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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 7DF1FC433FF for ; Wed, 7 Aug 2019 14:07:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5D41121E6C for ; Wed, 7 Aug 2019 14:07:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388084AbfHGOHm (ORCPT ); Wed, 7 Aug 2019 10:07:42 -0400 Received: from foss.arm.com ([217.140.110.172]:49116 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726773AbfHGOHl (ORCPT ); Wed, 7 Aug 2019 10:07:41 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 731E428; Wed, 7 Aug 2019 07:07:41 -0700 (PDT) Received: from [10.1.197.57] (e110467-lin.cambridge.arm.com [10.1.197.57]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D259A3F706; Wed, 7 Aug 2019 07:07:40 -0700 (PDT) Subject: Re: [PATCH] firmware: arm_scmi: Use {get,put}_unaligned_le32 accessors To: Sudeep Holla , Philipp Zabel Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20190807130038.26878-1-sudeep.holla@arm.com> <1565184971.5048.8.camel@pengutronix.de> <20190807135757.GA27278@e107155-lin> From: Robin Murphy Message-ID: <4e6de98c-833b-a80b-acef-6e88391e80f2@arm.com> Date: Wed, 7 Aug 2019 15:07:39 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190807135757.GA27278@e107155-lin> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/08/2019 14:57, Sudeep Holla wrote: > On Wed, Aug 07, 2019 at 03:36:11PM +0200, Philipp Zabel wrote: >> Hi Sudeep, >> >> On Wed, 2019-08-07 at 14:00 +0100, Sudeep Holla wrote: >>> Instead of type-casting the {tx,rx}.buf all over the place while >>> accessing them to read/write __le32 from/to the firmware, let's use >>> the nice existing {get,put}_unaligned_le32 accessors to hide all the >>> type cast ugliness. >>> >>> Suggested-by: Philipp Zabel >>> Signed-off-by: Sudeep Holla >>> --- >>> drivers/firmware/arm_scmi/base.c | 2 +- >>> drivers/firmware/arm_scmi/clock.c | 10 ++++------ >>> drivers/firmware/arm_scmi/common.h | 2 ++ >>> drivers/firmware/arm_scmi/perf.c | 8 ++++---- >>> drivers/firmware/arm_scmi/power.c | 6 +++--- >>> drivers/firmware/arm_scmi/reset.c | 2 +- >>> drivers/firmware/arm_scmi/sensors.c | 12 +++++------- >>> 7 files changed, 20 insertions(+), 22 deletions(-) >>> >>> diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c >>> index 204390297f4b..f804e8af6521 100644 >>> --- a/drivers/firmware/arm_scmi/base.c >>> +++ b/drivers/firmware/arm_scmi/base.c >> [...] >>> @@ -204,14 +204,12 @@ scmi_clock_rate_get(const struct scmi_handle *handle, u32 clk_id, u64 *value) >>> if (ret) >>> return ret; >>> >>> - *(__le32 *)t->tx.buf = cpu_to_le32(clk_id); >>> + put_unaligned_le32(clk_id, t->tx.buf); >>> >>> ret = scmi_do_xfer(handle, t); >>> if (!ret) { >>> - __le32 *pval = t->rx.buf; >>> - >>> - *value = le32_to_cpu(*pval); >>> - *value |= (u64)le32_to_cpu(*(pval + 1)) << 32; >>> + *value = get_unaligned_le32(t->rx.buf); >>> + *value |= (u64)get_unaligned_le32(t->rx.buf + 1) << 32; >> >> Isn't t->rx.buf a void pointer? If I am not mistaken, you'd either have >> to keep the pval local variables, or cast to (__le32 *) before doing >> pointer arithmetic. >> > > Ah right, that's the reason I added it at the first place. I will fix that. Couldn't you just use get_unaligned_le64() here anyway? Robin.