[VirtLayer] Changes to the interrupt handling in POK

[Cláudio Silva]

That's it! I didn't get that dual handler design from the implementation on
your blog.
You should also transition to "user mode" before calling the RTEMS handler.



On Sun, Aug 18, 2013 at 7:33 PM, Philipp Eppelt <
philipp.eppelt at mailbox.tu-dresden.de> wrote:

> Hi,
>
> why only talking about it and not implementing it right away? ;)
>
> POK administers now one meta_handler per HW IRQ line. Each meta_handler
> consists of a vector number and table of the size
> POK_CONFIG_NB_PARTITION + 1. So the meta_handler can administer one
> handler per partition and one handler for the kernel. The clock tick,
> for instance, needs a kernel handler and can now be forwarded to a
> partition.
> The kernel handler is invoked on each interrupt before the partition
> handler is called.
> So there is no overruling of the POK kernel.
>
> As far as I tested it, the partition handler runs side by side with the
> kernel handler with a constant offset, as it is registered later in time.
>
> Cheers,
> Philipp
>
>
>
>
> On 08/18/2013 08:01 PM, Cláudio Silva wrote:
> > Ok. That clarifies the next steps.
> > You are correct;  POK should be tested first without RTEMS integration.
> > My question was more about the separation between the RTEMS part of the
> > interrupt handler and the POK part. If RTEMS registers a handler it will
> > monopolize it; i.e. there is no possibility to run a POK handler and
> > then an RTEMS handler. This is required to maintain segregation and to
> > prevent RTEMS from interfering with POK. If RTEMS registers a handler
> > for a vector already user by POK (e.g. clock tick interrupt), POK cannot
> > be overruled and be dependent on RTEMS to run its own code. But for a
> > first iteration it's OK to ignore this.
> >
> >
> > Cláudio
> >
> >
> >
> > On Sun, Aug 18, 2013 at 3:03 PM, Philipp Eppelt
> > <philipp.eppelt at mailbox.tu-dresden.de
> > <mailto:philipp.eppelt at mailbox.tu-dresden.de>> wrote:
> >
> >     Hi,
> >
> >     currently I have no RTEMS partition running on POK, as these changes
> >     must first be validated with pure POK partitions. Also I haven't
> written
> >     the code to get a interrupt handler through the partition
> abstraction.
> >     CLOCK_HANDLER is a macro which is incrementing the tick counter and
> >     invoking the scheduler in the POK kernel.
> >
> >     To register IRQ handlers from a partition, e.g. an RTEMS partition, I
> >     need to create a new syscall first, to get the callback function into
> >     the meta_handler list.
> >
> >     So when RTEMS tries to attach to an interrupt, the virtualization
> layer
> >     implementation of POK is invoked and registers a predefined handler
> via
> >     a syscall with the meta_handler for this irq number. When the
> interrupt
> >     occurs the registered handler is invoked with the vector number as an
> >     argument. Then the handler invokes C_dispatch_isr() in RTEMS passing
> the
> >     vector number along.
> >
> >     That's the plan, for the next week.
> >
> >     Cheers,
> >     Philipp
> >
> >
> >     On 08/18/2013 02:45 PM, Cláudio Silva wrote:
> >     > Good job Philipp. It seems a nice first iteration for interrupt
> >     > virtualization. Did you get to try it?
> >     > If I got it right, the POK part of the interrupt handler
> >     (CLOCK_HANDLER
> >     > ??) is running after the virtualized RTEMS handler?
> >     >
> >     > Regards,
> >     > Cláudio
> >     >
> >     >
> >     > On Sun, Aug 18, 2013 at 12:18 AM, Philipp Eppelt
> >     > <philipp.eppelt at mailbox.tu-dresden.de
> >     <mailto:philipp.eppelt at mailbox.tu-dresden.de>
> >     > <mailto:philipp.eppelt at mailbox.tu-dresden.de
> >     <mailto:philipp.eppelt at mailbox.tu-dresden.de>>> wrote:
> >     >
> >     >     Hi,
> >     >
> >     >     lately I worked a lot to extend POK with necessary features to
> >     >     accommodate an RTEMS partition.
> >     >     Since hello world works, I need a way to pass clock ticks to
> >     the RTEMS
> >     >     partition running on POK. Therefore the interrupt handling
> >     needs to
> >     >     support custom handlers.
> >     >
> >     >     If everything works out, I can enable the virtualization layer
> to
> >     >     register an interrupt vector and if it occurs RTEMS is
> notified by
> >     >     invoking C_dispatch_isr().
> >     >
> >     >     Blog:
> >     >
> >
> http://phipse.github.io/rtems/blog/2013/08/17/pok-hardware-interrupt-handling/
> >     >
> >     >     Source:
> >     >     https://github.com/phipse/pok
> >     >
> >     >     Cheers,
> >     >     Philipp
> >     >     _______________________________________________
> >     >     rtems-devel mailing list
> >     >     rtems-devel at rtems.org <mailto:rtems-devel at rtems.org>
> >     <mailto:rtems-devel at rtems.org <mailto:rtems-devel at rtems.org>>
> >     >     http://www.rtems.org/mailman/listinfo/rtems-devel
> >     >
> >     >
> >
> >
>
>
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