platform_de...d_alloc_irqs(9)

📦 version 7.3.1, in nixpkgs unstable

💅 platform_device_msi_init_and_alloc_irqs — the glow-up your platform device deserves

okay so bestie, this page is from the Kernel API Manual, and the function name is a whole mouthful — platform_device_msi_init_and_alloc_irqs — but honestly? It's giving "set up my device's interrupts so it can actually slay". Let's get into it. ✨

🎀 SYNOPSIS 🎀

int platform_device_msi_init_and_alloc_irqs (struct device *dev ,
unsigned int nvec , irq_write_msi_msg_t write_msi_msg );

three args, one int coming back at you. no cap, that's the whole vibe. 💖

🌸 ARGUMENTS 🌸

  • dev — the device you're doing all this for 🫶 literally the main character here, the one getting interrupts allocated to it.
  • nvec — the number of interrupts to allocate. yes, nvec like "n vectors" — she's numeric and she's ready. 🔥
  • write_msi_msg — a callback (type irq_write_msi_msg_t) that writes an interrupt message for dev. you bring the function, she does the writing. 🎀

⭐ RETURN ⭐

  • Zero for success 🎉 (the good ending)
  • or an error code in case of failure 😭 (the not-so-good ending)

🦋 DESCRIPTION 🦋

so here's the tea ☕: this creates a MSI domain on dev, and that new domain has dev->msi.domain as its parent. The parent domain is the one that sets up the new domain — she's the mentor, the new one is the mentee. 🧚

The domain has a fixed size of nvec — it is not adjustable, it's set, periodt. 💅

And the best part? The domain is managed by devres ✨ which means it gets removed automatically when the device is removed. no manual cleanup, no leftover mess, we love a self-cleaning situation. 🌈

👑 SEE ALSO 👑

lowkey reminder: the domain's size is fixed at nvec, so don't come back later expecting to resize her. she is as she is. 🫶

anyway that's the whole page, bestie 💜 — big kisses from ./drivers/base, this drop is from October 2026, and it lives in the Kernel API Manual. go forth and allocate those interrupts, you iconic legend 👑✨🍓

📦 where this page comes from