[RFC/RFT PATCH v2 3/3] PCI/ACPI: Add ACPI pci_bus_find_numa_node() implementation

From: Lorenzo Pieralisi
Date: Mon May 15 2017 - 09:21:18 EST


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 ++++++++++++++++++++
drivers/pci/pci.c | 2 +-
include/linux/pci.h | 6 ++++++
3 files changed, 27 insertions(+), 1 deletion(-)

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;
+}
+
static int __init acpi_pci_init(void)
{
int ret;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e9803c1..451342d 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5406,7 +5406,7 @@ int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent)

int pci_bus_find_numa_node(struct pci_bus *bus)
{
- return NUMA_NO_NODE;
+ return acpi_disabled ? NUMA_NO_NODE : acpi_pci_bus_find_numa_node(bus);
}

/**
diff --git a/include/linux/pci.h b/include/linux/pci.h
index ccbeefd..ed89220 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1472,6 +1472,12 @@ 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 */
--
2.10.0