From patchwork Thu Feb 15 17:52:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Charles Keepax X-Patchwork-Id: 10222897 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C8A4A601D7 for ; Thu, 15 Feb 2018 17:53:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B649629143 for ; Thu, 15 Feb 2018 17:53:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AA278294BA; Thu, 15 Feb 2018 17:53:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 426F129143 for ; Thu, 15 Feb 2018 17:53:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1164213AbeBORxh (ORCPT ); Thu, 15 Feb 2018 12:53:37 -0500 Received: from mx0b-001ae601.pphosted.com ([67.231.152.168]:60706 "EHLO mx0b-001ae601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1165816AbeBORwy (ORCPT ); Thu, 15 Feb 2018 12:52:54 -0500 Received: from pps.filterd (m0077474.ppops.net [127.0.0.1]) by mx0b-001ae601.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1FHn8CV015384; Thu, 15 Feb 2018 11:52:30 -0600 Authentication-Results: ppops.net; spf=none smtp.mailfrom=ckeepax@opensource.cirrus.com Received: from mail1.cirrus.com (mail1.cirrus.com [141.131.3.20]) by mx0b-001ae601.pphosted.com with ESMTP id 2g1x1u68t4-1; Thu, 15 Feb 2018 11:52:30 -0600 Received: from EX17.ad.cirrus.com (unknown [172.20.9.81]) by mail1.cirrus.com (Postfix) with ESMTP id 8C91660D9746; Thu, 15 Feb 2018 11:52:29 -0600 (CST) Received: from imbe.wolfsonmicro.main (198.61.95.81) by EX17.ad.cirrus.com (172.20.9.81) with Microsoft SMTP Server id 14.3.301.0; Thu, 15 Feb 2018 17:52:29 +0000 Received: from algalon.ad.cirrus.com (algalon.ad.cirrus.com [198.90.251.122]) by imbe.wolfsonmicro.main (8.14.4/8.14.4) with ESMTP id w1FHqKQ4011950; Thu, 15 Feb 2018 17:52:20 GMT From: Charles Keepax To: CC: , , , , , , Subject: [PATCH 3/5] regmap: Use _regmap_read in regmap_bulk_read Date: Thu, 15 Feb 2018 17:52:18 +0000 Message-ID: <20180215175220.2691-3-ckeepax@opensource.cirrus.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20180215175220.2691-1-ckeepax@opensource.cirrus.com> References: <20180215175220.2691-1-ckeepax@opensource.cirrus.com> MIME-Version: 1.0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=870 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802150215 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Bulk reads may potentially read a lot of registers and regmap_read will take and release the regmap lock for each register. Avoid bouncing the lock so frequently by holding the lock locally and calling _regmap_read instead. This also has the nice side-effect that all the reads will be done atomically so no other threads can sneak a write in during the regmap_bulk_read. Signed-off-by: Charles Keepax --- drivers/base/regmap/regmap.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 93d4218c5569..872be065e3fe 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -2674,6 +2674,8 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val, if (!IS_ALIGNED(reg, map->reg_stride)) return -EINVAL; + if (val_count == 0) + return -EINVAL; if (map->bus && map->format.parse_inplace && (vol || map->cache_type == REGCACHE_NONE)) { ret = regmap_raw_read(map, reg, val, val_bytes * val_count); @@ -2690,13 +2692,15 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val, u16 *u16 = val; u8 *u8 = val; + map->lock(map->lock_arg); + for (i = 0; i < val_count; i++) { unsigned int ival; - ret = regmap_read(map, reg + regmap_get_offset(map, i), - &ival); + ret = _regmap_read(map, reg + regmap_get_offset(map, i), + &ival); if (ret != 0) - return ret; + goto out; switch (map->format.val_bytes) { #ifdef CONFIG_64BIT @@ -2714,12 +2718,16 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val, u8[i] = ival; break; default: - return -EINVAL; + ret = -EINVAL; + goto out; } } + +out: + map->unlock(map->lock_arg); } - return 0; + return ret; } EXPORT_SYMBOL_GPL(regmap_bulk_read);