From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeff Garzik <jgarzik@pobox.com>
Subject: Re: Submission #3  for S2io 10GbE driver
Date: Mon, 01 Mar 2004 01:53:33 -0500
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Cc: leonid.grossman@s2io.com, netdev@oss.sgi.com, shemminger@osdl.org,
        hch@infradead.org, ravinandan.arakali@s2io.com,
        raghavendra.koushik@s2io.com
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To: raghavendra.koushik@wipro.com
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raghavendra.koushik@wipro.com 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