Add MaxLanes and MaxPCIeType properties to the PCIeInterface

According to the Redfish Data Model specification PCIeInterface (v1.3+)
of the PCIeDevice model contains the following properties:

MaxLanes (v1.3+)
The number of PCIe lanes supported by this device.
- This property shall contain the maximum number of
  PCIe lanes supported by this device.

MaxPCIeType (v1.3+)
The highest version of the PCIe specification supported by
this device.
- This property shall contain the maximum PCIe
  specification that this device supports.

Since PCIeDevice interface from the phosphor-dbus-interfaces has these
values in the 'MaxLanes' and 'GenerationSupported' properties, populate
the fields to Redfish.

Tested: Redfish validator passed

Before:
redfish/v1/Systems/system/PCIeDevices/Bus_c3_Device_00
{
  "@odata.id": "/redfish/v1/Systems/system/PCIeDevices/Bus_c3_Device_00",
  "@odata.type": "#PCIeDevice.v1_9_0.PCIeDevice",
  ...
  "PCIeInterface": {
    "LanesInUse": 4,
    "PCIeType": "Gen3"
  },
  ...
}

After:
redfish/v1/Systems/system/PCIeDevices/Bus_c3_Device_00
{
  "@odata.id": "/redfish/v1/Systems/system/PCIeDevices/Bus_c3_Device_00",
  "@odata.type": "#PCIeDevice.v1_9_0.PCIeDevice",
  ...
  "PCIeInterface": {
    "LanesInUse": 4,
    "MaxLanes": 4,
    "MaxPCIeType": "Gen3",
    "PCIeType": "Gen3"
  },
  ...
}

Change-Id: Iec786e376cea8fd2aa516b5b2a3da4286e59627a
Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>

2 files changed, 36 insertions, 2 deletions

diff --git a/Redfish.md b/Redfish.md
index a7b3445d82..f2fb141916 100644
--- a/Redfish.md
+++ b/Redfish.md
@@ -861,6 +861,8 @@ other.
 - PCIeInterface
   - DeviceType
   - LanesInUse
+  - MaxLanes
+  - MaxPCIeType
   - PCIeType
 - SerialNumber
 - Slot
diff --git a/redfish-core/lib/pcie.hpp b/redfish-core/lib/pcie.hpp
index f5c5303554..195ec8727a 100644
--- a/redfish-core/lib/pcie.hpp
+++ b/redfish-core/lib/pcie.hpp
@@ -418,12 +418,14 @@ inline void addPCIeDeviceProperties(
 {
     const std::string* deviceType = nullptr;
     const std::string* generationInUse = nullptr;
+    const std::string* generationSupported = nullptr;
     const size_t* lanesInUse = nullptr;
+    const size_t* maxLanes = nullptr;
 
     const bool success = sdbusplus::unpackPropertiesNoThrow(
         dbus_utils::UnpackErrorPrinter(), pcieDevProperties, "DeviceType",
-        deviceType, "GenerationInUse", generationInUse, "LanesInUse",
-        lanesInUse);
+        deviceType, "GenerationInUse", generationInUse, "GenerationSupported",
+        generationSupported, "LanesInUse", lanesInUse, "MaxLanes", maxLanes);
 
     if (!success)
     {
@@ -460,12 +462,42 @@ inline void addPCIeDeviceProperties(
         }
     }
 
+    if (generationSupported != nullptr)
+    {
+        std::optional<pcie_device::PCIeTypes> redfishGenerationSupported =
+            pcie_util::redfishPcieGenerationFromDbus(*generationSupported);
+
+        if (!redfishGenerationSupported)
+        {
+            BMCWEB_LOG_WARNING << "Unknown PCIe Device Generation: "
+                               << *generationSupported;
+        }
+        else
+        {
+            if (*redfishGenerationSupported == pcie_device::PCIeTypes::Invalid)
+            {
+                BMCWEB_LOG_ERROR << "Invalid PCIe Device Generation: "
+                                 << *generationSupported;
+                messages::internalError(asyncResp->res);
+                return;
+            }
+            asyncResp->res.jsonValue["PCIeInterface"]["MaxPCIeType"] =
+                *redfishGenerationSupported;
+        }
+    }
+
     // The default value of LanesInUse is 0, and the field will be
     // left as off if it is a default value.
     if (lanesInUse != nullptr && *lanesInUse != 0)
     {
         asyncResp->res.jsonValue["PCIeInterface"]["LanesInUse"] = *lanesInUse;
     }
+    // The default value of MaxLanes is 0, and the field will be
+    // left as off if it is a default value.
+    if (maxLanes != nullptr && *maxLanes != 0)
+    {
+        asyncResp->res.jsonValue["PCIeInterface"]["MaxLanes"] = *maxLanes;
+    }
 
     asyncResp->res.jsonValue["PCIeFunctions"]["@odata.id"] =
         boost::urls::format(