Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 10 Jul 2023 08:54:10 -0600
From:   Rob Herring <robh@kernel.org>
To:     Baoquan He <bhe@redhat.com>
Cc:     devicetree@vger.kernel.org, mturquette@baylibre.com,
        kernel test robot <lkp@intel.com>,
        Jonathan.Cameron@huawei.com, maz@kernel.org, vkoul@kernel.org,
        dragan.cvetic@amd.com, edumazet@google.com, tglx@linutronix.de,
        tsbogend@alpha.franken.de, linux-kernel@vger.kernel.org,
        frowand.list@gmail.com, eli.billauer@gmail.com,
        derek.kiernan@amd.com, kuba@kernel.org, sboyd@kernel.org,
        schnelle@linux.ibm.com, robh+dt@kernel.org,
        linus.walleij@linaro.org, arnd@arndb.de, pabeni@redhat.com,
        davem@davemloft.net, linux-mm@kvack.org, akpm@linux-foundation.org,
        linux@dominikbrodowski.net, gregkh@linuxfoundation.org,
        joyce.ooi@intel.com
Subject: Re: [PATCH 8/8] of: make OF_EARLY_FLATTREE depend on HAS_IOMEM
Message-ID: <168900051598.1946989.3367114616050746231.robh@kernel.org>
References: <20230707135852.24292-1-bhe@redhat.com>
 <20230707135852.24292-9-bhe@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230707135852.24292-9-bhe@redhat.com>
Precedence: bulk


On Fri, 07 Jul 2023 21:58:52 +0800, Baoquan He wrote:
> On s390 systems (aka mainframes), it has classic channel devices for
> networking and permanent storage that are currently even more common
> than PCI devices. Hence it could have a fully functional s390 kernel
> with CONFIG_PCI=n, then the relevant iomem mapping functions
> [including ioremap(), devm_ioremap(), etc.] are not available.
> 
> In LKP error report at below on s390:
> ------
> ld: kernel/dma/coherent.o: in function `dma_init_coherent_memory':
> coherent.c:(.text+0x102): undefined reference to `memremap'
> ld: coherent.c:(.text+0x226): undefined reference to `memunmap'
> ld: kernel/dma/coherent.o: in function `dma_declare_coherent_memory':
> coherent.c:(.text+0x8b8): undefined reference to `memunmap'
> ld: kernel/dma/coherent.o: in function `dma_release_coherent_memory':
> coherent.c:(.text+0x9aa): undefined reference to `memunmap'
> ------
> 
> In the config file, several Kconfig options are:
> ------
> '# CONFIG_PCI is not set'
> CONFIG_OF_EARLY_FLATTREE=y
> CONFIG_DMA_DECLARE_COHERENT=y
> ------
> 
> So, enabling OF_EARLY_FLATTREE will select DMA_DECLARE_COHERENT
> and cause above building errors even though they are not needed
> because CONFIG_PCI is disabled.
> 
> Here let OF_EARLY_FLATTREE depend on HAS_IOMEM so that it won't
> be built to cause compiling error if PCI is unset.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202306211329.ticOJCSv-lkp@intel.com/
> Signed-off-by: Baoquan He <bhe@redhat.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: devicetree@vger.kernel.org
> ---
>  drivers/of/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Applied, thanks!