[PATCH v2 2/5] m68k: Fix writew(), writel(), readw(), readl() endianness

[Angelo Dureghello]

Hi Daniel,


On 4/6/26 16:24, Daniel Palmer wrote:
> In Linux these are meant to read a little-endian value and swap
> to the CPU endian.
> 
> In u-boot for m68k this is currently borken and prevents
> virtio-mmio from functioning.
> 

mmm, "currently broken" ?

If you remove bigendian read/write the driver framework will fail
to work with coldfire/m68k stuff.

I tested the patchset over master in stmark2 board, seems this patch is
breaking dspi cs init:

stmark2 $ saveenv
Saving Environment to SPIFlash... *** Warning - spi_flash_probe_bus_cs() failed, using default environment

Failed (-1)
stmark2 $ sf probe
spi_coldfire dspi at fc05c000: Invalid chip select 0:0 (err=-19)
Failed to initialize SPI flash at 0:0 (error -19)
stmark2 $ 

Please find a different solution, that may be using "xxx_le" stuff directly
from your code.

> Signed-off-by: Daniel Palmer <daniel at thingy.jp>
> ---
>  arch/m68k/include/asm/io.h | 17 +++++------------
>  1 file changed, 5 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/m68k/include/asm/io.h b/arch/m68k/include/asm/io.h
> index 35ad4a1c0444..f4877b0446cf 100644
> --- a/arch/m68k/include/asm/io.h
> +++ b/arch/m68k/include/asm/io.h
> @@ -24,18 +24,11 @@
>  #define __raw_writel(l,addr) ((*(volatile u32 *) (addr)) = (l))
>  
>  #define readb(addr)		in_8((volatile u8 *)(addr))
> -#define writeb(b,addr)		out_8((volatile u8 *)(addr), (b))
> -#if !defined(__BIG_ENDIAN)
> -#define readw(addr)		(*(volatile u16 *) (addr))
> -#define readl(addr)		(*(volatile u32 *) (addr))
> -#define writew(b,addr)		((*(volatile u16 *) (addr)) = (b))
> -#define writel(b,addr)		((*(volatile u32 *) (addr)) = (b))
> -#else
> -#define readw(addr)		in_be16((volatile u16 *)(addr))
> -#define readl(addr)		in_be32((volatile u32 *)(addr))
> -#define writew(b,addr)		out_be16((volatile u16 *)(addr),(b))
> -#define writel(b,addr)		out_be32((volatile u32 *)(addr),(b))
> -#endif
> +#define writeb(b, addr)		out_8((volatile u8 *)(addr), (b))
> +#define readw(addr)		in_le16((volatile u16 *)(addr))
> +#define readl(addr)		in_le32((volatile u32 *)(addr))
> +#define writew(b, addr)		out_le16((volatile u16 *)(addr), (b))
> +#define writel(b, addr)		out_le32((volatile u32 *)(addr), (b))
>  
>  /*
>   * The insw/outsw/insl/outsl macros don't do byte-swapping.

Regards,

-- Angelo