cpumask fallout: Initialize irq_default_affinity earlier et al. (v3)

This seems to have fallen through the cracks, so I am resending:

Now that mips/OCTEON support has been merged, this patch set has slightly more urgency.

The interrupt affinity on OCTEON is determined by irq_default_affinity, as that is what the code in kernel/irq/manage.c uses to set affinity. Since for the majority of devices (Serial, Compact Flash, Network...) we want interrupts to be handled on a single CPU, we set irq_default_affinity to the boot CPU in init_IRQ(). The problem we have is that with the new cpumask infrastructure, irq_default_affinity is being initialized in core_initcall which undoes our initialization.

As I said in 2/2:

Move the initialization of irq_default_affinity to early_irq_init as core_initcall is too late.

irq_default_affinity can be used in init_IRQ and potentially timer and SMP init as well. All of these happen before core_initcall. Moving the initialization to early_irq_init ensures that it is initialized before it is used.

Mike Travis pointed out that irq_default_affinity depends on CONFIG_GENERIC_HARDIRQS in addition to CONFIG_SMP. So to make things consistent, I added 1/2 so that the irq_*_affinity functions and irq_default_affinity are defined for the same conditions that they are declared.

I Took Linus' suggestion to move init_irq_default_affinity over to kernel/irq/handle.c, however due to the way that cpumask_*() are defined, it is still necessary to have the ugly ifdefs, but now they are localized to init_irq_default_affinity.

Mike Travis also suggested that alloc_bootmem_cpumask_var() be used in preference to alloc_cpumask_var, so I incorporated that suggestion as well.

I tested both with and without CONFIG_SMP, on mips/cavium_octeon, Mike tested a similar(but not identical patch) on x86_64.

Changes from v2 of this set are just a small rearrangement of the #ifdefs suggested by Ihar Hrachyshka that make the code look a bit cleaner.

I will reply with the two patches.

David Daney (2):
Make irq_*_affinity depend on CONFIG_GENERIC_HARDIRQS too. cpumask fallout: Initialize irq_default_affinity earlier (v3).

kernel/irq/handle.c |   16 ++++++++++++++++
kernel/irq/manage.c |   10 +---------
2 files changed, 17 insertions(+), 9 deletions(-)