[PATCH v2 2/2] powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias
Pali Rohár
pali at kernel.org
Wed Jul 6 20:21:48 AEST 2022
Other Linux architectures use DT property 'linux,pci-domain' for specifying
fixed PCI domain of PCI controller specified in Device-Tree.
And lot of Freescale powerpc boards have defined numbered pci alias in
Device-Tree for every PCIe controller which number specify preferred PCI
domain.
So prefer usage of DT property 'linux,pci-domain' (via function
of_get_pci_domain_nr()) and DT pci alias (via function of_alias_get_id())
on powerpc architecture for assigning PCI domain to PCI controller.
Fixes: 63a72284b159 ("powerpc/pci: Assign fixed PHB number based on device-tree properties")
Signed-off-by: Pali Rohár <pali at kernel.org>
---
Changes in v2:
* New patch
---
arch/powerpc/kernel/pci-common.c | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 7f959df34833..0715d74855b3 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -78,10 +78,25 @@ static int get_phb_number(struct device_node *dn)
/*
* Try fixed PHB numbering first, by checking archs and reading
- * the respective device-tree properties. Firstly, try powernv by
- * reading "ibm,opal-phbid", only present in OPAL environment.
+ * the respective device-tree properties. Firstly, try reading
+ * standard "linux,pci-domain", then try reading "ibm,opal-phbid"
+ * (only present in powernv OPAL environment), then try device-tree
+ * alias and as the last try to use lower bits of "reg" property
+ * (only if CONFIG_PPC_PCI_DOMAIN_FROM_OF_REG is enabled).
*/
- ret = of_property_read_u64(dn, "ibm,opal-phbid", &prop);
+ ret = of_get_pci_domain_nr(dn);
+ if (ret >= 0) {
+ prop = ret;
+ ret = 0;
+ }
+ if (ret)
+ ret = of_property_read_u64(dn, "ibm,opal-phbid", &prop);
+ if (ret)
+ ret = of_alias_get_id(dn, "pci");
+ if (ret >= 0) {
+ prop = ret;
+ ret = 0;
+ }
if (ret && IS_ENABLED(CONFIG_PPC_PCI_DOMAIN_FROM_OF_REG)) {
u32 prop_32;
ret = of_property_read_u32_index(dn, "reg", 1, &prop_32);
@@ -95,10 +110,7 @@ static int get_phb_number(struct device_node *dn)
if ((phb_id >= 0) && !test_and_set_bit(phb_id, phb_bitmap))
return phb_id;
- /*
- * If not pseries nor powernv, or if fixed PHB numbering tried to add
- * the same PHB number twice, then fallback to dynamic PHB numbering.
- */
+ /* If everything fails then fallback to dynamic PHB numbering. */
phb_id = find_first_zero_bit(phb_bitmap, MAX_PHBS);
BUG_ON(phb_id >= MAX_PHBS);
set_bit(phb_id, phb_bitmap);
--
2.20.1
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