irq-number in interrupt handlers

[Wolfram Sang]

Hello,

I am porting a device driver to RTAI. The driver should be able to 
handle up to four devices, each assigned to its own IRQ. To distinguish 
them, it would be helpful if the interrupt handler would get the current 
irq-number as a parameter on startup. Now, rt_request_gloabal_irq 
prototypes handlers as 'void handler(void)'. Digging in this 
mailing-list-archieve I have seen people simply defining a handler like 
'void handler(int irq)'. But mostly those people often wondered about 
crashes :) My question is: Can I really do this 'void handler(int irq)' 
or is there another way to get the current IRQ-number? I looked into 
rtHOWTO and RTAI_Prog_Guide, too, but couldn't find a hint.

Best wishes

    Wolfram Sang