[U-Boot] [PATCH 3/5] Data type defined for pointer addresses

[York Sun]

On 12/07/2015 09:14 AM, Scott Wood wrote:
> On Mon, 2015-12-07 at 12:08 -0500, Tom Rini wrote:
>> On Mon, Dec 07, 2015 at 08:50:28AM -0800, York Sun wrote:
>>> Guys,
>>>
>>> Please comment on this new typedef. I am not comfortable to accept it.
>>>
>>> On 11/18/2015 09:41 PM, Aneesh Bansal wrote:
>>>> A new data type uintptr_t has been defined for creating
>>>> pointers (32 or 64 bit depending on Core) from 32 bit variables
>>>> storing the address.
>>>> If a 32 bit variable (u32) is typecasted to a pointer (void *),
>>>> compiler gives a warning in case size of pointer on the core is 64 bit.
>>>>
>>>> Signed-off-by: Aneesh Bansal <aneesh.bansal at freescale.com>
>>>> ---
>>>>  arch/arm/include/asm/types.h     | 2 ++
>>>>  arch/powerpc/include/asm/types.h | 1 +
>>>>  2 files changed, 3 insertions(+)
>>>>
>>>> diff --git a/arch/arm/include/asm/types.h b/arch/arm/include/asm/types.h
>>>> index 388058e..5555765 100644
>>>> --- a/arch/arm/include/asm/types.h
>>>> +++ b/arch/arm/include/asm/types.h
>>>> @@ -56,6 +56,8 @@ typedef unsigned long phys_addr_t;
>>>>  typedef unsigned long phys_size_t;
>>>>  #endif
>>>>  
>>>> +typedef unsigned long uintptr_t;
>>>
>>> It is used in next patch of this series
>>> http://patchwork.ozlabs.org/patch/552669/, in two-step casting such as
>>>
>>> (u8 *)(uintptr_t)csf_hdr_addr
>>>
>>> As OP indicated, the variable is u32. Casting to a pointer causes
>>> compiling
>>> warning. Is this the right approach?
>>
>> Approach is OK.  But please do it as a "backport" of 142956af from the
>> linux kernel which adds 142956af to <linux/types.h> so everyone has it.
> 
> There's also an existing uintptr_t typedef in include/compiler.h...
> 

Tom,

We seem not having the abuse of ptrdiff_t. So the equivalent of Linux commit
142956af would be moving this typedef from include/compiler.h to
include/linux/types.h.

York