[PATCH 1/3] iommu/fsl: Fix PAMU window size check.

[Varun Sethi]

> -----Original Message-----
> From: Joerg Roedel [mailto:joro at 8bytes.org]
> Sent: Friday, July 04, 2014 4:15 PM
> To: Sethi Varun-B16395
> Cc: iommu at lists.linux-foundation.org; linux-kernel at vger.kernel.org;
> linuxppc-dev at lists.ozlabs.org; alex.williamson at redhat.com
> Subject: Re: [PATCH 1/3] iommu/fsl: Fix PAMU window size check.
> 
> On Tue, Jun 24, 2014 at 07:27:15PM +0530, Varun Sethi wrote:
> >  	/* window size is 2^(WSE+1) bytes */
> > -	return __ffs(addrspace_size) - 1;
> > +	return fls64(addrspace_size) - 2;
> 
> This looks bogus, why do you replace ffs (find-first-bit) by fls (find-
> last-bit)?
> 
Address space size is always a power of 2. This change was required to handle address sizes > 32bit width on 32 bit architectures.

-Varun