From 55567976629e58fde28fb70612ca73228271eef2 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 6 Oct 2020 10:10:20 +0100 Subject: genirq/irqdomain: Allow partial trimming of irq_data hierarchy It appears that some HW is ugly enough that not all the interrupts connected to a particular interrupt controller end up with the same hierarchy depth (some of them are terminated early). This leaves the irqchip hacker with only two choices, both equally bad: - create discrete domain chains, one for each "hierarchy depth", which is very hard to maintain - create fake hierarchy levels for the shallow paths, leading to all kind of problems (what are the safe hwirq values for these fake levels?) Implement the ability to cut short a single interrupt hierarchy from a level marked as being disconnected by using the new irq_domain_disconnect_hierarchy() helper. The irqdomain allocation code will then perform the trimming Signed-off-by: Marc Zyngier --- include/linux/irqdomain.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/irqdomain.h') diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index b37350c4fe37..a52b095bd404 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -509,6 +509,9 @@ extern void irq_domain_free_irqs_parent(struct irq_domain *domain, unsigned int irq_base, unsigned int nr_irqs); +extern int irq_domain_disconnect_hierarchy(struct irq_domain *domain, + unsigned int virq); + static inline bool irq_domain_is_hierarchy(struct irq_domain *domain) { return domain->flags & IRQ_DOMAIN_FLAG_HIERARCHY; -- cgit