From patchwork Tue Apr 6 04:59:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gao Xiang X-Patchwork-Id: 12184155 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 06547C433B4 for ; Tue, 6 Apr 2021 04:59:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDBC561369 for ; Tue, 6 Apr 2021 04:59:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230508AbhDFE7m (ORCPT ); Tue, 6 Apr 2021 00:59:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:56816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229704AbhDFE7m (ORCPT ); Tue, 6 Apr 2021 00:59:42 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6714361222; Tue, 6 Apr 2021 04:59:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617685174; bh=tIomgEeIuH8P7ze0EpjBfN/KC3eWyiZsxls9MV18GGA=; h=From:To:Cc:Subject:Date:From; b=QzWorqWMOHmMsSEBLrfFvgLArOfX2Ekm1OfbI7eT+hQDLXp+/NUlfq9OOrqg5arG7 CsqsYBpT5RT0YER+DPmVgJOtjhFlOcGrAAQxrJhEoGHutyjzkTyOXNQEWV+hqM6xvP 1MlTLEb/SM3VcUSvY5NmPb1ZNbRZBvutSi1eJZzWSzYORgyXInl0B2F9/CJq0ZrhhO Oewu+cSikyq4TH1ccc9oSRnlrMDh7yA+DC5gKkUY7j28zojOL7UivehwjX+hI6ielV VQ/p977dqnGomY7HvP2LlWMEhvNllTQfD9UKZFLyrwE7T1uWM2MpKV8bcpq40RA3q3 mL4Piw5bH9A6A== From: Gao Xiang To: linux-parisc@vger.kernel.org, Helge Deller Cc: Liam Beguin , linux-kernel@vger.kernel.org, Gao Xiang Subject: [PATCH] parisc: avoid a warning on u8 cast for cmpxchg on u8 pointers Date: Tue, 6 Apr 2021 12:59:29 +0800 Message-Id: <20210406045929.30331-1-xiang@kernel.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org From: Gao Xiang commit b344d6a83d01 ("parisc: add support for cmpxchg on u8 pointers") can generate a sparse warningi ("cast truncates bits from constant value"), which has been reported several times [1] [2] [3]. The original code worked as expected, but anyway, let silence such sparse warning as what others did [4]. [1] https://lore.kernel.org/r/202104061220.nRMBwCXw-lkp@intel.com [2] https://lore.kernel.org/r/202012291914.T5Agcn99-lkp@intel.com [3] https://lore.kernel.org/r/202008210829.KVwn7Xeh%25lkp@intel.com [4] https://lore.kernel.org/r/20210315131512.133720-2-jacopo+renesas@jmondi.org Cc: Liam Beguin Cc: Helge Deller Signed-off-by: Gao Xiang --- arch/parisc/include/asm/cmpxchg.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/parisc/include/asm/cmpxchg.h b/arch/parisc/include/asm/cmpxchg.h index cf5ee9b0b393..84ee232278a6 100644 --- a/arch/parisc/include/asm/cmpxchg.h +++ b/arch/parisc/include/asm/cmpxchg.h @@ -72,7 +72,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) #endif case 4: return __cmpxchg_u32((unsigned int *)ptr, (unsigned int)old, (unsigned int)new_); - case 1: return __cmpxchg_u8((u8 *)ptr, (u8)old, (u8)new_); + case 1: return __cmpxchg_u8((u8 *)ptr, old & 0xff, new_ & 0xff); } __cmpxchg_called_with_bad_pointer(); return old;