summaryrefslogtreecommitdiffstats
path: root/drivers/pci/pci.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r--drivers/pci/pci.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index cab05f31223f..c419554d0b4b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -10,6 +10,8 @@
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/of_pci.h>
#include <linux/pci.h>
#include <linux/pm.h>
#include <linux/slab.h>
@@ -4439,6 +4441,53 @@ int pci_get_new_domain_nr(void)
{
return atomic_inc_return(&__domain_nr);
}
+
+#ifdef CONFIG_PCI_DOMAINS_GENERIC
+void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
+{
+ static int use_dt_domains = -1;
+ int domain = of_get_pci_domain_nr(parent->of_node);
+
+ /*
+ * Check DT domain and use_dt_domains values.
+ *
+ * If DT domain property is valid (domain >= 0) and
+ * use_dt_domains != 0, the DT assignment is valid since this means
+ * we have not previously allocated a domain number by using
+ * pci_get_new_domain_nr(); we should also update use_dt_domains to
+ * 1, to indicate that we have just assigned a domain number from
+ * DT.
+ *
+ * If DT domain property value is not valid (ie domain < 0), and we
+ * have not previously assigned a domain number from DT
+ * (use_dt_domains != 1) we should assign a domain number by
+ * using the:
+ *
+ * pci_get_new_domain_nr()
+ *
+ * API and update the use_dt_domains value to keep track of method we
+ * are using to assign domain numbers (use_dt_domains = 0).
+ *
+ * All other combinations imply we have a platform that is trying
+ * to mix domain numbers obtained from DT and pci_get_new_domain_nr(),
+ * which is a recipe for domain mishandling and it is prevented by
+ * invalidating the domain value (domain = -1) and printing a
+ * corresponding error.
+ */
+ if (domain >= 0 && use_dt_domains) {
+ use_dt_domains = 1;
+ } else if (domain < 0 && use_dt_domains != 1) {
+ use_dt_domains = 0;
+ domain = pci_get_new_domain_nr();
+ } else {
+ dev_err(parent, "Node %s has inconsistent \"linux,pci-domain\" property in DT\n",
+ parent->of_node->full_name);
+ domain = -1;
+ }
+
+ bus->domain_nr = domain;
+}
+#endif
#endif
/**