From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Date: Fri, 11 Sep 2020 11:12:00 +0000 Subject: Re: [PATCH 2/3] ARM/keystone: move the DMA offset handling under ifdef CONFIG_ARM_LPAE Message-Id: List-Id: References: <20200910054038.324517-1-hch@lst.de> <20200910054038.324517-3-hch@lst.de> In-Reply-To: <20200910054038.324517-3-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Christoph Hellwig , iommu@lists.linux-foundation.org, Russell King , Santosh Shilimkar Cc: devicetree@vger.kernel.org, Florian Fainelli , linux-sh@vger.kernel.org, Frank Rowand , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, Rob Herring , Jim Quinlan , linux-pci@vger.kernel.org, Nathan Chancellor , linux-arm-kernel@lists.infradead.org On 2020-09-10 06:40, Christoph Hellwig wrote: > The DMA offset notifier can only be used if PHYS_OFFSET is at least > KEYSTONE_HIGH_PHYS_START, which can't be represented by a 32-bit > phys_addr_t. Currently the code compiles fine despite that, a pending > change to the DMA offset handling would create a compiler warning for > this case. Add an ifdef to not compile the code except for LPAE > configs. Seems reasonable - once again I wonder whether this notifier is really needed any more since "dma-ranges" should now be handled properly for PCI devices as well, but that's not something to worry about in this series. Reviewed-by: Robin Murphy > Signed-off-by: Christoph Hellwig > --- > arch/arm/mach-keystone/keystone.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/arch/arm/mach-keystone/keystone.c b/arch/arm/mach-keystone/keystone.c > index 638808c4e12247..dcd031ba84c2e0 100644 > --- a/arch/arm/mach-keystone/keystone.c > +++ b/arch/arm/mach-keystone/keystone.c > @@ -24,6 +24,7 @@ > > #include "keystone.h" > > +#ifdef CONFIG_ARM_LPAE > static unsigned long keystone_dma_pfn_offset __read_mostly; > > static int keystone_platform_notifier(struct notifier_block *nb, > @@ -48,14 +49,17 @@ static int keystone_platform_notifier(struct notifier_block *nb, > static struct notifier_block platform_nb = { > .notifier_call = keystone_platform_notifier, > }; > +#endif /* CONFIG_ARM_LPAE */ > > static void __init keystone_init(void) > { > +#ifdef CONFIG_ARM_LPAE > if (PHYS_OFFSET >= KEYSTONE_HIGH_PHYS_START) { > keystone_dma_pfn_offset = PFN_DOWN(KEYSTONE_HIGH_PHYS_START - > KEYSTONE_LOW_PHYS_START); > bus_register_notifier(&platform_bus_type, &platform_nb); > } > +#endif > keystone_pm_runtime_init(); > } > >