From patchwork Tue Nov 12 20:31:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dmitry Torokhov X-Patchwork-Id: 1193847 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="bswZwNR7"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 47CKCs0VLHz9sR4 for ; Wed, 13 Nov 2019 07:31:53 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727312AbfKLUbm (ORCPT ); Tue, 12 Nov 2019 15:31:42 -0500 Received: from mail-pg1-f194.google.com ([209.85.215.194]:45264 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727302AbfKLUbl (ORCPT ); Tue, 12 Nov 2019 15:31:41 -0500 Received: by mail-pg1-f194.google.com with SMTP id w11so12576686pga.12; Tue, 12 Nov 2019 12:31:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=Rv3NgB/HI4HOG6PeUsJv3rPgClgEcZt4wiNXEd63Cgw=; b=bswZwNR7sRmVA3WWoPIHeJJIu1Z4xq/oDcvC/1osBDKlvgVxOyEcZ8YgDtjf8xjusN 6Err1SFQbWaWqlRrtkdnR25r/Iec126QRoW8Rm2s079btBpfNpwAZsZTocwFMxuy18im inyMBaaV1xDfsh8kxoLqZ9JLhOYlEhTo7A9L2A33Ug7+XtbxvM43I1KUtwJvSNWzarwu 5GkQs4ytCb5OMAwZ/CVOSiJuYa3KBHJ73eR6CTsbn1TbTBjv6gSohPmXXBf6kWyrmA6s 9Svhldh1nRgCO+DaNicBNCrP78wU3/F2d3BSNSbN9MEL/69q3ZLUHL/D5G5jYTniqmt9 0VGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Rv3NgB/HI4HOG6PeUsJv3rPgClgEcZt4wiNXEd63Cgw=; b=m+DcntiTIEFUdNA/i3wLZH8B1poJPuWn1PRcI7ewLha5vNJkDTAgoNrp30NwuZeBds kcJqwRb7+YzCikWGoBym93wiZWdNro0GHfeRUOM8bAFHWhnGf01wzPQyjsI383UEfBvl mvgo9VxIK8PwXQpjcfn36tqkkIilAUUVfKmNKh8qoRwG6qo5bUmQAQGdg/vzXQS3I+Po pEpQl84ONOnuyh8ndZhX/VPq2E7bvcOTH4yz+iNtXwWJ0/hni+f4zIEAIqkvdfy0u/OI QADc4mNie3tb0OXn8yMnIRU3JsHPCPDkUYuJVL8RqC1nfOYZwIEYaTt+Vn0FsTyei6RG mWew== X-Gm-Message-State: APjAAAWhJJ8M7DKj0UA0DVLkw8oDl6iZ3zjqndBn/MoahkSOO8T1t/5Q gfMEyakKXSQcSUsdnjBqqCs= X-Google-Smtp-Source: APXvYqw+QqaH2zk3DQvOgVXtpKLNg/CK4RYGmbqYsj2kGca1XXvsMOc5klvGa+NuoxuMYiI46Z7Okg== X-Received: by 2002:a62:aa0d:: with SMTP id e13mr39529400pff.214.1573590700755; Tue, 12 Nov 2019 12:31:40 -0800 (PST) Received: from dtor-ws.mtv.corp.google.com ([2620:15c:202:201:3adc:b08c:7acc:b325]) by smtp.gmail.com with ESMTPSA id h13sm23264084pfr.98.2019.11.12.12.31.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Nov 2019 12:31:40 -0800 (PST) From: Dmitry Torokhov To: Wolfram Sang Cc: linux-iio@vger.kernel.orgi, Luca Ceresoli , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 3/3] i2c: smbus: switch from loops to memcpy Date: Tue, 12 Nov 2019 12:31:32 -0800 Message-Id: <20191112203132.163306-4-dmitry.torokhov@gmail.com> X-Mailer: git-send-email 2.24.0.rc1.363.gb1bccd3e3d-goog In-Reply-To: <20191112203132.163306-1-dmitry.torokhov@gmail.com> References: <20191112203132.163306-1-dmitry.torokhov@gmail.com> MIME-Version: 1.0 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org When copying memory from one buffer to another, instead of open-coding loops with byte-by-byte copies let's use memcpy() which might be a bit faster and makes intent more clear. Signed-off-by: Dmitry Torokhov Reviewed-by: Luca Ceresoli Acked-by: Uwe Kleine-König --- Changes in v3: - new patch using memcpy() for moving data around drivers/i2c/i2c-core-smbus.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c index 7b4e2270eeda1..bbafdd3b1b114 100644 --- a/drivers/i2c/i2c-core-smbus.c +++ b/drivers/i2c/i2c-core-smbus.c @@ -397,8 +397,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, } i2c_smbus_try_get_dmabuf(&msg[0], command); - for (i = 1; i < msg[0].len; i++) - msg[0].buf[i] = data->block[i - 1]; + memcpy(msg[0].buf + 1, data->block, msg[0].len - 1); } break; case I2C_SMBUS_BLOCK_PROC_CALL: @@ -413,8 +412,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, msg[0].len = data->block[0] + 2; i2c_smbus_try_get_dmabuf(&msg[0], command); - for (i = 1; i < msg[0].len; i++) - msg[0].buf[i] = data->block[i - 1]; + memcpy(msg[0].buf + 1, data->block, msg[0].len - 1); msg[1].flags |= I2C_M_RECV_LEN; msg[1].len = 1; /* block length will be added by @@ -436,8 +434,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, msg[0].len = data->block[0] + 1; i2c_smbus_try_get_dmabuf(&msg[0], command); - for (i = 1; i <= data->block[0]; i++) - msg[0].buf[i] = data->block[i]; + memcpy(msg[0].buf + 1, data->block + 1, data->block[0]); } break; default: @@ -489,13 +486,11 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, data->word = get_unaligned_le16(msgbuf1); break; case I2C_SMBUS_I2C_BLOCK_DATA: - for (i = 0; i < data->block[0]; i++) - data->block[i + 1] = msg[1].buf[i]; + memcpy(data->block + 1, msg[1].buf, data->block[0]); break; case I2C_SMBUS_BLOCK_DATA: case I2C_SMBUS_BLOCK_PROC_CALL: - for (i = 0; i < msg[1].buf[0] + 1; i++) - data->block[i] = msg[1].buf[i]; + memcpy(data->block, msg[1].buf, msg[1].buf[0] + 1); break; }