[RFC PATCH] Remove CONFIG_DCACHE_WORD_ACCESS

Benjamin Herrenschmidt
2014-03-11T20:37:20Z

On Tue, 2014-03-04 at 12:23 -0800, Joe Perches wrote:
> It seems to duplicate CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
> so use that instead.
>
> This changes the !CPU_LITTLE_ENDIAN powerpc arch to use unaligned
> accesses in fs/dcache.c and fs/namei.c as
> CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is enabled for that arch.
>
> Remove the now unused DCACHE_WORD_ACCESS defines & uses.

Interesting.. we have word-at-a-time but we never enabled
DCACHE_WORD_ACCESS, I wonder why that is. In fact, we should
probably do it for LE as well for P8 if we can make a P8
only config option...

Anton, what do you reckon here ?

Cheers,
Ben.

> Signed-off-by: Joe Perches <joe@perches.com>
> ---
> arch/arm/Kconfig | 1 -
> arch/arm/include/asm/word-at-a-time.h | 4 ++--
> arch/arm64/Kconfig | 1 -
> arch/x86/Kconfig | 1 -
> fs/Kconfig | 4 ----
> fs/dcache.c | 2 +-
> fs/namei.c | 2 +-
> 7 files changed, 4 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 623a272..d5a2e60 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -12,7 +12,6 @@ config ARM
> select BUILDTIME_EXTABLE_SORT if MMU
> select CLONE_BACKWARDS
> select CPU_PM if (SUSPEND || CPU_IDLE)
> - select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
> select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI)
> select GENERIC_CLOCKEVENTS_BROADCAST if SMP
> select GENERIC_IDLE_POLL_SETUP
> diff --git a/arch/arm/include/asm/word-at-a-time.h b/arch/arm/include/asm/word-at-a-time.h
> index a6d0a29..778b2ad 100644
> --- a/arch/arm/include/asm/word-at-a-time.h
> +++ b/arch/arm/include/asm/word-at-a-time.h
> @@ -54,7 +54,7 @@ static inline unsigned long find_zero(unsigned long mask)
> #include <asm-generic/word-at-a-time.h>
> #endif
>
> -#ifdef CONFIG_DCACHE_WORD_ACCESS
> +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
>
> /*
> * Load an unaligned word from kernel space.
> @@ -94,5 +94,5 @@ static inline unsigned long load_unaligned_zeropad(const void *addr)
> return ret;
> }
>
> -#endif /* DCACHE_WORD_ACCESS */
> +#endif /* HAVE_EFFICIENT_UNALIGNED_ACCESS */
> #endif /* __ASM_ARM_WORD_AT_A_TIME_H */
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 764d682..2d6978c 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -13,7 +13,6 @@ config ARM64
> select CLONE_BACKWARDS
> select COMMON_CLK
> select CPU_PM if (SUSPEND || CPU_IDLE)
> - select DCACHE_WORD_ACCESS
> select GENERIC_CLOCKEVENTS
> select GENERIC_CLOCKEVENTS_BROADCAST if SMP
> select GENERIC_IOMAP
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index abb261e..60cfa073 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -98,7 +98,6 @@ config X86
> select CLKEVT_I8253
> select ARCH_HAVE_NMI_SAFE_CMPXCHG
> select GENERIC_IOMAP
> - select DCACHE_WORD_ACCESS
> select GENERIC_SMP_IDLE_THREAD
> select ARCH_WANT_IPC_PARSE_VERSION if X86_32
> select HAVE_ARCH_SECCOMP_FILTER
> diff --git a/fs/Kconfig b/fs/Kconfig
> index 312393f..7511271 100644
> --- a/fs/Kconfig
> +++ b/fs/Kconfig
> @@ -4,10 +4,6 @@
>
> menu "File systems"
>
> -# Use unaligned word dcache accesses
> -config DCACHE_WORD_ACCESS
> - bool
> -
> if BLOCK
>
> source "fs/ext2/Kconfig"
> diff --git a/fs/dcache.c b/fs/dcache.c
> index 265e0ce..4e3c195 100644
> --- a/fs/dcache.c
> +++ b/fs/dcache.c
> @@ -163,7 +163,7 @@ int proc_nr_dentry(ctl_table *table, int write, void __user *buffer,
> * Compare 2 name strings, return 0 if they match, otherwise non-zero.
> * The strings are both count bytes long, and count is non-zero.
> */
> -#ifdef CONFIG_DCACHE_WORD_ACCESS
> +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
>
> #include <asm/word-at-a-time.h>
> /*
> diff --git a/fs/namei.c b/fs/namei.c
> index 385f781..1ee33ca 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -1618,7 +1618,7 @@ static inline int nested_symlink(struct path *path, struct nameidata *nd)
> * the final mask". Again, that could be replaced with a
> * efficient population count instruction or similar.
> */
> -#ifdef CONFIG_DCACHE_WORD_ACCESS
> +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
>
> #include <asm/word-at-a-time.h>
>
>
>
> --
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