of/pci: Add pci_get_new_domain_nr() and of_get_pci_domain_nr()

Add pci_get_new_domain_nr() to allocate a new domain number and
of_get_pci_domain_nr() to retrieve the PCI domain number of a given device
from DT.  Host bridge drivers or architecture-specific code can choose to
implement their PCI domain number policy using these two functions.

Using of_get_pci_domain_nr() guarantees a stable PCI domain number on every
boot provided that all host bridge controllers are assigned a number in the
device tree using "linux,pci-domain" property.  Mixing use of
pci_get_new_domain_nr() and of_get_pci_domain_nr() is not recommended as it
can lead to potentially conflicting domain numbers being assigned to root
buses behind different host bridges.

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Grant Likely <grant.likely@linaro.org>
CC: Rob Herring <robh+dt@kernel.org>
CC: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Liviu Dudau 2014-09-29 15:29:27 +01:00 committed by Bjorn Helgaas
parent 670ba0c888
commit 41e5c0f81d
4 changed files with 44 additions and 0 deletions

View file

@ -15,6 +15,7 @@ struct device_node *of_pci_find_child_device(struct device_node *parent,
int of_pci_get_devfn(struct device_node *np);
int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin);
int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
int of_get_pci_domain_nr(struct device_node *node);
#else
static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
{
@ -43,6 +44,12 @@ of_pci_parse_bus_range(struct device_node *node, struct resource *res)
{
return -EINVAL;
}
static inline int
of_get_pci_domain_nr(struct device_node *node)
{
return -1;
}
#endif
#if defined(CONFIG_OF) && defined(CONFIG_PCI_MSI)