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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EEFB6ECAAD8 for ; Wed, 21 Sep 2022 08:35:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230338AbiIUIfH (ORCPT ); Wed, 21 Sep 2022 04:35:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230453AbiIUIe5 (ORCPT ); Wed, 21 Sep 2022 04:34:57 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C92346216; Wed, 21 Sep 2022 01:34:54 -0700 (PDT) Received: from dggpemm500021.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MXWnH3N6hzMn6D; Wed, 21 Sep 2022 16:30:11 +0800 (CST) Received: from dggpemm500013.china.huawei.com (7.185.36.172) by dggpemm500021.china.huawei.com (7.185.36.109) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 21 Sep 2022 16:34:53 +0800 Received: from [10.67.108.67] (10.67.108.67) by dggpemm500013.china.huawei.com (7.185.36.172) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 21 Sep 2022 16:34:52 +0800 Message-ID: Date: Wed, 21 Sep 2022 16:34:52 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.0 Subject: Re: [PATCH V5 08/11] riscv: Support HAVE_IRQ_EXIT_ON_IRQ_STACK Content-Language: en-US To: , , , , , , , , , , , , , , , , , , , CC: , , , Guo Ren References: <20220918155246.1203293-1-guoren@kernel.org> <20220918155246.1203293-9-guoren@kernel.org> From: Chen Zhongjin In-Reply-To: <20220918155246.1203293-9-guoren@kernel.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.67.108.67] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500013.china.huawei.com (7.185.36.172) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 2022/9/18 23:52, guoren@kernel.org wrote: > diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S > index 5f49517cd3a2..426529b84db0 100644 > --- a/arch/riscv/kernel/entry.S > +++ b/arch/riscv/kernel/entry.S > @@ -332,6 +332,33 @@ ENTRY(ret_from_kernel_thread) > tail syscall_exit_to_user_mode > ENDPROC(ret_from_kernel_thread) > > +#ifdef CONFIG_IRQ_STACKS > +ENTRY(call_on_stack) > + /* Create a frame record to save our ra and fp */ > + addi sp, sp, -RISCV_SZPTR > + REG_S ra, (sp) > + addi sp, sp, -RISCV_SZPTR > + REG_S fp, (sp) > + > + /* Save sp in fp */ > + move fp, sp > + > + /* Move to the new stack and call the function there */ > + li a3, IRQ_STACK_SIZE > + add sp, a1, a3 > + jalr a2 > + > + /* > + * Restore sp from prev fp, and fp, ra from the frame > + */ > + move sp, fp > + REG_L fp, (sp) > + addi sp, sp, RISCV_SZPTR > + REG_L ra, (sp) > + addi sp, sp, RISCV_SZPTR > + ret > +ENDPROC(call_on_stack) > +#endif Seems my compiler (riscv64-linux-gnu-gcc 8.4.0, cross compiling from x86) cannot recognize the register `fp`. After I changed it to `s0` this can pass compiling. Seems there is nowhere else using `fp`, can this just using `s0` instead? Best, Chen