runtime: implement distributed DMA

artiq/coredevice/dma.py

@@ -6,7 +6,7 @@ alone could achieve.
 """
 
 from artiq.language.core import syscall, kernel
-from artiq.language.types import TInt32, TInt64, TStr, TNone, TTuple
+from artiq.language.types import TInt32, TInt64, TStr, TNone, TTuple, TBool
 from artiq.coredevice.exceptions import DMAError
 
 from numpy import int64
@@ -17,7 +17,7 @@ def dma_record_start(name: TStr) -> TNone:
     raise NotImplementedError("syscall not simulated")
 
 @syscall
-def dma_record_stop(duration: TInt64) -> TNone:
+def dma_record_stop(duration: TInt64, enable_ddma: TBool) -> TNone:
     raise NotImplementedError("syscall not simulated")
 
 @syscall
@@ -47,6 +47,7 @@ class DMARecordContextManager:
     def __init__(self):
         self.name = ""
         self.saved_now_mu = int64(0)
+        self.enable_ddma = False
 
     @kernel
     def __enter__(self):
@@ -56,7 +57,7 @@ class DMARecordContextManager:
 
     @kernel
     def __exit__(self, type, value, traceback):
-        dma_record_stop(now_mu()) # see above
+        dma_record_stop(now_mu(), self.enable_ddma) # see above
         at_mu(self.saved_now_mu)
 
 
@@ -74,12 +75,18 @@ class CoreDMA:
         self.epoch    = 0
 
     @kernel
-    def record(self, name):
+    def record(self, name, enable_ddma=False):
         """Returns a context manager that will record a DMA trace called ``name``.
         Any previously recorded trace with the same name is overwritten.
-        The trace will persist across kernel switches."""
+        The trace will persist across kernel switches.
+        In DRTIO context, you can toggle distributed DMA with ``enable_ddma``.
+        Enabling it allows running DMA on satellites, rather than sending all
+        events from the master.
+        Disabling it may improve performance in some scenarios, 
+        e.g. when there are many small satellite buffers."""
         self.epoch += 1
         self.recorder.name = name
+        self.recorder.enable_ddma = enable_ddma
         return self.recorder
 
     @kernel

artiq/firmware/ksupport/lib.rs

@@ -269,7 +269,7 @@ extern fn dma_record_start(name: &CSlice<u8>) {
 }
 
 #[unwind(allowed)]
-extern fn dma_record_stop(duration: i64) {
+extern fn dma_record_stop(duration: i64, enable_ddma: bool) {
     unsafe {
         dma_record_flush();
 
@@ -285,7 +285,8 @@ extern fn dma_record_stop(duration: i64) {
 
         DMA_RECORDER.active = false;
         send(&DmaRecordStop {
-            duration: duration as u64
+            duration: duration as u64,
+            enable_ddma: enable_ddma
         });
     }
 }
@@ -370,7 +371,7 @@ extern fn dma_erase(name: &CSlice<u8>) {
 #[repr(C)]
 struct DmaTrace {
     duration: i64,
-    address:  i32,
+    address:  i32
 }
 
 #[unwind(allowed)]
@@ -404,6 +405,7 @@ extern fn dma_playback(timestamp: i64, ptr: i32) {
 
         csr::cri_con::selected_write(1);
         csr::rtio_dma::enable_write(1);
+        send(&DmaStartRemoteRequest { id: ptr as i32, timestamp: timestamp });
         while csr::rtio_dma::enable_read() != 0 {}
         csr::cri_con::selected_write(0);
 
@@ -424,6 +426,24 @@ extern fn dma_playback(timestamp: i64, ptr: i32) {
             }
         }
     }
+
+    send(&DmaAwaitRemoteRequest { id: ptr as i32 });
+    recv!(&DmaAwaitRemoteReply { timeout, error, channel, timestamp } => {
+        if timeout {
+            raise!("DMAError",
+                "Error running DMA on satellite device, timed out waiting for results");
+        }
+        if error & 1 != 0 {
+            raise!("RTIOUnderflow",
+                "RTIO underflow at channel {rtio_channel_info:0}, {1} mu",
+                channel as i64, timestamp as i64, 0);
+        }
+        if error & 2 != 0 {
+            raise!("RTIODestinationUnreachable",
+                "RTIO destination unreachable, output, at channel {rtio_channel_info:0}, {1} mu",
+                channel as i64, timestamp as i64, 0);
+        }
+    });
 }
 
 #[cfg(not(has_rtio_dma))]

artiq/firmware/libproto_artiq/drtioaux_proto.rs

@@ -14,8 +14,8 @@ impl<T> From<IoError<T>> for Error<T> {
     }
 }
 
-/* 512 (max size) - 4 (CRC) - 1 (packet ID) - 4 (trace ID) - 1 (last) - 2 (length) */
+/* 512 (max size) - 4 (CRC) - 1 (packet ID) - 1 (destination) - 4 (trace ID) - 1 (last) - 2 (length) */
-const DMA_TRACE_MAX_SIZE: usize = 500;
+pub const DMA_TRACE_MAX_SIZE: usize = 499;
 
 #[derive(PartialEq, Debug)]
 pub enum Packet {
@@ -58,13 +58,13 @@ pub enum Packet {
     SpiReadReply { succeeded: bool, data: u32 },
     SpiBasicReply { succeeded: bool },
 
-    DmaAddTraceRequest { id: u32, last: bool, length: u16, trace: [u8; DMA_TRACE_MAX_SIZE] },
+    DmaAddTraceRequest { destination: u8, id: u32, last: bool, length: u16, trace: [u8; DMA_TRACE_MAX_SIZE] },
     DmaAddTraceReply { succeeded: bool },
-    DmaRemoveTraceRequest { id: u32 },
+    DmaRemoveTraceRequest { destination: u8, id: u32 },
     DmaRemoveTraceReply { succeeded: bool },
-    DmaPlaybackRequest { id: u32, timestamp: u64 },
+    DmaPlaybackRequest { destination: u8, id: u32, timestamp: u64 },
     DmaPlaybackReply { succeeded: bool },
-    DmaPlaybackStatus { id: u32, error: u8, channel: u32, timestamp: u64 }
+    DmaPlaybackStatus { destination: u8, id: u32, error: u8, channel: u32, timestamp: u64 }
 
 }
 
@@ -198,12 +198,14 @@ impl Packet {
             },
 
             0xb0 => { 
+                let destination = reader.read_u8()?;
                 let id = reader.read_u32()?;
                 let last = reader.read_bool()?;
                 let length = reader.read_u16()?;
                 let mut trace: [u8; DMA_TRACE_MAX_SIZE] = [0; DMA_TRACE_MAX_SIZE];
                 reader.read_exact(&mut trace[0..length as usize])?;
                 Packet::DmaAddTraceRequest {
+                    destination: destination,
                     id: id,
                     last: last,
                     length: length as u16,
@@ -214,12 +216,14 @@ impl Packet {
                 succeeded: reader.read_bool()?
             },
             0xb2 => Packet::DmaRemoveTraceRequest {
+                destination: reader.read_u8()?,
                 id: reader.read_u32()?
             },
             0xb3 => Packet::DmaRemoveTraceReply {
                 succeeded: reader.read_bool()?
             },
             0xb4 => Packet::DmaPlaybackRequest {
+                destination: reader.read_u8()?,
                 id: reader.read_u32()?,
                 timestamp: reader.read_u64()?
             },
@@ -227,6 +231,7 @@ impl Packet {
                 succeeded: reader.read_bool()?
             },
             0xb6 => Packet::DmaPlaybackStatus {
+                destination: reader.read_u8()?,
                 id: reader.read_u32()?,
                 error: reader.read_u8()?,
                 channel: reader.read_u32()?,
@@ -392,8 +397,9 @@ impl Packet {
                 writer.write_bool(succeeded)?;
             },
 
-            Packet::DmaAddTraceRequest { id, last, trace, length } => {
+            Packet::DmaAddTraceRequest { destination, id, last, trace, length } => {
                 writer.write_u8(0xb0)?;
+                writer.write_u8(destination)?;
                 writer.write_u32(id)?;
                 writer.write_bool(last)?;
                 // trace may be broken down to fit within drtio aux memory limit
@@ -405,16 +411,18 @@ impl Packet {
                 writer.write_u8(0xb1)?;
                 writer.write_bool(succeeded)?;
             },
-            Packet::DmaRemoveTraceRequest { id } => {
+            Packet::DmaRemoveTraceRequest { destination, id } => {
                 writer.write_u8(0xb2)?;
+                writer.write_u8(destination)?;
                 writer.write_u32(id)?;
             },
             Packet::DmaRemoveTraceReply { succeeded } => {
                 writer.write_u8(0xb3)?;
                 writer.write_bool(succeeded)?;
             },
-            Packet::DmaPlaybackRequest { id, timestamp } => {
+            Packet::DmaPlaybackRequest { destination, id, timestamp } => {
                 writer.write_u8(0xb4)?;
+                writer.write_u8(destination)?;
                 writer.write_u32(id)?;
                 writer.write_u64(timestamp)?;
             },
@@ -422,8 +430,9 @@ impl Packet {
                 writer.write_u8(0xb5)?;
                 writer.write_bool(succeeded)?;
             },
-            Packet::DmaPlaybackStatus { id, error, channel, timestamp } => {
+            Packet::DmaPlaybackStatus { destination, id, error, channel, timestamp } => {
                 writer.write_u8(0xb6)?;
+                writer.write_u8(destination)?;
                 writer.write_u32(id)?;
                 writer.write_u8(error)?;
                 writer.write_u32(channel)?;

artiq/firmware/libproto_artiq/kernel_proto.rs

@@ -20,7 +20,8 @@ pub enum Message<'a> {
     DmaRecordStart(&'a str),
     DmaRecordAppend(&'a [u8]),
     DmaRecordStop {
-        duration:  u64
+        duration:  u64,
+        enable_ddma: bool
     },
 
     DmaEraseRequest {
@@ -32,9 +33,24 @@ pub enum Message<'a> {
     },
     DmaRetrieveReply {
         trace:    Option<&'a [u8]>,
-        duration: u64
+        duration: u64,
     },
 
+    DmaStartRemoteRequest {
+        id: i32,
+        timestamp: i64,
+    },
+    DmaAwaitRemoteRequest {
+        id: i32
+    },
+    DmaAwaitRemoteReply {
+        timeout: bool,
+        error: u8,
+        channel: u32,
+        timestamp: u64
+    },
+
+
     RunFinished,
     RunException {
         exceptions: &'a [Option<eh::eh_artiq::Exception<'a>>],

artiq/firmware/runtime/main.rs

@@ -182,6 +182,8 @@ fn startup() {
     drtio_routing::interconnect_disable_all();
     let aux_mutex = sched::Mutex::new();
 
+    let ddma_mutex = sched::Mutex::new();
+
     let mut scheduler = sched::Scheduler::new(interface);
     let io = scheduler.io();
 
@@ -189,14 +191,15 @@ fn startup() {
         io.spawn(4096, dhcp::dhcp_thread);
     }
 
-    rtio_mgt::startup(&io, &aux_mutex, &drtio_routing_table, &up_destinations);
+    rtio_mgt::startup(&io, &aux_mutex, &drtio_routing_table, &up_destinations, &ddma_mutex);
 
     io.spawn(4096, mgmt::thread);
     {
         let aux_mutex = aux_mutex.clone();
         let drtio_routing_table = drtio_routing_table.clone();
         let up_destinations = up_destinations.clone();
-        io.spawn(16384, move |io| { session::thread(io, &aux_mutex, &drtio_routing_table, &up_destinations) });
+        let ddma_mutex = ddma_mutex.clone();
+        io.spawn(16384, move |io| { session::thread(io, &aux_mutex, &drtio_routing_table, &up_destinations, &ddma_mutex) });
     }
     #[cfg(any(has_rtio_moninj, has_drtio))]
     {

artiq/firmware/runtime/rtio_dma.rs

@@ -1,10 +1,182 @@
 use core::mem;
 use alloc::{vec::Vec, string::String, collections::btree_map::BTreeMap};
+use sched::{Io, Mutex};
 
 const ALIGNMENT: usize = 64;
 
+#[cfg(has_drtio)]
+pub mod remote_dma {
+    use super::*;
+    use board_artiq::drtio_routing::RoutingTable;
+    use rtio_mgt::drtio;
+    use board_misoc::clock;
+
+    #[derive(Debug, PartialEq, Clone)]
+    pub enum RemoteState {
+        NotLoaded,
+        Loaded,
+        PlaybackEnded { error: u8, channel: u32, timestamp: u64 }
+    }
+    #[derive(Debug, Clone)]
+    struct RemoteTrace {
+        trace: Vec<u8>,
+        pub state: RemoteState
+    }
+
+    impl From<Vec<u8>> for RemoteTrace {
+        fn from(trace: Vec<u8>) -> Self {
+            RemoteTrace {
+                trace: trace,
+                state: RemoteState::NotLoaded
+            }
+        }
+    }
+    
+    impl RemoteTrace {
+        pub fn get_trace(&self) -> &Vec<u8> {
+            &self.trace
+        }
+    }
+
+    // remote traces map. ID -> destination, trace pair
+    static mut TRACES: BTreeMap<u32, BTreeMap<u8, RemoteTrace>> = BTreeMap::new();
+
+    pub fn add_traces(io: &Io, ddma_mutex: &Mutex, id: u32, traces: BTreeMap<u8, Vec<u8>>) {
+        let _lock = ddma_mutex.lock(io);
+        let mut trace_map: BTreeMap<u8, RemoteTrace> = BTreeMap::new();
+        for (destination, trace) in traces {
+            trace_map.insert(destination, trace.into());
+        }
+        unsafe { TRACES.insert(id, trace_map); }
+    }
+
+    pub fn await_done(io: &Io, ddma_mutex: &Mutex, id: u32, timeout: u64) -> Result<RemoteState, &'static str> {
+        let max_time = clock::get_ms() + timeout as u64;
+        io.until(|| {
+            if clock::get_ms() > max_time {
+                return true;
+            }
+            if ddma_mutex.test_lock() {
+                // cannot lock again within io.until - scheduler guarantees
+                // that it will not be interrupted - so only test the lock
+                return false;
+            }
+            let traces = unsafe { TRACES.get(&id).unwrap() };
+            for (_dest, trace) in traces {
+                match trace.state {
+                    RemoteState::PlaybackEnded {error: _, channel: _, timestamp: _} => (),
+                    _ => return false
+                }
+            }
+            true
+        }).unwrap();
+        if clock::get_ms() > max_time {
+            error!("Remote DMA await done timed out");
+            return Err("Timed out waiting for results.");
+        }
+        // clear the internal state, and if there have been any errors, return one of them
+        let mut playback_state: RemoteState = RemoteState::PlaybackEnded { error: 0, channel: 0, timestamp: 0 };
+        {
+            let _lock = ddma_mutex.lock(io).unwrap();
+            let traces = unsafe { TRACES.get_mut(&id).unwrap() };
+            for (_dest, trace) in traces {
+                match trace.state {
+                    RemoteState::PlaybackEnded {error: e, channel: _c, timestamp: _ts} => if e != 0 { playback_state = trace.state.clone(); },
+                    _ => (),
+                }
+                trace.state = RemoteState::Loaded;
+            }
+        }
+        Ok(playback_state)
+    }
+
+    pub fn erase(io: &Io, aux_mutex: &Mutex, routing_table: &RoutingTable,
+            ddma_mutex: &Mutex, id: u32) {
+        let _lock = ddma_mutex.lock(io).unwrap();
+        let destinations = unsafe { TRACES.get(&id).unwrap() };
+        for destination in destinations.keys() {
+            match drtio::ddma_send_erase(io, aux_mutex, routing_table, id, *destination) {
+                Ok(_) => (),
+                Err(e) => error!("Error erasing trace on DMA: {}", e)
+            } 
+        }
+        unsafe { TRACES.remove(&id); }
+    }
+
+    pub fn upload_traces(io: &Io, aux_mutex: &Mutex, routing_table: &RoutingTable,
+            ddma_mutex: &Mutex, id: u32) {
+        let _lock = ddma_mutex.lock(io);
+        let traces = unsafe { TRACES.get_mut(&id).unwrap() };
+        for (destination, mut trace) in traces {
+            match drtio::ddma_upload_trace(io, aux_mutex, routing_table, id, *destination, trace.get_trace())
+            {
+                Ok(_) => trace.state = RemoteState::Loaded,
+                Err(e) => error!("Error adding DMA trace on destination {}: {}", destination, e)
+            }
+        }
+    }
+
+    pub fn playback(io: &Io, aux_mutex: &Mutex, routing_table: &RoutingTable,
+            ddma_mutex: &Mutex, id: u32, timestamp: u64) {
+        // triggers playback on satellites
+        let destinations = unsafe { 
+            let _lock = ddma_mutex.lock(io).unwrap();
+            TRACES.get(&id).unwrap() };
+        for (destination, trace) in destinations {
+            {
+                // need to drop the lock before sending the playback request to avoid a deadlock
+                // if a PlaybackStatus is returned from another satellite in the meanwhile.
+                let _lock = ddma_mutex.lock(io).unwrap();
+                if trace.state != RemoteState::Loaded {
+                    error!("Destination {} not ready for DMA, state: {:?}", *destination, trace.state);
+                    continue;
+                }
+            }
+            match drtio::ddma_send_playback(io, aux_mutex, routing_table, ddma_mutex, id, *destination, timestamp) {
+                Ok(_) => (),
+                Err(e) => error!("Error during remote DMA playback: {}", e)
+            }
+        }
+    }
+
+    pub fn playback_done(io: &Io, ddma_mutex: &Mutex, 
+            id: u32, destination: u8, error: u8, channel: u32, timestamp: u64) {
+        // called upon receiving PlaybackDone aux packet
+        let _lock = ddma_mutex.lock(io).unwrap();
+        let mut trace = unsafe { TRACES.get_mut(&id).unwrap().get_mut(&destination).unwrap() };
+        trace.state = RemoteState::PlaybackEnded {
+            error: error, 
+            channel: channel, 
+            timestamp: timestamp 
+        };
+    }
+
+    pub fn destination_changed(io: &Io, aux_mutex: &Mutex, routing_table: &RoutingTable,
+            ddma_mutex: &Mutex, destination: u8, up: bool) {
+        // update state of the destination, resend traces if it's up
+        let _lock = ddma_mutex.lock(io).unwrap();
+        let traces_iter = unsafe { TRACES.iter_mut() };
+        for (id, dest_traces) in traces_iter {
+            if let Some(trace) = dest_traces.get_mut(&destination) {
+                if up {
+                    match drtio::ddma_upload_trace(io, aux_mutex, routing_table, *id, destination, trace.get_trace())
+                    {
+                        Ok(_) => trace.state = RemoteState::Loaded,
+                        Err(e) => error!("Error adding DMA trace on destination {}: {}", destination, e)
+                    }
+                } else {
+                    trace.state = RemoteState::NotLoaded;
+                }
+            }
+        }
+
+    }
+
+}
+
+
 #[derive(Debug)]
-struct Entry {
+struct LocalEntry {
     trace: Vec<u8>,
     padding_len: usize,
     duration: u64
@@ -12,7 +184,8 @@ struct Entry {
 
 #[derive(Debug)]
 pub struct Manager {
-    entries: BTreeMap<String, Entry>,
+    entries: BTreeMap<u32, LocalEntry>,
+    name_map: BTreeMap<String, u32>,
     recording_name: String,
     recording_trace: Vec<u8>
 }
@@ -21,59 +194,116 @@ impl Manager {
     pub fn new() -> Manager {
         Manager {
             entries: BTreeMap::new(),
-            recording_name: String::new(),
+            name_map: BTreeMap::new(),
             recording_trace: Vec::new(),
+            recording_name: String::new()
         }
     }
 
-    pub fn record_start(&mut self, name: &str) {
+    pub fn record_start(&mut self, name: &str) -> Option<u32> {
         self.recording_name = String::from(name);
         self.recording_trace = Vec::new();
-
+        if let Some(id) = self.name_map.get(&self.recording_name) {
-        // or we could needlessly OOM replacing a large trace
+            // replacing a trace
-        self.entries.remove(name);
+            let old_id = id.clone();
+            self.entries.remove(&id);
+            self.name_map.remove(&self.recording_name);
+            // return old ID
+            return Some(old_id);
+        }
+        return None;
     }
 
     pub fn record_append(&mut self, data: &[u8]) {
         self.recording_trace.extend_from_slice(data)
     }
 
-    pub fn record_stop(&mut self, duration: u64) {
+    pub fn record_stop(&mut self, duration: u64, enable_ddma: bool,
-        let mut trace = Vec::new();
+            _io: &Io, _ddma_mutex: &Mutex) -> u32 {
-        mem::swap(&mut self.recording_trace, &mut trace);
+        let mut local_trace = Vec::new();
-        trace.push(0);
+        let mut remote_traces: BTreeMap<u8, Vec<u8>> = BTreeMap::new();
-        let data_len = trace.len();
 
-        // Realign.
+        if enable_ddma {
-        trace.reserve(ALIGNMENT - 1);
+            let mut trace = Vec::new();
-        let padding = ALIGNMENT - trace.as_ptr() as usize % ALIGNMENT;
+            mem::swap(&mut self.recording_trace, &mut trace);
+            trace.push(0);
+            // analyze each entry and put in proper buckets, as the kernel core
+            // sends whole chunks, to limit comms/kernel CPU communication,
+            // and as only comms core has access to varios DMA buffers.
+            let mut ptr = 0;
+            while trace[ptr] != 0 {
+                // ptr + 3 = tgt >> 24 (destination)
+                let len = trace[ptr] as usize;
+                let destination = trace[ptr+3];
+                if destination == 0 {
+                    local_trace.extend(&trace[ptr..ptr+len]);
+                }
+                else {
+                    if let Some(remote_trace) = remote_traces.get_mut(&destination) {
+                        remote_trace.extend(&trace[ptr..ptr+len]);
+                    } else {
+                        remote_traces.insert(destination, trace[ptr..ptr+len].to_vec());
+                    }
+                }
+                // and jump to the next event
+                ptr += len;
+            }
+        } else {
+            // with disabled DDMA, move the whole trace to local
+            mem::swap(&mut self.recording_trace, &mut local_trace);
+        }
+
+        local_trace.push(0);
+        let data_len = local_trace.len();
+        // Realign the local entry.
+        local_trace.reserve(ALIGNMENT - 1);
+        let padding = ALIGNMENT - local_trace.as_ptr() as usize % ALIGNMENT;
         let padding = if padding == ALIGNMENT { 0 } else { padding };
         for _ in 0..padding {
             // Vec guarantees that this will not reallocate
-            trace.push(0)
+            local_trace.push(0)
         }
         for i in 1..data_len + 1 {
-            trace[data_len + padding - i] = trace[data_len - i]
+            local_trace[data_len + padding - i] = local_trace[data_len - i]
         }
-
+        // trace ID is its pointer
+        let id = local_trace[padding..].as_ptr() as u32;
+        self.entries.insert(id, LocalEntry {
+            trace: local_trace,
+            padding_len: padding,
+            duration: duration,
+        });
         let mut name = String::new();
         mem::swap(&mut self.recording_name, &mut name);
-        self.entries.insert(name, Entry {
+        self.name_map.insert(name, id);
-            trace: trace,
+
-            padding_len: padding,
+        #[cfg(has_drtio)]
-            duration: duration
+        remote_dma::add_traces(_io, _ddma_mutex, id, remote_traces);
-        });
+
+        id
     }
 
     pub fn erase(&mut self, name: &str) {
-        self.entries.remove(name);
+        if let Some(id) = self.name_map.get(name) {
+            self.entries.remove(&id);
+        }
+        self.name_map.remove(name);
+    }
+
+    #[cfg(has_drtio)]
+    pub fn get_id(&mut self, name: &str) -> Option<&u32> {
+        self.name_map.get(name)
     }
 
     pub fn with_trace<F, R>(&self, name: &str, f: F) -> R
             where F: FnOnce(Option<&[u8]>, u64) -> R {
-        match self.entries.get(name) {
+        if let Some(ptr) = self.name_map.get(name) {
-            Some(entry) => f(Some(&entry.trace[entry.padding_len..]), entry.duration),
+            match self.entries.get(ptr) {
-            None => f(None, 0)
+                Some(entry) => f(Some(&entry.trace[entry.padding_len..]), entry.duration),
+                None => f(None, 0)
+            }
+        } else {
+            f(None, 0)
         }
     }
 }

artiq/firmware/runtime/rtio_mgt.rs

@@ -18,17 +18,22 @@ static mut RTIO_DEVICE_MAP: BTreeMap<u32, String> = BTreeMap::new();
 #[cfg(has_drtio)]
 pub mod drtio {
     use super::*;
+    use alloc::vec::Vec;
     use drtioaux;
+    use proto_artiq::drtioaux_proto::DMA_TRACE_MAX_SIZE;
+    use rtio_dma::remote_dma;
 
     pub fn startup(io: &Io, aux_mutex: &Mutex,
             routing_table: &Urc<RefCell<drtio_routing::RoutingTable>>,
-            up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>) {
+            up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
+            ddma_mutex: &Mutex) {
         let aux_mutex = aux_mutex.clone();
         let routing_table = routing_table.clone();
         let up_destinations = up_destinations.clone();
-        io.spawn(4096, move |io| {
+        let ddma_mutex = ddma_mutex.clone();
+        io.spawn(8192, move |io| {
             let routing_table = routing_table.borrow();
-            link_thread(io, &aux_mutex, &routing_table, &up_destinations);
+            link_thread(io, &aux_mutex, &routing_table, &up_destinations, &ddma_mutex);
         });
     }
 
@@ -147,9 +152,12 @@ pub mod drtio {
         }
     }
 
-    fn process_unsolicited_aux(io: &Io, aux_mutex: &Mutex, linkno: u8) {
+    fn process_unsolicited_aux(io: &Io, aux_mutex: &Mutex, linkno: u8, ddma_mutex: &Mutex) {
         let _lock = aux_mutex.lock(io).unwrap();
         match drtioaux::recv(linkno) {
+            Ok(Some(drtioaux::Packet::DmaPlaybackStatus { id, destination, error, channel, timestamp })) => {
+                remote_dma::playback_done(io, ddma_mutex, id, destination, error, channel, timestamp);
+            }
             Ok(Some(packet)) => warn!("[LINK#{}] unsolicited aux packet: {:?}", linkno, packet),
             Ok(None) => (),
             Err(_) => warn!("[LINK#{}] aux packet error", linkno)
@@ -198,7 +206,8 @@ pub mod drtio {
 
     fn destination_survey(io: &Io, aux_mutex: &Mutex, routing_table: &drtio_routing::RoutingTable,
             up_links: &[bool],
-            up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>) {
+            up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
+            ddma_mutex: &Mutex) {
         for destination in 0..drtio_routing::DEST_COUNT {
             let hop = routing_table.0[destination][0];
             let destination = destination as u8;
@@ -216,8 +225,10 @@ pub mod drtio {
                             destination: destination
                         });
                         match reply {
-                            Ok(drtioaux::Packet::DestinationDownReply) =>
+                            Ok(drtioaux::Packet::DestinationDownReply) => {
-                                destination_set_up(routing_table, up_destinations, destination, false),
+                                destination_set_up(routing_table, up_destinations, destination, false);
+                                remote_dma::destination_changed(io, aux_mutex, routing_table, ddma_mutex, destination, false);
+                            }
                             Ok(drtioaux::Packet::DestinationOkReply) => (),
                             Ok(drtioaux::Packet::DestinationSequenceErrorReply { channel }) => {
                                 error!("[DEST#{}] RTIO sequence error involving channel 0x{:04x}:{}", destination, channel, resolve_channel_name(channel as u32));
@@ -236,6 +247,7 @@ pub mod drtio {
                         }
                     } else {
                         destination_set_up(routing_table, up_destinations, destination, false);
+                        remote_dma::destination_changed(io, aux_mutex, routing_table, ddma_mutex, destination, false);
                     }
                 } else {
                     if up_links[linkno as usize] {
@@ -247,6 +259,7 @@ pub mod drtio {
                             Ok(drtioaux::Packet::DestinationOkReply) => {
                                 destination_set_up(routing_table, up_destinations, destination, true);
                                 init_buffer_space(destination as u8, linkno);
+                                remote_dma::destination_changed(io, aux_mutex, routing_table, ddma_mutex, destination, true);
                             },
                             Ok(packet) => error!("[DEST#{}] received unexpected aux packet: {:?}", destination, packet),
                             Err(e) => error!("[DEST#{}] communication failed ({})", destination, e)
@@ -259,7 +272,8 @@ pub mod drtio {
 
     pub fn link_thread(io: Io, aux_mutex: &Mutex,
             routing_table: &drtio_routing::RoutingTable,
-            up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>) {
+            up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
+            ddma_mutex: &Mutex) {
         let mut up_links = [false; csr::DRTIO.len()];
         loop {
             for linkno in 0..csr::DRTIO.len() {
@@ -267,7 +281,7 @@ pub mod drtio {
                 if up_links[linkno as usize] {
                     /* link was previously up */
                     if link_rx_up(linkno) {
-                        process_unsolicited_aux(&io, aux_mutex, linkno);
+                        process_unsolicited_aux(&io, aux_mutex, linkno, ddma_mutex);
                         process_local_errors(linkno);
                     } else {
                         info!("[LINK#{}] link is down", linkno);
@@ -297,7 +311,7 @@ pub mod drtio {
                     }
                 }
             }
-            destination_survey(&io, aux_mutex, routing_table, &up_links, up_destinations);
+            destination_survey(&io, aux_mutex, routing_table, &up_links, up_destinations, ddma_mutex);
             io.sleep(200).unwrap();
         }
     }
@@ -328,6 +342,72 @@ pub mod drtio {
             }
         }
     }
+
+    pub fn ddma_upload_trace(io: &Io, aux_mutex: &Mutex, 
+            routing_table: &drtio_routing::RoutingTable,
+            id: u32, destination: u8, trace: &Vec<u8>) -> Result<(), &'static str> {
+        let linkno = routing_table.0[destination as usize][0] - 1;
+        let mut i = 0;
+        while i < trace.len() {
+            let mut trace_slice: [u8; DMA_TRACE_MAX_SIZE] = [0; DMA_TRACE_MAX_SIZE];
+            let len: usize = if i + DMA_TRACE_MAX_SIZE < trace.len() { DMA_TRACE_MAX_SIZE } else { trace.len() - i } as usize;
+            let last = i + len == trace.len();
+            trace_slice[..len].clone_from_slice(&trace[i..i+len]);
+            i += len;
+            let reply = aux_transact(io, aux_mutex, linkno, 
+                &drtioaux::Packet::DmaAddTraceRequest {
+                    id: id, destination: destination, last: last, length: len as u16, trace: trace_slice});
+            match reply {
+                Ok(drtioaux::Packet::DmaAddTraceReply { succeeded: true }) => (),
+                Ok(drtioaux::Packet::DmaAddTraceReply { succeeded: false }) => { 
+                    return Err("error adding trace on satellite"); },
+                Ok(_) => { return Err("adding DMA trace failed, unexpected aux packet"); },
+                Err(_) => { return Err("adding DMA trace failed, aux error"); }
+            }
+        }
+        Ok(())
+    }
+
+
+    pub fn ddma_send_erase(io: &Io, aux_mutex: &Mutex,
+            routing_table: &drtio_routing::RoutingTable, 
+            id: u32, destination: u8) -> Result<(), &'static str> {
+        let linkno = routing_table.0[destination as usize][0] - 1;
+        let reply = aux_transact(io, aux_mutex, linkno, 
+            &drtioaux::Packet::DmaRemoveTraceRequest { id: id, destination: destination });
+        match reply {
+            Ok(drtioaux::Packet::DmaRemoveTraceReply { succeeded: true }) => Ok(()),
+            Ok(drtioaux::Packet::DmaRemoveTraceReply { succeeded: false }) => Err("satellite DMA erase error"),
+            Ok(_) => Err("adding trace failed, unexpected aux packet"),
+            Err(_) => Err("erasing trace failed, aux error")
+        }
+    }
+
+    pub fn ddma_send_playback(io: &Io, aux_mutex: &Mutex,
+            routing_table: &drtio_routing::RoutingTable,
+            ddma_mutex: &Mutex, id: u32, destination: u8, timestamp: u64) -> Result<(), &'static str> {
+        let linkno = routing_table.0[destination as usize][0] - 1;
+        let _lock = aux_mutex.lock(io).unwrap();
+        drtioaux::send(linkno, &drtioaux::Packet::DmaPlaybackRequest{
+                id: id, destination: destination, timestamp: timestamp }).unwrap();
+        loop {
+            let reply = recv_aux_timeout(io, linkno, 200);
+            match reply {
+                Ok(drtioaux::Packet::DmaPlaybackReply { succeeded: true }) => { return Ok(()) },
+                Ok(drtioaux::Packet::DmaPlaybackReply { succeeded: false }) => {
+                        return Err("error on DMA playback request") },
+                // in case we received status from another destination
+                // but we want to get DmaPlaybackReply anyway, thus the loop
+                Ok(drtioaux::Packet::DmaPlaybackStatus { id, destination, error, channel, timestamp }) => {
+                    remote_dma::playback_done(io, ddma_mutex, id, destination, error, channel, timestamp);
+                },
+                Ok(_) => { return Err("received unexpected aux packet while DMA playback") },
+                Err(_) => { return Err("aux error on DMA playback") }
+            }
+        }
+    }
+
+
 }
 
 #[cfg(not(has_drtio))]
@@ -336,7 +416,8 @@ pub mod drtio {
 
     pub fn startup(_io: &Io, _aux_mutex: &Mutex,
         _routing_table: &Urc<RefCell<drtio_routing::RoutingTable>>,
-        _up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>) {}
+        _up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
+        _ddma_mutex: &Mutex) {}
     pub fn reset(_io: &Io, _aux_mutex: &Mutex) {}
 }
 
@@ -410,9 +491,10 @@ pub fn resolve_channel_name(channel: u32) -> String {
 
 pub fn startup(io: &Io, aux_mutex: &Mutex,
         routing_table: &Urc<RefCell<drtio_routing::RoutingTable>>,
-        up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>) {
+        up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
+        ddma_mutex: &Mutex) {
     unsafe { RTIO_DEVICE_MAP = read_device_map(); }
-    drtio::startup(io, aux_mutex, routing_table, up_destinations);
+    drtio::startup(io, aux_mutex, routing_table, up_destinations, ddma_mutex);
     unsafe {
         csr::rtio_core::reset_phy_write(1);
     }

artiq/firmware/runtime/sched.rs

@@ -301,6 +301,10 @@ impl Mutex {
         self.0.set(true);
         Ok(MutexGuard(&*self.0))
     }
+
+    pub fn test_lock<'a>(&'a self) -> bool {
+        self.0.get()
+    }
 }
 
 pub struct MutexGuard<'a>(&'a Cell<bool>);

artiq/firmware/runtime/session.rs

@@ -10,6 +10,8 @@ use urc::Urc;
 use sched::{ThreadHandle, Io, Mutex, TcpListener, TcpStream, Error as SchedError};
 use rtio_clocking;
 use rtio_dma::Manager as DmaManager;
+#[cfg(has_drtio)]
+use rtio_dma::remote_dma;
 use rtio_mgt::{get_async_errors, resolve_channel_name};
 use cache::Cache;
 use kern_hwreq;
@@ -329,7 +331,7 @@ fn process_host_message(io: &Io,
 fn process_kern_message(io: &Io, aux_mutex: &Mutex,
                         routing_table: &drtio_routing::RoutingTable,
                         up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
-                        mut stream: Option<&mut TcpStream>,
+                        ddma_mutex: &Mutex, mut stream: Option<&mut TcpStream>,
                         session: &mut Session) -> Result<bool, Error<SchedError>> {
     kern_recv_notrace(io, |request| {
         match (request, session.kernel_state) {
@@ -368,19 +370,31 @@ fn process_kern_message(io: &Io, aux_mutex: &Mutex,
             }
 
             &kern::DmaRecordStart(name) => {
-                session.congress.dma_manager.record_start(name);
+                if let Some(_id) = session.congress.dma_manager.record_start(name) {
+                    // replace the record
+                    #[cfg(has_drtio)]
+                    remote_dma::erase(io, aux_mutex, routing_table, ddma_mutex, _id);
+                }
                 kern_acknowledge()
             }
             &kern::DmaRecordAppend(data) => {
                 session.congress.dma_manager.record_append(data);
                 kern_acknowledge()
             }
-            &kern::DmaRecordStop { duration } => {
+            &kern::DmaRecordStop { duration, enable_ddma } => {
-                session.congress.dma_manager.record_stop(duration);
+                let _id = session.congress.dma_manager.record_stop(duration, enable_ddma, io, ddma_mutex);
+                #[cfg(has_drtio)]
+                {
+                    remote_dma::upload_traces(io, aux_mutex, routing_table, ddma_mutex, _id);
+                }
                 cache::flush_l2_cache();
                 kern_acknowledge()
             }
             &kern::DmaEraseRequest { name } => {
+                #[cfg(has_drtio)]
+                if let Some(id) = session.congress.dma_manager.get_id(name) {
+                    remote_dma::erase(io, aux_mutex, routing_table, ddma_mutex, *id);
+                }
                 session.congress.dma_manager.erase(name);
                 kern_acknowledge()
             }
@@ -392,6 +406,27 @@ fn process_kern_message(io: &Io, aux_mutex: &Mutex,
                     })
                 })
             }
+            &kern::DmaStartRemoteRequest { id: _id, timestamp: _timestamp } => {
+                #[cfg(has_drtio)]
+                remote_dma::playback(io, aux_mutex, routing_table, ddma_mutex, _id as u32, _timestamp as u64);
+                kern_acknowledge()
+            }
+            &kern::DmaAwaitRemoteRequest { id: _id } => {
+                #[cfg(has_drtio)]
+                let reply = match remote_dma::await_done(io, ddma_mutex, _id as u32, 10_000) {
+                    Ok(remote_dma::RemoteState::PlaybackEnded { error, channel, timestamp }) =>
+                        kern::DmaAwaitRemoteReply {
+                            timeout: false,
+                            error: error,
+                            channel: channel,
+                            timestamp: timestamp
+                        },
+                    _ => kern::DmaAwaitRemoteReply { timeout: true, error: 0, channel: 0, timestamp: 0},
+                };
+                #[cfg(not(has_drtio))]
+                let reply = kern::DmaAwaitRemoteReply { timeout: false, error: 0, channel: 0, timestamp: 0};
+                kern_send(io, &reply)
+            }
 
             &kern::RpcSend { async, service, tag, data } => {
                 match stream {
@@ -511,7 +546,7 @@ fn process_kern_queued_rpc(stream: &mut TcpStream,
 fn host_kernel_worker(io: &Io, aux_mutex: &Mutex,
                       routing_table: &drtio_routing::RoutingTable,
                       up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
-                      stream: &mut TcpStream,
+                      ddma_mutex: &Mutex, stream: &mut TcpStream,
                       congress: &mut Congress) -> Result<(), Error<SchedError>> {
     let mut session = Session::new(congress);
 
@@ -529,6 +564,7 @@ fn host_kernel_worker(io: &Io, aux_mutex: &Mutex,
         if mailbox::receive() != 0 {
             process_kern_message(io, aux_mutex,
                 routing_table, up_destinations,
+                ddma_mutex,
                 Some(stream), &mut session)?;
         }
 
@@ -546,7 +582,7 @@ fn host_kernel_worker(io: &Io, aux_mutex: &Mutex,
 fn flash_kernel_worker(io: &Io, aux_mutex: &Mutex,
                        routing_table: &drtio_routing::RoutingTable,
                        up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
-                       congress: &mut Congress,
+                       ddma_mutex: &Mutex, congress: &mut Congress,
                        config_key: &str) -> Result<(), Error<SchedError>> {
     let mut session = Session::new(congress);
 
@@ -568,7 +604,7 @@ fn flash_kernel_worker(io: &Io, aux_mutex: &Mutex,
         }
 
         if mailbox::receive() != 0 {
-            if process_kern_message(io, aux_mutex, routing_table, up_destinations, None, &mut session)? {
+            if process_kern_message(io, aux_mutex, routing_table, up_destinations, ddma_mutex, None, &mut session)? {
                 return Ok(())
             }
         }
@@ -598,7 +634,8 @@ fn respawn<F>(io: &Io, handle: &mut Option<ThreadHandle>, f: F)
 
 pub fn thread(io: Io, aux_mutex: &Mutex,
         routing_table: &Urc<RefCell<drtio_routing::RoutingTable>>,
-        up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>) {
+        up_destinations: &Urc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
+        ddma_mutex: &Mutex) {
     let listener = TcpListener::new(&io, 65535);
     listener.listen(1381).expect("session: cannot listen");
     info!("accepting network sessions");
@@ -609,7 +646,7 @@ pub fn thread(io: Io, aux_mutex: &Mutex,
     {
         let mut congress = congress.borrow_mut();
         info!("running startup kernel");
-        match flash_kernel_worker(&io, &aux_mutex, &routing_table.borrow(), &up_destinations, &mut congress, "startup_kernel") {
+        match flash_kernel_worker(&io, &aux_mutex, &routing_table.borrow(), &up_destinations, ddma_mutex, &mut congress, "startup_kernel") {
             Ok(()) =>
                 info!("startup kernel finished"),
             Err(Error::KernelNotFound) =>
@@ -649,12 +686,13 @@ pub fn thread(io: Io, aux_mutex: &Mutex,
             let routing_table = routing_table.clone();
             let up_destinations = up_destinations.clone();
             let congress = congress.clone();
+            let ddma_mutex = ddma_mutex.clone();
             let stream = stream.into_handle();
             respawn(&io, &mut kernel_thread, move |io| {
                 let routing_table = routing_table.borrow();
                 let mut congress = congress.borrow_mut();
                 let mut stream = TcpStream::from_handle(&io, stream);
-                match host_kernel_worker(&io, &aux_mutex, &routing_table, &up_destinations, &mut stream, &mut *congress) {
+                match host_kernel_worker(&io, &aux_mutex, &routing_table, &up_destinations, &ddma_mutex, &mut stream, &mut *congress) {
                     Ok(()) => (),
                     Err(Error::Protocol(host::Error::Io(IoError::UnexpectedEnd))) =>
                         info!("connection closed"),
@@ -677,10 +715,11 @@ pub fn thread(io: Io, aux_mutex: &Mutex,
             let routing_table = routing_table.clone();
             let up_destinations = up_destinations.clone();
             let congress = congress.clone();
+            let ddma_mutex = ddma_mutex.clone();
             respawn(&io, &mut kernel_thread, move |io| {
                 let routing_table = routing_table.borrow();
                 let mut congress = congress.borrow_mut();
-                match flash_kernel_worker(&io, &aux_mutex, &routing_table, &up_destinations, &mut *congress, "idle_kernel") {
+                match flash_kernel_worker(&io, &aux_mutex, &routing_table, &up_destinations, &ddma_mutex, &mut *congress, "idle_kernel") {
                     Ok(()) =>
                         info!("idle kernel finished, standing by"),
                     Err(Error::Protocol(host::Error::Io(

artiq/firmware/satman/dma.rs

@@ -1,4 +1,4 @@
-use board_misoc::csr;
+use board_misoc::{csr, cache::flush_l2_cache};
 use alloc::{vec::Vec, collections::btree_map::BTreeMap};
 
 const ALIGNMENT: usize = 64;
@@ -52,7 +52,19 @@ impl Manager {
 
     pub fn add(&mut self, id: u32, last: bool, trace: &[u8], trace_len: usize) -> Result<(), Error> {
         let entry = match self.entries.get_mut(&id) {
-            Some(entry) => entry,
+            Some(entry) => {
+                if entry.complete {
+                    // replace entry
+                    self.entries.remove(&id);
+                    self.entries.insert(id, Entry {
+                        trace: Vec::new(),
+                        padding_len: 0,
+                        complete: false });
+                    self.entries.get_mut(&id).unwrap()
+                } else {
+                    entry
+                }
+            },
             None => {
                 self.entries.insert(id, Entry {
                     trace: Vec::new(),
@@ -80,6 +92,7 @@ impl Manager {
             }
             entry.complete = true;
             entry.padding_len = padding;
+            flush_l2_cache();
         }
         Ok(())
     }

artiq/firmware/satman/main.rs

@@ -301,19 +301,22 @@ fn process_aux_packet(_manager: &mut DmaManager, _repeaters: &mut [repeater::Rep
             }
         }
         #[cfg(has_rtio_dma)]
-        drtioaux::Packet::DmaAddTraceRequest { id, last, length, trace } => {
+        drtioaux::Packet::DmaAddTraceRequest { destination: _destination, id, last, length, trace } => {
+            forward!(_routing_table, _destination, *_rank, _repeaters, &packet);
             let succeeded = _manager.add(id, last, &trace, length as usize).is_ok();
             drtioaux::send(0,
                 &drtioaux::Packet::DmaAddTraceReply { succeeded: succeeded })
         }
         #[cfg(has_rtio_dma)]
-        drtioaux::Packet::DmaRemoveTraceRequest { id } => {
+        drtioaux::Packet::DmaRemoveTraceRequest { destination: _destination, id } => {
+            forward!(_routing_table, _destination, *_rank, _repeaters, &packet);
             let succeeded = _manager.erase(id).is_ok();
             drtioaux::send(0,
                 &drtioaux::Packet::DmaRemoveTraceReply { succeeded: succeeded })
         }
         #[cfg(has_rtio_dma)]
-        drtioaux::Packet::DmaPlaybackRequest { id, timestamp } => {
+        drtioaux::Packet::DmaPlaybackRequest { destination: _destination, id, timestamp } => {
+            forward!(_routing_table, _destination, *_rank, _repeaters, &packet);
             let succeeded = _manager.playback(id, timestamp).is_ok();
             drtioaux::send(0,
                 &drtioaux::Packet::DmaPlaybackReply { succeeded: succeeded })
@@ -463,7 +466,8 @@ pub extern fn main() -> i32 {
 
     unsafe {
         ALLOC.add_range(&mut _fheap, &mut _eheap);
-        pmp::init_stack_guard(&_sstack_guard as *const u8 as usize);
+        // stack guard disabled, see https://github.com/m-labs/artiq/issues/2067
+        // pmp::init_stack_guard(&_sstack_guard as *const u8 as usize);
     }
 
     clock::init();
@@ -571,8 +575,9 @@ pub extern fn main() -> i32 {
                 }
             }
             if let Some(status) = dma_manager.check_state() {
+                info!("playback done, error: {}, channel: {}, timestamp: {}", status.error, status.channel, status.timestamp);
                 if let Err(e) = drtioaux::send(0, &drtioaux::Packet::DmaPlaybackStatus { 
-                    id: status.id, error: status.error, channel: status.channel, timestamp: status.timestamp }) {
+                    destination: rank, id: status.id, error: status.error, channel: status.channel, timestamp: status.timestamp }) {
                     error!("error sending DMA playback status: {}", e);
                 }
             }