[llvm] [OFFLOAD] Add plugin with support for Intel oneAPI Level Zero (PR #158900)

[Alex Duran via llvm-commits]

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@@ -0,0 +1,138 @@
+//===--- 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 "AsyncQueue.h"
+#include "L0Defs.h"
+#include "L0Device.h"
+#include "L0Memory.h"
+#include "L0Options.h"
+#include "L0Program.h"
+#include "TLS.h"
+
+namespace llvm::omp::target::plugin {
+
+/// Class implementing the LevelZero specific functionalities of the plugin.
+class LevelZeroPluginTy final : public GenericPluginTy {
+private:
+  /// Number of devices available including subdevices
+  uint32_t NumDevices = 0;
+
+  /// Context (and Driver) specific data
+  std::list<L0ContextTy> ContextList;
+
+  /// L0 device used by each OpenMP device
+  using DeviceContainerTy = llvm::SmallVector<L0DeviceTy *>;
+  DeviceContainerTy L0Devices;
+
+  // Table containing per-thread information using TLS
+  L0ThreadTblTy ThreadTLSTable;
+  // Table containing per-thread information for each device using TLS
+  L0DeviceTLSTableTy DeviceTLSTable;
+  // Table containing per-thread information for each Context using TLS
+  L0ContextTLSTableTy ContextTLSTable;
+
+  /// L0 plugin global options
+  static L0OptionsTy Options;
+
+  std::mutex GlobalMutex;
+
+  /// Common pool of AsyncQueue
+  AsyncQueuePoolTy AsyncQueuePool;
+
+  auto &getTLS() { return ThreadTLSTable.get(); }
+
+public:
+  LevelZeroPluginTy() : GenericPluginTy(getTripleArch()) {}
+  virtual ~LevelZeroPluginTy() {}
+
+  auto &getDeviceTLS(int32_t DeviceId) { return DeviceTLSTable.get(DeviceId); }
+  auto &getContextTLS(ze_context_handle_t Context) {
+    return ContextTLSTable.get(Context);
+  }
+
+  static const auto &getOptions() { return Options; }
+
+  auto &getGlobalMutex() { return GlobalMutex; }
+
+  struct DevicesRangeTy {
+    using iterator = DeviceContainerTy::iterator;
+
+    iterator BeginIt;
+    iterator EndIt;
+
+    DevicesRangeTy(iterator BeginIt, iterator EndIt)
+        : BeginIt(BeginIt), EndIt(EndIt) {}
+
+    auto &begin() { return BeginIt; }
+    auto &end() { return EndIt; }
+  };
+
+  auto getDevicesRange() {
+    return DevicesRangeTy(L0Devices.begin(), L0Devices.end());
+  }
+
+  /// Clean-up routine to be invoked by the destructor or
+  /// LevelZeroPluginTy::deinit.
+  void closeRTL();
+
+  /// Find L0 devices and initialize device properties.
+  /// Returns number of devices reported to omptarget.
+  int32_t findDevices();
+
+  L0DeviceTy &getDeviceFromId(int32_t DeviceId) const {
----------------
adurang wrote:

These are all related, answer again "because subdevices" :) Will change with others if possible.

https://github.com/llvm/llvm-project/pull/158900