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 EC22DC433EF for ; Wed, 29 Dec 2021 10:38:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239754AbhL2KiP (ORCPT ); Wed, 29 Dec 2021 05:38:15 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:36576 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231732AbhL2KiP (ORCPT ); Wed, 29 Dec 2021 05:38:15 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 8DBF9B817B0; Wed, 29 Dec 2021 10:38:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 86DC2C36AE7; Wed, 29 Dec 2021 10:38:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640774292; bh=MExT51K+cGJEBXy7Nsv/QpJxU3pTYvrD4E5i8bK9DOk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=e9QYlMttgSRarsJgqy6RTpuJPTLqpMOm2PuYI3d9KxksJUGpT47Bq9VIOTAc22POh BWK6a7geSXy8NtvXs0ch5Beu0/OCyOgYTARgWZ6NDq2ND0lfvc224daBqzAcKD2V7f k/ACoPlzyJu83nevIpGgKhTsdTJTseONUAqkts6M= Date: Wed, 29 Dec 2021 11:38:09 +0100 From: Greg Kroah-Hartman To: Niklas Schnelle Cc: Arnd Bergmann , Bjorn Helgaas , John Garry , Nick Hu , Greentime Hu , Vincent Chen , Paul Walmsley , Palmer Dabbelt , Albert Ou , Guo Ren , Arnd Bergmann , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-pci@vger.kernel.org, linux-riscv@lists.infradead.org, linux-csky@vger.kernel.org Subject: Re: [RFC 30/32] /dev/port: don't compile file operations without CONFIG_DEVPORT Message-ID: References: <20211227164317.4146918-1-schnelle@linux.ibm.com> <20211227164317.4146918-31-schnelle@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Wed, Dec 29, 2021 at 11:25:12AM +0100, Niklas Schnelle wrote: > On Tue, 2021-12-28 at 09:17 +0100, Greg Kroah-Hartman wrote: > > On Mon, Dec 27, 2021 at 05:43:15PM +0100, Niklas Schnelle wrote: > > > In the future inb() and friends will not be available when compiling > > > with CONFIG_HAS_IOPORT=n so we must only try to access them here if > > > CONFIG_DEVPORT is set which depends on HAS_IOPORT. > > > > > > Co-developed-by: Arnd Bergmann > > > Signed-off-by: Arnd Bergmann > > > Signed-off-by: Niklas Schnelle > > > --- > > > drivers/char/mem.c | 6 +++++- > > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/char/mem.c b/drivers/char/mem.c > > > index cc296f0823bd..c1373617153f 100644 > > > --- a/drivers/char/mem.c > > > +++ b/drivers/char/mem.c > > > @@ -402,6 +402,7 @@ static int mmap_mem(struct file *file, struct vm_area_struct *vma) > > > return 0; > > > } > > > > > > +#ifdef CONFIG_DEVPORT > > > static ssize_t read_port(struct file *file, char __user *buf, > > > size_t count, loff_t *ppos) > > > { > > > @@ -443,6 +444,7 @@ static ssize_t write_port(struct file *file, const char __user *buf, > > > *ppos = i; > > > return tmp-buf; > > > } > > > +#endif > > > > > > static ssize_t read_null(struct file *file, char __user *buf, > > > size_t count, loff_t *ppos) > > > @@ -665,12 +667,14 @@ static const struct file_operations null_fops = { > > > .splice_write = splice_write_null, > > > }; > > > > > > -static const struct file_operations __maybe_unused port_fops = { > > > +#ifdef CONFIG_DEVPORT > > > +static const struct file_operations port_fops = { > > > .llseek = memory_lseek, > > > .read = read_port, > > > .write = write_port, > > > .open = open_port, > > > }; > > > +#endif > > > > Why is this #ifdef needed if it is already __maybe_unused? > > Because read_port() calls inb() and write_port() calls outb() they > wouldn't compile once these are no longer defined. Then however the > read_port/write_port symbols in the struct initialization above > couldn't be resolved. > > > > > In looking closer, this change could be taken now as the use of this > > variable already is behind this same #ifdef statement, right? > > Yes Great, feel free to send this individually, not as a RFC patch, and I will be glad to queue it up. thanks, greg k-h