pcie_bifurcation: Fetch bifurcation at a PCIe slot with hardcoded values
This will read a json config and return the bifurcation based on that.
It will read the configure file in a persistent file to see if it is
valid machine config and return the bifurcation information
accordingly.
For example,
If it is valid config, it will return 8x8 for PE1,3,4,6.
Tested:
Unit tests passed.
Physical Tests.
PE0 -> no bifurcation
PE1 -> x8x8
```
$ ipmitool raw 0x2e 0x32 0x79 0x2b 0x00 0x0f 0
79 2b 00 0b 00
$ ipmitool raw 0x2e 0x32 0x79 0x2b 0x00 0x0f 1
79 2b 00 0b 02 08 08
```
Change-Id: I44aefbfb26372f8bc0069343c8a6d07d3cf6f42d
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/pcie_bifurcation.cpp b/pcie_bifurcation.cpp
new file mode 100644
index 0000000..71c25cd
--- /dev/null
+++ b/pcie_bifurcation.cpp
@@ -0,0 +1,75 @@
+// Copyright 2022 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "config.h"
+
+#include "pcie_bifurcation.hpp"
+
+#include "commands.hpp"
+#include "errors.hpp"
+#include "handler.hpp"
+
+#include <fmt/format.h>
+
+#include <ipmid/api-types.hpp>
+#include <span>
+#include <vector>
+
+namespace google
+{
+namespace ipmi
+{
+
+namespace
+{
+#ifndef MAX_IPMI_BUFFER
+#define MAX_IPMI_BUFFER 64
+#endif
+} // namespace
+
+struct PcieBifurcationRequest
+{
+ uint8_t pcieIndex;
+} __attribute__((packed));
+
+Resp pcieBifurcation(std::span<const uint8_t> data, HandlerInterface* handler)
+{
+ if (data.size() < sizeof(struct PcieBifurcationRequest))
+ {
+ fmt::print(stderr, "Invalid command length: {}\n",
+ static_cast<uint32_t>(data.size()));
+ return ::ipmi::responseReqDataLenInvalid();
+ }
+
+ auto bifurcation = handler->pcieBifurcation(/*index=*/data[0]);
+
+ int length = sizeof(struct PcieBifurcationReply) + bifurcation.size();
+
+ if (length > MAX_IPMI_BUFFER)
+ {
+ std::fprintf(stderr, "Response would overflow response buffer\n");
+ return ::ipmi::responseInvalidCommand();
+ }
+
+ std::vector<std::uint8_t> reply;
+ reply.reserve(bifurcation.size() + sizeof(struct PcieBifurcationReply));
+ reply.emplace_back(bifurcation.size()); /* bifurcationLength */
+ reply.insert(reply.end(), bifurcation.begin(),
+ bifurcation.end()); /* bifurcation */
+
+ return ::ipmi::responseSuccess(SysOEMCommands::SysPCIeSlotBifurcation,
+ reply);
+}
+} // namespace ipmi
+} // namespace google