ntb_msg_outbits(9)

🌸 ntb_msg_outbits (9) — Kernel API Manual energy 💅

okay so bestie, welcome to the Kernel API Manual, section 9, where we learn about one (1) tiny function that tells you a whole lot about your outbound message registers. she's small, she's specific, she slays. let's go 🎀

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✨ NAME ✨

ntb_msg_outbits — get a bitfield of outbound message registers status. that's it, that's her whole job, and she does it beautifully 🫶

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✨ SYNOPSIS ✨

u64 ntb_msg_outbits (struct ntb_dev *ntb );

literally one argument, one return value, zero drama. iconic behavior ngl ⭐

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✨ ARGUMENTS ✨

• ntb — the NTB device context. your device, your vibe, your context. you hand her the struct ntb_dev * and she does the rest 💖

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✨ DESCRIPTION ✨

so the way this works: the method returns the bitfield of status and mask registers, which related to outbound message registers. yes bestie, a whole bitfield — every bit is a little status flag doing its own thing, masked and matching, all bundled up in one u64 like a cute little gift box 🎁

it's giving "I asked for the outbound message register situation and got a whole bitmap back." no cap. and honestly? we love a function that knows exactly what it is 🔥

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✨ RETURN ✨

the bitfield of outbound message registers. that's the whole return value. one u64, all the bits, done. periodt 💅

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✨ SEE ALSO ✨

the entire extended universe, fr fr. read these next if you wanna be a real NTB main character 👑

The enums and structs (the lore) 🌈

• enum ntb_topo(9), enum ntb_speed(9), enum ntb_width(9), enum ntb_default_port(9)
• struct ntb_client_ops(9), struct ntb_ctx_ops(9), struct ntb_dev_ops(9)
• struct ntb_client(9), struct ntb_dev(9)

Client & device registration 🧚

• ntb_register_client(9), ntb_unregister_client(9)
• ntb_register_device(9), ntb_unregister_device(9)

Context & events 🦋

• ntb_set_ctx(9), ntb_clear_ctx(9)
• ntb_link_event(9), ntb_db_event(9), ntb_msg_event(9)

Ports (so many ports) 🌸

• ntb_default_port_number(9), ntb_default_peer_port_count(9), ntb_default_peer_port_number(9), ntb_default_peer_port_idx(9)
• ntb_port_number(9), ntb_peer_port_count(9), ntb_peer_port_number(9)
• ntb_logical_port_number(9), ntb_peer_logical_port_number(9), ntb_peer_port_idx(9)

Links 💜

• ntb_link_is_up(9), ntb_link_enable(9), ntb_link_disable(9)

Memory windows ✨

• ntb_mw_count(9), ntb_mw_get_align(9), ntb_mw_set_trans(9), ntb_mw_clear_trans(9)
• ntb_peer_mw_count(9), ntb_peer_mw_get_addr(9), ntb_peer_mw_set_trans(9), ntb_peer_mw_clear_trans(9)

Doorbells 🔔

• ntb_db_is_unsafe(9), ntb_db_valid_mask(9), ntb_db_vector_count(9), ntb_db_vector_mask(9)
• ntb_db_read(9), ntb_db_set(9), ntb_db_clear(9)
• ntb_db_read_mask(9), ntb_db_set_mask(9), ntb_db_clear_mask(9)
• ntb_peer_db_addr(9), ntb_peer_db_read(9), ntb_peer_db_set(9), ntb_peer_db_clear(9)
• ntb_peer_db_read_mask(9), ntb_peer_db_set_mask(9), ntb_peer_db_clear_mask(9)

Scratchpads 🍓

• ntb_spad_is_unsafe(9), ntb_spad_count(9), ntb_spad_read(9), ntb_spad_write(9)
• ntb_peer_spad_addr(9), ntb_peer_spad_read(9), ntb_peer_spad_write(9)

Messages (her home turf, where our girl lives) 💌

• ntb_msg_count(9), ntb_msg_inbits(9), ntb_msg_read_sts(9), ntb_msg_clear_sts(9)
• ntb_msg_set_mask(9), ntb_msg_clear_mask(9), ntb_msg_read(9), ntb_peer_msg_write(9)

The stragglers, but make them fancy 😭

• ntb_get_dma_dev(9), ntb_peer_resource_idx(9), ntb_peer_highest_mw_idx(9)

lowkey that's the whole include/linux/ntb.h friend group. go read ntb_msg_inbits(9) next, she's literally the inbound mirror of this one. matching set 🫶

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and that's the page bestie! it lives in ./include/linux and this version is dated October 2026 — so yeah, fresh off the press, go forth and read your bitfields 💖✨🎀