msi_parent_i...dev_msi_info(9)

💖 NAME 💖

okay so bestie, this is the Kernel API Manual page for msi_parent_init_dev_msi_info, and the header is out here looking like msi_parent_i...dev_msi_info(9) because truncation said slay 💅. Its whole mission? Delegate initialization of device MSI info down in the domain hierarchy. That's the name, that's the vibe, no cap. 🫶

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✨ SYNOPSIS ✨

bool msi_parent_init_dev_msi_info (struct device *dev , struct
irq_domain *domain , struct irq_domain *msi_parent_domain , struct
msi_domain_info *msi_child_info );

---

🎀 ARGUMENTS 🎀

• dev — the device for which the domain should be created. like, the main character device in question 💅
• domain — the domain in the hierarchy this op is being called on.
• msi_parent_domain — the IRQ_DOMAIN_FLAG_MSI_PARENT domain for the child to be created.
• msi_child_info — the MSI domain info of the IRQ_DOMAIN_FLAG_MSI_DEVICE domain to be created.

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🔥 RETURN 🔥

true on success, false otherwise. that's it. binary slay. ✨

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🧚 DESCRIPTION 🧚

This is the most complex problem of per device MSI domains and the underlying interrupt domain hierarchy — like the final boss of domain setup, fr fr. 😭

The device domain to be initialized requests the broadest feature set possible, and the underlying domain hierarchy puts restrictions on it.

That's trivial for a simple parent->child relationship, but it gets interesting with an intermediate domain: root->parent->child. The intermediate 'parent' can expand the capabilities which the 'root' domain is providing. So that creates a classic hen and egg problem: Which entity is doing the restrictions/expansions? 🐣

One solution is to let the root domain handle the initialization — that's why there is the domain and the msi_parent_domain pointer. periodt. 💖

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🌈 SEE ALSO 🌈

the whole gang is here, bestie:

• Kernel file ./kernel/irq/msi.c
• struct msi_device_data(9)
• struct msi_ctrl(9)
• msi_alloc_desc(9)
• msi_domain_insert_msi_desc(9)
• msi_domain_free_msi_descs_range(9)
• msi_domain_add_simple_msi_descs(9)
• msi_setup_device_data(9)
• __msi_lock_descs(9)
• __msi_unlock_descs(9)
• msi_domain_first_desc(9)
• msi_next_desc(9)
• msi_domain_get_virq(9)
• msi_device_populate_sysfs(9)
• msi_device_destroy_sysfs(9)
• msi_domain_set_affinity(9)
• msi_create_irq_domain(9)
• msi_create_parent_irq_domain(9)
• msi_create_device_irq_domain(9)
• msi_remove_device_irq_domain(9)
• msi_match_device_irq_domain(9)
• msi_domain_alloc_irqs_range_locked(9)
• msi_domain_alloc_irqs_range(9)
• msi_domain_alloc_irqs_all_locked(9)
• msi_domain_alloc_irq_at(9)
• msi_device_domain_alloc_wired(9)
• msi_domain_free_irqs_range_locked(9)
• msi_domain_free_irqs_range(9)
• msi_domain_free_irqs_all_locked(9)
• msi_domain_free_irqs_all(9)
• msi_device_domain_free_wired(9)
• msi_get_domain_info(9)
• msi_device_has_isolated_msi(9)

mwah 💋 — this page came from ./kernel/irq, stamped October 2026, and signed msi_parent_i...dev_msi_info(9). bye bestie, go delegate those MSI infos 💖