revert SafeCPReadPointer

Source/Core/VideoCommon/CommandProcessor.cpp

@@ -60,9 +60,6 @@ void SCPFifoStruct::DoState(PointerWrap& p)
   p.Do(CPWritePointer);
   p.Do(CPReadPointer);
   p.Do(CPBreakpoint);
-
-  // keep compatible
-  u32 SafeCPReadPointer = 0;
   p.Do(SafeCPReadPointer);
 
   p.Do(bFF_GPLinkEnable);
@@ -255,33 +252,56 @@ void RegisterMMIO(MMIO::Mapping* mmio, u32 base)
 
   // Some MMIOs have different handlers for single core vs. dual core mode.
   mmio->Register(base | FIFO_RW_DISTANCE_LO,
+                 IsOnThread() ?
+                 MMIO::ComplexRead<u16>([](u32) {
+                     if (fifo.CPWritePointer >= fifo.SafeCPReadPointer)
+                       return ReadLow(fifo.CPWritePointer - fifo.SafeCPReadPointer);
+                     else
+                       return ReadLow(fifo.CPEnd - fifo.SafeCPReadPointer + fifo.CPWritePointer -
+                                      fifo.CPBase + 32);
+                 }) :
                  MMIO::DirectRead<u16>(MMIO::Utils::LowPart(&fifo.CPReadWriteDistance)),
                  MMIO::DirectWrite<u16>(MMIO::Utils::LowPart(&fifo.CPReadWriteDistance),
                                         WMASK_LO_ALIGN_32BIT));
   mmio->Register(base | FIFO_RW_DISTANCE_HI,
+                 IsOnThread() ?
+                 MMIO::ComplexRead<u16>([](u32) {
+                     if (fifo.CPWritePointer >= fifo.SafeCPReadPointer)
+                       return ReadHigh(fifo.CPWritePointer - fifo.SafeCPReadPointer);
+                     else
+                       return ReadHigh(fifo.CPEnd - fifo.SafeCPReadPointer + fifo.CPWritePointer -
+                                       fifo.CPBase + 32);
+                 }) :
                  MMIO::DirectRead<u16>(MMIO::Utils::HighPart(&fifo.CPReadWriteDistance)),
                  MMIO::ComplexWrite<u16>([WMASK_HI_RESTRICT](u32, u16 val) {
-                   WriteHigh(fifo.CPReadWriteDistance, val & WMASK_HI_RESTRICT);
-                   Fifo::SyncGPU(Fifo::SyncGPUReason::Other);
-                   if (fifo.CPReadWriteDistance == 0)
-                   {
-                     GPFifo::ResetGatherPipe();
-                     Fifo::ResetVideoBuffer();
-                   }
-                   else
-                   {
-                     Fifo::ResetVideoBuffer();
-                   }
-                   Fifo::RunGpu();
+                     WriteHigh(fifo.CPReadWriteDistance, val & WMASK_HI_RESTRICT);
+                     Fifo::SyncGPU(Fifo::SyncGPUReason::Other);
+                     if (fifo.CPReadWriteDistance == 0)
+                     {
+                       GPFifo::ResetGatherPipe();
+                       Fifo::ResetVideoBuffer();
+                     }
+                     else
+                     {
+                       Fifo::ResetVideoBuffer();
+                     }
+                     Fifo::RunGpu();
                  }));
-  mmio->Register(base | FIFO_READ_POINTER_LO,
-                 MMIO::DirectRead<u16>(MMIO::Utils::LowPart(&fifo.CPReadPointer)),
-                 MMIO::DirectWrite<u16>(MMIO::Utils::LowPart(&fifo.CPReadPointer),
-                                        WMASK_LO_ALIGN_32BIT));
-  mmio->Register(base | FIFO_READ_POINTER_HI,
-                 MMIO::DirectRead<u16>(MMIO::Utils::HighPart(&fifo.CPReadPointer)),
-                 MMIO::DirectWrite<u16>(MMIO::Utils::HighPart(&fifo.CPReadPointer),
-                                        WMASK_HI_RESTRICT));
+  mmio->Register(
+    base | FIFO_READ_POINTER_LO,
+    IsOnThread() ? MMIO::DirectRead<u16>(MMIO::Utils::LowPart(&fifo.SafeCPReadPointer)) :
+    MMIO::DirectRead<u16>(MMIO::Utils::LowPart(&fifo.CPReadPointer)),
+    MMIO::DirectWrite<u16>(MMIO::Utils::LowPart(&fifo.CPReadPointer), WMASK_LO_ALIGN_32BIT));
+  mmio->Register(
+    base | FIFO_READ_POINTER_HI,
+    IsOnThread() ? MMIO::DirectRead<u16>(MMIO::Utils::HighPart(&fifo.SafeCPReadPointer)) :
+    MMIO::DirectRead<u16>(MMIO::Utils::HighPart(&fifo.CPReadPointer)),
+    IsOnThread() ?
+    MMIO::ComplexWrite<u16>([WMASK_HI_RESTRICT](u32, u16 val) {
+        WriteHigh(fifo.CPReadPointer, val & WMASK_HI_RESTRICT);
+        fifo.SafeCPReadPointer = fifo.CPReadPointer;
+    }) :
+    MMIO::DirectWrite<u16>(MMIO::Utils::HighPart(&fifo.CPReadPointer), WMASK_HI_RESTRICT));
 }
 
 void GatherPipeBursted()

Source/Core/VideoCommon/CommandProcessor.h

@@ -25,6 +25,7 @@ struct SCPFifoStruct
   volatile u32 CPWritePointer;
   volatile u32 CPReadPointer;
   volatile u32 CPBreakpoint;
+  volatile u32 SafeCPReadPointer;
 
   volatile u32 bFF_GPLinkEnable;
   volatile u32 bFF_GPReadEnable;

Source/Core/VideoCommon/Fifo.cpp

@@ -365,6 +365,9 @@ void RunGpuLoop()
               s_video_buffer_read_ptr = OpcodeDecoder::Run(
                   DataReader(s_video_buffer_read_ptr, write_ptr), &cyclesExecuted, false, &needSize);
 
+              if ((write_ptr - s_video_buffer_read_ptr) == 0)
+                Common::AtomicStore(fifo.SafeCPReadPointer, fifo.CPReadPointer);
+
               if (param.bSyncGPU)
               {
                 cyclesExecuted = (u32)(cyclesExecuted / param.fSyncGpuOverclock);