[PATCH V7 06/11] pci, acpi: Provide a way to assign bus domain number.

[Tomasz Nowicki]

This patch provides a way to set the ACPI domain number in PCI code.
pci_create_root_bus is called with NULL as parent in ACPI. This
ends up calling pci_bus_assign_domain_nr with a NULL parent.
So we define acpi_pci_bus_domain_nr() which is meant to retrieve
the PCI domain number based on 'struct pci_bus' in the ACPI way.
pci_bus_assign_domain_nr() is updated to call acpi_pci_bus_domain_nr()
and assign domain number on the root bus, in case of ACPI.

acpi_pci_bus_domain_nr function is stub for now.

While at it, for the sake of code clarity we put ACPI and DT domain
assign methods into the corresponding helpers.

Signed-off-by: Jayachandran C <jchandra@xxxxxxxxxxxx>
Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
---
 drivers/pci/pci.c        | 11 +++++++++--
 include/linux/pci-acpi.h |  5 +++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ff97a0b..a1d7bcf 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -19,6 +19,7 @@
 #include <linux/spinlock.h>
 #include <linux/string.h>
 #include <linux/log2.h>
+#include <linux/pci-acpi.h>
 #include <linux/pci-aspm.h>
 #include <linux/pm_wakeup.h>
 #include <linux/interrupt.h>
@@ -4918,7 +4919,7 @@ int pci_get_new_domain_nr(void)
 }
 
 #ifdef CONFIG_PCI_DOMAINS_GENERIC
-void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
+static int of_pci_bus_domain_nr(struct device *parent)
 {
 	static int use_dt_domains = -1;
 	int domain = -1;
@@ -4962,7 +4963,13 @@ void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
 		domain = -1;
 	}
 
-	bus->domain_nr = domain;
+	return domain;
+}
+
+void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
+{
+	bus->domain_nr = acpi_disabled ? of_pci_bus_domain_nr(parent) :
+					 acpi_pci_bus_domain_nr(bus);
 }
 #endif
 #endif
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index 89ab057..09f9f02 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -111,6 +111,11 @@ static inline void acpi_pci_add_bus(struct pci_bus *bus) { }
 static inline void acpi_pci_remove_bus(struct pci_bus *bus) { }
 #endif	/* CONFIG_ACPI */
 
+static inline int acpi_pci_bus_domain_nr(struct pci_bus *bus)
+{
+	return 0;
+}
+
 #ifdef CONFIG_ACPI_APEI
 extern bool aer_acpi_firmware_first(void);
 #else
-- 
1.9.1