Re: [PATCH 1/1] ipr: add writeq definition if needed

[James Bottomley <James.Bottomley@suse.de>]

On Wed, 2010-06-09 at 08:24 -0700, Wayne Boyer wrote:
> Compiling the driver will fail on 32 bit powerpc and other
> architectures where writeq is not defined.  This patch adds a
> definition for writeq.
> 
> Signed-off-by: Wayne Boyer <wayneb@linux.vnet.ibm.com>
> ---
> 
>  drivers/scsi/ipr.h |    8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> Index: b/drivers/scsi/ipr.h
> ===================================================================
> --- a/drivers/scsi/ipr.h	2010-06-08 10:06:48.000000000 -0700
> +++ b/drivers/scsi/ipr.h	2010-06-08 15:14:42.000000000 -0700
> @@ -1860,4 +1860,12 @@ static inline int ipr_sdt_is_fmt2(u32 sd
>  	return 0;
>  }
> 
> +#ifndef writeq
> +static inline void writeq(u64 val, void __iomem *addr)
> +{
> +        writel(((u32) (val >> 32)), addr);
> +        writel(((u32) (val)), (addr + 4));

Are you sure this is what you want?  The point about writeq is to do an
atomic write of a 64 bit quantity.  Doing two writel's loses the
atomicity (and can confuse some hardware if not done in the right
order).  If this code above works correctly, why bother with the writeq?

James