generic_handle_domain_nmi(9)

💅 generic_handle_domain_nmi — Kernel API Manual, bestie edition ✨

Okay so picture this: you're deep in the kernel, you've got a hardware NMI that belongs to a domain, and somebody's gotta actually invoke the handler for it. That's this function. It's giving "middle management for interrupts" and honestly it ate. 🎀

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🌸 NAME 🌸

generic_handle_domain_nmi — invoke the handler for a HW nmi belonging to a domain. That's it, that's the whole vibe. 🦋

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✨ SYNOPSIS ✨

int generic_handle_domain_nmi (struct irq_domain *domain ,
       irq_hw_number_t hwirq );

Like, look at her. Two args, one int return, no drama. 🔥

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🫶 ARGUMENTS 🫶

• domain — the domain where to perform the lookup. This is your "where am I even" parameter. 👑
• hwirq — the HW irq number to convert to a logical one. It's the hardware's raw little number, and we're translating it into something the kernel can actually work with. No cap. 💅

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💖 RETURN 💖

0 on success (slay), or -EINVAL if conversion has failed 😭 — which, lowkey, means the lookup didn't work out. It's not you, it's the numbers.

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🌈 DESCRIPTION 🌈

So here's the important part, and I need you to listen: this function must be called from an NMI context with irq regs initialized. Not optional. Not "if you feel like it." It's a whole requirement, periodt. 🙈

No fr fr, if you're not in NMI context with the irq regs initialized, this is not the function for you. Read the room.

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🧚 SEE ALSO 🧚

Kernel file ./kernel/irq/irqdesc.c — go read it, bestie, it's iconic:

• irq_get_nr_irqs(9)
• irq_set_nr_irqs(9)
• generic_handle_irq(9)
• generic_handle_irq_safe(9)
• generic_handle_domain_irq(9)
• generic_handle_demux_domain_irq(9)
• irq_free_descs(9)
• __irq_alloc_descs(9)
• irq_get_next_irq(9)
• kstat_irqs_cpu(9)
• kstat_irqs_usr(9)

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And that's the whole page! Mwah 💋 — this gem lives in ./kernel/irq and the docs are stamped October 2026, so if you're reading this from the future, hi, hope the irq regs are initialized. 🍓✨