dev-amdgpu: Add memory manager for GPU VRAM

The memory manager is responsible for reading and writes to VRAM memory
for direct requests that bypass GPU caches.

Change-Id: I4aa1e77737ce52f2f2c01929b58984126bdcb925
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/51850
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/dev/amdgpu/amdgpu_device.hh

@@ -36,6 +36,7 @@
 
 #include "base/bitunion.hh"
 #include "dev/amdgpu/amdgpu_defines.hh"
+#include "dev/amdgpu/memory_manager.hh"
 #include "dev/amdgpu/mmio_reader.hh"
 #include "dev/io_device.hh"
 #include "dev/pci/device.hh"
@@ -100,6 +101,8 @@ class AMDGPUDevice : public PciDevice
      */
     AMDMMIOReader mmioReader;
 
+    AMDGPUMemoryManager *gpuMemMgr;
+
     /**
      * Blocks of the GPU
      */
@@ -183,7 +186,7 @@ class AMDGPUDevice : public PciDevice
     /**
      * Methods related to translations and system/device memory.
      */
-    RequestorID vramRequestorId() { return 0; }
+    RequestorID vramRequestorId() { return gpuMemMgr->getRequestorID(); }
 
     Addr
     getPageTableBase(uint16_t vmid)