kernel: add ddma support

src/runtime/src/kernel/dma.rs

@@ -167,6 +167,9 @@ pub extern "C" fn dma_playback(timestamp: i64, ptr: i32) {
 
         csr::cri_con::selected_write(1);
         csr::rtio_dma::enable_write(1);
+        #[cfg(has_drtio)]
+        KERNEL_CHANNEL_1TO0.as_mut().unwrap().send(
+            Message::DmaStartRemoteRequest{ id: ptr, timestamp: timestamp });
         while csr::rtio_dma::enable_read() != 0 {}
         csr::cri_con::selected_write(0);
 
@@ -194,5 +197,41 @@ pub extern "C" fn dma_playback(timestamp: i64, ptr: i32) {
                 );
             }
         }
+        #[cfg(has_drtio)]
+        {
+            KERNEL_CHANNEL_1TO0.as_mut().unwrap().send(
+                Message::DmaAwaitRemoteRequest(ptr));
+            match KERNEL_CHANNEL_0TO1.as_mut().unwrap().recv() {
+                Message::DmaAwaitRemoteReply { 
+                    timeout: timeout, error: error, channel: channel, timestamp: timestamp 
+                } => {
+                    if timeout {
+                        artiq_raise!(
+                            "DMAError",
+                            "Error running DMA on satellite device, timed out waiting for results"
+                        );
+                    }
+                    if error & 1 != 0 {
+                        artiq_raise!(
+                            "RTIOUnderflow",
+                            "RTIO underflow at {1} mu, channel {rtio_channel_info:0}",
+                            channel as i64,
+                            timestamp as i64,
+                            0
+                        );
+                    }
+                    if error & 2 != 0 {
+                        artiq_raise!(
+                            "RTIODestinationUnreachable",
+                            "RTIO destination unreachable, output, at {1} mu, channel {rtio_channel_info:0}",
+                            channel as i64,
+                            timestamp as i64,
+                            0
+                        );
+                    }
+                }
+                _ => panic!("Expected DmaAwaitRemoteReply after DmaAwaitRemoteRequest!"),
+            } 
+        }
     }
 }

src/runtime/src/kernel/mod.rs

@@ -59,9 +59,7 @@ pub enum Message {
         timestamp: i64
     },
     #[cfg(has_drtio)]
-    DmaAwaitRemoteRequest {
-        id: i32
-    },
+    DmaAwaitRemoteRequest(i32),
     #[cfg(has_drtio)]
     DmaAwaitRemoteReply {
         timeout: bool,