[PATCH 1/2] use cache type functions for arch_get_unmapped_area

Stefan Bader stefan.bader at canonical.com
Fri Jan 13 09:37:06 UTC 2012


On 13.01.2012 10:24, Paolo Pisati wrote:
> From: Rob Herring <rob.herring at calxeda.com>
> 
> There are already cache type decoding functions, so use those instead
> of custom decode code which only works for ARMv6.
> 
> BugLink: http://bugs.launchpad.net/bugs/861296
> 
> Signed-off-by: Rob Herring <rob.herring at calxeda.com>
> Acked-by: Nicolas Pitre <nico at linaro.org>
> Acked-by: Will Deacon <will.deacon at arm.com>
> Signed-off-by: Paolo Pisati <paolo.pisati at canonical.com>
> Acked-by: Seth Forshee <seth.forshee at canonical.com>
> Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
> ---
>  arch/arm/mm/mmap.c |   23 ++++++-----------------
>  1 files changed, 6 insertions(+), 17 deletions(-)
> 
> diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
> index 4f5b396..0cbf50b 100644
> --- a/arch/arm/mm/mmap.c
> +++ b/arch/arm/mm/mmap.c
> @@ -8,8 +8,7 @@
>  #include <linux/sched.h>
>  #include <linux/io.h>
>  #include <linux/random.h>
> -#include <asm/cputype.h>
> -#include <asm/system.h>
> +#include <asm/cachetype.h>
>  
>  #define COLOUR_ALIGN(addr,pgoff)		\
>  	((((addr)+SHMLBA-1)&~(SHMLBA-1)) +	\
> @@ -31,25 +30,15 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
>  	struct mm_struct *mm = current->mm;
>  	struct vm_area_struct *vma;
>  	unsigned long start_addr;
> -#ifdef CONFIG_CPU_V6
> -	unsigned int cache_type;
> -	int do_align = 0, aliasing = 0;
> +	int do_align = 0;
> +	int aliasing = cache_is_vipt_aliasing();
>  
>  	/*
>  	 * We only need to do colour alignment if either the I or D
> -	 * caches alias.  This is indicated by bits 9 and 21 of the
> -	 * cache type register.
> +	 * caches alias.
>  	 */
> -	cache_type = read_cpuid_cachetype();
> -	if (cache_type != read_cpuid_id()) {
> -		aliasing = (cache_type | cache_type >> 12) & (1 << 11);
> -		if (aliasing)
> -			do_align = filp || flags & MAP_SHARED;
> -	}
> -#else
> -#define do_align 0
> -#define aliasing 0
> -#endif
> +	if (aliasing)
> +		do_align = filp || (flags & MAP_SHARED);
>  
>  	/*
>  	 * We enforce the MAP_FIXED case.

Seems to be

commit 41dfaa934c5d866d626de9bea785e6168524a47e
Author: Rob Herring <rob.herring at calxeda.com>
Date:   Tue Nov 22 04:01:06 2011 +0100

    ARM: 7168/1: use cache type functions for arch_get_unmapped_area

Think it would be good to add backported-from or cherry-picked line




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