libnvme(9)

💅 libnvme(9) — okay bestie, let's talk about enum nvme_lm_queue_attributes

Hi hi hiii 🫶 so this is a page from the libnvme API manual (section 9, iykyk), and today's main character is this enum. Lowkey it's a whole vibe check for how the controller tells you stuff about its I/O submission and I/O completion queues — masks and shifts, masks and shifts, that's the energy. Let's get into it ✨

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🌸 NAME

enum nvme_lm_queue_attributes — I/O Submission and I/O Completion Queue Attributes.

That's it, that's the name. Short, iconic, does exactly what it says on the tin 💅

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🦋 SYNOPSIS

enum nvme_lm_queue_attributes {
    NVME_LM_IOSQPC_MASK ,
    NVME_LM_IOSQPC_SHIFT ,
    NVME_LM_IOSQPRIO_MASK ,
    NVME_LM_IOSQPRIO_SHIFT ,
    NVME_LM_IOCQPC_MASK ,
    NVME_LM_IOCQPC_SHIFT ,
    NVME_LM_IOCQIEN_MASK ,
    NVME_LM_IOCQIEN_SHIFT ,
    NVME_LM_S0PT_MASK ,
    NVME_LM_S0PT_SHIFT ,
    NVME_LM_IOCQIV_MASK ,
    NVME_LM_IOCQIV_SHIFT

};

Twelve entries, all dressed up with nowhere to go except straight into your bit-twiddling ✨ Every one of them is either a _MASK or a _SHIFT, and honestly? That's the whole personality.

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🎀 Constants

Grab a snack 🍓 — here's every single one, no skips, no cap.

• NVME_LM_IOSQPC_MASK — the mask that snags the Physically Contiguous (PC) bit for this I/O submission queue.
• NVME_LM_IOSQPC_SHIFT — the shift that gets you the PC bit for this I/O submission queue.
• NVME_LM_IOSQPRIO_MASK — the mask that pulls out the Priority for this I/O submission queue.
• NVME_LM_IOSQPRIO_SHIFT — the shift that gets you the Priority for this I/O submission queue.
• NVME_LM_IOCQPC_MASK — the mask for the Physicaly Contiguous (PC) bit for this I/O completion queue.

🫶 tiny heads-up: yes, the original spells it "Physicaly" — that's literally how it's written in the doc, so we're keeping it exactly as-is. No autocorrect in this house 💅

• NVME_LM_IOCQPC_SHIFT — the shift that gets you the PC bit for this I/O completion queue.
• NVME_LM_IOCQIEN_MASK — the mask that grabs the Interrupts Enabled bit for this I/O completion queue.
• NVME_LM_IOCQIEN_SHIFT — the shift that gets you the Interrupts Enabled bit for this I/O completion.
• NVME_LM_S0PT_MASK — the mask that fishes out the value of the Phase Tag bit for Slot 0 of this I/O completion queue.
• NVME_LM_S0PT_SHIFT — the shift that gets you the value of the Phase Tag bit for Slot 0 of this I/O completion queue.
• NVME_LM_IOCQIV_MASK — the mask that pulls the Interrupt Vector (IV) for this I/O completion queue.
• NVME_LM_IOCQIV_SHIFT — the shift that gets you the IV for this I/O completion queue.

Mask then shift, mask then shift — it's giving choreography 🔥 You & with the mask, you >> by the shift, and boom, the field is yours. That's the pattern for every single pair up there, no exceptions, fr fr.

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💜 That's the whole page bestie — all twelve constants, accounted for, nothing dropped. Go forth and bit-twiddle responsibly.

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And that's a wrap! 🌈 This was libnvme(9) — source/version is libnvme, dated October 2026 📅 mwah, drink some water, and may your queues always be properly masked 💖🎀🦋