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

Message ID 20220901085416.204378-1-ruanjinjie@huawei.com (mailing list archive)
State Changes Requested
Headers show
Series [-next] powerpc/mpic_msgr: fix cast removes address space of expression warnings | expand

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Commit Message

Jinjie Ruan Sept. 1, 2022, 8:54 a.m. UTC
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.

Signed-off-by: ruanjinjie <ruanjinjie@huawei.com>
---
 arch/powerpc/sysdev/mpic_msgr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Jinjie Ruan Sept. 30, 2022, 1:34 a.m. UTC | #1
Ping.

On 2022/9/1 16:54, ruanjinjie wrote:
> 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.
> 
> 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);
Christophe Leroy Sept. 30, 2022, 6:09 a.m. UTC | #2
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;

> 
> 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
>
Jinjie Ruan Sept. 30, 2022, 6:37 a.m. UTC | #3
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
Michael Ellerman Sept. 30, 2022, 7:25 a.m. UTC | #4
Christophe Leroy <christophe.leroy@csgroup.eu> writes:
> 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;

Or:

#define MPIC_MSGR_MER_OFFSET    (0x100 / sizeof(u32))

To document that it's 0x100 bytes, but the the offset is in units of u32.

cheers
diff mbox series

Patch

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);