Object FIFO: fix DMA channel detection (#1933)

Co-authored-by: AndraBisca <[email protected]>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: 3 people

lib/Dialect/AIE/Transforms/AIEObjectFifoStatefulTransform.cpp

@@ -69,47 +69,65 @@ class LockAnalysis {
 };
 
 //===----------------------------------------------------------------------===//
-// TileDMA Channel Analysis
+// DMA Channel Analysis
 //===----------------------------------------------------------------------===//
 class DMAChannelAnalysis {
-  DenseMap<Value, int> masterChannelsPerTile;
-  DenseMap<Value, int> slaveChannelsPerTile;
+  DenseMap<std::tuple<Value, DMAChannelDir, int>, int> channelsPerTile;
 
 public:
   DMAChannelAnalysis(DeviceOp &device) {
-    // go over the channels used for each tile and update the master/slave
-    // channel maps
+    // go over the channels used for each tile and update channel map
     for (auto memOp : device.getOps<MemOp>()) {
       Region &r = memOp.getBody();
       for (auto &bl : r.getBlocks()) {
         for (auto op : bl.getOps<DMAStartOp>()) {
-          if (op.isSend())
-            getMasterDMAChannel(memOp.getTile());
-          else
-            getSlaveDMAChannel(memOp.getTile());
+          channelsPerTile[{memOp.getTile(), op.getChannelDir(),
+                           op.getChannelIndex()}] = 1;
+        }
+      }
+    }
+    for (auto memOp : device.getOps<MemTileDMAOp>()) {
+      Region &r = memOp.getBody();
+      for (auto &bl : r.getBlocks()) {
+        for (auto op : bl.getOps<DMAStartOp>()) {
+          channelsPerTile[{memOp.getTile(), op.getChannelDir(),
+                           op.getChannelIndex()}] = 1;
+        }
+      }
+    }
+    for (auto memOp : device.getOps<ShimDMAOp>()) {
+      Region &r = memOp.getBody();
+      for (auto &bl : r.getBlocks()) {
+        for (auto op : bl.getOps<DMAStartOp>()) {
+          channelsPerTile[{memOp.getTile(), op.getChannelDir(),
+                           op.getChannelIndex()}] = 1;
         }
       }
     }
   }
 
-  /// Given an AIE tile, returns its next usable master channel.
-  DMAChannel getMasterDMAChannel(Value tile) {
-    if (masterChannelsPerTile.find(tile) == masterChannelsPerTile.end())
-      masterChannelsPerTile[tile] = 0;
-    else
-      masterChannelsPerTile[tile]++;
-    DMAChannel dmaChan = {DMAChannelDir::MM2S, masterChannelsPerTile[tile]};
-    return dmaChan;
-  }
-
-  /// Given an AIE tile, returns its next usable slave channel.
-  DMAChannel getSlaveDMAChannel(Value tile) {
-    if (slaveChannelsPerTile.find(tile) == slaveChannelsPerTile.end())
-      slaveChannelsPerTile[tile] = 0;
-    else
-      slaveChannelsPerTile[tile]++;
-    DMAChannel dmaChan = {DMAChannelDir::S2MM, slaveChannelsPerTile[tile]};
-    return dmaChan;
+  /// Given a tile and DMAChannelDir, returns next usable channel index for
+  /// that tile.
+  int getDMAChannelIndex(TileOp tileOp, DMAChannelDir dir) {
+    const auto &targetModel = getTargetModel(tileOp);
+    int maxChannelNum = 0;
+    if (tileOp.isShimTile())
+      maxChannelNum = 2;
+    else {
+      if (dir == DMAChannelDir::MM2S)
+        maxChannelNum = targetModel.getNumSourceSwitchboxConnections(
+            tileOp.getCol(), tileOp.getRow(), WireBundle::DMA);
+      else
+        maxChannelNum = targetModel.getNumDestSwitchboxConnections(
+            tileOp.getCol(), tileOp.getRow(), WireBundle::DMA);
+    }
+    for (int i = 0; i < maxChannelNum; i++)
+      if (int usageCnt = channelsPerTile[{tileOp.getResult(), dir, i}];
+          usageCnt == 0) {
+        channelsPerTile[{tileOp.getResult(), dir, i}] = 1;
+        return i;
+      }
+    return -1;
   }
 };
 
@@ -1518,8 +1536,12 @@ struct AIEObjectFifoStatefulTransformPass
     // rely on shared memory and share the same buffers.
     for (auto &[producer, consumers] : splitFifos) {
       // create producer tile DMA
-      DMAChannel producerChan =
-          dmaAnalysis.getMasterDMAChannel(producer.getProducerTile());
+      int producerChanIndex = dmaAnalysis.getDMAChannelIndex(
+          producer.getProducerTileOp(), DMAChannelDir::MM2S);
+      if (producerChanIndex == -1)
+        producer.getProducerTileOp().emitOpError(
+            "number of output DMA channel exceeded!");
+      DMAChannel producerChan = {DMAChannelDir::MM2S, producerChanIndex};
       createDMA(device, builder, producer, producerChan.direction,
                 producerChan.channel, 0, producer.getDimensionsToStreamAttr(),
                 producer.getPadDimensionsAttr());
@@ -1535,8 +1557,12 @@ struct AIEObjectFifoStatefulTransformPass
       for (auto consumer : consumers) {
 
         // create consumer tile DMA
-        DMAChannel consumerChan =
-            dmaAnalysis.getSlaveDMAChannel(consumer.getProducerTile());
+        int consumerChanIndex = dmaAnalysis.getDMAChannelIndex(
+            consumer.getProducerTileOp(), DMAChannelDir::S2MM);
+        if (consumerChanIndex == -1)
+          consumer.getProducerTileOp().emitOpError(
+              "number of input DMA channel exceeded!");
+        DMAChannel consumerChan = {DMAChannelDir::S2MM, consumerChanIndex};
         BDDimLayoutArrayAttr consumerDims =
             consumer.getDimensionsFromStreamPerConsumer()[0];
         createDMA(device, builder, consumer, consumerChan.direction,