Messages in this thread | | | From | (Eric W. Biederman) | Subject | Re: [RFC] killing the NR_IRQS arrays. | Date | Sat, 17 Feb 2007 02:06:43 -0700 |
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Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:
> In addition, if we remove the numbers, archs will need basically the > exact same services provided by the powerpc irq core for reverse mapping > (going from a HW irq number on a given PIC back to an irq_desc *).
Ben you seem to be under misapprehension that except for the case of ISA (0-16) the linux IRQ number is a hardware number. It is an arbitrary software enumeration, and I think it has been that way a very long time.
> Either using a linear array for simple PICs or a radix tree for > platforms with very big interrupt numbers (BTW. I think we have lockless > radix trees nowadays, I can remove the spinlocks to protect it in the > powerpc remapper).
I can only tell you that my impression of this last is that all the world's not a PPC.
I have a version of the x86 code with a partial conversion done and I didn't need a reverse mapping. What you call the hardware interrupt number never happens to be interesting to me after the system is setup.
I do suspect there may be an interesting chunk of your ppc work that probably makes sense as a library so other arches could use it.
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