Re: [PATCH v7 1/4] acpi: pci: Setup MSI domain for ACPI based pci devices

[Bjorn Helgaas <helgaas@kernel.org>]

On Thu, Dec 10, 2015 at 08:55:27AM -0800, Suravee Suthikulpanit wrote:
> This patch introduces pci_msi_register_fwnode_provider() for irqchip
> to register a callback, to provide a way to determine appropriate MSI
> domain for a pci device.
> 
> It also introduces pci_host_bridge_acpi_msi_domain(), which returns
> the MSI domain of the specified PCI host bridge with DOMAIN_BUS_PCI_MSI
> bus token. Then, it is assigned to pci device.
> 
> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>

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

I assume the whole series will be queued via a non-PCI tree.

> ---
>  drivers/pci/pci-acpi.c    | 42 ++++++++++++++++++++++++++++++++++++++++++
>  drivers/pci/probe.c       |  2 ++
>  include/linux/irqdomain.h |  5 +++++
>  include/linux/pci.h       | 10 ++++++++++
>  4 files changed, 59 insertions(+)
> 
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index a32ba75..d3f32d6 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -9,7 +9,9 @@
>  
>  #include <linux/delay.h>
>  #include <linux/init.h>
> +#include <linux/irqdomain.h>
>  #include <linux/pci.h>
> +#include <linux/msi.h>
>  #include <linux/pci_hotplug.h>
>  #include <linux/module.h>
>  #include <linux/pci-aspm.h>
> @@ -689,6 +691,46 @@ static struct acpi_bus_type acpi_pci_bus = {
>  	.cleanup = pci_acpi_cleanup,
>  };
>  
> +
> +static struct fwnode_handle *(*pci_msi_get_fwnode_cb)(struct device *dev);
> +
> +/**
> + * pci_msi_register_fwnode_provider - Register callback to retrieve fwnode
> + * @fn:       Callback matching a device to a fwnode that identifies a PCI
> + *            MSI domain.
> + *
> + * This should be called by irqchip driver, which is the parent of
> + * the MSI domain to provide callback interface to query fwnode.
> + */
> +void
> +pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *))
> +{
> +	pci_msi_get_fwnode_cb = fn;
> +}
> +
> +/**
> + * pci_host_bridge_acpi_msi_domain - Retrieve MSI domain of a PCI host bridge
> + * @bus:      The PCI host bridge bus.
> + *
> + * This function uses the callback function registered by
> + * pci_msi_register_fwnode_provider() to retrieve the irq_domain with
> + * type DOMAIN_BUS_PCI_MSI of the specified host bridge bus.
> + * This returns NULL on error or when the domain is not found.
> + */
> +struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
> +{
> +	struct fwnode_handle *fwnode;
> +
> +	if (!pci_msi_get_fwnode_cb)
> +		return NULL;
> +
> +	fwnode = pci_msi_get_fwnode_cb(&bus->dev);
> +	if (!fwnode)
> +		return NULL;
> +
> +	return irq_find_matching_fwnode(fwnode, DOMAIN_BUS_PCI_MSI);
> +}
> +
>  static int __init acpi_pci_init(void)
>  {
>  	int ret;
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index edb1984..553a029 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -672,6 +672,8 @@ static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus)
>  	 * should be called from here.
>  	 */
>  	d = pci_host_bridge_of_msi_domain(bus);
> +	if (!d)
> +		d = pci_host_bridge_acpi_msi_domain(bus);
>  
>  	return d;
>  }
> diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> index d5e5c5b..a06feda 100644
> --- a/include/linux/irqdomain.h
> +++ b/include/linux/irqdomain.h
> @@ -410,6 +410,11 @@ static inline bool irq_domain_is_hierarchy(struct irq_domain *domain)
>  static inline void irq_dispose_mapping(unsigned int virq) { }
>  static inline void irq_domain_activate_irq(struct irq_data *data) { }
>  static inline void irq_domain_deactivate_irq(struct irq_data *data) { }
> +static inline struct irq_domain *irq_find_matching_fwnode(
> +	struct fwnode_handle *fwnode, enum irq_domain_bus_token bus_token)
> +{
> +	return NULL;
> +}
>  #endif /* !CONFIG_IRQ_DOMAIN */
>  
>  #endif /* _LINUX_IRQDOMAIN_H */
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 6ae25aa..d86378c 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1946,6 +1946,16 @@ static inline struct irq_domain *
>  pci_host_bridge_of_msi_domain(struct pci_bus *bus) { return NULL; }
>  #endif  /* CONFIG_OF */
>  
> +#ifdef CONFIG_ACPI
> +struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus);
> +
> +void
> +pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *));
> +#else
> +static inline struct irq_domain *
> +pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; }
> +#endif
> +
>  #ifdef CONFIG_EEH
>  static inline struct eeh_dev *pci_dev_to_eeh_dev(struct pci_dev *pdev)
>  {
> -- 
> 2.1.0
> 
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