intel_gt_mc...ast_write_fw(9)

💅 NAME 💅

ok so bestie, welcome to the Kernel API Manual</p> ✨ this page is all about intel_gt_mcr_multicast_write_fw — and what it does is, like, write a value to all instances of an MCR register. yep. all of them. every single one. no cap 🫶

(also yes the page title up top is all smushed like intel_gt_mc...ast_write_fw(9) — that's just the terminal doing its little truncation thing, the real name is the full one, iykyk 💅)

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✨ SYNOPSIS ✨

void intel_gt_mcr_multicast_write_fw (struct intel_gt *gt ,
i915_mcr_reg_t reg , u32 value );

like literally that's the whole signature, she's not complicated 💖

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🎀 ARGUMENTS 🎀

• gt — the GT structure 🌸 that's your graphics tile situation, she's the main character here
• reg — the MCR register to write 👑 the one you're targeting
• value — value to write ✨ like, the actual number going in. that's it. that's the payload

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🦋 DESCRIPTION 🦋

okay so 🫶 what this does is: it writes an MCR register in multicast mode to update all instances. all of them at once. one write, every instance, slay 💅

⚠️ but hear me out — this function assumes the caller is already holding any necessary forcewake domains. it does not grab them for you. so if you haven't sorted your forcewake, that's on you bestie 😭

and if you're in a situation where forcewake should be obtained automatically, then don't use this one — use intel_gt_mcr_multicast_write instead. that's literally what she's for 🧚

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🔥 CONTEXT 🔥

the one rule, the vibe check you must pass:

The caller must hold gt->mcr_lock.

no lock, no write. periodt 💀 like please don't skip this, the kernel will simply not be having a good time 🙈

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🌈 SEE ALSO 🌈

• Kernel file ./drivers/gpu/drm/i915/gt/intel_gt_mcr.c
• GT Multicast/Replicated (MCR) Register Support(9) — the big one, start here fr fr
• intel_gt_mcr_lock(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) — the auto-forcewake one 💖
• 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)

like the whole MCR friend group is linked here, go say hi 🎀

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and that's the whole page bestie, you ate 💅✨ this icon came out of ./drivers/gpu/drm/i915/gt, dated October 2026, and she's serving full Kernel API Manual energy 🌸🦋 go forth and multicast responsibly 💜