[PATCH v3 15/20] ARM: LPAE: use phys_addr_t instead of unsigned long for physical addresses

Catalin Marinas catalin.marinas at arm.com
Wed Nov 17 05:47:43 EST 2010


On 16 November 2010 19:33, Russell King - ARM Linux
<linux at arm.linux.org.uk> wrote:
> On Tue, Nov 16, 2010 at 11:14:25AM -0800, Stephen Boyd wrote:
>> On 11/15/2010 09:40 AM, Catalin Marinas wrote:
>> > @@ -188,21 +189,21 @@
>> >   * translation for translating DMA addresses.  Use the driver
>> >   * DMA support - see dma-mapping.h.
>> >   */
>> > -static inline unsigned long virt_to_phys(void *x)
>> > +static inline phys_addr_t virt_to_phys(void *x)
>> >  {
>> >     return __virt_to_phys((unsigned long)(x));
>> >  }
>>
>> As you're already in the area can you mark the argument to
>> virt_to_phys() as const? I ran into a compiler warning due to that the
>> other day.
>
> It may make sense to mark it const volatile, as that's the most
> permissive set of attributes possible (iow, it'll accept any pointer
> without warning.)  However, might be an idea to check what other
> arches do.

The majority of architectures use volatile and a few add both const
and volatile.

I usually use the generic headers as reference for function prototypes
and that's just using volatile without a const (cc'ing Arnd for any
view on this).

-- 
Catalin



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