riscv_get_hart_index(9)

💅 riscv_get_hart_index — a Kernel API Manual moment

okay bestie, welcome to riscv_get_hart_index(9) from the Kernel API Manual — yes that's the whole vibe, this is a kernel API page and we're gonna get through it together 🫶

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✨ NAME ✨

riscv_get_hart_index — literally just "get hart index for interrupt delivery". that's the job. that's what she does 💅

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🌸 SYNOPSIS 🌸

int riscv_get_hart_index (struct fwnode_handle *fwnode , u32
logical_index , u32 *hart_index );

yup, that's the whole signature, copied exactly, no notes 👑

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🎀 ARGUMENTS 🎀

• fwnode — the interrupt controller node, that's her 🦋
• logical_index — the index within the "interrupts-extended" property, iykyk
• hart_index — gets filled with the hart index to use ✨

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💜 DESCRIPTION 💜

so RISC-V uses the term "hart index" for its interrupt controllers, specifically for the purpose of interrupt routing to destination harts. and the thing is — these can be arbitrary numbers assigned to each destination hart in the context of a particular interrupt domain. no cap, arbitrary 🔥

these numbers get encoded in the optional property "riscv,hart-indexes", which should contain the hart index for each interrupt destination in the same order as in the "interrupts-extended" property. order matters bestie, we love a matching-order situation 🌈

and if this property does not exist? it's assumed equal to the logical index — i.e. the index within the "interrupts-extended" property. slay, fallback behavior 🙈

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⭐ RETURN ⭐

error code. that's it, that's the return value 💀

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🧚 SEE ALSO 🧚

• Kernel file ./arch/riscv/kernel/irq.c — go read it, it's giving main character energy 👑

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just a lil reminder: keep those property names exactly as written ("riscv,hart-indexes" and "interrupts-extended"), and keep your destinations in order. the kernel is watching 🫶

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and that's the page!! brought to you by ./arch/riscv/kernel, October 2026 edition — mwah, go route some interrupts, bestie 💖✨🎀