Re: [2.6 patch] re-add required code to include/asm-v850/unistd.h

[Arnd Bergmann <arnd@arndb.de>]

On Saturday 07 July 2007, Adrian Bunk wrote:
> 
> Commit f5738ceed46782aea7663d62cb6398eb05fc4ce0 removed a bit too much, 
> resulting in the following compile error:

Sorry about the trouble this has caused you.

>  #ifdef __KERNEL__
>  
> +/* Syscall protocol:
> +   Syscall number in r12, args in r6-r9, r13-r14
> +   Return value in r10
> +   Trap 0 for `short' syscalls, where all the args can fit in function
> +   call argument registers, and trap 1 when there are additional args in
> +   r13-r14.  */
> +
> +#define SYSCALL_NUM    "r12"
> +#define SYSCALL_ARG0   "r6"
> +#define SYSCALL_ARG1   "r7"
> +#define SYSCALL_ARG2   "r8"
> +#define SYSCALL_ARG3   "r9"
> +#define SYSCALL_ARG4   "r13"
> +#define SYSCALL_ARG5   "r14"
> +#define SYSCALL_RET    "r10"
> +
> +#define SYSCALL_SHORT_TRAP     "0"
> +#define SYSCALL_LONG_TRAP      "1"
> +
> +/* Registers clobbered by any syscall.  This _doesn't_ include the syscall
> +   number (r12) or the `extended arg' registers (r13, r14), even though
> +   they are actually clobbered too (this is because gcc's `asm' statement
> +   doesn't allow a clobber to be used as an input or output).  */
> +#define SYSCALL_CLOBBERS       "r1", "r5", "r11", "r15", "r16", \
> +                               "r17", "r18", "r19"
> +
> +/* Registers clobbered by a `short' syscall.  This includes all clobbers
> +   except the syscall number (r12).  */
> +#define SYSCALL_SHORT_CLOBBERS SYSCALL_CLOBBERS, "r13", "r14"
> +

Wouldn't it be more appropriate to just open-code the contents of these
macros in the place where they are used?

Even better probably would be to convert the v850 kernel_thread code
to call do_fork directly, like most other architectures do.

	Arnd <><