From 41e5c0f81d3e676d671d96a0a1fafb27abfbd9d7 Mon Sep 17 00:00:00 2001
From: Liviu Dudau <Liviu.Dudau@arm.com>
Date: Mon, 29 Sep 2014 15:29:27 +0100
Subject: 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>
---
drivers/pci/pci.c | 9 +++++++++
1 file changed, 9 insertions(+)
(limited to 'drivers/pci/pci.c')
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 2c9ac70..d36f35f 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?
*
--
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