Re: [PATCH] Consolidate mm_context_t definition in mmu.h

[Josh Boyer <jwboyer@linux.vnet.ibm.com>]

On Tue, 2007-07-10 at 18:36 +0200, Arnd Bergmann wrote:
> On Tuesday 10 July 2007, Josh Boyer wrote:
> > +#ifdef CONFIG_PPC64
> > +typedef unsigned long mm_context_id_t;
> > +
> > +typedef struct {
> > +       mm_context_id_t id;
> > +       u16 user_psize;         /* page size index */
> > +
> > +#ifdef CONFIG_PPC_MM_SLICES
> > +       u64 low_slices_psize;   /* SLB page size encodings */
> > +       u64 high_slices_psize;  /* 4 bits per slice for now */
> > +#else
> > +       u16 sllp;               /* SLB page size encoding */
> > +#endif
> > +       unsigned long vdso_base;
> > +} mm_context_t;
> > +
> > +#else /* !CONFIG_PPC64 */
> > +
> > +typedef struct {
> > +       unsigned long id;
> > +       unsigned long vdso_base;
> > +} mm_context_t;
> > +
> > +#endif /* CONFIG_PPC64 */
> 
> 
> It seems to me that you can easily consolidate this further, if you
> allow the mm_context_id_t on 32 bit, or remove it on 64 bit:

Hm... good point.  Though...

> 
> +typedef unsigned long mm_context_id_t;
> +
> +typedef struct {
> +       mm_context_id_t id;
> +       u16 user_psize;         /* page size index */
> +
> +#ifdef CONFIG_PPC64

This needs to be moved up to encompass the u16 user_psize member as
well, yes?

> +#ifdef CONFIG_PPC_MM_SLICES
> +       u64 low_slices_psize;   /* SLB page size encodings */
> +       u64 high_slices_psize;  /* 4 bits per slice for now */
> +#else
> +       u16 sllp;               /* SLB page size encoding */
> +#endif
> +#endif
> +       unsigned long vdso_base;
> +} mm_context_t;

josh