[PATCH 4.14 136/229] powerpc/pci: Prefer PCI domain assignment via DT linux,pci-domain and alias

Greg Kroah-Hartman
2022-08-23T10:00:23Z

From: Pali Rohár <pali@kernel.org>

[ Upstream commit 0fe1e96fef0a5c53b4c0d1500d356f3906000f81 ]

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@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220706102148.5060-2-pali@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/kernel/pci-common.c | 27 +++++++++++++++++++--------
1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 02831a396419..2e2cc80bf592 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -80,16 +80,30 @@ EXPORT_SYMBOL(get_pci_dma_ops);
static int get_phb_number(struct device_node *dn)
{
int ret, phb_id = -1;
- u32 prop_32;
u64 prop;

/*
* 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.
*/
- 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) {
+ u32 prop_32;
ret = of_property_read_u32_index(dn, "reg", 1, &prop_32);
prop = prop_32;
}
@@ -101,10 +115,7 @@ 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);
--
2.35.1