gpu_compute_driver.hh

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/*
 * Copyright (c) 2015-2018 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
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#ifndef __GPU_COMPUTE_GPU_COMPUTE_DRIVER_HH__
#define __GPU_COMPUTE_GPU_COMPUTE_DRIVER_HH__
 
#include <cassert>
#include <cstdint>
#include <set>
#include <unordered_map>
 
#include "base/addr_range_map.hh"
#include "base/types.hh"
#include "enums/GfxVersion.hh"
#include "mem/request.hh"
#include "sim/emul_driver.hh"
 
namespace gem5
{
 
struct GPUComputeDriverParams;
class GPUCommandProcessor;
class PortProxy;
class ThreadContext;
 
class GPUComputeDriver final : public EmulatedDriver
{
  public:
    typedef GPUComputeDriverParams Params;
    GPUComputeDriver(const Params &p);
    int ioctl(ThreadContext *tc, unsigned req, Addr ioc_buf) override;
 
    int open(ThreadContext *tc, int mode, int flags) override;
    Addr mmap(ThreadContext *tc, Addr start, uint64_t length,
              int prot, int tgt_flags, int tgt_fd, off_t offset) override;
    virtual void signalWakeupEvent(uint32_t event_id);
    void sleepCPU(ThreadContext *tc, uint32_t milliSecTimeout);
    void setMtype(RequestPtr req);
 
    int
    doorbellSize()
    {
        switch (gfxVersion) {
          case GfxVersion::gfx902:
            return 4;
          case GfxVersion::gfx900:
            // gfx900 supports large BAR, so it has a larger doorbell
            return 8;
          default:
            fatal("Invalid GPU type\n");
        }
        return 4;
    }
 
    class DriverWakeupEvent : public Event
    {
      public:
        DriverWakeupEvent(GPUComputeDriver *gpu_driver,
                          ThreadContext *thrd_cntxt)
          : driver(gpu_driver), tc(thrd_cntxt) {}
        void process() override;
        const char *description() const override;
        void scheduleWakeup(Tick wakeup_delay);
      private:
        GPUComputeDriver *driver;
        ThreadContext *tc;
    };
 
    class EventTableEntry
    {
      public:
        EventTableEntry() :
            mailBoxPtr(0), tc(nullptr), threadWaiting(false), setEvent(false)
        {}
        // Mail box pointer for this address. Current implementation does not
        // use this mailBoxPtr to notify events but directly calls
        // signalWakeupEvent from dispatcher (GPU) to notifiy events. So,
        // currently this mailBoxPtr is not used. But a future implementation
        // may communicate to the driver using mailBoxPtr.
        Addr mailBoxPtr;
        // Thread context waiting on this even. We do not support multiple
        // threads waiting on an event currently.
        ThreadContext *tc;
        // threadWaiting = true, if some thread context is waiting on this
        // event. A thread context waiting on this event is put to sleep.
        bool threadWaiting;
        // setEvent = true, if this event is triggered but when this event
        // triggered, no thread context was waiting on it. In the future, some
        // thread context will try to wait on this event but since event has
        // already happened, we will not allow that thread context to go to
        // sleep. The above mentioned scneario can happen when the waiting
        // thread and wakeup thread race on this event and the wakeup thread
        // beat the waiting thread at the driver.
        bool setEvent;
    };
    typedef class EventTableEntry ETEntry;
 
    GfxVersion getGfxVersion() const { return gfxVersion; }
 
  private:
    GPUCommandProcessor *device;
    uint32_t queueId;
    bool isdGPU;
    GfxVersion gfxVersion;
    int dGPUPoolID;
    Addr eventPage;
    uint32_t eventSlotIndex;
    //Event table that keeps track of events. It is indexed with event ID.
    std::unordered_map<uint32_t, ETEntry> ETable;
 
    AddrRangeMap<Request::CacheCoherenceFlags, 1> gpuVmas;
 
    enum MtypeFlags
    {
        SHARED                  = 0,
        READ_WRITE              = 1,
        CACHED                  = 2,
        NUM_MTYPE_BITS
    };
 
    Request::CacheCoherenceFlags defaultMtype;
 
    // TCEvents map keeps trak of the events that can wakeup this thread. When
    // multiple events can wake up this thread, this data structure helps to
    // reset all events when one of those events wake up this thread. the
    // signal events that can wake up this thread are stored in signalEvents
    // whereas the timer wakeup event is stored in timerEvent.
    class EventList
    {
      public:
        EventList() : driver(nullptr), timerEvent(nullptr, nullptr) {}
        EventList(GPUComputeDriver *gpu_driver, ThreadContext *thrd_cntxt)
            : driver(gpu_driver), timerEvent(gpu_driver, thrd_cntxt)
        { }
        void clearEvents() {
            assert(driver);
            for (auto event : signalEvents) {
                assert(event < driver->eventSlotIndex);
                driver->ETable[event].tc = nullptr;
                driver->ETable[event].threadWaiting = false;
            }
            signalEvents.clear();
            if (timerEvent.scheduled()) {
                driver->deschedule(timerEvent);
            }
        }
        GPUComputeDriver *driver;
        DriverWakeupEvent timerEvent;
        // The set of events that can wake up the same thread.
        std::set<uint32_t> signalEvents;
    };
    std::unordered_map<ThreadContext *, EventList> TCEvents;
 
    void registerUncacheableMemory(Addr start, Addr length);
 
    Addr gpuVmApeBase(int gpuNum) const;
    Addr gpuVmApeLimit(Addr apeBase) const;
    Addr scratchApeBase(int gpuNum) const;
    Addr scratchApeBaseV9() const;
    Addr scratchApeLimit(Addr apeBase) const;
    Addr ldsApeBase(int gpuNum) const;
    Addr ldsApeBaseV9() const;
    Addr ldsApeLimit(Addr apeBase) const;
 
    void allocateGpuVma(Request::CacheCoherenceFlags mtype, Addr start,
                        Addr length);
    Addr deallocateGpuVma(Addr start);
 
    void allocateQueue(PortProxy &mem_proxy, Addr ioc_buf_addr);
 
};
 
} // namespace gem5
 
#endif // __GPU_COMPUTE_GPU_COMPUTE_DRIVER_HH__