Re: drivers/net/can/kvaser_pciefd.c:801:17: sparse: sparse: cast removes address space '<asn:2>' of expression

[Greg Ungerer]

On 13/6/20 2:35 am, Luc Van Oostenryck wrote:
> On Sat, Jun 13, 2020 at 01:33:16AM +1000, Greg Ungerer wrote:
> > On 12/6/20 5:48 pm, Marc Kleine-Budde wrote:
> > I think this one is due to not forcing the volatile cast in __raw_write().
> > So this change will fix that:
> >
> > diff --git a/arch/m68k/include/asm/io_no.h b/arch/m68k/include/asm/io_no.h
> > index 0498192e1d98..1bc739f1f1ad 100644
> > --- a/arch/m68k/include/asm/io_no.h
> > +++ b/arch/m68k/include/asm/io_no.h
> > @@ -14,15 +14,15 @@
> >    * that behavior here first before we include asm-generic/io.h.
> >    */
> >   #define __raw_readb(addr) \
> > -    ({ unsigned char __v = (*(volatile unsigned char *) (addr)); __v; })
> > +    ({ u8 __v = (*(__force volatile u8 *) (addr)); __v; })
> >   #define __raw_readw(addr) \
> > -    ({ unsigned short __v = (*(volatile unsigned short *) (addr)); __v; })
> > +    ({ u16 __v = (*(__force volatile u16 *) (addr)); __v; })
> >   #define __raw_readl(addr) \
> > -    ({ unsigned int __v = (*(volatile unsigned int *) (addr)); __v; })
> > +    ({ u32 __v = (*(__force volatile u32 *) (addr)); __v; })
> > -#define __raw_writeb(b, addr) (void)((*(volatile unsigned char *) (addr)) = (b))
> > -#define __raw_writew(b, addr) (void)((*(volatile unsigned short *) (addr)) = (b))
> > -#define __raw_writel(b, addr) (void)((*(volatile unsigned int *) (addr)) = (b))
> > +#define __raw_writeb(b, addr) (void)((*(__force volatile u8 *) (addr)) = (b))
> > +#define __raw_writew(b, addr) (void)((*(__force volatile u16 *) (addr)) = (b))
> > +#define __raw_writel(b, addr) (void)((*(__force volatile u32 *) (addr)) = (b))
>
> Look good to me but isn't easier to leave them undefined and include
> asm-generic/io.h?

Not so simple at the moment. Although juggling a few things around within
io_no.h will let you use the asm-generic functions it will now throw up
a _lot_ of warnings in many of the architecture files that pass int constant
addresses to the raw_* functions. That is on my todo list.

Regards
Greg