PCI: Add generic domain handling
The handling of PCI domains (or PCI segments in ACPI speak) is usually a
straightforward affair but its implementation is currently left to the
architectural code, with pci_domain_nr(b) querying the value of the domain
associated with bus b.
This patch introduces CONFIG_PCI_DOMAINS_GENERIC as an option that can be
selected if an architecture wants a simple implementation where the value
of the domain associated with a bus is stored in struct pci_bus.
The architectures that select CONFIG_PCI_DOMAINS_GENERIC will then have to
implement pci_bus_assign_domain_nr() as a way of setting the domain number
associated with a root bus. All child buses except the root bus will
inherit the domain_nr value from their parent.
Signed-off-by: Catalin Marinas <Catalin.Marinas@arm.com>
[Renamed pci_set_domain_nr() to pci_bus_assign_domain_nr()]
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Arnd Bergmann <arnd@arndb.de>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 61978a4..a494e5d 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -456,6 +456,9 @@
unsigned char primary; /* number of primary bridge */
unsigned char max_bus_speed; /* enum pci_bus_speed */
unsigned char cur_bus_speed; /* enum pci_bus_speed */
+#ifdef CONFIG_PCI_DOMAINS_GENERIC
+ int domain_nr;
+#endif
char name[48];
@@ -1288,6 +1291,24 @@
static inline int pci_proc_domain(struct pci_bus *bus) { return 0; }
#endif /* CONFIG_PCI_DOMAINS */
+/*
+ * Generic implementation for PCI domain support. If your
+ * architecture does not need custom management of PCI
+ * domains then this implementation will be used
+ */
+#ifdef CONFIG_PCI_DOMAINS_GENERIC
+static inline int pci_domain_nr(struct pci_bus *bus)
+{
+ return bus->domain_nr;
+}
+void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent);
+#else
+static inline void pci_bus_assign_domain_nr(struct pci_bus *bus,
+ struct device *parent)
+{
+}
+#endif
+
/* some architectures require additional setup to direct VGA traffic */
typedef int (*arch_set_vga_state_t)(struct pci_dev *pdev, bool decode,
unsigned int command_bits, u32 flags);