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

[Ruan Jinjie <ruanjinjie@huawei.com>]

On 2022/9/30 14:09, Christophe Leroy wrote:
> 
> 
> Le 01/09/2022 à 10:54, ruanjinjie a écrit :
>> [Vous ne recevez pas souvent de courriers de ruanjinjie@huawei.com. Découvrez pourquoi ceci est important à https://aka.ms/LearnAboutSenderIdentification ]
>>
>> 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
>> recover their data types to fix these warnings.
> 
> I think the best would be to change MPIC_MSGR_MER_OFFSET to 0x40 and 
> then drop the casts completely:
> 
> 	msgr->mer = msgr->base + MPIC_MSGR_MER_OFFSET;
> 
I think this is good to solve the warning.

>>
>> Signed-off-by: ruanjinjie <ruanjinjie@huawei.com>
>> ---
>>   arch/powerpc/sysdev/mpic_msgr.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/powerpc/sysdev/mpic_msgr.c b/arch/powerpc/sysdev/mpic_msgr.c
>> index 698fefaaa6dd..cbb0d24f15ba 100644
>> --- a/arch/powerpc/sysdev/mpic_msgr.c
>> +++ b/arch/powerpc/sysdev/mpic_msgr.c
>> @@ -227,7 +227,7 @@ 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 = (u32 __iomem *)((u8 __iomem *)msgr->base + MPIC_MSGR_MER_OFFSET);
>>                  msgr->in_use = MSGR_FREE;
>>                  msgr->num = i;
>>                  raw_spin_lock_init(&msgr->lock);
>> --
>> 2.25.1