[PATCH] PTR_ALIGN

[PATCH] PTR_ALIGN

[Matthew Wilcox]

The AdvanSys driver wants to align some pointers, and the ALIGN macro
doesn't work for pointers.  Rather than try to make it work, add a new
PTR_ALIGN macro which is typesafe.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index f592df7..47160fe 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -34,6 +34,7 @@ extern const char linux_proc_banner[];
 
 #define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
 #define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
+#define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
 
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
 
-- 
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."

Re: [PATCH] PTR_ALIGN

[Andrew Morton]

On Thu, 23 Aug 2007 05:47:03 -0600 Matthew Wilcox <matthew@wil.cx> wrote:

> 
> The AdvanSys driver wants to align some pointers, and the ALIGN macro
> doesn't work for pointers.  Rather than try to make it work, add a new
> PTR_ALIGN macro which is typesafe.
> 
> Signed-off-by: Matthew Wilcox <matthew@wil.cx>
> 
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index f592df7..47160fe 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -34,6 +34,7 @@ extern const char linux_proc_banner[];
>  
>  #define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
>  #define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
> +#define PTR_ALIGN(p, a)		((typeof(p))ALIGN((unsigned long)(p), (a)))
>  
>  #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
>  

I'll plan on getting this thing of beauty into mainline in the next week or
so, so you can get those advansys changes into James's tree.