[U-Boot] [PATCH 2/4] MIPS: Fix _ACAST32_ for pointers on MIPS64

[Paul Burton]

On Thu, May 26, 2016 at 01:18:21AM +0200, Daniel Schwierzeck wrote:
> 
> 
> Am 17.05.2016 um 12:56 schrieb Paul Burton:
> > When building for MIPS64 and providing a pointer to _ACAST32_,
> > optionally via CPHYSADDR or one of the CKSEGxADDR macros, the cast
> > directly to a 32 bit int leads to compilation warnings such as the
> > following:
> > 
> >   In file included from ./arch/mips/include/asm/io.h:17:0,
> >                    from drivers/net/pcnet.c:14:
> >   drivers/net/pcnet.c: In function ‘pcnet_virt_to_mem’:
> >   ./arch/mips/include/asm/addrspace.h:39:29: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
> >    #define _ACAST32_  (_ATYPE_)(_ATYPE32_) /* widen if necessary */
> >                                ^
> >   ./arch/mips/include/asm/addrspace.h:51:25: note: in expansion of macro ‘_ACAST32_’
> >    #define CPHYSADDR(a)  ((_ACAST32_(a)) & 0x1fffffff)
> >                            ^
> >   ./arch/mips/include/asm/addrspace.h:71:25: note: in expansion of macro ‘CPHYSADDR’
> >    #define CKSEG0ADDR(a)  (CPHYSADDR(a) | CKSEG0)
> >                            ^
> >   drivers/net/pcnet.c:144:23: note: in expansion of macro ‘CKSEG0ADDR’
> >      virt_addr = (void *)CKSEG0ADDR(addr);
> >                          ^
> > 
> > Fix this by first casting provided values to a pointer-width integer,
> > then truncating to a 32 bit int & widening back to pointer-width.
> > 
> > Signed-off-by: Paul Burton <paul.burton at imgtec.com>
> > ---
> > 
> >  arch/mips/include/asm/addrspace.h | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arch/mips/include/asm/addrspace.h b/arch/mips/include/asm/addrspace.h
> > index 0994e96..fe497b5 100644
> > --- a/arch/mips/include/asm/addrspace.h
> > +++ b/arch/mips/include/asm/addrspace.h
> > @@ -36,8 +36,8 @@
> >  #define _ACAST32_
> >  #define _ACAST64_
> >  #else
> > -#define _ACAST32_		(_ATYPE_)(_ATYPE32_)	/* widen if necessary */
> > -#define _ACAST64_		(_ATYPE64_)		/* do _not_ narrow */
> > +#define _ACAST32_	(_ATYPE_)(_ATYPE32_)(_ATYPE_)	/* widen if necessary */
> > +#define _ACAST64_	(_ATYPE64_)		/* do _not_ narrow */
> >  #endif
> >  
> >  /*
> > 
> 
> could you fix this in the pcnet driver? If possible I want to avoid
> U-Boot specific changes on files imported from Linux.
> 
> -- 
> - Daniel
> 

Hi Daniel,

I've submitted an alternate fix in v2 of the series just now. It still
requires a change to MIPS code but it mirrors one I have submitted to
Linux, and hopefully one you'll find acceptable. It makes MIPS32 &
MIPS64 more consistent & prevents drivers needing to care about which
segment of the virtual address space an address is in when calling
virt_to_phys.

Thanks,
    Paul