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 msalter@redhat.com
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 rjw@rjwysocki.net Signed-off-by: Mark Salter msalter@redhat.com Signed-off-by: Hanjun Guo hanjun.guo@linaro.org
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 <linux/mm.h> #include <linux/io.h> 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 msalter@redhat.com 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 rjw@rjwysocki.net Signed-off-by: Mark Salter msalter@redhat.com
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 <linux/irqchip/arm-gic-acpi.h> +#include <linux/mm.h> #include <asm/smp_plat.h> /* 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.