Exactly, I mean ppc_md.init_IRQ(). Ok. What have I to setup in this function ? I set the mask and other registers. Is it right ? How do I chose the mask ? At the end of this funtion, IRQ are disable. Is that right ? So who does enable IRQs ?
Sorry for all this questions, I am learning the low layer of Linux. 2008/8/21, Michael Ellerman <[EMAIL PROTECTED]>: > > On Thu, 2008-08-21 at 09:13 +0200, Sébastien Chrétien wrote: > > Hello, > > > > What are the constraints in order to implement a irq_init function ? > > > You mean ppc_md.init_IRQ() ? > > If so, it's a hook you can use to setup your interrupt controller. It's > called from init_IRQ() (arch/powerpc/kernel/irq.c), which is called from > start_kernel() (init/main.c). > > Not long after it is called irqs are enabled. I think it is the last > callback into arch code before irqs are enabled. > > When it is called the device tree is unflattened, so you can use the of_ > API. Bootmem is setup so you can use alloc_bootmem(), but you can't > kmalloc yet. ioremap should work. > > > > > What is the aim or get_irq ? Does it retun an information about the > > mask, the states, or... ? > > > The aim of ppc_md.get_irq() ? It's called from do_IRQ() > (arch/powerpc/kernel/irq.c) which is called from assembler in the > appropriate head_x.S > > It just returns the number (virtual number) of the irq that just fired. > If for some reason you took a spurious interrupt it should return > NO_IRQ. > > I'm not sure what you mean about masks or states, someone else might > though. > > cheers > > -- > Michael Ellerman > OzLabs, IBM Australia Development Lab > > wwweb: http://michael.ellerman.id.au > phone: +61 2 6212 1183 (tie line 70 21183) > > We do not inherit the earth from our ancestors, > we borrow it from our children. - S.M.A.R.T Person > >
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