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/memory_manager.hh

@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2021 Advanced Micro Devices, Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __DEV_AMDGPU_MEMORY_MANAGER_HH__
+#define __DEV_AMDGPU_MEMORY_MANAGER_HH__
+
+#include <deque>
+
+#include "base/callback.hh"
+#include "mem/port.hh"
+#include "params/AMDGPUMemoryManager.hh"
+#include "sim/clocked_object.hh"
+
+namespace gem5
+{
+
+class AMDGPUMemoryManager : public ClockedObject
+{
+    class GPUMemPort : public MasterPort
+    {
+        public:
+        GPUMemPort(const std::string &_name, AMDGPUMemoryManager *_gpuMemMgr)
+            : MasterPort(_name, _gpuMemMgr)
+        {
+        }
+
+        bool recvTimingResp(PacketPtr pkt) override;
+        void recvReqRetry() override;
+
+        struct SenderState : public Packet::SenderState
+        {
+            SenderState(Event *callback, Addr addr)
+                : _callback(callback), _addr(addr)
+            {}
+
+            Event *_callback;
+            Addr _addr;
+        };
+
+        std::deque<PacketPtr> retries;
+    };
+
+    GPUMemPort _gpuMemPort;
+    const int cacheLineSize;
+    const RequestorID _requestorId;
+
+  public:
+    AMDGPUMemoryManager(const AMDGPUMemoryManagerParams &p);
+    ~AMDGPUMemoryManager() {};
+
+    /**
+     * Write size amount of data to device memory at addr using flags and
+     * callback.
+     *
+     * @param addr Device address to write.
+     * @param data Pointer to data to write.
+     * @param size Number of bytes to write.
+     * @param flag Additional request flags for write packets.
+     * @param callback Event callback to call after all bytes are written.
+     */
+    void writeRequest(Addr addr, uint8_t *data, int size,
+                      Request::Flags flag = 0, Event *callback = nullptr);
+
+    /**
+     * Get the requestorID for the memory manager. This ID is used for all
+     * packets which should be routed through the device network.
+     *
+     * @return requestorID of this object.
+     */
+    RequestorID getRequestorID() const { return _requestorId; }
+
+    Port &
+    getPort(const std::string &if_name, PortID idx) override
+    {
+        if (if_name == "port") {
+            return _gpuMemPort;
+        } else {
+            return ClockedObject::getPort(if_name, idx);
+        }
+    }
+};
+
+} // namespace gem5
+
+#endif // __DEV_AMDGPU_MEMORY_MANAGER_HH__