Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966492AbbBDQKL (ORCPT ); Wed, 4 Feb 2015 11:10:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45700 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965247AbbBDQKH (ORCPT ); Wed, 4 Feb 2015 11:10:07 -0500 Message-ID: <1423066107.18187.99.camel@deneb.redhat.com> Subject: Re: [PATCH v8 02/21] acpi: fix acpi_os_ioremap for arm64 From: Mark Salter To: Catalin Marinas Cc: "Rafael J. Wysocki" , "hanjun.guo@linaro.org" , Olof Johansson , Arnd Bergmann , Mark Rutland , "grant.likely@linaro.org" , Will Deacon , Lorenzo Pieralisi , "graeme.gregory@linaro.org" , Sudeep Holla , "jcm@redhat.com" , Jason Cooper , Marc Zyngier , Bjorn Helgaas , Daniel Lezcano , Mark Brown , Rob Herring , Robert Richter , Randy Dunlap , Charles Garcia-Tobin , "phoenix.liyi@huawei.com" , Timur Tabi , Ashwin Chaugule , "suravee.suthikulpanit@amd.com" , Mark Langsdorf , "wangyijing@huawei.com" , "linux-acpi@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linaro-acpi@lists.linaro.org" Date: Wed, 04 Feb 2015 11:08:27 -0500 In-Reply-To: <20150204112508.GB26006@e104818-lin.cambridge.arm.com> References: <1422881149-8177-1-git-send-email-hanjun.guo@linaro.org> <1422881149-8177-3-git-send-email-hanjun.guo@linaro.org> <2422968.Es7R0p3loO@vostro.rjw.lan> <1422984576.18187.82.camel@deneb.redhat.com> <20150204112508.GB26006@e104818-lin.cambridge.arm.com> Organization: Red Hat, Inc Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4077 Lines: 107 On Wed, 2015-02-04 at 11:25 +0000, Catalin Marinas wrote: > On Tue, Feb 03, 2015 at 05:29:36PM +0000, Mark Salter wrote: > > On Mon, 2015-02-02 at 23:14 +0100, Rafael J. Wysocki wrote: > > > On Monday, February 02, 2015 08:45:30 PM Hanjun Guo wrote: > > > > From: Mark Salter > > > > > > > > The acpi_os_ioremap() function may be used to map normal RAM or IO > > > > regions. The current implementation simply uses ioremap_cache(). This > > > > will work for some architectures, but arm64 ioremap_cache() cannot be > > > > used to map IO regions which don't support caching. So for arm64, use > > > > ioremap() for non-RAM regions. > > > > > > > > CC: Rafael J Wysocki > > > > Signed-off-by: Mark Salter > > > > Signed-off-by: Hanjun Guo > > > > --- > > > > include/acpi/acpi_io.h | 6 ++++++ > > > > 1 file changed, 6 insertions(+) > > > > > > > > diff --git a/include/acpi/acpi_io.h b/include/acpi/acpi_io.h > > > > index 444671e..9d573db 100644 > > > > --- a/include/acpi/acpi_io.h > > > > +++ b/include/acpi/acpi_io.h > > > > @@ -1,11 +1,17 @@ > > > > #ifndef _ACPI_IO_H_ > > > > #define _ACPI_IO_H_ > > > > > > > > +#include > > > > #include > > > > > > > > static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys, > > > > acpi_size size) > > > > { > > > > +#ifdef CONFIG_ARM64 > > > > + if (!page_is_ram(phys >> PAGE_SHIFT)) > > > > + return ioremap(phys, size); > > > > +#endif > > > > > > I don't want to see #ifdef CONFIG_ARM64 in this file. > > > > How about something like: > > > > From: Mark Salter > > Date: Tue, 3 Feb 2015 10:51:16 -0500 > > Subject: [PATCH] acpi: fix acpi_os_ioremap for arm64 > > > > The acpi_os_ioremap() function may be used to map normal RAM or IO > > regions. The current implementation simply uses ioremap_cache(). This > > will work for some architectures, but arm64 ioremap_cache() cannot be > > used to map IO regions which don't support caching. So for arm64, use > > ioremap() for non-RAM regions. > > > > CC: Rafael J Wysocki > > Signed-off-by: Mark Salter > > --- > > arch/arm64/include/asm/acpi.h | 14 ++++++++++++++ > > include/acpi/acpi_io.h | 3 +++ > > 2 files changed, 17 insertions(+) > > > > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h > > index ea4d2b3..db82bc3 100644 > > --- a/arch/arm64/include/asm/acpi.h > > +++ b/arch/arm64/include/asm/acpi.h > > @@ -14,6 +14,7 @@ > > > > #include > > > > +#include > > #include > > > > /* Basic configuration for ACPI */ > > @@ -100,4 +101,17 @@ static inline bool acpi_psci_use_hvc(void) { return false; } > > static inline void acpi_init_cpus(void) { } > > #endif /* CONFIG_ACPI */ > > > > +/* > > + * ACPI table mapping > > + */ > > +static inline void __iomem *acpi_os_ioremap(acpi_physical_address phys, > > + acpi_size size) > > +{ > > + if (!page_is_ram(phys >> PAGE_SHIFT)) > > + return ioremap(phys, size); > > + > > + return ioremap_cache(phys, size); > > +} > > +#define acpi_os_ioremap acpi_os_ioremap > > That's one way of doing this, I'm not too bothered with the approach > (define the function name, an ARCH_HAS macro or a Kconfig option, it's > up to Rafael). > > But a question I already asked is what we need ioremap_cache() for? We > don't use NVS on arm64 yet, so is there anything else requiring > cacheable mapping? acpi_os_remap() is used to map ACPI tables. These tables may be in ram which are already included in the kernel's linear RAM mapping. So we need ioremap_cache to avoid two mappings to the same physical page having different caching attributes. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/