core-api/irq/irq-domain.rst

229 interrupt controller and those irq_domains are organized into hierarchy.
230 When building irq_domain hierarchy, the irq_domain near to the device is
231 child and the irq_domain near to CPU is parent. So a hierarchy structure
242 There are four major interfaces to use hierarchy irq_domain:
253 The following is needed to support hierarchy irq_domain:
256    maintain irq_domain hierarchy information.
258    build hierarchy irq_data to match hierarchy irq_domains. The
262    struct irq_domain_ops to support hierarchy irq_domain operations.
264 With the support of hierarchy irq_domain and hierarchy irq_data ready,
269 For an interrupt controller driver to support hierarchy irq_domain, it
278    irq_domain_ops.unmap(). They are unused with hierarchy irq_domain.
280 Note the hierarchy irq_domain is in no way x86-specific, and is
286 Now, we could go one step further to support stacked (hierarchy)
288 the hierarchy. A child irq_chip may implement a required action by