Re: [PATCH 1/5] Convert resource to u64 from unsigned long

[Dave <dave.jiang@gmail.com>]

On Thu, 13 Jan 2005 16:23:09 -0800, Andrew Morton <akpm@osdl.org> wrote:
> Dave <dave.jiang@gmail.com> wrote:
> >
> > ere's my first attempt of trying to convert the struct resource
> > start/end to u64 per blessed by Linus =) This is to support >32bit
> > physical address on 32bit archs such as some of the newer ARMv6 and
> > XSC3 based platforms and perhaps IA32 PAE.  I left the PCI stuff alone
> > functionally. Supporting 64bit PCI BAR on 32bit archs is for another
> > day. I fixed most of the core stuff I can think of, fixed ARM and i386
> > hopefully and a few of the device drivers as examples. I have tested
> > on an IQ31244 XScale IOP (ARM) platform and a dual-xeon platform for
> > i386. Matt Porter has graciously sent me PPC fixes that he tested on.
> 
> OK, well Greg KH will be the main target of this work..
> 
> Can you do something a bit more friendly than application/octet-stream
> encoding, btw?
> 
> +#if BITS_PER_LONG == 64
> +#define U64FMT "016lx"
> +#else
> +#define U64FMT "016Lx"
> +#endif
> 
> We've avoided doing this.  We prefer to do
> 
>         printk("%llx", (unsigned long long)foo);
> 
> which is tidier, although a little more runtime-costly.
> 
> Your approach assumes that all 64-bit architectures implement u64 as
> unsigned long (as opposed to unsigned long long, which I guess is legal?) I
> don't know if that's a problem or not.
> 
> Also, the patches introduce tons of ifdefs such as:
> 
> +#if BITS_PER_LONG == 64
>         return (void __iomem *)pci_resource_start(pdev, PCI_ROM_RESOURCE);
> +#else
> +       return (void __iomem *)(u32)pci_resource_start(pdev, PCI_ROM_RESOURCE);
> +#endif
> 
> We really should find a way of avoiding this.  Even if it is
> 
> #if BITS_PER_LONG == 64
> #define resource_to_ptr(r) ((void *)(r))
> #else
> #define resource_to_ptr(r) ((void *)((u32)r))
> #endif
> 
> in a header file somewhere.  Open-coding the decision all over the place is
> unsightly.
> 
 
Ok, I shall rework the patches w/ ull. I wasn't sure that ull would
cause problems on 64bit archs or not for u64....thus the ugly
workarounds....

BTW, anyone know how to inline patches via gmail? 

-- 
-= Dave =-

Software Engineer - Advanced Development Engineering Team 
Storage Component Division - Intel Corp. 
mailto://dave.jiang @ intel
http://sourceforge.net/projects/xscaleiop/
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