Re: [RFC/RFT PATCH 3/3] PCI/ACPI: Add ACPI pci_bus_find_numa_node() implementation

[Zhou Wang]

On 2017/4/26 18:06, Lorenzo Pieralisi wrote:
> The introduction of pci_bus_find_numa_node(pci_bus) allows at PCI
> host bridge registration to detect the NUMA node for a given
> struct pci_bus.dev. Implement an ACPI method that, through
> the struct pci_bus.bridge ACPI companion, retrieve and return
> the NUMA node corresponding to a given struct pci_bus.dev.
> 
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
>  drivers/pci/pci-acpi.c | 20 ++++++++++++++++++++
>  include/linux/pci.h    |  6 ++++++
>  2 files changed, 26 insertions(+)
> 
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index 0018603..915da79 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -10,6 +10,7 @@
>  #include <linux/delay.h>
>  #include <linux/init.h>
>  #include <linux/irqdomain.h>
> +#include <linux/numa.h>
>  #include <linux/pci.h>
>  #include <linux/msi.h>
>  #include <linux/pci_hotplug.h>
> @@ -853,6 +854,25 @@ struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus)
>  	return irq_find_matching_fwnode(fwnode, DOMAIN_BUS_PCI_MSI);
>  }
>  
> +int acpi_pci_bus_find_numa_node(struct pci_bus *bus)
> +{
> +	int node = NUMA_NO_NODE;
> +	struct device *bridge = get_device(bus->bridge);
> +
> +	if (!bridge)
> +		return node;
> +
> +	if (has_acpi_companion(bridge)) {
> +		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
> +
> +		node = acpi_get_node(adev->handle);
> +	}
> +
> +	put_device(bridge);
> +
> +	return node;
> +}
> +

It seems there is no function to call this, am I right?

Another question is that:
in the latest IORT revision C, "Proximity domain" has been added to the IORT spec.
So when we enable NUMA for a PCIe device, should we also consider this?

Thanks,
Zhou

>  static int __init acpi_pci_init(void)
>  {
>  	int ret;
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 9e62462..b40d095 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1481,6 +1481,12 @@ static inline int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
>  #endif
>  int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent);
>  #endif
> +#ifdef CONFIG_ACPI
> +int acpi_pci_bus_find_numa_node(struct pci_bus *bus);
> +#else
> +static inline int acpi_pci_bus_find_numa_node(struct pci_bus *bus)
> +{ return NUMA_NO_NODE; }
> +#endif
>  int pci_bus_find_numa_node(struct pci_bus *bus);
>  
>  /* some architectures require additional setup to direct VGA traffic */
>