Re: [PATCH] x86/intel/quark: Parameterize the kernel's IMR lock logic

[Bryan O'Donoghue]

On Thu, 2016-02-18 at 08:58 +0100, Ingo Molnar wrote:
> So why not simply do the patch below? Very few people use boot
> parameters, and the 
> complexity does not seem to be worth it.
> 
> Furthermore I think an IMR range in itself is safe enough - it's not
> like such 
> register state is going to be randomly corrupted, even with the
> 'lock' bit unset. 


Hi Ingo.

I agree - to flip the lock bit you need to be in ring-0 anyway.

> So it's a perfectly fine protective measure against accidental memory
> corruption 
> from the DMA space. It should not try to be more than that.
> 
> And once we do this, I suggest we get rid of the 'lock' parameter
> altogether - 
> that will further simplify the code.
> 
> Thanks,
> 
>         Ingo

That was the V1 of this patch

https://groups.google.com/forum/#!topic/linux.kernel/6ZuVOF3TJow

Andriy asked for the boot parameter to control the state of the IMR
lock bit, I'm just as happy to go back to that version TBH