[U-Boot] [PATCH V4 1/6] io: add and* and or* operation api to set and clear bit

[Scott Wood]

On Sun, 27 Mar 2011 22:48:50 -0700
Lei Wen <leiwen at marvell.com> wrote:

> Those api take use of read*/write* to align the current dmb usage.
> Also this could short the code length in one line.
> 
> Signed-off-by: Lei Wen <leiwen at marvell.com>
> ---
>  arch/arm/include/asm/io.h |    8 ++++++++
>  1 files changed, 8 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/include/asm/io.h b/arch/arm/include/asm/io.h
> index 1fbc531..71e85e8 100644
> --- a/arch/arm/include/asm/io.h
> +++ b/arch/arm/include/asm/io.h
> @@ -141,6 +141,14 @@ extern inline void __raw_readsl(unsigned int addr, void *data, int longlen)
>  #define readw(c)	({ u16 __v = __arch_getw(c); __iormb(); __v; })
>  #define readl(c)	({ u32 __v = __arch_getl(c); __iormb(); __v; })
>  
> +#define orb(v,c)       writeb(readb(c) | v, c)
> +#define orw(v,c)       writew(readw(c) | v, c)
> +#define orl(v,c)       writel(readl(c) | v, c)
> +
> +#define andb(v,c)      writeb(readb(c) & v, c)
> +#define andw(v,c)      writew(readw(c) & v, c)
> +#define andl(v,c)      writel(readl(c) & v, c)
> +
>  /*
>   * The compiler seems to be incapable of optimising constants
>   * properly.  Spell it out to the compiler in some cases.

What does this do that setbits*/clrbits* don't?

Other than be missing parentheses around "v", causing problems if a
complex expression is passed in.

-scott