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authorLiviu Dudau <Liviu.Dudau@arm.com>2014-09-29 18:29:27 +0400
committerBjorn Helgaas <bhelgaas@google.com>2014-10-01 03:08:57 +0400
commit41e5c0f81d3e676d671d96a0a1fafb27abfbd9d7 (patch)
tree674d5c5bc98998014d5b454f059bb052660057d5 /drivers/pci/pci.c
parent670ba0c8883b576d0aec28bd7a838358a4be1406 (diff)
downloadlinux-41e5c0f81d3e676d671d96a0a1fafb27abfbd9d7.tar.xz
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>
Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r--drivers/pci/pci.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 2c9ac70254e2..d36f35ff6c5d 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4406,6 +4406,15 @@ static void pci_no_domains(void)
#endif
}
+#ifdef CONFIG_PCI_DOMAINS
+static atomic_t __domain_nr = ATOMIC_INIT(-1);
+
+int pci_get_new_domain_nr(void)
+{
+ return atomic_inc_return(&__domain_nr);
+}
+#endif
+
/**
* pci_ext_cfg_avail - can we access extended PCI config space?
*