Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161395AbbBDR5w (ORCPT ); Wed, 4 Feb 2015 12:57:52 -0500 Received: from foss-mx-na.foss.arm.com ([217.140.108.86]:41261 "EHLO foss-mx-na.foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161028AbbBDR5s (ORCPT ); Wed, 4 Feb 2015 12:57:48 -0500 Date: Wed, 4 Feb 2015 17:57:34 +0000 From: Catalin Marinas To: Mark Salter 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" Subject: Re: [PATCH v8 02/21] acpi: fix acpi_os_ioremap for arm64 Message-ID: <20150204175734.GI26006@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> <1423066107.18187.99.camel@deneb.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1423066107.18187.99.camel@deneb.redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4664 Lines: 115 On Wed, Feb 04, 2015 at 04:08:27PM +0000, Mark Salter wrote: > 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. What's the call path to acpi_os_ioremap() on such tables already in the linear mapping? I can see an acpi_map() function which already takes care of the RAM mapping case but there are other cases where acpi_os_ioremap() is called directly. For example, acpi_os_read_memory(), can it be called on both RAM and I/O? -- Catalin -- 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/