qc2: add 4 edge counters to the end of rtio

This ports over the following commits from the main ARTIQ repo:
 - 8740ec3dd52d85084237797881ea137492bfe070
 - dbbe8e8ed4f852e623775b7bd3aec818cdd03376
 - b9f13d48aa7e2c0652210152b971b21c3c419347

README.md

@@ -4,7 +4,7 @@ ARTIQ on Zynq
 How to use
 ----------
 
-1. Install ARTIQ-6 or newer.
+1. Install ARTIQ-7 or newer.
 2. Select the latest successful build on Hydra: https://nixbld.m-labs.hk/jobset/artiq/zynq
 3. Search for the job named ``<board>-<variant>-sd`` (for example: ``zc706-nist_clock-sd`` or ``zc706-nist_qc2-sd``).
 4. Download the ``boot.bin`` "binary distribution" and place it at the root of a FAT-formatted SD card.
@@ -33,7 +33,7 @@ not implemented as it seems not very useful.
 Development instructions
 ------------------------
 
-ARTIQ on Zynq is packaged using the [Nix](https://nixos.org) Flakes system. Install Nix 2.4+ and enable flakes by adding ``experimental-features = nix-command flakes`` to ``nix.conf`` (e.g. ``~/.config/nix/nix.conf``). 
+ARTIQ on Zynq is packaged using the [Nix](https://nixos.org) Flakes system. Install Nix 2.8+ and enable flakes by adding ``experimental-features = nix-command flakes`` to ``nix.conf`` (e.g. ``~/.config/nix/nix.conf``).
 
 Pure build with Nix and execution on a remote JTAG server:
 

examples/device_db.py

@@ -8,7 +8,7 @@ device_db = {
         "arguments": {
             "host": "192.168.1.52",
             "ref_period": 1e-9,
-            "ref_multiplier": 1,
+            "ref_multiplier": 8,
             "target": "cortexa9"
         }
     },
@@ -59,6 +59,14 @@ device_db["ad9914dds1"] = {
     "arguments": {"sysclk": 3e9, "bus_channel": 50, "channel": 1},
 }
 
+for i in range(4):
+    device_db["ttl"+str(i)+"_counter"] = {
+        "type": "local",
+        "module": "artiq.coredevice.edge_counter",
+        "class": "EdgeCounter",
+        "arguments": {"channel": 52+i}
+    }
+
 # for ARTIQ test suite
 device_db.update(
     loop_out="ttl0",

flake.lock

@@ -11,21 +11,23 @@
         "src-pythonparser": "src-pythonparser"
       },
       "locked": {
-        "lastModified": 1654087576,
+        "lastModified": 1676885665,
-        "narHash": "sha256-d+LCvCXikhhEjsf4qBZakx3Sda85p+4vVZVwE1YuS90=",
+        "narHash": "sha256-DCi2fyz/vOM82YGBTgkmruw2tOm+EepTWeF7+oNs1+s=",
-        "ref": "master",
+        "ref": "release-7",
-        "rev": "68ef0073ea66fe9c7f7c178979ecb8c681c47caa",
+        "rev": "8a2ea578b81dd4d8576c8e2b939474f418e03ad7",
-        "revCount": 8068,
+        "revCount": 8161,
         "type": "git",
         "url": "https://github.com/m-labs/artiq.git"
       },
       "original": {
+        "ref": "release-7",
         "type": "git",
         "url": "https://github.com/m-labs/artiq.git"
       }
     },
     "artiq-comtools": {
       "inputs": {
+        "flake-utils": "flake-utils",
         "nixpkgs": [
           "artiq",
           "nixpkgs"
@@ -36,11 +38,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1654007592,
+        "lastModified": 1664405593,
-        "narHash": "sha256-vaDFhE1ItjqtIcinC/6RAJGbj44pxxMUEeQUa3FtgEE=",
+        "narHash": "sha256-yP441NerlLGig7n+9xHsx8yCtZ+Ggd0VqfBSzc20E04=",
         "owner": "m-labs",
         "repo": "artiq-comtools",
-        "rev": "cb73281154656ee8f74db1866859e31bf42755cd",
+        "rev": "15ddac62813ef623a076ccf982b3bc63d314e651",
         "type": "github"
       },
       "original": {
@@ -49,14 +51,29 @@
         "type": "github"
       }
     },
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1659877975,
+        "narHash": "sha256-zllb8aq3YO3h8B/U0/J1WBgAL8EX5yWf5pMj3G0NAmc=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c0e246b9b83f637f4681389ecabcb2681b4f3af0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
     "mozilla-overlay": {
       "flake": false,
       "locked": {
-        "lastModified": 1650459918,
+        "lastModified": 1664789696,
-        "narHash": "sha256-sroCK+QJTmoXtcRkwZyKOP9iAYOPID2Bwdxn4GkG16w=",
+        "narHash": "sha256-UGWJHQShiwLCr4/DysMVFrYdYYHcOqAOVsWNUu+l6YU=",
         "owner": "mozilla",
         "repo": "nixpkgs-mozilla",
-        "rev": "e1f7540fc0a8b989fb8cf701dc4fd7fc76bcf168",
+        "rev": "80627b282705101e7b38e19ca6e8df105031b072",
         "type": "github"
       },
       "original": {
@@ -68,11 +85,11 @@
     "mozilla-overlay_2": {
       "flake": false,
       "locked": {
-        "lastModified": 1650459918,
+        "lastModified": 1675354105,
-        "narHash": "sha256-sroCK+QJTmoXtcRkwZyKOP9iAYOPID2Bwdxn4GkG16w=",
+        "narHash": "sha256-ZAJGIZ7TjOCU7302lSUabNDz+rxM4If0l8/ZbE/7R5U=",
         "owner": "mozilla",
         "repo": "nixpkgs-mozilla",
-        "rev": "e1f7540fc0a8b989fb8cf701dc4fd7fc76bcf168",
+        "rev": "85eb0ba7d8e5d6d4b79e5b0180aadbdd25d76404",
         "type": "github"
       },
       "original": {
@@ -84,11 +101,11 @@
     "mozilla-overlay_3": {
       "flake": false,
       "locked": {
-        "lastModified": 1650459918,
+        "lastModified": 1664789696,
-        "narHash": "sha256-sroCK+QJTmoXtcRkwZyKOP9iAYOPID2Bwdxn4GkG16w=",
+        "narHash": "sha256-UGWJHQShiwLCr4/DysMVFrYdYYHcOqAOVsWNUu+l6YU=",
         "owner": "mozilla",
         "repo": "nixpkgs-mozilla",
-        "rev": "e1f7540fc0a8b989fb8cf701dc4fd7fc76bcf168",
+        "rev": "80627b282705101e7b38e19ca6e8df105031b072",
         "type": "github"
       },
       "original": {
@@ -99,11 +116,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1653920503,
+        "lastModified": 1666056570,
-        "narHash": "sha256-BBeCZwZImtjP3oYy4WogkQYy5OxNyfNciVSc1AfZgLQ=",
+        "narHash": "sha256-e7EkIY68Tp7NKyp9JSHh6CgPPdsKYYWxiL4wZQN8Cwg=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "a634c8f6c1fbf9b9730e01764999666f3436f10a",
+        "rev": "47edaa313fc3767ce3026037a5b62352f22f3602",
         "type": "github"
       },
       "original": {
@@ -128,11 +145,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1654006751,
+        "lastModified": 1664319253,
-        "narHash": "sha256-OWAnoTCutvTQcYdtdtLQuL6uRtG+7Jz7sbRhcScv8bo=",
+        "narHash": "sha256-hycJAgy+NFF9f5I6++7yo8KdhMSyKCPKJazRPxeedI4=",
         "owner": "m-labs",
         "repo": "sipyco",
-        "rev": "b3d03a94c751a24769c54a61a0dbe9d6af52dade",
+        "rev": "d58ded7280e0f020be2446d4fee70f4393e6045f",
         "type": "github"
       },
       "original": {
@@ -144,11 +161,11 @@
     "src-migen": {
       "flake": false,
       "locked": {
-        "lastModified": 1650337393,
+        "lastModified": 1662111470,
-        "narHash": "sha256-rm1SlFmF2ASz0vIy2nDEzGlyRw2oYNeJRr8Kh8Mg2Qc=",
+        "narHash": "sha256-IPyhoFZLhY8d3jHB8jyvGdbey7V+X5eCzBZYSrJ18ec=",
         "owner": "m-labs",
         "repo": "migen",
-        "rev": "d4e3f34177c32f09904397179e6ed9c83175e528",
+        "rev": "639e66f4f453438e83d86dc13491b9403bbd8ec6",
         "type": "github"
       },
       "original": {
@@ -160,11 +177,11 @@
     "src-misoc": {
       "flake": false,
       "locked": {
-        "lastModified": 1649324486,
+        "lastModified": 1665395741,
-        "narHash": "sha256-Mw/fQS3lHFvCm7L1k63joRkz5uyijQfywcOq+X2+o2s=",
+        "narHash": "sha256-7ULMGBPPn5NxZX6rdxU5GheoSNBiJklHQEVf04jU9tI=",
         "ref": "master",
-        "rev": "f1dc58d2b8c222ba41c25cee4301626625f46e43",
+        "rev": "4fb0730db4c5de7e86f82fa3bd204e6c4608af85",
-        "revCount": 2420,
+        "revCount": 2427,
         "submodules": true,
         "type": "git",
         "url": "https://github.com/m-labs/misoc.git"
@@ -200,11 +217,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1654002148,
+        "lastModified": 1669819016,
-        "narHash": "sha256-Ztzx7ze8o0gdu+sDpc+PS2M88h/b22rwFq0b12wMqZQ=",
+        "narHash": "sha256-WvNMUekL4Elc55RdqX8XP43QPnBrK8Rbd0bsoI61E5U=",
-        "ref": "master",
+        "ref": "refs/heads/master",
-        "rev": "6cd32f6ee0e7bb7ce5a279f8be943903a393a476",
+        "rev": "67dbb5932fa8ff5f143983476f741f945871d286",
-        "revCount": 617,
+        "revCount": 624,
         "type": "git",
         "url": "https://git.m-labs.hk/m-labs/zynq-rs"
       },

flake.nix

@@ -1,7 +1,7 @@
 {
   description = "ARTIQ port to the Zynq-7000 platform";
 
-  inputs.artiq.url = git+https://github.com/m-labs/artiq.git;
+  inputs.artiq.url = git+https://github.com/m-labs/artiq.git?ref=release-7;
   inputs.mozilla-overlay = { url = github:mozilla/nixpkgs-mozilla; flake = false; };
   inputs.zynq-rs.url = git+https://git.m-labs.hk/m-labs/zynq-rs;
   inputs.zynq-rs.inputs.nixpkgs.follows = "artiq/nixpkgs";

src/gateware/kasli_soc.py

@@ -15,6 +15,7 @@ from misoc.integration import cpu_interface
 from artiq.coredevice import jsondesc
 from artiq.gateware import rtio, eem_7series
 from artiq.gateware.rtio.phy import ttl_simple
+from artiq.gateware.rtio.xilinx_clocking import fix_serdes_timing_path
 from artiq.gateware.rtio.xilinx_clocking import RTIOClockMultiplier
 from artiq.gateware.drtio.transceiver import gtx_7series
 from artiq.gateware.drtio.siphaser import SiPhaser7Series
@@ -118,7 +119,7 @@ class GenericStandalone(SoCCore):
         platform.toolchain.bitstream_commands.extend([
             "set_property BITSTREAM.GENERAL.COMPRESS True [current_design]",
         ])
-        ident = self.__class__.__name__
+        ident = description["variant"]
         if self.acpki:
             ident = "acpki_" + ident
         SoCCore.__init__(self, platform=platform, csr_data_width=32, ident=ident)
@@ -138,6 +139,7 @@ class GenericStandalone(SoCCore):
         self.platform.add_false_path_constraints(
             self.ps7.cd_sys.clk,
             self.rtio_crg.cd_rtio.clk)
+        fix_serdes_timing_path(platform)
 
         self.rtio_channels = []
         has_grabber = any(peripheral["type"] == "grabber" for peripheral in description["peripherals"])
@@ -204,7 +206,7 @@ class GenericMaster(SoCCore):
         platform.toolchain.bitstream_commands.extend([
             "set_property BITSTREAM.GENERAL.COMPRESS True [current_design]",
         ])
-        ident = self.__class__.__name__
+        ident = description["variant"]
         if self.acpki:
             ident = "acpki_" + ident
         SoCCore.__init__(self, platform=platform, csr_data_width=32, ident=ident)
@@ -225,6 +227,7 @@ class GenericMaster(SoCCore):
         self.crg = self.ps7 # HACK for eem_7series to find the clock
         self.submodules.rtio_crg = RTIOClockMultiplier(rtio_clk_freq)
         self.csr_devices.append("rtio_crg")
+        fix_serdes_timing_path(platform)
 
         self.rustc_cfg["has_si5324"] = None
         self.rustc_cfg["si5324_soft_reset"] = None
@@ -329,7 +332,7 @@ class GenericSatellite(SoCCore):
         platform.toolchain.bitstream_commands.extend([
             "set_property BITSTREAM.GENERAL.COMPRESS True [current_design]",
         ])
-        ident = self.__class__.__name__
+        ident = description["variant"]
         if self.acpki:
             ident = "acpki_" + ident
         SoCCore.__init__(self, platform=platform, csr_data_width=32, ident=ident)
@@ -341,6 +344,7 @@ class GenericSatellite(SoCCore):
         self.submodules.rtio_crg = RTIOClockMultiplier(rtio_clk_freq)
         self.csr_devices.append("rtio_crg")
         self.rustc_cfg["has_rtio_crg"] = None
+        fix_serdes_timing_path(platform)
         
         data_pads = [platform.request("sfp", i) for i in range(4)]
         

src/gateware/zc706.py

@@ -14,7 +14,7 @@ from misoc.integration import cpu_interface
 from misoc.cores import gpio
 
 from artiq.gateware import rtio, nist_clock, nist_qc2
-from artiq.gateware.rtio.phy import ttl_simple, ttl_serdes_7series, dds, spi2
+from artiq.gateware.rtio.phy import ttl_simple, ttl_serdes_7series, dds, spi2, edge_counter
 from artiq.gateware.rtio.xilinx_clocking import RTIOClockMultiplier, fix_serdes_timing_path
 from artiq.gateware.drtio.transceiver import gtx_7series
 from artiq.gateware.drtio.siphaser import SiPhaser7Series
@@ -562,12 +562,16 @@ class _NIST_QC2_RTIO:
         platform.add_extension(pmod1_33)
 
         rtio_channels = []
+        edge_counter_phy = []
 
         # All TTL channels are In+Out capable
         for i in range(40):
             phy = ttl_serdes_7series.InOut_8X(platform.request("ttl", i))
             self.submodules += phy
             rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=512))
+            # first four TTLs will also have edge counters
+            if i < 4:
+                edge_counter_phy.append(phy)
 
         # no SMA GPIO, replaced with PMOD1_0
         phy = ttl_serdes_7series.InOut_8X(platform.request("pmod1_33", 0))
@@ -607,6 +611,11 @@ class _NIST_QC2_RTIO:
             self.submodules += phy
             rtio_channels.append(rtio.Channel.from_phy(phy, ififo_depth=4))
         
+        for phy in edge_counter_phy:
+            counter = edge_counter.SimpleEdgeCounter(phy.input_state)
+            self.submodules += counter
+            rtio_channels.append(rtio.Channel.from_phy(counter))
+
         self.config["RTIO_LOG_CHANNEL"] = len(rtio_channels)
         rtio_channels.append(rtio.LogChannel())
 

src/libboard_artiq/src/io_expander.rs

@@ -0,0 +1,145 @@
+use libboard_zynq::i2c;
+use log::info;
+
+// Only the bare minimum registers. Bits/IO connections equivalent between IC types.
+struct Registers {
+    // PCA9539 equivalent register names in comments
+    iodira: u8, // Configuration Port 0
+    iodirb: u8, // Configuration Port 1
+    gpioa: u8,  // Output Port 0
+    gpiob: u8,  // Output Port 1
+}
+
+pub struct IoExpander<'a> {
+    i2c: &'a mut i2c::I2c,
+    address: u8,
+    iodir: [u8; 2],
+    out_current: [u8; 2],
+    out_target: [u8; 2],
+    registers: Registers,
+}
+
+
+impl<'a> IoExpander<'a> {
+    pub fn new(i2c: &'a mut i2c::I2c, index: u8) -> Result<Self, &'static str> {
+
+        // Both expanders on SHARED I2C bus
+        let mut io_expander = match index {
+            0 => IoExpander {
+                i2c,
+                address: 0x40,
+                iodir: [0xff; 2],
+                out_current: [0; 2],
+                out_target: [0; 2],
+                registers: Registers {
+                    iodira: 0x00,
+                    iodirb: 0x01,
+                    gpioa: 0x12,
+                    gpiob: 0x13,
+                },
+            },
+            1 => IoExpander {
+                i2c,
+                address: 0x42,
+                iodir: [0xff; 2],
+                out_current: [0; 2],
+                out_target: [0; 2],
+                registers: Registers {
+                    iodira: 0x00,
+                    iodirb: 0x01,
+                    gpioa: 0x12,
+                    gpiob: 0x13,
+                },
+            },
+            _ => return Err("incorrect I/O expander index"),
+        };
+        if !io_expander.check_ack()? {
+            info!(
+                "MCP23017 io expander {} not found. Checking for PCA9539.",
+                index
+            );
+            io_expander.address += 0xa8; // translate to PCA9539 addresses (see schematic)
+            io_expander.registers = Registers {
+                iodira: 0x06,
+                iodirb: 0x07,
+                gpioa: 0x02,
+                gpiob: 0x03,
+            };
+            if !io_expander.check_ack()? {
+                return Err("Neither MCP23017 nor PCA9539 io expander found.");
+            };
+        }
+        Ok(io_expander)
+    }
+
+    fn select(&mut self) -> Result<(), &'static str> {
+        self.i2c.pca954x_select(0x70, None)?;
+        self.i2c.pca954x_select(0x71, Some(3))?;
+        Ok(())
+    }
+
+    fn write(&mut self, addr: u8, value: u8) -> Result<(), &'static str> {
+        self.i2c.start()?;
+        self.i2c.write(self.address)?;
+        self.i2c.write(addr)?;
+        self.i2c.write(value)?;
+        self.i2c.stop()?;
+        Ok(())
+    }
+
+    fn check_ack(&mut self) -> Result<bool, &'static str> {
+        // Check for ack from io expander
+        self.select()?;
+        self.i2c.start()?;
+        let ack = self.i2c.write(self.address)?;
+        self.i2c.stop()?;
+        Ok(ack)
+    }
+
+    fn update_iodir(&mut self) -> Result<(), &'static str> {
+        self.write(self.registers.iodira, self.iodir[0])?;
+        self.write(self.registers.iodirb, self.iodir[1])?;
+        Ok(())
+    }
+
+    pub fn init(&mut self) -> Result<(), &'static str> {
+        self.select()?;
+        self.update_iodir()?;
+
+        self.out_current[0] = 0x00;
+        self.write(self.registers.gpioa, 0x00)?;
+        self.out_current[1] = 0x00;
+        self.write(self.registers.gpiob, 0x00)?;
+        Ok(())
+    }
+
+    pub fn set_oe(&mut self, port: u8, outputs: u8) -> Result<(), &'static str> {
+        self.iodir[port as usize] &= !outputs;
+        self.update_iodir()?;
+        Ok(())
+    }
+
+    pub fn set(&mut self, port: u8, bit: u8, high: bool) {
+        if high {
+            self.out_target[port as usize] |= 1 << bit;
+        } else {
+            self.out_target[port as usize] &= !(1 << bit);
+        }
+    }
+
+    pub fn service(&mut self) -> Result<(), &'static str> {
+        if self.out_target != self.out_current {
+            self.select()?;
+            if self.out_target[0] != self.out_current[0] {
+                self.write(self.registers.gpioa, self.out_target[0])?;
+                self.out_current[0] = self.out_target[0];
+            }
+            if self.out_target[1] != self.out_current[1] {
+                self.write(self.registers.gpiob, self.out_target[1])?;
+                self.out_current[1] = self.out_target[1];
+            }
+        }
+
+        Ok(())
+    }
+}

src/libboard_artiq/src/lib.rs

@@ -27,6 +27,8 @@ pub mod drtioaux_async;
 #[cfg(has_drtio)]
 #[path = "../../../build/mem.rs"]
 pub mod mem;
+#[cfg(feature = "target_kasli_soc")]
+pub mod io_expander;
 
 use core::{cmp, str};
 use libboard_zynq::slcr;

src/runtime/src/comms.rs

@@ -427,8 +427,8 @@ pub fn main(timer: GlobalTimer, cfg: Config) {
     moninj::start(timer, aux_mutex, drtio_routing_table);
 
     let control: Rc<RefCell<kernel::Control>> = Rc::new(RefCell::new(kernel::Control::start()));
-    let idle_kernel = Rc::new(cfg.read("idle").ok());
+    let idle_kernel = Rc::new(cfg.read("idle_kernel").ok());
-    if let Ok(buffer) = cfg.read("startup") {
+    if let Ok(buffer) = cfg.read("startup_kernel") {
         info!("Loading startup kernel...");
         if let Ok(()) = task::block_on(load_kernel(&buffer, &control, None)) {
             info!("Starting startup kernel...");

src/runtime/src/main.rs

@@ -21,6 +21,8 @@ use void::Void;
 use libconfig::Config;
 use libcortex_a9::l2c::enable_l2_cache;
 use libboard_artiq::{logger, identifier_read, init_gateware, pl};
+#[cfg(feature = "target_kasli_soc")]
+use libboard_artiq::io_expander;
 
 const ASYNC_ERROR_COLLISION: u8 = 1 << 0;
 const ASYNC_ERROR_BUSY: u8 = 1 << 1;
@@ -109,10 +111,25 @@ pub fn main_core0() {
     gic::InterruptController::gic(mpcore::RegisterBlock::mpcore()).enable_interrupts();
 
     init_gateware();
-    info!("detected gateware: {}", identifier_read(&mut [0; 64]));
+    info!("gateware ident: {}", identifier_read(&mut [0; 64]));
 
     i2c::init();
 
+    #[cfg(feature = "target_kasli_soc")]
+    {
+        let i2c = unsafe { (&mut i2c::I2C_BUS).as_mut().unwrap() };
+        for expander_i in 0..=1 {
+            let mut io_expander = io_expander::IoExpander::new(i2c, expander_i).unwrap();
+            io_expander.init().expect("I2C I/O expander #0 initialization failed");
+            // Actively drive TX_DISABLE to false on SFP0..3
+            io_expander.set_oe(0, 1 << 1).unwrap();
+            io_expander.set_oe(1, 1 << 1).unwrap();
+            io_expander.set(0, 1, false);
+            io_expander.set(1, 1, false);
+            io_expander.service().unwrap();
+        }
+    }
+
     let cfg = match Config::new() {
         Ok(cfg) => cfg,
         Err(err) => {

src/runtime/src/rpc.rs

@@ -15,22 +15,85 @@ use crate::proto_async;
 use self::tag::{Tag, TagIterator, split_tag};
 
 #[inline]
-fn alignment_offset(alignment: isize, ptr: isize) -> isize {
+fn round_up(val: usize, power_of_two: usize) -> usize {
-    (alignment - ptr % alignment) % alignment
+    assert!(power_of_two.is_power_of_two());
+    let max_rem = power_of_two - 1;
+    (val + max_rem) & (!max_rem)
 }
 
+#[inline]
+unsafe fn round_up_mut<T>(ptr: *mut T, power_of_two: usize) -> *mut T {
+    round_up(ptr as usize, power_of_two) as *mut T
+}
+
+#[inline]
+unsafe fn round_up_const<T>(ptr: *const T, power_of_two: usize) -> *const T {
+    round_up(ptr as usize, power_of_two) as *const T
+}
+
+#[inline]
 unsafe fn align_ptr<T>(ptr: *const ()) -> *const T {
-    let alignment = core::mem::align_of::<T>() as isize;
+    round_up_const(ptr, core::mem::align_of::<T>()) as *const T
-    let fix = alignment_offset(alignment, ptr as isize);
-    ((ptr as isize) + fix) as *const T
 }
 
+#[inline]
 unsafe fn align_ptr_mut<T>(ptr: *mut ()) -> *mut T {
-    let alignment = core::mem::align_of::<T>() as isize;
+    round_up_mut(ptr, core::mem::align_of::<T>()) as *mut T
-    let fix = alignment_offset(alignment, ptr as isize);
-    ((ptr as isize) + fix) as *mut T
 }
 
+/// Reads (deserializes) `length` array or list elements of type `tag` from `stream`,
+/// writing them into the buffer given by `storage`.
+///
+/// `alloc` is used for nested allocations (if elements themselves contain
+/// lists/arrays), see [recv_value].
+#[async_recursion(?Send)]
+async unsafe fn recv_elements<F>(
+    stream: &TcpStream,
+    elt_tag: Tag<'async_recursion>,
+    length: usize,
+    storage: *mut (),
+    alloc: &(impl Fn(usize) -> F + 'async_recursion)
+) -> Result<(), smoltcp::Error>
+where
+    F: Future<Output=*mut ()>,
+{
+    // List of simple types are special-cased in the protocol for performance.
+    match elt_tag {
+        Tag::Bool => {
+            let dest = core::slice::from_raw_parts_mut(storage as *mut u8, length);
+            proto_async::read_chunk(stream, dest).await?;
+        },
+        Tag::Int32 => {
+            let ptr = storage as *mut u32;
+            let dest = core::slice::from_raw_parts_mut(ptr as *mut u8, length * 4);
+            proto_async::read_chunk(stream, dest).await?;
+            drop(dest);
+            let dest = core::slice::from_raw_parts_mut(ptr, length);
+            NativeEndian::from_slice_u32(dest);
+        },
+        Tag::Int64 | Tag::Float64 => {
+            let ptr = storage as *mut u64;
+            let dest = core::slice::from_raw_parts_mut(ptr as *mut u8, length * 8);
+            proto_async::read_chunk(stream, dest).await?;
+            drop(dest);
+            let dest = core::slice::from_raw_parts_mut(ptr, length);
+            NativeEndian::from_slice_u64(dest);
+        },
+        _ => {
+            let mut data = storage;
+            for _ in 0..length {
+                recv_value(stream, elt_tag, &mut data, alloc).await?
+            }
+        }
+    }
+    Ok(())
+}
+
+/// Reads (deserializes) a value of type `tag` from `stream`, writing the results to
+/// the kernel-side buffer `data` (the passed pointer to which is incremented to point
+/// past the just-received data). For nested allocations (lists/arrays), `alloc` is
+/// invoked any number of times with the size of the required allocation as a parameter
+/// (which is assumed to be correctly aligned for all payload types).
 #[async_recursion(?Send)]
 async unsafe fn recv_value<F>(stream: &TcpStream, tag: Tag<'async_recursion>, data: &mut *mut (),
                               alloc: &(impl Fn(usize) -> F + 'async_recursion))
@@ -71,120 +134,63 @@ async unsafe fn recv_value<F>(stream: &TcpStream, tag: Tag<'async_recursion>, da
             })
         }
         Tag::Tuple(it, arity) => {
-            *data = (*data).offset(alignment_offset(tag.alignment() as isize, *data as isize));
+            let alignment = tag.alignment();
+            *data = round_up_mut(*data, alignment);
             let mut it = it.clone();
             for _ in 0..arity {
                 let tag = it.next().expect("truncated tag");
-                recv_value(stream, tag, data, alloc).await?;
+                recv_value(stream, tag, data, alloc).await?
             }
+            // Take into account any tail padding (if element(s) with largest alignment
+            // are not at the end).
+            *data = round_up_mut(*data, alignment);
             Ok(())
         }
         Tag::List(it) => {
             #[repr(C)]
-            struct List { elements: *mut (), length: u32 }
+            struct List { elements: *mut (), length: usize }
-            consume_value!(*mut List, |ptr| {
+            consume_value!(*mut List, |ptr_to_list| {
-                let length = proto_async::read_i32(stream).await? as usize;
                 let tag = it.clone().next().expect("truncated tag");
-                let data_size = tag.size() * length as usize +
+                let length = proto_async::read_i32(stream).await? as usize;
-                    match tag {
-                        Tag::Int64 | Tag::Float64 => 4,
-                        _ => 0
-                    };
-                let data = alloc(data_size + 8).await as *mut u8;
-                *ptr = data as *mut List;
-                let ptr = data as *mut List;
-                let data = data.offset(8);
 
-                let alignment = tag.alignment();
+                // To avoid multiple kernel CPU roundtrips, use a single allocation for
-                let mut data = data.offset(alignment_offset(alignment as isize, data as isize)) as *mut ();
+                // both the pointer/length List (slice) and the backing storage for the
-                (*ptr).length  = length as u32;
+                // elements. We can assume that alloc() is aligned suitably, so just
-                (*ptr).elements = data;
+                // need to take into account any extra padding required.
-                match tag {
+                // (Note: At the time of writing, there will never actually be any types
-                    Tag::Bool => {
+                // with alignment larger than 8 bytes, so storage_offset == 0 always.)
-                        let ptr = data as *mut u8;
+                let list_size = 4 + 4;
-                        let dest = core::slice::from_raw_parts_mut(ptr, length);
+                let storage_offset = round_up(list_size, tag.alignment());
-                        proto_async::read_chunk(stream, dest).await?;
+                let storage_size = tag.size() * length;
-                    },
+
-                    Tag::Int32 => {
+                let allocation = alloc(storage_offset + storage_size).await as *mut u8;
-                        let ptr = data as *mut u32;
+                *ptr_to_list = allocation as *mut List;
-                        // reading as raw bytes and do endianness conversion later
+                let storage = allocation.offset(storage_offset as isize) as *mut ();
-                        let dest = core::slice::from_raw_parts_mut(ptr as *mut u8, length * 4);
+
-                        proto_async::read_chunk(stream, dest).await?;
+                (**ptr_to_list).length = length;
-                        drop(dest);
+                (**ptr_to_list).elements = storage;
-                        let dest = core::slice::from_raw_parts_mut(ptr, length);
+                recv_elements(stream, tag, length, storage, alloc).await
-                        NativeEndian::from_slice_u32(dest);
-                    },
-                    Tag::Int64 | Tag::Float64 => {
-                        let ptr = data as *mut u64;
-                        let dest = core::slice::from_raw_parts_mut(ptr as *mut u8, length * 8);
-                        proto_async::read_chunk(stream, dest).await?;
-                        drop(dest);
-                        let dest = core::slice::from_raw_parts_mut(ptr, length);
-                        NativeEndian::from_slice_u64(dest);
-                    },
-                    _ => {
-                        for _ in 0..(*ptr).length as usize {
-                            recv_value(stream, tag, &mut data, alloc).await?
-                        }
-                    }
-                }
-                Ok(())
             })
         }
         Tag::Array(it, num_dims) => {
             consume_value!(*mut (), |buffer| {
-                let mut total_len: u32 = 1;
+                // Deserialize length along each dimension and compute total number of
+                // elements.
+                let mut total_len: usize = 1;
                 for _ in 0..num_dims {
-                    let len = proto_async::read_i32(stream).await? as u32;
+                    let len = proto_async::read_i32(stream).await? as usize;
                     total_len *= len;
-                    consume_value!(u32, |ptr| *ptr = len )
+                    consume_value!(usize, |ptr| *ptr = len )
                 }
 
+                // Allocate backing storage for elements; deserialize them.
                 let elt_tag = it.clone().next().expect("truncated tag");
-                let data_size = elt_tag.size() * total_len as usize +
+                *buffer = alloc(elt_tag.size() * total_len).await;
-                    match elt_tag {
+                recv_elements(stream, elt_tag, total_len, *buffer, alloc).await
-                        Tag::Int64 | Tag::Float64 => 4,
-                        _ => 0
-                    };
-                let mut data = alloc(data_size).await;
-
-                let alignment = tag.alignment();
-                data = data.offset(alignment_offset(alignment as isize, data as isize));
-                *buffer = data;
-                let length = total_len as usize;
-                match elt_tag {
-                    Tag::Bool => {
-                        let ptr = data as *mut u8;
-                        let dest = core::slice::from_raw_parts_mut(ptr, length);
-                        proto_async::read_chunk(stream, dest).await?;
-                    },
-                    Tag::Int32 => {
-                        let ptr = data as *mut u32;
-                        let dest = core::slice::from_raw_parts_mut(ptr as *mut u8, length * 4);
-                        proto_async::read_chunk(stream, dest).await?;
-                        drop(dest);
-                        let dest = core::slice::from_raw_parts_mut(ptr, length);
-                        NativeEndian::from_slice_u32(dest);
-                    },
-                    Tag::Int64 | Tag::Float64 => {
-                        let ptr = data as *mut u64;
-                        let dest = core::slice::from_raw_parts_mut(ptr as *mut u8, length * 8);
-                        proto_async::read_chunk(stream, dest).await?;
-                        drop(dest);
-                        let dest = core::slice::from_raw_parts_mut(ptr, length);
-                        NativeEndian::from_slice_u64(dest);
-                    },
-                    _ => {
-                        for _ in 0..length {
-                            recv_value(stream, elt_tag, &mut data, alloc).await?
-                        }
-                    }
-                }
-                Ok(())
             })
         }
         Tag::Range(it) => {
-            *data = (*data).offset(alignment_offset(tag.alignment() as isize, *data as isize));
+            *data = round_up_mut(*data, tag.alignment());
             let tag = it.clone().next().expect("truncated tag");
             recv_value(stream, tag, data, alloc).await?;
             recv_value(stream, tag, data, alloc).await?;
@@ -211,6 +217,36 @@ pub async fn recv_return<F>(stream: &TcpStream, tag_bytes: &[u8], data: *mut (),
     Ok(())
 }
 
+unsafe fn send_elements<W>(writer: &mut W, elt_tag: Tag, length: usize, data: *const ())
+                          -> Result<(), Error>
+    where W: Write + ?Sized
+{
+    writer.write_u8(elt_tag.as_u8())?;
+    match elt_tag {
+        // we cannot use NativeEndian::from_slice_i32 as the data is not mutable,
+        // and that is not needed as the data is already in native endian
+        Tag::Bool => {
+            let slice = core::slice::from_raw_parts(data as *const u8, length);
+            writer.write_all(slice)?;
+        },
+        Tag::Int32 => {
+            let slice = core::slice::from_raw_parts(data as *const u8, length * 4);
+            writer.write_all(slice)?;
+        },
+        Tag::Int64 | Tag::Float64 => {
+            let slice = core::slice::from_raw_parts(data as *const u8, length * 8);
+            writer.write_all(slice)?;
+        },
+        _ => {
+            let mut data = data;
+            for _ in 0..length {
+                send_value(writer, elt_tag, &mut data)?;
+            }
+        }
+    }
+    Ok(())
+}
+
 unsafe fn send_value<W>(writer: &mut W, tag: Tag, data: &mut *const ())
                        -> Result<(), Error>
     where W: Write + ?Sized
@@ -244,46 +280,23 @@ unsafe fn send_value<W>(writer: &mut W, tag: Tag, data: &mut *const ())
         Tag::Tuple(it, arity) => {
             let mut it = it.clone();
             writer.write_u8(arity)?;
+            let mut max_alignment = 0;
             for _ in 0..arity {
                 let tag = it.next().expect("truncated tag");
+                max_alignment = core::cmp::max(max_alignment, tag.alignment());
                 send_value(writer, tag, data)?
             }
+            *data = round_up_const(*data, max_alignment);
             Ok(())
         }
         Tag::List(it) => {
             #[repr(C)]
             struct List { elements: *const (), length: u32 }
             consume_value!(&List, |ptr| {
-                let length = (**ptr).length as isize;
+                let length = (**ptr).length as usize;
                 writer.write_u32((*ptr).length)?;
                 let tag = it.clone().next().expect("truncated tag");
-                let mut data = (**ptr).elements;
+                send_elements(writer, tag, length, (**ptr).elements)
-                writer.write_u8(tag.as_u8())?;
-                match tag {
-                    Tag::Bool => {
-                        // we can pretend this is u8...
-                        let ptr1 = align_ptr::<u8>(data);
-                        let slice = core::slice::from_raw_parts(ptr1, length as usize);
-                        writer.write_all(slice)?;
-                    },
-                    Tag::Int32 => {
-                        let ptr1 = align_ptr::<i32>(data);
-                        let slice = core::slice::from_raw_parts(ptr1 as *const u8, length as usize * 4);
-                        writer.write_all(slice)?;
-                    },
-                    Tag::Int64 | Tag::Float64 => {
-                        let ptr1 = align_ptr::<i64>(data);
-                        let slice = core::slice::from_raw_parts(ptr1 as *const u8, length as usize * 8);
-                        writer.write_all(slice)?;
-                    },
-                    // non-primitive types, not sure if this would happen but we can handle it...
-                    _ => {
-                        for _ in 0..length {
-                            send_value(writer, tag, &mut data)?;
-                        }
-                    }
-                };
-                Ok(())
             })
         }
         Tag::Array(it, num_dims) => {
@@ -298,33 +311,8 @@ unsafe fn send_value<W>(writer: &mut W, tag: Tag, data: &mut *const ())
                         total_len *= *len;
                     })
                 }
-                let mut data = *buffer;
+                let length = total_len as usize;
-                let length = total_len as isize;
+                send_elements(writer, elt_tag, length, *buffer)
-                writer.write_u8(elt_tag.as_u8())?;
-                match elt_tag {
-                    Tag::Bool => {
-                        let ptr1 = align_ptr::<u8>(data);
-                        let slice = core::slice::from_raw_parts(ptr1, length as usize);
-                        writer.write_all(slice)?;
-                    },
-                    Tag::Int32 => {
-                        let ptr1 = align_ptr::<i32>(data);
-                        let slice = core::slice::from_raw_parts(ptr1 as *const u8, length as usize * 4);
-                        writer.write_all(slice)?;
-                    },
-                    Tag::Int64 | Tag::Float64 => {
-                        let ptr1 = align_ptr::<i64>(data);
-                        let slice = core::slice::from_raw_parts(ptr1 as *const u8, length as usize * 8);
-                        writer.write_all(slice)?;
-                    },
-                    // non-primitive types, not sure if this would happen but we can handle it...
-                    _ => {
-                        for _ in 0..length {
-                            send_value(writer, elt_tag, &mut data)?;
-                        }
-                    }
-                };
-                Ok(())
             })
         }
         Tag::Range(it) => {
@@ -448,18 +436,15 @@ mod tag {
                     let it = it.clone();
                     it.take(3).map(|t| t.alignment()).max().unwrap()
                 }
-                // CSlice basically
+                // the ptr/length(s) pair is basically CSlice
-                Tag::Bytes | Tag::String | Tag::ByteArray =>
+                Tag::Bytes | Tag::String | Tag::ByteArray | Tag::List(_) | Tag::Array(_, _) =>
                     core::mem::align_of::<CSlice<()>>(),
-                // array buffer is allocated, so no need for alignment first
+                Tag::Keyword(_) => unreachable!("Tag::Keyword should not appear in composite types"),
-                Tag::List(_) | Tag::Array(_, _) => 1,
+                Tag::Object => core::mem::align_of::<u32>(),
-                // will not be sent from the host
-                _ => unreachable!("unexpected tag from host")
             }
         }
 
         pub fn size(self) -> usize {
-            use super::alignment_offset;
             match self {
                 Tag::None => 0,
                 Tag::Bool => 1,
@@ -471,13 +456,18 @@ mod tag {
                 Tag::ByteArray => 8,
                 Tag::Tuple(it, arity) => {
                     let mut size = 0;
+                    let mut max_alignment = 0;
                     let mut it = it.clone();
                     for _ in 0..arity {
                         let tag = it.next().expect("truncated tag");
+                        let alignment = tag.alignment();
+                        max_alignment = core::cmp::max(max_alignment, alignment);
+                        size = super::round_up(size, alignment);
                         size += tag.size();
-                        // includes padding
-                        size += alignment_offset(tag.alignment() as isize, size as isize) as usize;
                     }
+                    // Take into account any tail padding (if element(s) with largest
+                    // alignment are not at the end).
+                    size = super::round_up(size, max_alignment);
                     size
                 }
                 Tag::List(_) => 4,

src/satman/src/main.rs

@@ -22,6 +22,8 @@ use libboard_zynq::{i2c::I2c, timer::GlobalTimer, time::Milliseconds, print, pri
 use libsupport_zynq::ram;
 #[cfg(has_si5324)]
 use libboard_artiq::si5324;
+#[cfg(feature = "target_kasli_soc")]
+use libboard_artiq::io_expander;
 use libboard_artiq::{pl::csr, drtio_routing, drtioaux, logger, identifier_read, init_gateware};
 use libcortex_a9::{spin_lock_yield, interrupt_handler, regs::{MPIDR, SP}, notify_spin_lock, asm, l2c::enable_l2_cache};
 use libregister::{RegisterW, RegisterR};
@@ -468,6 +470,19 @@ pub extern fn main_core0() -> i32 {
 
     let mut i2c = I2c::i2c0();
     i2c.init().expect("I2C initialization failed");
+    #[cfg(feature = "target_kasli_soc")]
+    {
+        for expander_i in 0..=1 {
+            let mut io_expander = io_expander::IoExpander::new(&mut i2c, expander_i).unwrap();
+            io_expander.init().expect("I2C I/O expander #0 initialization failed");
+            // Actively drive TX_DISABLE to false on SFP0..3
+            io_expander.set_oe(0, 1 << 1).unwrap();
+            io_expander.set_oe(1, 1 << 1).unwrap();
+            io_expander.set(0, 1, false);
+            io_expander.set(1, 1, false);
+            io_expander.service().unwrap();
+        }
+    }
 
     #[cfg(has_si5324)]
     si5324::setup(&mut i2c, &SI5324_SETTINGS, si5324::Input::Ckin1, &mut timer).expect("cannot initialize Si5324");