Not sure about that. These functions are solely used by x86 and there
is really no need to generalize them. The problem you try to solve is
x86/xen specific and can be solved by x86_platform_ops as well w/o
adding extra function pointers to irq_chip.
Err, that argument is totally bogus. The calling convention of
irq_to_desc_alloc_node and arch_init_chip_data/arch_init_irq_desc is
still the same. It does not explain why the heck we need that function
pointer at all.
AFAICT the function pointer to irq_to_desc_alloc_node is completely
pointless. It just solves a Xen/x86 specific problem which can be
solved by using x86_platform_ops and keeps the churn x86 internal.
Aside of the general objection against this, please use descriptive
function names and do not distinguish functions by adding random
characters which tell us absolutely nothing about the purpose.