Add shared memory free/total for Intel iGPU (#1328)

LibreHardwareMonitorLib/Hardware/Gpu/IntelIntegratedGpu.cs

@@ -11,6 +11,8 @@ internal class IntelIntegratedGpu : GenericGpu
     private const uint MSR_RAPL_POWER_UNIT = 0x606;
 
     private readonly Sensor _dedicatedMemoryUsage;
+    private readonly Sensor _sharedMemoryLimit;
+    private readonly Sensor _sharedMemoryFree;
     private readonly string _deviceId;
     private readonly float _energyUnitMultiplier;
     private readonly Sensor[] _nodeUsage;
@@ -38,6 +40,12 @@ internal class IntelIntegratedGpu : GenericGpu
 
         _sharedMemoryUsage = new Sensor("D3D Shared Memory Used", memorySensorIndex++, SensorType.SmallData, this, settings);
 
+        if (deviceInfo.GpuSharedLimit > 0)
+        {
+            _sharedMemoryFree = new Sensor("D3D Shared Memory Free", memorySensorIndex++, SensorType.SmallData, this, settings);
+            _sharedMemoryLimit = new Sensor("D3D Shared Memory Total", memorySensorIndex++, SensorType.SmallData, this, settings);
+        }
+
         if (Ring0.ReadMsr(MSR_RAPL_POWER_UNIT, out uint eax, out uint _))
         {
             _energyUnitMultiplier = intelCpu.EnergyUnitsMultiplier;
@@ -78,6 +86,17 @@ internal class IntelIntegratedGpu : GenericGpu
                 ActivateSensor(_dedicatedMemoryUsage);
             }
 
+            if (_sharedMemoryLimit != null)
+            {
+                _sharedMemoryLimit.Value = 1f * deviceInfo.GpuSharedLimit / 1024 / 1024;
+                ActivateSensor(_sharedMemoryLimit);
+                if (_sharedMemoryUsage != null)
+                {
+                    _sharedMemoryFree.Value = _sharedMemoryLimit.Value - _sharedMemoryUsage.Value;
+                    ActivateSensor(_sharedMemoryFree);
+                }
+            }
+
             _sharedMemoryUsage.Value = 1f * deviceInfo.GpuSharedUsed / 1024 / 1024;
             ActivateSensor(_sharedMemoryUsage);