//===--- Level Zero Target RTL Implementation -----------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Plugin interface for SPIR-V/Xe machine.
//
//===----------------------------------------------------------------------===//

#ifndef OPENMP_LIBOMPTARGET_PLUGINS_NEXTGEN_LEVEL_ZERO_L0PLUGIN_H
#define OPENMP_LIBOMPTARGET_PLUGINS_NEXTGEN_LEVEL_ZERO_L0PLUGIN_H

#include "L0Device.h"
#include "L0Memory.h"
#include "L0Options.h"
#include "L0Program.h"
#include "L0Queue.h"

namespace llvm::omp::target::plugin {

/// Plugin-side context for Level Zero. Owns a ze_context_handle_t that is
/// scoped to the set of devices grouped by the user through olCreateContext.
class LevelZeroPluginContextTy final : public PluginContextTy {
public:
  LevelZeroPluginContextTy(GenericPluginTy &Plugin,
                           llvm::ArrayRef<GenericDeviceTy *> Devices,
                           ze_driver_handle_t Driver,
                           ze_context_handle_t ZeContext, bool OwnsZeContext)
      : PluginContextTy(Plugin, Devices), Driver(Driver), ZeContext(ZeContext),
        OwnsZeContext(OwnsZeContext), QueueCache(*this) {}

  ~LevelZeroPluginContextTy() override = default;

  Error deinit() override;

  ze_driver_handle_t getZeDriver() const { return Driver; }
  ze_context_handle_t getZeContext() const { return ZeContext; }

  Error initAsyncInfoImpl(GenericDeviceTy &Device,
                          AsyncInfoWrapperTy &AsyncInfoWrapper) override;

  /// Pop an idle queue for \p Device from the cache, or create a new one.
  Expected<L0QueueTy *> takeCachedQueue(L0DeviceTy *Device) {
    return QueueCache.getQueue(*Device);
  }

  /// Return an idle queue to the cache.
  void returnCachedQueue(L0QueueTy *Queue) { QueueCache.releaseQueue(Queue); }

private:
  ze_driver_handle_t Driver;
  ze_context_handle_t ZeContext;
  bool OwnsZeContext;

  L0QueueCacheTy QueueCache;
};

/// Class implementing the LevelZero specific functionalities of the plugin.
class LevelZeroPluginTy final : public GenericPluginTy {
private:
  struct DeviceInfoTy {
    L0DeviceIdTy Id;
    L0ContextTy *Driver;
    bool isRoot() const { return Id.SubId < 0 && Id.CCSId < 0; }
  };
  llvm::SmallVector<DeviceInfoTy> DetectedDevices;

  /// Context (and Driver) specific data.
  std::list<L0ContextTy> ContextList;

  // Table containing per-thread information for each Context using TLS.
  L0ContextTLSTableTy ContextTLSTable;

  /// L0 plugin options.
  L0OptionsTy Options;

  /// Find L0 devices and initialize device properties.
  /// Returns number of devices reported to omptarget.
  Expected<int32_t> findDevices();

public:
  LevelZeroPluginTy() : GenericPluginTy(getTripleArch()) {}
  virtual ~LevelZeroPluginTy() = default;

  L0ContextTLSTy &getContextTLS(ze_context_handle_t Context) {
    return ContextTLSTable.get(Context);
  }

  const L0OptionsTy &getOptions() { return Options; }

  const L0DeviceTy &getDeviceFromId(int32_t DeviceId) const {
    return static_cast<const L0DeviceTy &>(getDevice(DeviceId));
  }
  L0DeviceTy &getDeviceFromId(int32_t DeviceId) {
    return static_cast<L0DeviceTy &>(getDevice(DeviceId));
  }

  // Plugin interface.
  Expected<int32_t> initImpl() override;
  Error deinitImpl() override;
  GenericDeviceTy *createDevice(GenericPluginTy &Plugin, int32_t DeviceId,
                                int32_t NumDevices) override;
  GenericGlobalHandlerTy *createGlobalHandler() override;

  Expected<std::unique_ptr<PluginContextTy>>
  createPluginContext(llvm::ArrayRef<GenericDeviceTy *> Devices) override;

  uint16_t getMagicElfBits() const override { return ELF::EM_INTELGT; }
  Triple::ArchType getTripleArch() const override { return Triple::spirv64; }
  const char *getName() const override { return GETNAME(TARGET_NAME); }

  Expected<bool> isELFCompatible(uint32_t DeviceId,
                                 StringRef Image) const override;

  Error flushQueueImpl(omp_interop_val_t *Interop) override;
  Error syncBarrierImpl(omp_interop_val_t *Interop) override;
  Error asyncBarrierImpl(omp_interop_val_t *Interop) override;

  Expected<bool> isImageCompatible(StringRef Image) const override;
};

} // namespace llvm::omp::target::plugin

#endif // OPENMP_LIBOMPTARGET_PLUGINS_NEXTGEN_LEVEL_ZERO_L0PLUGIN_H