Re: [PATCH 0/6] Implement generic IPI support mechanism

[Qais Yousef]

On 09/30/2015 03:03 PM, Thomas Gleixner wrote:
> On Wed, 30 Sep 2015, Qais Yousef wrote:
>
> > On 09/29/2015 09:48 PM, Thomas Gleixner wrote:
> > > 	 Now how these hwirqs are allocated is a domain/architecture
> > > 	 specific issue.
> > >
> > > 	 x86 will just find a vector which is available on all target
> > > 	 cpus and mark it as used. That's a single hw irq number.
> > >
> > > 	 mips and others, which implement IPIs as regular hw interrupt
> > > 	 numbers, will allocate a these (consecutive) hw interrupt
> > > 	 numbers either from a reserved region or just from the
> > > 	 regular space. That's a bunch of hw irq numbers and we need
> > > 	 to come up with a proper storage format in the irqdata for
> > > 	 that. That might be
> > >
> > > 	       struct ipi_mapping {
> > > 		      unsigned int	nr_hwirqs;
> > > 		      unsigned int	cpumap[NR_CPUS];
> > > 	       };
> > Can we use NR_CPUS here? If we run in UP configuration for instance, this will
> > be one. The coprocessor could be outside the NR_CPUS range in general, no?
> >
> > How about
> >
> >                          struct ipi_mapping {
> >                                  unsigned int        nr_hwirqs;
> >                                  unsigned int        nr_cpus;
> >                                  unsigned int        *cpumap;
> >                          }
> >
> > where cpumap is dynamically allocated by the controller which has better
> > knowledge about the supported cpu range it can talk to?
> Sure. As I said: 'That might be' ....
>   


OK thanks. I just wanted to make sure I didn't misunderstand anything.

Will try to send an updated version with all the changes soon.

Thanks,
Qais
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