dcmihandler: Add DCMI Power management support check

According to section 6.6 Power management of DCMI specification,
if power management feature is disabled,
the related commands (Get/Set/Activate/Deactive Power Limit)
should be unsupported.

Change-Id: I887f33babb2fe7a1ab97bb2d0720a693171e48a1
Signed-off-by: Kirill Pakhomov <k.pakhomov@yadro.com>

2 files changed, 44 insertions, 0 deletions

diff --git a/dcmihandler.cpp b/dcmihandler.cpp
index 7a4db9f..e9cc39a 100644
--- a/dcmihandler.cpp
+++ b/dcmihandler.cpp
@@ -65,6 +65,13 @@ static const std::map<uint8_t, std::string> entityIdToName{
     {0x40, "inlet"}, {0x37, "inlet"},     {0x41, "cpu"},
     {0x03, "cpu"},   {0x42, "baseboard"}, {0x07, "baseboard"}};
 
+bool isDCMIPowerMgmtSupported()
+{
+    auto data = parseJSONConfig(gDCMICapabilitiesConfig);
+
+    return (gDCMIPowerMgmtSupported == data.value(gDCMIPowerMgmtCapability, 0));
+}
+
 uint32_t getPcap(sdbusplus::bus::bus& bus)
 {
     auto settingService = ipmi::getService(bus, PCAP_INTERFACE, PCAP_PATH);
@@ -298,6 +305,13 @@ ipmi_ret_t getPowerLimit(ipmi_netfn_t netfn, ipmi_cmd_t cmd,
                          ipmi_request_t request, ipmi_response_t response,
                          ipmi_data_len_t data_len, ipmi_context_t context)
 {
+    if (!dcmi::isDCMIPowerMgmtSupported())
+    {
+        *data_len = 0;
+        log<level::ERR>("DCMI Power management is unsupported!");
+        return IPMI_CC_INVALID;
+    }
+
     auto requestData =
         reinterpret_cast<const dcmi::GetPowerLimitRequest*>(request);
     std::vector<uint8_t> outPayload(sizeof(dcmi::GetPowerLimitResponse));
@@ -359,6 +373,13 @@ ipmi_ret_t setPowerLimit(ipmi_netfn_t netfn, ipmi_cmd_t cmd,
                          ipmi_request_t request, ipmi_response_t response,
                          ipmi_data_len_t data_len, ipmi_context_t context)
 {
+    if (!dcmi::isDCMIPowerMgmtSupported())
+    {
+        *data_len = 0;
+        log<level::ERR>("DCMI Power management is unsupported!");
+        return IPMI_CC_INVALID;
+    }
+
     auto requestData =
         reinterpret_cast<const dcmi::SetPowerLimitRequest*>(request);
     std::vector<uint8_t> outPayload(sizeof(dcmi::SetPowerLimitResponse));
@@ -398,6 +419,13 @@ ipmi_ret_t applyPowerLimit(ipmi_netfn_t netfn, ipmi_cmd_t cmd,
                            ipmi_request_t request, ipmi_response_t response,
                            ipmi_data_len_t data_len, ipmi_context_t context)
 {
+    if (!dcmi::isDCMIPowerMgmtSupported())
+    {
+        *data_len = 0;
+        log<level::ERR>("DCMI Power management is unsupported!");
+        return IPMI_CC_INVALID;
+    }
+
     auto requestData =
         reinterpret_cast<const dcmi::ApplyPowerLimitRequest*>(request);
     std::vector<uint8_t> outPayload(sizeof(dcmi::ApplyPowerLimitResponse));
@@ -1220,6 +1248,13 @@ ipmi_ret_t getPowerReading(ipmi_netfn_t netfn, ipmi_cmd_t cmd,
                            ipmi_request_t request, ipmi_response_t response,
                            ipmi_data_len_t data_len, ipmi_context_t context)
 {
+    if (!dcmi::isDCMIPowerMgmtSupported())
+    {
+        *data_len = 0;
+        log<level::ERR>("DCMI Power management is unsupported!");
+        return IPMI_CC_INVALID;
+    }
+
     ipmi_ret_t rc = IPMI_CC_OK;
     auto requestData =
         reinterpret_cast<const dcmi::GetPowerReadingRequest*>(request);
diff --git a/dcmihandler.hpp b/dcmihandler.hpp
index e3fa9de..8b16e3d 100644
--- a/dcmihandler.hpp
+++ b/dcmihandler.hpp
@@ -56,6 +56,8 @@ static constexpr auto systemPath = "/org/freedesktop/systemd1";
 static constexpr auto systemIntf = "org.freedesktop.systemd1.Manager";
 static constexpr auto gDCMICapabilitiesConfig =
     "/usr/share/ipmi-providers/dcmi_cap.json";
+static constexpr auto gDCMIPowerMgmtCapability = "PowerManagement";
+static constexpr auto gDCMIPowerMgmtSupported = 0x1;
 
 namespace assettag
 {
@@ -161,6 +163,13 @@ struct SetAssetTagResponse
     uint8_t tagLength; //!< Total asset tag length.
 } __attribute__((packed));
 
+/** @brief Check whether DCMI power management is supported
+ *         in the DCMI Capabilities config file.
+ *
+ *  @return True if DCMI power management is supported
+ */
+bool isDCMIPowerMgmtSupported();
+
 /** @brief Read the object tree to fetch the object path that implemented the
  *         Asset tag interface.
  *