devm_cxl_add_region(9)

✨ NAME ✨

okay so bestie, welcome to devm_cxl_add_region(9) from the Kernel API Manual 💅 this one adds a region to a decoder, and it's giving important kernel-core energy 🎀

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🌸 SYNOPSIS 🌸

struct cxl_region * devm_cxl_add_region (struct cxl_root_decoder *cxlrd
, int id , enum cxl_partition_mode mode , enum cxl_decoder_type type );

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🦋 ARGUMENTS 🦋

• cxlrd — the root decoder 👑 no cap, that's the whole vibe.
• id — the memregion id to create, or memregion_free on failure 🫶
• mode — the mode for the endpoint decoders of this region ✨
• type — select whether this is an expander or accelerator (type-2 or type-3) 💖

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🎀 DESCRIPTION 🎀

This is the second step of region initialization, bestie. Regions exist within an address space which is mapped by a cxlrd 🌈 that's the whole setup, and this function is here to add one to the decoder.

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🔥 RETURN 🔥

Returns 0 if the region was added to the cxlrd, else returns a negative error code 😭

The region will be named "regionZ" where Z is the unique region number — yes, literally "regionZ", iconic naming fr fr ⭐

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💜 SEE ALSO 💜

• Kernel file ./drivers/cxl/core/region.c
• cxl core region(9)
• cxl_port_pick_region_decoder(9)
• cxl_port_attach_region(9)
• cxl_calc_interleave_pos(9)
• cxl_validate_translation_params(9)

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made with 💖 from ./drivers/cxl/core, October 2026 — devm_cxl_add_region(9) 🧚✨