[PATCH][RFC] remove paca pointer from the naca

[Anton Blanchard]

Hi Stephen,

> This patch just removes the paca pointer from the naca (and the one
> reference to it).  It turns out that it was just there so that the
> iSeries startup code could find the paca in order to pass a member
> of it to iSeries_early_init - which now takes no arguments ...
> 
> Built and booted on iSeries (which is the only thing affected).
> Built on pSeries and pmac.

Nice!

FYI The naca and systemcfg structures are pointers to try and make early
boot easier (they relocate the pointer at boot once while we are
running at an offset, then again once we have copied down). However this
makes things strange (only the boot cpu sees this, the secondary threads
get the paca + systemcfg in their final place). We would also save a
load if they were structs and not pointers to structs

However making these changes would involve a fair amount of churn :(

Anton