ipi_get_hwirq(9)

💅 ipi_get_hwirq 💅

okay bestie, welcome to the Kernel API Manual — section 9, no big deal, just your girl explaining how to grab the hwirq for an IPI headed to a CPU. iykyk 🎀

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✨ NAME ✨

ipi_get_hwirq — literally just: get the hwirq associated with an IPI to a CPU. that's the whole vibe. 🦋

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🌸 SYNOPSIS 🌸

irq_hw_number_t ipi_get_hwirq (unsigned int irq , unsigned int cpu );

copy it exactly like that, no cap. the spaces are part of the ~aesthetic~ and also part of the actual signature, so don't get cute with it 💅

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🎀 ARGUMENTS 🎀

• irq — the Linux IRQ number. yes, the normal one. the Linux-y one. 🐧
• cpu — the target CPU. like, the CPU you're aiming at. main character CPU. 👑

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💖 DESCRIPTION 💖

okay so here's the situation. when you're dealing with coprocessors and their IPIs, you gotta tell the coprocessor which hwirq it needs to use — both to receive and to send IPIs. that's it. that's the whole reason this function exists. it's giving middleman energy and honestly? iconic. ✨

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🔥 RETURN 🔥

on success you get the hwirq value 🎉

on failure you get INVALID_HWIRQ 💀 — so like, check it. fr fr.

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🌈 SEE ALSO 🌈

check out the kernel file ./kernel/irq/ipi.c for the whole squad:

• irq_reserve_ipi(9)
• irq_destroy_ipi(9)
• __ipi_send_single(9)
• __ipi_send_mask(9)
• ipi_send_single(9)
• ipi_send_mask(9)

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🫶 friendly reminder bestie: this page lives in ./kernel/irq, and it's dated October 2026. that's the source/version deets and the date, all wrapped up cute so you never have to wonder. slay, go read ipi.c, mwah 💜🧚