Re: [PATCH v2 02/17] powerpc/cell: Move data segment faulting code out of cell platform

[Michael Neuling <mikey@neuling.org>]

On Wed, 2014-10-01 at 15:15 +0530, Aneesh Kumar K.V wrote:
> Michael Neuling <mikey@neuling.org> writes:
> 
> > From: Ian Munsie <imunsie@au1.ibm.com>
> >
> > __spu_trap_data_seg() currently contains code to determine the VSID and ESID
> > required for a particular EA and mm struct.
> >
> > This code is generically useful for other co-processors.  This moves the code
> > of the cell platform so it can be used by other powerpc code.  It also adds 1TB
> > segment handling which Cell didn't have.
> >
> > Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
> > Signed-off-by: Michael Neuling <mikey@neuling.org>
> > ---
> >  arch/powerpc/include/asm/mmu-hash64.h  |  7 ++++-
> >  arch/powerpc/mm/copro_fault.c          | 48 ++++++++++++++++++++++++++++++++++
> >  arch/powerpc/mm/slb.c                  |  3 ---
> >  arch/powerpc/platforms/cell/spu_base.c | 41 +++--------------------------
> >  4 files changed, 58 insertions(+), 41 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h
> > index d765144..6d0b7a2 100644
> > --- a/arch/powerpc/include/asm/mmu-hash64.h
> > +++ b/arch/powerpc/include/asm/mmu-hash64.h
> > @@ -189,7 +189,12 @@ static inline unsigned int mmu_psize_to_shift(unsigned int mmu_psize)
> >  #define LP_MASK(i)	((0xFF >> (i)) << LP_SHIFT)
> >  
> >  #ifndef __ASSEMBLY__
> > -
> > +static inline int slb_vsid_shift(int ssize)
> > +{
> > +	if (ssize == MMU_SEGSIZE_256M)
> > +		return SLB_VSID_SHIFT;
> > +	return SLB_VSID_SHIFT_1T;
> > +}
> >  static inline int segment_shift(int ssize)
> >  {
> >  	if (ssize == MMU_SEGSIZE_256M)
> > diff --git a/arch/powerpc/mm/copro_fault.c b/arch/powerpc/mm/copro_fault.c
> > index ba7df14..b865697 100644
> > --- a/arch/powerpc/mm/copro_fault.c
> > +++ b/arch/powerpc/mm/copro_fault.c
> > @@ -90,3 +90,51 @@ out_unlock:
> >  	return ret;
> >  }
> >  EXPORT_SYMBOL_GPL(copro_handle_mm_fault);
> > +
> > +int copro_data_segment(struct mm_struct *mm, u64 ea, u64 *esid, u64 *vsid)
> > +{
> > +	int psize, ssize;
> > +
> > +	*esid = (ea & ESID_MASK) | SLB_ESID_V;
> > +
> > +	switch (REGION_ID(ea)) {
> > +	case USER_REGION_ID:
> > +		pr_devel("copro_data_segment: 0x%llx -- USER_REGION_ID\n", ea);
> > +#ifdef CONFIG_PPC_MM_SLICES
> > +		psize = get_slice_psize(mm, ea);
> > +#else
> > +		psize = mm->context.user_psize;
> > +#endif
> 
> We don't really need that as explained in last review.

That cleanup is in patch 10. I avoided changing it here so it's clearer
that what is being removed is the same as what is being added.

Mikey