Re: Add private syscalls to support NPTL

[Maxim Kuvyrkov <maxim@codesourcery.com>]

Andreas Schwab wrote:
> Maxim Kuvyrkov <maxim@codesourcery.com> writes:
> 
>> diff --git a/arch/m68k/include/asm/unistd.h b/arch/m68k/include/asm/unistd.h
>> index aa29a86..619677c 100644
>> --- a/arch/m68k/include/asm/unistd.h
>> +++ b/arch/m68k/include/asm/unistd.h
>> @@ -335,9 +335,16 @@
>>  #define __NR_preadv		329
>>  #define __NR_pwritev		330
>>  
>> +/* Private syscalls.  */
>> +#define __M68K_NR_read_tp		0xffffffff
>> +#define __M68K_NR_write_tp		0xfffffffe
>> +#define __M68K_NR_atomic_cmpxchg_32	0xfffffffd
>> +#define __M68K_NR_atomic_barrier	0xfffffffc
> 
> I don't see the need for these weird syscall numbers.

The need would be (a) use numbers that are very unlikely to used for 
normal syscalls, and (b) using -1..-4 for the syscall numbers works out 
quite nicely for the code in entry.S.  It adds just a couple of 
instructions to the execution path.

Do you think it's better to assign different numbers to the 
m68k-specific syscall?

--
Maxim