Re: [PATCH 2/7] MIPS: SGI-IP27: clean up bridge access and header files

[Thomas Bogendoerfer]

On Mon, 28 Jan 2019 05:20:03 -0800
Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:

> On Thu, Jan 24, 2019 at 06:47:23PM +0100, Thomas Bogendoerfer wrote:
> >  #ifndef __ASSEMBLY__
> > +/* Address translation entry for mapped pci32 accesses */
> > +union bridge_ate {
> > +	u64	ent;
> > +	struct ate_s {
> > +		u64	rmf:16;
> > +		u64	addr:36;
> > +		u64	targ:4;
> > +		u64	reserved:3;
> > +		u64	barrier:1;
> > +		u64	prefetch:1;
> > +		u64	precise:1;
> > +		u64	coherent:1;
> > +		u64	valid:1;
> > +	} field;
> 
> Note that we generally try to avoid using bitfields for hardware
> descriptions and instead use masking/shifting, possibly hidden in
> macros.  The portability argument for that doesn't really apply
> here as the code is obviously MIPS/big endian specific, but I think
> it generally is a good example and more readable as well.

I totally agreed. I only moved the original defintion around while cleaning
up the header file. Right now there is no code using it. Should I remove it
and access macros as soon there is a need for it ?

Thomas.

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