Added support for the Global\\Access_PCI mutex to synchronize the PCI bus access for reading AMD temperature sensors.

Hardware/CPU/AMD0FCPU.cs

@@ -4,7 +4,7 @@
   License, v. 2.0. If a copy of the MPL was not distributed with this
   file, You can obtain one at http://mozilla.org/MPL/2.0/.
  
-  Copyright (C) 2009-2010 Michael Möller <mmoeller@openhardwaremonitor.org>
+  Copyright (C) 2009-2020 Michael Möller <mmoeller@openhardwaremonitor.org>
   Copyright (C) 2010 Paul Werelds <paul@werelds.net>
 
 */
@@ -102,6 +102,8 @@ namespace OpenHardwareMonitor.Hardware.CPU {
     public override void Update() {
       base.Update();
 
+      if (Ring0.WaitPciBusMutex(10)) { 
+
         if (miscellaneousControlAddress != Ring0.InvalidPciAddress) {
           for (uint i = 0; i < coreTemperatures.Length; i++) {
             if (Ring0.WritePciConfig(
@@ -122,6 +124,9 @@ namespace OpenHardwareMonitor.Hardware.CPU {
           }
         }
 
+        Ring0.ReleasePciBusMutex();
+      }
+
       if (HasTimeStampCounter) {
         double newBusClock = 0;
 

Hardware/CPU/AMD10CPU.cs

@@ -311,11 +311,22 @@ namespace OpenHardwareMonitor.Hardware.CPU {
     }
 
     private bool ReadSmuRegister(uint address, out uint value) {
+      if (Ring0.WaitPciBusMutex(10)) {
+
         if (!Ring0.WritePciConfig(0, 0xB8, address)) {
           value = 0;
+
+          Ring0.ReleasePciBusMutex();
+          return false;
+        }
+        var result = Ring0.ReadPciConfig(0, 0xBC, out value);
+
+        Ring0.ReleasePciBusMutex();
+        return result;
+      } else {
+        value = 0;
         return false;
       }
-      return Ring0.ReadPciConfig(0, 0xBC, out value);
     }
 
     public override void Update() {

Hardware/CPU/AMD17CPU.cs

@@ -160,10 +160,12 @@ namespace OpenHardwareMonitor.Hardware.CPU {
         CultureInfo.InvariantCulture));
       r.AppendLine();
 
+      if (Ring0.WaitPciBusMutex(100)) {
         r.AppendLine("SMN Registers");
         r.AppendLine();
         r.AppendLine(" Register  Value");
         var registers = GetSmnRegisters();
+
         for (int i = 0; i < registers.Count; i++)
           if (ReadSmnRegister(registers[i], out uint value)) {
             r.Append(" ");
@@ -174,6 +176,9 @@ namespace OpenHardwareMonitor.Hardware.CPU {
           }
         r.AppendLine();
 
+        Ring0.ReleasePciBusMutex();
+      }
+
       return r.ToString();
     }
 
@@ -195,6 +200,8 @@ namespace OpenHardwareMonitor.Hardware.CPU {
     public override void Update() {
       base.Update();
 
+      if (Ring0.WaitPciBusMutex(10)) { 
+
         uint value;
         if (ReadSmnRegister(FAMILY_17H_M01H_THM_TCON_TEMP, out value)) {
           float temperature = ((value >> 21) & 0x7FF) / 8.0f;
@@ -243,6 +250,9 @@ namespace OpenHardwareMonitor.Hardware.CPU {
           ActivateSensor(ccdAvgTemperature);
         }
 
+        Ring0.ReleasePciBusMutex();
+      }
+
       if (energyUnitMultiplier != 0 && 
         Ring0.Rdmsr(MSR_PKG_ENERGY_STAT, out uint energyConsumed, out _)) 
       {

Hardware/Ring0.cs

@@ -22,6 +22,7 @@ namespace OpenHardwareMonitor.Hardware {
     private static KernelDriver driver;
     private static string fileName;
     private static Mutex isaBusMutex;
+    private static Mutex pciBusMutex;
     private static readonly StringBuilder report = new StringBuilder();
 
     private const uint OLS_TYPE = 40000;
@@ -196,12 +197,21 @@ namespace OpenHardwareMonitor.Hardware {
       if (!driver.IsOpen) 
         driver = null;
 
-      string mutexName = "Global\\Access_ISABUS.HTP.Method";
+      string isaMutexName = "Global\\Access_ISABUS.HTP.Method";
       try {
-        isaBusMutex = new Mutex(false, mutexName);
+        isaBusMutex = new Mutex(false, isaMutexName);
       } catch (UnauthorizedAccessException) {
         try {
-          isaBusMutex = Mutex.OpenExisting(mutexName, MutexRights.Synchronize);
+          isaBusMutex = Mutex.OpenExisting(isaMutexName, MutexRights.Synchronize);
+        } catch { }
+      }
+
+      string pciMutexName = "Global\\Access_PCI";
+      try {
+        pciBusMutex = new Mutex(false, pciMutexName);
+      } catch (UnauthorizedAccessException) {
+        try {
+          pciBusMutex = Mutex.OpenExisting(pciMutexName, MutexRights.Synchronize);
         } catch { }
       }
     }
@@ -229,6 +239,11 @@ namespace OpenHardwareMonitor.Hardware {
         isaBusMutex = null;
       }
 
+      if (pciBusMutex != null) {
+        pciBusMutex.Close();
+        pciBusMutex = null;
+      }
+
       // try to delete temporary driver file again if failed during open
       if (fileName != null && File.Exists(fileName)) {
         try {
@@ -266,6 +281,21 @@ namespace OpenHardwareMonitor.Hardware {
       isaBusMutex.ReleaseMutex();
     }
 
+    public static bool WaitPciBusMutex(int millisecondsTimeout) {
+      if (pciBusMutex == null)
+        return true;
+      try {
+        return pciBusMutex.WaitOne(millisecondsTimeout, false);
+      } catch (AbandonedMutexException) { return true; }
+        catch (InvalidOperationException) { return false; }
+    }
+
+    public static void ReleasePciBusMutex() {
+      if (pciBusMutex == null)
+        return;
+      pciBusMutex.ReleaseMutex();
+    }
+
     public static bool Rdmsr(uint index, out uint eax, out uint edx) {
       if (driver == null) {
         eax = 0;

Properties/AssemblyVersion.cs

@@ -10,5 +10,5 @@
 
 using System.Reflection;
 
-[assembly: AssemblyVersion("0.9.3.3")]
+[assembly: AssemblyVersion("0.9.3.4")]
-[assembly: AssemblyInformationalVersion("0.9.3.3 Alpha")]
+[assembly: AssemblyInformationalVersion("0.9.3.4 Alpha")]