iommu_group_mutex_assert(9)

💖 NAME 💖

Okay so bestie, this page is for iommu_group_mutex_assert(9) from the Kernel API Manual, and its whole personality is: check device group mutex lock. Like, a tiny lock vibe check. 💅

✨ SYNOPSIS ✨

void iommu_group_mutex_assert (struct device *dev );

🎀 ARGUMENTS 🎀

• dev — the device that has group param set. That’s the one you’re checking on, periodt. 🫶

🦋 DESCRIPTION 🦋

An iommu driver calls this function to check whether it holds the group mutex lock for the given device or not. It’s giving “do I have the lock, or do I need to rethink my choices?” energy. 🔥

Important note, no cap: this function must be called after the device group param is set. Not before. That order is the whole assignment. 😭

💅 SEE ALSO 💅

The kernel file for this one is ./drivers/iommu/iommu.c, and the linked squad is: 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_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_device_unuse_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). Obsessed with a complete roster, honestly. 🌈

Cute lil footer sign-off: source/version is ./drivers/iommu, date is October 2026, and the page is iommu_group_mutex_assert(9) 💜✨