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

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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' ....
 
Thanks,

	tglx
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[PATCH 0/6] Implement generic IPI support mechanism Qais Yousef <qais.yousef@imgtec.com> - 2015-09-23 16:50 +0200
  [PATCH 1/6] irqdomain: add new IRQ_DOMAIN_FLAGS_IPI Qais Yousef <qais.yousef@imgtec.com> - 2015-09-23 16:50 +0200
  [PATCH 2/6] irqdomain: add a new send_ipi() to irq_domain_ops Qais Yousef <qais.yousef@imgtec.com> - 2015-09-23 16:50 +0200
    Re: [PATCH 2/6] irqdomain: add a new send_ipi() to irq_domain_ops Jiang Liu <jiang.liu@linux.intel.com> - 2015-09-23 18:50 +0200
      Re: [PATCH 2/6] irqdomain: add a new send_ipi() to irq_domain_ops Qais Yousef <qais.yousef@imgtec.com> - 2015-09-24 10:20 +0200
  [PATCH 5/6] irqchip: mips-gic: add a IPI hierarchy domain Qais Yousef <qais.yousef@imgtec.com> - 2015-09-23 17:00 +0200
  [PATCH 6/6] irqchip: mips-gic: use the new generic IPI API Qais Yousef <qais.yousef@imgtec.com> - 2015-09-23 17:00 +0200
  [PATCH 4/6] irq: add a new generic IPI handling code to irq core Qais Yousef <qais.yousef@imgtec.com> - 2015-09-23 17:00 +0200
    Re: [PATCH 4/6] irq: add a new generic IPI handling code to irq core Jiang Liu <jiang.liu@linux.intel.com> - 2015-09-23 19:00 +0200
      Re: [PATCH 4/6] irq: add a new generic IPI handling code to irq core Qais Yousef <qais.yousef@imgtec.com> - 2015-09-24 10:30 +0200
        Re: [PATCH 4/6] irq: add a new generic IPI handling code to irq  core Thomas Gleixner <tglx@linutronix.de> - 2015-09-29 18:20 +0200
  [PATCH 3/6] irqdomain: add struct irq_hwcfg and helper functions Qais Yousef <qais.yousef@imgtec.com> - 2015-09-23 17:00 +0200
  Re: [PATCH 0/6] Implement generic IPI support mechanism Jiang Liu <jiang.liu@linux.intel.com> - 2015-09-23 19:00 +0200
    Re: [PATCH 0/6] Implement generic IPI support mechanism Qais Yousef <qais.yousef@imgtec.com> - 2015-09-24 10:40 +0200
      Re: [PATCH 0/6] Implement generic IPI support mechanism Thomas Gleixner <tglx@linutronix.de> - 2015-09-29 22:50 +0200
        Re: [PATCH 0/6] Implement generic IPI support mechanism Qais Yousef <qais.yousef@imgtec.com> - 2015-09-30 15:40 +0200
          Re: [PATCH 0/6] Implement generic IPI support mechanism Thomas Gleixner <tglx@linutronix.de> - 2015-09-30 16:10 +0200
            Re: [PATCH 0/6] Implement generic IPI support mechanism Qais Yousef <qais.yousef@imgtec.com> - 2015-09-30 16:10 +0200

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