iommu_devic...fault_domain(9)

💅 NAME 💅

iommu_device_unuse_default_domain — bestie, this is how a device driver stops doing DMA through the kernel DMA API. Like, it's handing in its little hall pass and walking away from the default domain. No cap.

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✨ SYNOPSIS ✨

void iommu_device_unuse_default_domain (struct device *dev );

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🎀 ARGUMENTS 🎀

• dev — the device. That's it, that's the whole argument. The device in question. The main character, if you will. 🫶

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🌸 DESCRIPTION 🌸

Okay so picture this: the device driver is done. It no longer wants to do DMA through the kernel DMA API anymore. It's over, it's not me, it's you, etc. 💔

So you call this function and it's like officially breaking up with the default domain handling. The way that it makes it tidy is iconic.

🚨 real talk though: this must be called after iommu_device_use_default_domain. Like, you have to actually use the thing before you can un-use it. Order matters, bestie. Don't come in here trying to un-use something you never used, that's not the vibe and it's not gonna slay.

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👑 SEE ALSO 👑

Kernel file ./drivers/iommu/iommu.c — and honestly the whole friend group is here, say hi to everybody:

• iommu_device_register(9)
• iommu_insert_resv_region(9)
• iommu_group_alloc(9)
• iommu_group_get_iommudata(9)
• iommu_group_set_iommudata(9)
• iommu_group_set_name(9)
• iommu_group_add_device(9)
• iommu_group_remove_device(9)
• iommu_group_mutex_assert(9)
• iommu_group_for_each_dev(9)
• iommu_group_get(9)
• iommu_group_ref_get(9)
• iommu_group_put(9)
• iommu_group_id(9)
• device_iommu_capable(9)
• iommu_group_has_isolated_msi(9)
• iommu_set_fault_handler(9)
• iommu_paging_domain_alloc_flags(9)
• iommu_attach_device(9)
• iommu_get_domain_for_dev(9)
• iommu_driver_get_domain_for_dev(9)
• iommu_attach_group(9)
• iommu_unmap(9)
• iommu_unmap_fast(9)
• report_iommu_fault(9)
• iommu_get_resv_regions(9)
• iommu_put_resv_regions(9)
• iommu_setup_default_domain(9)
• iommu_device_use_default_domain(9)
• iommu_group_claim_dma_owner(9)
• iommu_device_claim_dma_owner(9)
• iommu_group_release_dma_owner(9)
• iommu_device_release_dma_owner(9)
• iommu_group_dma_owner_claimed(9)
• iommu_replace_device_pasid(9)
• iommu_attach_handle_get(9)
• iommu_attach_group_handle(9)
• iommu_detach_group_handle(9)
• iommu_replace_group_handle(9)
• pci_dev_reset_iommu_prepare(9)
• pci_dev_reset_iommu_done(9)
• iommu_dma_prepare_msi(9)

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and that's the whole page, bestie ✨ it lives in ./drivers/iommu and the version you're looking at is dated October 2026 — genuinely obsessed, see u in the next manpage 💖🎀🦋