TASK_SIZE default 0x80000000 ?

[Benjamin Herrenschmidt]

> Can you explain (a) further -- I'm assuming the BAT mapping is 1:1  
> for that region?
> 
> For (b) it looks like:
> * 40x, 44x, fsl-booke compare against TASK_SIZE in their software  
> handlers.
> * 8xx still tests 0x80000000
> * 6xx (603) compares against KERNELBASE
> 
> It would seem like we should set the default on 8xx & PReP to  
> 0x80000000 and not allow it to be modified since that will break the  
> world and for everything else move it to match KERNELBASE.  Any  
> issues with that?

The proper value is neither :-)

It should be compared against PAGE_OFFSET.

Ben.