cxl_port_pic...gion_decoder(9)

🌸 cxl_port_pic...gion_decoder(9) 🌸

okay so this is a page from the Kernel API Manual bestie, and it's all about cxl_port_pick_region_decoder — yes the header up there is truncated, that's just how it's printed, don't come for me 💅

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✨ NAME ✨

cxl_port_pick_region_decoder — the one where we assign or look up a decoder for a region 🎀

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✨ SYNOPSIS ✨

struct cxl_decoder * cxl_port_pick_region_decoder (struct cxl_port *port
, struct cxl_endpoint_decoder *cxled , struct cxl_region *cxlr );

like, it returns a struct cxl_decoder *, periodt 💖

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✨ ARGUMENTS ✨

• port — a port in the ancestry of the endpoint implied by cxled 🦋 (yes, implied, we're being indirect here, iykyk)
• cxled — the endpoint decoder that is to be — or currently — mapped by port. it's giving "past or future, no in-between" 😭
• cxlr — the region we're using to establish, or to validate, the decode port ✨

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✨ DESCRIPTION ✨

okay so this function is lowkey doing double duty depending on which path you're on, and honestly? main character energy 👑

In the region creation path, cxl_port_pick_region_decoder is literally just an allocator — its whole job is to go find a free port 🔥

In the region assembly path, it's doing a totally different vibe: it's recalling the decoder that platform firmware picked, purely for validation purposes 👀

And where does the result go? it gets recorded in a 'struct cxl_region_ref' in port — that's the receipts, fr fr 🧾💜

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✨ SEE ALSO ✨

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

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ngl bestie, that ./drivers/cxl/core path is where the magic lives 🌈

and that's the whole page!! sourced from ./drivers/cxl/core, dated October 2026, in the Kernel API Manual — slay, go read the CXL region code, ily, bye 🫶💖✨