intel_gt_mcr_lock(9)

💅 intel_gt_mcr_lock(9) 💅

okay so welcome to the Kernel API Manual, bestie — section 9, and today’s main character is intel_gt_mcr_lock. she’s here to acquire the MCR steering lock, and honestly? iconic behavior. ✨

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🌸 NAME 🌸

intel_gt_mcr_lock — Acquire MCR steering lock 🎀

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✨ SYNOPSIS ✨

void intel_gt_mcr_lock (struct intel_gt *gt , unsigned long *flags );

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🫶 ARGUMENTS 🫶

• gt — GT structure
• flags — storage to save IRQ flags to

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💖 DESCRIPTION 💖

Performs locking to protect the steering for the duration of an MCR operation. no cap, that’s the whole vibe: lock it down so the steering stays protected while the MCR operation does its thing. 💅

On MTL and beyond, a hardware lock will also be taken to serialize access not only for the driver, but also for external hardware and firmware agents. so yeah, it’s not just a driver-only situation — external hardware and firmware agents are in the group chat too. 🔥

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🦋 CONTEXT 🦋

Takes gt->mcr_lock.

uncore->lock should not be held when this function is called — like, seriously, do not hold it — although it may be acquired after this function call. 💀

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🌈 SEE ALSO 🌈

go read these next, bestie, they’re all part of the same lore:

• Kernel file ./drivers/gpu/drm/i915/gt/intel_gt_mcr.c
• GT Multicast/Replicated (MCR) Register Support(9)
• intel_gt_mcr_unlock(9)
• intel_gt_mcr_lock_sanitize(9)
• intel_gt_mcr_read(9)
• intel_gt_mcr_unicast_write(9)
• intel_gt_mcr_multicast_write(9)
• intel_gt_mcr_multicast_write_fw(9)
• intel_gt_mcr_multicast_rmw(9)
• intel_gt_mcr_get_nonterminated_steering(9)
• intel_gt_mcr_read_any_fw(9)
• intel_gt_mcr_read_any(9)
• intel_gt_mcr_get_ss_steering(9)
• intel_gt_mcr_wait_for_reg(9)

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this lil page lives under ./drivers/gpu/drm/i915/gt and is dated October 2026. mwah, love that for us. 💋🎀