[PATCH] PowerPC 4xx: Add dcri_clrset() for locked read/modify/write functionality

[Benjamin Herrenschmidt]

On Wed, 2008-03-05 at 21:38 +0300, Valentine Barshak wrote:
> This adds dcri_clrset() macro which does read/modify/write
> on indirect dcr registers while holding indirect dcr lock.
> 
> Signed-off-by: Valentine Barshak <vbarshak at ru.mvista.com>

Acked-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
> ---
>  include/asm-powerpc/dcr-native.h |   17 +++++++++++++++++
>  1 files changed, 17 insertions(+)
> 
> --- linux-2.6.orig/include/asm-powerpc/dcr-native.h	2008-03-05 17:32:31.000000000 +0300
> +++ linux-2.6/include/asm-powerpc/dcr-native.h	2008-03-05 17:53:16.000000000 +0300
> @@ -82,6 +82,19 @@ static inline void __mtdcri(int base_add
>  	spin_unlock_irqrestore(&dcr_ind_lock, flags);
>  }
>  
> +static inline void __dcri_clrset(int base_addr, int base_data, int reg,
> +				 unsigned clr, unsigned set)
> +{
> +	unsigned long flags;
> +	unsigned int val;
> +
> +	spin_lock_irqsave(&dcr_ind_lock, flags);
> +	__mtdcr(base_addr, reg);
> +	val = (__mfdcr(base_data) & ~clr) | set;
> +	__mtdcr(base_data, val);
> +	spin_unlock_irqrestore(&dcr_ind_lock, flags);
> +}
> +
>  #define mfdcri(base, reg)	__mfdcri(DCRN_ ## base ## _CONFIG_ADDR,	\
>  					 DCRN_ ## base ## _CONFIG_DATA,	\
>  					 reg)
> @@ -90,6 +103,10 @@ static inline void __mtdcri(int base_add
>  					 DCRN_ ## base ## _CONFIG_DATA,	\
>  					 reg, data)
>  
> +#define dcri_clrset(base, reg, clr, set)	__dcri_clrset(DCRN_ ## base ## _CONFIG_ADDR,	\
> +							      DCRN_ ## base ## _CONFIG_DATA,	\
> +							      reg, clr, set)
> +
>  #endif /* __ASSEMBLY__ */
>  #endif /* __KERNEL__ */
>  #endif /* _ASM_POWERPC_DCR_NATIVE_H */