Re: [PATCH -next v2] powerpc/mpic_msgr: fix cast removes address space of expression warnings

[Christophe Leroy]

Le 19/10/2022 à 08:34, ruanjinjie a écrit :
> When build Linux kernel, encounter the following warnings:
> 
> ./arch/powerpc/sysdev/mpic_msgr.c:230:38: warning: cast removes address space '__iomem' of expression
> ./arch/powerpc/sysdev/mpic_msgr.c:230:27: warning: incorrect type in assignment (different address spaces)
> 
> The data type of msgr->mer and msgr->base are 'u32 __iomem *', but
> converted to 'u32 *' and 'u8 *' directly and cause above warnings, now
> instead of using a type cast, change the size of the pointer offset to fix
> these warnings.
> 
> Signed-off-by: ruanjinjie <ruanjinjie@xxxxxxxxxx>

Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>

> ---
> v2:
> - change the macro of MPIC_MSGR_MER_OFFSET to avoid type cast and
>    simplify the fix
> ---
>   arch/powerpc/sysdev/mpic_msgr.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/sysdev/mpic_msgr.c b/arch/powerpc/sysdev/mpic_msgr.c
> index a439e33eae06..d75064fb7d12 100644
> --- a/arch/powerpc/sysdev/mpic_msgr.c
> +++ b/arch/powerpc/sysdev/mpic_msgr.c
> @@ -20,7 +20,7 @@
>   
>   #define MPIC_MSGR_REGISTERS_PER_BLOCK	4
>   #define MPIC_MSGR_STRIDE		0x10
> -#define MPIC_MSGR_MER_OFFSET		0x100
> +#define MPIC_MSGR_MER_OFFSET		(0x100 / sizeof(u32))
>   #define MSGR_INUSE			0
>   #define MSGR_FREE			1
>   
> @@ -234,7 +234,7 @@ static int mpic_msgr_probe(struct platform_device *dev)
>   
>   		reg_number = block_number * MPIC_MSGR_REGISTERS_PER_BLOCK + i;
>   		msgr->base = msgr_block_addr + i * MPIC_MSGR_STRIDE;
> -		msgr->mer = (u32 *)((u8 *)msgr->base + MPIC_MSGR_MER_OFFSET);
> +		msgr->mer = msgr->base + MPIC_MSGR_MER_OFFSET;
>   		msgr->in_use = MSGR_FREE;
>   		msgr->num = i;
>   		raw_spin_lock_init(&msgr->lock);