Re: [PATCH] asm-generic/io.h: Fix sparse warnings on big-endian architectures

[Stafford Horne]

On Mon, Aug 03, 2020 at 09:50:59PM +0200, Arnd Bergmann wrote:
> On Mon, Aug 3, 2020 at 5:11 PM Stafford Horne <shorne@xxxxxxxxx> wrote:
> >
> > On big-endian architectures like OpenRISC, sparse outputs below warnings on
> > asm-generic/io.h.  This is due to io statements like:
> >
> >   __raw_writel(cpu_to_le32(value), PCI_IOBASE + addr);
> >
> > The __raw_writel() function expects native endianness, however
> > cpu_to_le32() returns __le32.  On little-endian machines these match up
> > and there is no issue.  However, on big-endian we get warnings, for IO
> > that is defined as little-endian the mismatch is expected.
> >
> > The fix I propose is to __force to native endian.
> >
> > Warnings:
> >
> > ./include/asm-generic/io.h:166:15: warning: cast to restricted __le16
> > ./include/asm-generic/io.h:166:15: warning: cast to restricted __le16
> > ./include/asm-generic/io.h:166:15: warning: cast to restricted __le16
> > ./include/asm-generic/io.h:166:15: warning: cast to restricted __le16
> > ./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
> > ./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
> > ./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
> > ./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
> > ./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
> > ./include/asm-generic/io.h:179:15: warning: cast to restricted __le32
> > ./include/asm-generic/io.h:215:22: warning: incorrect type in argument 1 (different base types)
> > ./include/asm-generic/io.h:215:22:    expected unsigned short [usertype] value
> > ./include/asm-generic/io.h:215:22:    got restricted __le16 [usertype]
> > ./include/asm-generic/io.h:225:22: warning: incorrect type in argument 1 (different base types)
> > ./include/asm-generic/io.h:225:22:    expected unsigned int [usertype] value
> > ./include/asm-generic/io.h:225:22:    got restricted __le32 [usertype]
> >
> > Signed-off-by: Stafford Horne <shorne@xxxxxxxxx>
> 
> Looks good to me.
> 
> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
> 
> Can you just merge that through your openrisc tree? I don't have
> any other asm-generic changes for this merge window.

That's fine with me.  Thank you.

-Stafford