RE: Thoughts about the new X.2 spec...

[Volkmar Uhlig]

> I was already thinking ahead w.r.t. a driver architecture 
> which resembles
> somewhat this:
> 
>  +------------------------+
>  |   Int-Handler thread   |
>  | ...................... |          +----------+
>  |  list of reg. drivers  |--------->| Driver 1 |
>  +------------------------+\         +----------+
>                             \        +----------+
>                              \------>| Driver 2 |
>                               \      +----------+
>                                \     +----------+
>                                 \--->| Driver 3 |
>                                      +----------+
> 
> Here, Driver 1, 2 or 3 would map the IO fpages from Int-Handler
> instead of getting the data in messages. IPCs from the int handler
> to the drivers would only function as triggers/notifications.

Interrupt messages are delivered to _exactly_ one thread. Hence, any
distribution scheme is a user policy. The thread which got the IRQ
messages also is the only one which can re-enable the IRQ. A potential
forwarding scheme is in sight but not fully sorted out yet (read:
evaluated and specified).

- Volkmar