +EXPORT_SYMBOL(sgl_memset);