Re: [Xen-devel] [RFC PATCH V3 16/22] Introduce some macros for event channels

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 27.02.13 at 18:04, Ian Campbell <Ian.Campbell@xxxxxxxxxx> wrote:
> On Wed, 2013-02-27 at 16:53 +0000, Jan Beulich wrote:
>> >>> On 27.02.13 at 15:34, Wei Liu <wei.liu2@xxxxxxxxxx> wrote:
>> > --- a/xen/include/asm-arm/types.h
>> > +++ b/xen/include/asm-arm/types.h
>> > @@ -41,10 +41,13 @@ typedef char bool_t;
>> >  #define test_and_clear_bool(b) xchg(&(b), 0)
>> >  
>> >  #endif /* __ASSEMBLY__ */
>> > +#define BYTE_BITORDER  3
>> > +#define BITS_PER_BYTE  (1 << BYTE_BITORDER)
>> >  
>> > -#define BITS_PER_LONG 32
>> > -#define BYTES_PER_LONG 4
>> > +#define BITS_PER_LONG  (1 << LONG_BITORDER)
>> >  #define LONG_BYTEORDER 2
>> > +#define LONG_BITORDER  (LONG_BYTEORDER + BYTE_BITORDER)
>> > +#define BYTES_PER_LONG (1 << LONG_BYTEORDER)
>> 
>> Is that all really correct and complete in the context of arm64 and
>> an ABI-long not being 32 bits on arm32?
> 
> This header is about the internal types, I think, and so should
> represent the compiler's idea of what the actual long type is for the
> benefit of common code.
> 
> Of course if these are also being used for ABI things, this is a bug on
> ARM.

Wei - could you please clarify/double check? I was under the
impression that these were used e.g. for thing like the event
channel bit maps and selector words, and those are clearly
xen_ulong_t, not unsigned long.

Thanks, Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel