pci_epc_unmap_addr(9)

💅 pci_epc_unmap_addr(9) — the Kernel API Manual, bestie edition 🎀

okay so real talk, this is a page from the Kernel API Manual, and the star of the show is pci_epc_unmap_addr 💖

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✨ NAME ✨

pci_epc_unmap_addr — unmap CPU address from PCI address 🦋

Literally what it says on the tin: it unhooks a CPU address from a PCI address. The un-map. The breakup arc. 💔

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🌸 SYNOPSIS 🌸

void pci_epc_unmap_addr (struct pci_epc *epc , u8 func_no , u8 vfunc_no
, phys_addr_t phys_addr );

notice how it returns void? yeah, it's not giving you anything back, it's giving you closure and that's it 💀

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🫶 ARGUMENTS 🫶

• epc — the EPC device on which address is allocated. like, the actual device this whole thing lives on, okay? 🏠
• func_no — the physical endpoint function number in the EPC device. the physical one, keep that straight ✨
• vfunc_no — the virtual endpoint function number in the physical function. yes there's a virtual one too, it's giving layers 👑
• phys_addr — physical address of the local system. the local one, bestie, don't get it twisted 🌈

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🧚 DESCRIPTION 🧚

Invoke this when you need to unmap the CPU address from the PCI address. that's the whole vibe. it's the undo button, the "jk", the never mind 💅✨

ngl this is the counterpart operation — you mapped it, now you're un-mapping it. no cap, that's the entire description in the source, so I'm not gonna manifest extra lore that isn't there 🙈

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🔥 SEE ALSO 🔥

• Kernel file ./drivers/pci/endpoint/pci-epc-core.c — that's where the magic lives, go read it 📖
• pci_epc_put(9)
• pci_epc_get(9)
• pci_epc_get_first_free_bar(9)
• pci_epc_get_next_free_bar(9)
• pci_epc_get_features(9)
• pci_epc_get_aux_resources_count(9)
• pci_epc_get_aux_resources(9)
• pci_epc_stop(9)
• pci_epc_start(9)
• pci_epc_raise_irq(9)
• pci_epc_map_msi_irq(9)
• pci_epc_get_msi(9)
• pci_epc_set_msi(9)
• pci_epc_get_msix(9)
• pci_epc_set_msix(9)
• pci_epc_map_addr(9) — the other half of this situationship, obviously 👀
• pci_epc_mem_map(9)
• pci_epc_mem_unmap(9)
• pci_epc_clear_bar(9)
• pci_epc_set_bar(9)
• pci_epc_bar_size_to_rebar_cap(9)
• pci_epc_write_header(9)
• pci_epc_add_epf(9)
• pci_epc_remove_epf(9)
• pci_epc_linkup(9)
• pci_epc_linkdown(9)
• pci_epc_init_notify(9)
• pci_epc_notify_pending_init(9)
• pci_epc_deinit_notify(9)
• pci_epc_bus_master_enable_notify(9)
• pci_epc_destroy(9)
• __pci_epc_create(9)
• __devm_pci_epc_create(9)

that's a whole friend group fr fr, they all ate 💖

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and that's the page, bestie! cute lil sign-off: this one's filed under ./drivers/pci/endpoint and dated October 2026, so mark your calendar 🎀✨🦋 slay, you now understand pci_epc_unmap_addr(9), periodt 💜