Re: switching to interrupt contex when no interrupts

[george anzinger <george@mvista.com>]

arun4linux wrote:
> 
> Hello,
> 
> I used
> 
> asm volatile ("int 41");

That should be: asm volatile ("int $41");
> 
> in my code.
> My card's irq number is 9.
> I get the error message.
> 
> Error: suffix or operabds invalid for 'in'
> 
> This is the case, if I change the 41 to 0x29 or 29h.
> 
> Where can I get some documentation on using asm?

I use the info file that comes with gcc.  In emacs it is
^Hi, then search for gcc.  There is also an info program for
browsing the info stuff, but I don't use it so don't know
much about it.

-g
> 
> Warm Regards
> Arun
> 
> "george anzinger" wrote:
> 
> george anzinger wrote:
> >
> > arun4linux wrote:
> > >
> > > Hello,
> > >
> > > <> > interrupt handler.
> > > >>Yes. But my requirement is to force my code to run in interrupt context.
> > >
> > > <> >
> > > You will get a better answer from the list if you describe what you are trying to do (in concrete terms), not how you think you might do it.
> > >
> > > >>My requirement is to simulate a PCI based controller and its behaviour in software. I knew the different type of interrupts and the timings my device produces.
> > >
> > > I need to simulate this PCI device, its interrupts in sequence and I have to process them in my driver software.
> > >
> > > Hope this make sense now.
> > >
> > > Anyway, my requrirement is to simulate the interrupts and process them in the interrupt context.
> > >
> > > It would be helpful, if anyone could help me how to do it.
> > > My idea is to use task queues and bottom halves for this. But I'd like to get clarified on simulating interrupts (rasing the process/task context to interrupt context) and its consequences.
> > >
> > Why simulate the interrupts when you can just program them?
> > On the x86 machine the "int x" instruction generates an
> > interrupt to irq "x"+32. You do need to be in kernel land
> > to do this, but then I assume that is not a problem.
> 
> Uh, make that "x"-32, i.e. "int 34" give irq 2.
> 
> -g
> >
> > -g
> >
> > >
> > > Thanks & Warm Regards
> > > Arun
> > >
> > > "John K Luebs" wrote:
> > >
> > > On Sat, Nov 23, 2002 at 07:37:33AM +0530, arun4linux wrote:
> > > > Hello,
> > > >
> > > > I'd like to force my kernel module to run at interrupt context at some specific points/time and then come back from interrrupt contex after executing that particular portion of code..
> > >
> > > You seem to be over complexifying what interrupt context is. It is
> > > simply a generic term for a context that executes on account of an
> > > architecture interrupt. One is forced to run in interrupt context in an
> > > interrupt handler.
> > >
> > > You "run" in interrupt context by calling request_irq attached to the
> > > interrupt line that you are interested in installing a handler for.
> > >
> > > >
> > > > Is it possible?
> > >
> > > Possibility is undefined here because what you said makes no sense.
> > >
> > > You will get a better answer from the list if you describe what you are
> > > trying to do (in concrete terms), not how you think you might do it.
> > >
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> > --
> > George Anzinger george@mvista.com
> > High-res-timers:
> > http://sourceforge.net/projects/high-res-timers/
> > Preemption patch:
> > http://www.kernel.org/pub/linux/kernel/people/rml
> > -
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> 
> --
> George Anzinger george@mvista.com
> High-res-timers:
> http://sourceforge.net/projects/high-res-timers/
> Preemption patch:
> http://www.kernel.org/pub/linux/kernel/people/rml
> 
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-- 
George Anzinger   george@mvista.com
High-res-timers: 
http://sourceforge.net/projects/high-res-timers/
Preemption patch:
http://www.kernel.org/pub/linux/kernel/people/rml