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

From: Arnd Bergmann
Date: Mon Aug 03 2020 - 15:51:20 EST


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.