powerpc/pseries: Add Gen3 definitions for PCIE link speed

Rev3 of the PCI Express Base Specification defines a Supported Link
Speeds Vector where the bit definitions within this field are:

Bit 0 - 2.5 GT/s
Bit 1 - 5.0 GT/s
Bit 2 - 8.0 GT/s

This vector definition is used by the platform firmware to export the
maximum and current link speeds of the PCI bus via the
"ibm,pcie-link-speed-stats" device-tree property.

This patch updates pseries_root_bridge_prepare() to detect Gen3
speed buses (defined by 0x04).

Signed-off-by: Kleber Sacilotto de Souza <klebers@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pseries/pci.c b/arch/powerpc/platforms/pseries/pci.c
index a6f7a1460e2f..c413ec158ff5 100644
--- a/arch/powerpc/platforms/pseries/pci.c
+++ b/arch/powerpc/platforms/pseries/pci.c
@@ -144,6 +144,9 @@ int pseries_root_bridge_prepare(struct pci_host_bridge *bridge)
         case 0x02:
                 bus->max_bus_speed = PCIE_SPEED_5_0GT;
                 break;
+        case 0x04:
+                bus->max_bus_speed = PCIE_SPEED_8_0GT;
+                break;
         default:
                 bus->max_bus_speed = PCI_SPEED_UNKNOWN;
                 break;
@@ -156,6 +159,9 @@ int pseries_root_bridge_prepare(struct pci_host_bridge *bridge)
         case 0x02:
                 bus->cur_bus_speed = PCIE_SPEED_5_0GT;
                 break;
+        case 0x04:
+                bus->cur_bus_speed = PCIE_SPEED_8_0GT;
+                break;
         default:
                 bus->cur_bus_speed = PCI_SPEED_UNKNOWN;
                 break;