Re: Submission #3 for S2io 10GbE driver

[Jeff Garzik <jgarzik@xxxxxxxxx>]

raghavendra.koushik@xxxxxxxxx wrote:
> Jeff,
>  Regarding Point # 37
>
>
> > > 37) kill all of this:
> > >
> > > +/*  OS related system calls */
> > > +
> > > +#ifndef readq
> > > +static inline u64 read64(void *addr)
> > > +{
> > > +       u64 ret = 0;
> > > +       ret = readl(addr + 4);
> > > +       (u64) ret <<= 32;
> > > +       (u64) ret |= readl(addr);
>
>     [....]
>
> I agree that read/write(32,16,8) are not used so can be eliminated,
> but the read/write64 macros are essential because not all platforms
> have defined the readq and writeq system calls. i386 for example
> doesn't have readq/writeq and to write into the 64 bit registers
> of the NIC, I use 2 successive 32 bits (readl/writel) operation to
> achieve the 64 bit equivalent. This procedure does work on all the
> platforms that we have tested on.

The code should use the kernel API -- readq/writeq -- not define its own 
API.  With regards to the missing readq/writeq on some architectures...

Short term, if some arches do not provide readq/writeq, provide your own 
definition (i.e. rename your write64 to a conditionally-defined writeq).

Long term, all Linux platforms need to provide readq/writeq, so we need 
to modify the architectures with the missing pieces.


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Oh really?  ;-)  You should talk to your lawyers and sysadmins about 
sending email to open source people and lists...

Regards,

        Jeff