Use of MTX_UNOWNED in booke/trap_subr.S

[Rafal Jaworowski]

On 2010-11-10, at 23:14, John Baldwin wrote:

> First of, sorry for breaking the build.  I built a powerpc GENERIC and a 
> powerpc64 GENERIC before I committed, but that obviously wasn't sufficient.  
> dim@ pointed me at the use of MTX_UNOWNED in booke/trap_subr.S.  The first 
> thought I had was to re-allow <sys/mutex.h> in assembly code, or to expose 
> MTX_UNOWNED via assym.s.  However, it looks like the tlb lock in trap_subr.S 
> is a home-grown spinlock rather than an actual 'struct mtx'.  For that reason, 
> I'd prefer it use its own constant to avoid confusion.  To that end, the patch 
> below adds a TLB_UNLOCKED constant to <machine/tlb.h> and uses it for the tlb 
> locks.
> 
> (I do wonder if we couldn't put the tlb_lock/unlock prototypes in 
> machine/tlb.h as well rather than booke/pmap.c?  Then it could all be grouped 
> together to be more consistent.)


Thanks, it's true the MTX_UNOWNED was a bit abused in this context. The changes are good (I have tested with MPC8572), I also moved the prototypes to machine/tlb.h per suggestion. Commited as r215119.

Rafal