Revert "[SYCL][L0] Report multiple CCS as SYCL sub-devices on a single tile machine" (#7083)

Reverts #6946 due to reported regressions

Author: smaslov-intel

sycl/plugins/level_zero/pi_level_zero.cpp

@@ -2553,45 +2553,24 @@ pi_result _pi_platform::populateDeviceCacheIfNeeded() {
       // Additionally we need to cache all sub-devices too, such that they
       // are readily visible to the piextDeviceCreateWithNativeHandle.
       //
-      std::vector<pi_device> PiSubDevices;
       pi_uint32 SubDevicesCount = 0;
       ZE_CALL(zeDeviceGetSubDevices,
               (Device->ZeDevice, &SubDevicesCount, nullptr));
 
-      if (SubDevicesCount) {
-        auto ZeSubdevices = new ze_device_handle_t[SubDevicesCount];
-        ZE_CALL(zeDeviceGetSubDevices,
-                (Device->ZeDevice, &SubDevicesCount, ZeSubdevices));
-
-        // Wrap the Level Zero sub-devices into PI sub-devices
-        // and add them to cache.
-        for (uint32_t I = 0; I < SubDevicesCount; ++I) {
-          std::unique_ptr<_pi_device> PiSubDevice(
-              new _pi_device(ZeSubdevices[I], this, Device.get()));
-          pi_result Result = PiSubDevice->initialize();
-          if (Result != PI_SUCCESS) {
-            delete[] ZeSubdevices;
-            return Result;
-          }
-          // save pointers to sub-devices for quick retrieval in the future.
-          Device->SubDevices.push_back(PiSubDevice.get());
-          PiDevicesCache.push_back(std::move(PiSubDevice));
-        }
-        delete[] ZeSubdevices;
-        PiSubDevices = Device->SubDevices;
-      } else {
-        // Level Zero will not report the sub-device on a single tile
-        // machine, but we still want that to be partitionable into
-        // multiple CCS-s. In this case the loop below will find out
-        // the CCS-s and report them as sub-devices of the root
-        // device.
-        SubDevicesCount = 1;
-        PiSubDevices.push_back(Device.get());
-      }
+      auto ZeSubdevices = new ze_device_handle_t[SubDevicesCount];
+      ZE_CALL(zeDeviceGetSubDevices,
+              (Device->ZeDevice, &SubDevicesCount, ZeSubdevices));
 
-      // Find out CCCs.
+      // Wrap the Level Zero sub-devices into PI sub-devices, and add them to
+      // cache.
       for (uint32_t I = 0; I < SubDevicesCount; ++I) {
-        auto PiSubDevice = PiSubDevices[I];
+        std::unique_ptr<_pi_device> PiSubDevice(
+            new _pi_device(ZeSubdevices[I], this, Device.get()));
+        pi_result Result = PiSubDevice->initialize();
+        if (Result != PI_SUCCESS) {
+          delete[] ZeSubdevices;
+          return Result;
+        }
 
         // collect all the ordinals for the sub-sub-devices
         std::vector<int> Ordinals;
@@ -2628,7 +2607,7 @@ pi_result _pi_platform::populateDeviceCacheIfNeeded() {
           for (uint32_t K = 0; K < QueueGroupProperties[Ordinals[J]].numQueues;
                ++K) {
             std::unique_ptr<_pi_device> PiSubSubDevice(
-                new _pi_device(PiSubDevice->ZeDevice, this, PiSubDevice));
+                new _pi_device(ZeSubdevices[I], this, PiSubDevice.get()));
             pi_result Result = PiSubSubDevice->initialize(Ordinals[J], K);
             if (Result != PI_SUCCESS) {
               return Result;
@@ -2640,7 +2619,13 @@ pi_result _pi_platform::populateDeviceCacheIfNeeded() {
             PiDevicesCache.push_back(std::move(PiSubSubDevice));
           }
         }
+
+        // save pointers to sub-devices for quick retrieval in the future.
+        Device->SubDevices.push_back(PiSubDevice.get());
+        PiDevicesCache.push_back(std::move(PiSubDevice));
       }
+      delete[] ZeSubdevices;
+
       // Save the root device in the cache for future uses.
       PiDevicesCache.push_back(std::move(Device));
     }