Re: [UPDATED PATCH 21/27] sparc32, smpboot: Use generic SMPbooting infrastructure

From: Sam Ravnborg
Date: Sat Jun 02 2012 - 12:23:39 EST


>
> As I mentioned in my other mail, I am thinking of changing them to
> arch_cpu_pre_starting(), arch_cpu_pre_online() and arch_cpu_post_online().
> Let me know what you think of those names.
Much better than "__" - so if none of the guys that excel in core
code objects go for that.

> Would you kindly add a changelog and your sign-off to this patch?
Will do in next revision.

...

Thanks for the throughfull review.
I will address all points - including passing the pointer down,
as I assume you have some future plans with that pointer.

>
> I still didn't get how this solves the original problem of
> not having sparc_cpu_model set to sparc_leon. You mentioned
> that by the time we reach leon_smp_cpu_startup, that variable
> is not set. Even inside leon_smp_cpu_startup, I don't immediately
> see where it is set. Am I missing something?

After looking more closely at the code it is my understanding
that a leon CPU when started will actually jump to the reset
vector and start from there.
So the secondary CPU's will run long time after
sparc_cpu_model is set so we can safely use it.

The sun based cpu will in comparsion jump to
an address supplied to a prom call - so they do not
jump to the reset vector.
But they also have sparc_cpu_model set so no problem there
either.

All this are my deductions from reading the code - but this
is not an area I have looked at otherwise..

I may not find time today to cook up a new version of
the patch - but then you will have it tomorrow.

Sam
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