On creation of irq_desc and irq_data.
Subhra S. Sarkar
sarkar at g.clemson.edu
Thu Jun 20 22:49:21 EDT 2013
mind entropy <mindentropy <at> gmail.com> writes:
> > Hi,
> > I am reading through mini2440 code. I am going through the init_irq
> > (http://lxr.free-electrons.com/source/arch/arm/mach-s3c24xx/mach-
> > code. In it (http://lxr.free-electrons.com/source/arch/arm/mach-
> > there is irq_domain_add_legacy(..) which references irq_desc and
> > irq_data. I am not sure where these descriptors are created? In the
> > irq_domain_add_legacy there is a lookup for irq_data from the number.
> > Could someone tell where these descriptors are created?
> > Thanks.
> I think it is statically created here
> and the initialization happens in early_irq_init(..) here
> Please correct me if I am wrong.
Within the function definition for irq_domain_add_legacy (), a pointer to
the structure irq_data is obtained [$KERN_HOME/kernel/irq/irqdomain.c, L:
232] by returning from function irq_get_irq_data()
[$KERN_HOME/kernel/irq/chip.c, L: 147]. Function irq_get_irq_data() in turn
retrieves the pointer to corresponding irq_desc structure from array of the
same type in $KERN_HOME/kernel/irq/irqdesc.c, L: 243. So, you're correct,
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