Re: [PATCH] PCI/MSI: Delete pci_msi_create_irq_domain()

[Bjorn Helgaas <helgaas@kernel.org>]

On Mon, Jul 21, 2025 at 08:36:26AM +0200, Nam Cao wrote:
> pci_msi_create_irq_domain() is unused. Delete it.
> 
> Signed-off-by: Nam Cao <namcao@linutronix.de>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

I verified that pci_msi_create_irq_domain() no longer referenced in
current upstream: cd5a0afbdf80 ("Merge tag 'mailbox-v6.18' of
git://git.kernel.org/pub/scm/linux/kernel/git/jassibrar/mailbox")

Thomas, you've merged most irqdomain.c changes; let me know if you
want me to do anything.

> ---
> This is the final step in converting to the new MSI interrupt domain setup:
> deleting the old setup.
> 
> This patch depends on the driver conversion patches listed below. Most
> patches have been applied somewhere, except for the first one.
> 
> https://lore.kernel.org/lkml/cover.1752868165.git.namcao@linutronix.de/
>    -> has not been applied anywhere
> 
> https://lore.kernel.org/lkml/cover.1750861319.git.namcao@linutronix.de/
>    -> applied to powerpc/next-test
> 
> https://lore.kernel.org/linux-um/cover.1751266049.git.namcao@linutronix.de/
>    -> applied to uml/next
> 
> https://lore.kernel.org/lkml/cover.1750858083.git.namcao@linutronix.de/
>    -> applied to pci/next
> 
> https://lore.kernel.org/lkml/cover.1751875853.git.namcao@linutronix.de/
>    -> applied to netdev/net-next
> 
> https://lore.kernel.org/lkml/cover.1750860131.git.namcao@linutronix.de/
>    -> applied to tip/irq/drivers
> ---
>  drivers/pci/msi/irqdomain.c | 90 -------------------------------------
>  include/linux/msi.h         |  3 --
>  2 files changed, 93 deletions(-)
> 
> diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
> index c05152733993..926a16e80192 100644
> --- a/drivers/pci/msi/irqdomain.c
> +++ b/drivers/pci/msi/irqdomain.c
> @@ -49,96 +49,6 @@ static void pci_msi_domain_write_msg(struct irq_data *irq_data, struct msi_msg *
>  		__pci_write_msi_msg(desc, msg);
>  }
>  
> -/**
> - * pci_msi_domain_calc_hwirq - Generate a unique ID for an MSI source
> - * @desc:	Pointer to the MSI descriptor
> - *
> - * The ID number is only used within the irqdomain.
> - */
> -static irq_hw_number_t pci_msi_domain_calc_hwirq(struct msi_desc *desc)
> -{
> -	struct pci_dev *dev = msi_desc_to_pci_dev(desc);
> -
> -	return (irq_hw_number_t)desc->msi_index |
> -		pci_dev_id(dev) << 11 |
> -		((irq_hw_number_t)(pci_domain_nr(dev->bus) & 0xFFFFFFFF)) << 27;
> -}
> -
> -static void pci_msi_domain_set_desc(msi_alloc_info_t *arg,
> -				    struct msi_desc *desc)
> -{
> -	arg->desc = desc;
> -	arg->hwirq = pci_msi_domain_calc_hwirq(desc);
> -}
> -
> -static struct msi_domain_ops pci_msi_domain_ops_default = {
> -	.set_desc	= pci_msi_domain_set_desc,
> -};
> -
> -static void pci_msi_domain_update_dom_ops(struct msi_domain_info *info)
> -{
> -	struct msi_domain_ops *ops = info->ops;
> -
> -	if (ops == NULL) {
> -		info->ops = &pci_msi_domain_ops_default;
> -	} else {
> -		if (ops->set_desc == NULL)
> -			ops->set_desc = pci_msi_domain_set_desc;
> -	}
> -}
> -
> -static void pci_msi_domain_update_chip_ops(struct msi_domain_info *info)
> -{
> -	struct irq_chip *chip = info->chip;
> -
> -	BUG_ON(!chip);
> -	if (!chip->irq_write_msi_msg)
> -		chip->irq_write_msi_msg = pci_msi_domain_write_msg;
> -	if (!chip->irq_mask)
> -		chip->irq_mask = pci_msi_mask_irq;
> -	if (!chip->irq_unmask)
> -		chip->irq_unmask = pci_msi_unmask_irq;
> -}
> -
> -/**
> - * pci_msi_create_irq_domain - Create a MSI interrupt domain
> - * @fwnode:	Optional fwnode of the interrupt controller
> - * @info:	MSI domain info
> - * @parent:	Parent irq domain
> - *
> - * Updates the domain and chip ops and creates a MSI interrupt domain.
> - *
> - * Returns:
> - * A domain pointer or NULL in case of failure.
> - */
> -struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
> -					     struct msi_domain_info *info,
> -					     struct irq_domain *parent)
> -{
> -	if (WARN_ON(info->flags & MSI_FLAG_LEVEL_CAPABLE))
> -		info->flags &= ~MSI_FLAG_LEVEL_CAPABLE;
> -
> -	if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS)
> -		pci_msi_domain_update_dom_ops(info);
> -	if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS)
> -		pci_msi_domain_update_chip_ops(info);
> -
> -	/* Let the core code free MSI descriptors when freeing interrupts */
> -	info->flags |= MSI_FLAG_FREE_MSI_DESCS;
> -
> -	info->flags |= MSI_FLAG_ACTIVATE_EARLY | MSI_FLAG_DEV_SYSFS;
> -	if (IS_ENABLED(CONFIG_GENERIC_IRQ_RESERVATION_MODE))
> -		info->flags |= MSI_FLAG_MUST_REACTIVATE;
> -
> -	/* PCI-MSI is oneshot-safe */
> -	info->chip->flags |= IRQCHIP_ONESHOT_SAFE;
> -	/* Let the core update the bus token */
> -	info->bus_token = DOMAIN_BUS_PCI_MSI;
> -
> -	return msi_create_irq_domain(fwnode, info, parent);
> -}
> -EXPORT_SYMBOL_GPL(pci_msi_create_irq_domain);
> -
>  /*
>   * Per device MSI[-X] domain functionality
>   */
> diff --git a/include/linux/msi.h b/include/linux/msi.h
> index 77227d23ea84..0c0e59af043c 100644
> --- a/include/linux/msi.h
> +++ b/include/linux/msi.h
> @@ -703,9 +703,6 @@ void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg);
>  void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg);
>  void pci_msi_mask_irq(struct irq_data *data);
>  void pci_msi_unmask_irq(struct irq_data *data);
> -struct irq_domain *pci_msi_create_irq_domain(struct fwnode_handle *fwnode,
> -					     struct msi_domain_info *info,
> -					     struct irq_domain *parent);
>  u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev);
>  struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev);
>  #else /* CONFIG_PCI_MSI */
> -- 
> 2.39.5
>