[PATCH] Emulate sync instruction variants

[David Laight]

> Reserved fields of the sync instruction have been used for other
> instructions (e.g. lwsync).  On processors that do not support variants
> of the sync instruction, emulate it by executing a sync to subsume the
> effect of the intended instruction.
...
> +	/* Emulate sync instruction variants */
> +	if ((instword & PPC_INST_SYNC_MASK) == PPC_INST_SYNC) {
> +		PPC_WARN_EMULATED(sync, regs);
> +		asm volatile ("sync");
> +		return 0;
> +	}

Do you need to execute 'sync' here?
It is worth checking whether the trap entry/exit doesn't
do an implicit one for you.

	David