pci: pci-uclass: Add support for Alternate-RoutingID capability
If ARI capability is found on device, use it to update next function
number in bus scan and also helps to skip unnecessary bdf scans.
Signed-off-by: Suneel Garapati <sgarapati@marvell.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 4635752..377806f 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -63,6 +63,15 @@
if available on a PCI Physical Function device and probe for
applicable drivers.
+config PCI_ARID
+ bool "Enable Alternate Routing-ID support for PCI"
+ depends on PCI || DM_PCI
+ default n
+ help
+ Say Y here if you want to enable Alternate Routing-ID capability
+ support on PCI devices. This helps to skip some devices in BDF
+ scan that are not present.
+
config PCIE_ECAM_GENERIC
bool "Generic ECAM-based PCI host controller support"
default n
diff --git a/drivers/pci/pci-uclass.c b/drivers/pci/pci-uclass.c
index 23135eb..fc60dfe 100644
--- a/drivers/pci/pci-uclass.c
+++ b/drivers/pci/pci-uclass.c
@@ -798,6 +798,7 @@
ulong header_type;
pci_dev_t bdf, end;
bool found_multi;
+ int ari_off;
int ret;
found_multi = false;
@@ -871,6 +872,31 @@
pplat->vendor = vendor;
pplat->device = device;
pplat->class = class;
+
+ if (IS_ENABLED(CONFIG_PCI_ARID)) {
+ ari_off = dm_pci_find_ext_capability(dev,
+ PCI_EXT_CAP_ID_ARI);
+ if (ari_off) {
+ u16 ari_cap;
+
+ /*
+ * Read Next Function number in ARI Cap
+ * Register
+ */
+ dm_pci_read_config16(dev, ari_off + 4,
+ &ari_cap);
+ /*
+ * Update next scan on this function number,
+ * subtract 1 in BDF to satisfy loop increment.
+ */
+ if (ari_cap & 0xff00) {
+ bdf = PCI_BDF(PCI_BUS(bdf),
+ PCI_DEV(ari_cap),
+ PCI_FUNC(ari_cap));
+ bdf = bdf - 0x100;
+ }
+ }
+ }
}
return 0;