On Sat, 29 Nov 2008 11:52:29 +0100 Sam Ravnborg <sam@xxxxxxxxxxxx> wrote: > > > > But this is old way. ARCH_HAS_READQ and ARCH_HAS_WRITEQ are new ways > > to determine existence of readq/writeq. Drivers which use readq/writeq should > > depend on these values in their Kconfig file. > > If we look at arch/x86/Kconfig we see: > ### Arch settings > config X86 > def_bool y > select HAVE_AOUT if X86_32 > select HAVE_UNSTABLE_SCHED_CLOCK > select HAVE_IDE > select HAVE_OPROFILE > select HAVE_IOREMAP_PROT > select HAVE_KPROBES > select ARCH_WANT_OPTIONAL_GPIOLIB > ... > > So the normal syntax here is "HAVE_XXX_XXX" - not ARCH_HAS_XXX_XXX > > If you update your patch please use this syntax, > and locate the select under X86 - not under the 32/64 entries. Thanks for your notification. I didn't notice that syntax rule. > > But I do not see why adding these in the first place. > Andrew Morton told that drivers which need readq/writeq should use ones of kernel, and if architecture part of kernel does not provide readq/writeq, drivers should be disabled. This is Andrew's mail: http://marc.info/?l=linux-kernel&m=122625885124798&w=2 ===> Quote: #ifdef readq Is a suitable way of determining whether the architecture implements readq and writeq. It isn't pretty, but it will suffice. A problem with it is that drivers will then do #ifndef readq <provide a local implementation here> #endif which rather sucks - we don't want lots of little private readq/writeq implementations all over the tree. Perhaps it would be better to have a CONFIG_ARCH_HAS_READQ and to then disable these drivers on the architectures which don't provide readq/writeq support. <==== This is new patch. description of this patch Adding implementation of readq/writeq to x86_32, and adding config value to x86 architecture to determine existence of readq/writeq Signed-off-by: Hitoshi Mitake <h.mitake@xxxxxxxxx> --- arch/x86/Kconfig | 2 ++ arch/x86/include/asm/io.h | 24 ++++++++++++++++++++++++ 2 files changed, 26 insertions(+), 0 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index ac22bb7..75408fe 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -34,6 +34,8 @@ config X86 select HAVE_ARCH_TRACEHOOK select HAVE_GENERIC_DMA_COHERENT if X86_32 select HAVE_EFFICIENT_UNALIGNED_ACCESS + select HAVE_READQ + select HAVE_WRITEQ config ARCH_DEFCONFIG string diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index ac2abc8..ddc67aa 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -4,6 +4,7 @@ #define ARCH_HAS_IOREMAP_WC #include <linux/compiler.h> +#include <asm-generic/int-ll64.h> #define build_mmio_read(name, size, type, reg, barrier) \ static inline type name(const volatile void __iomem *addr) \ @@ -57,6 +58,29 @@ build_mmio_write(__writeq, "q", unsigned long, "r", ) /* Let people know we have them */ #define readq readq #define writeq writeq + +#else /* CONFIG_X86_32 from here */ + +static inline __u64 readq(const volatile void __iomem *addr) +{ + const volatile u32 __iomem *p = addr; + u32 l, h; + + l = readl(p); + h = readl(p+1); + + return l + ((u64)h << 32); +} + +static inline void writeq(__u64 val, volatile void __iomem *addr) +{ + writel(val, addr); + writel(val >> 32, addr+4); +} + +#define readq readq +#define writeq writeq + #endif extern int iommu_bio_merge; -- 1.5.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
