Atomic extension

.gitignore

@@ -6,3 +6,10 @@ out
 .classpath
 .project
 examples/riscv
+
+# RARS build
+build/
+rars.jar
+
+# macOS
+.DS_Store

examples/atomic_increment.s

@@ -0,0 +1,15 @@
+.globl main
+.data
+num:
+    .word 0x12345678
+
+.text
+main:
+    la      t0, num
+retry:
+    lr.w    t1, (t0)
+    # increment by 1
+    addi    t1, t1, 1
+    sc.w    t2, t1, (t0)
+    # if save fails; retry operations again
+    bne     zero, t2, retry

src/rars/Globals.java

@@ -2,6 +2,7 @@
 
 import rars.assembler.SymbolTable;
 import rars.riscv.hardware.Memory;
+import rars.riscv.hardware.ReservationTables;
 import rars.riscv.InstructionSet;
 import rars.riscv.SyscallNumberOverride;
 import rars.util.PropertiesFile;
@@ -68,6 +69,10 @@ public class Globals {
      * Simulated memory component.
      **/
     public static Memory memory;
+    /**
+     * Simulated reservation tables component.
+     **/
+    public static ReservationTables reservationTables;
     /**
      * Lock variable used at head of synchronized block to guard memory and registers
      **/
@@ -140,6 +145,11 @@ public class Globals {
 
     public static boolean runSpeedPanelExists = false;
 
+    private static int harts = 1;
+
+    public static int getHarts() {
+        return harts;
+    }
     private static String getCopyrightYears() {
         return "2003-2019";
     }
@@ -166,7 +176,8 @@ public static Settings getSettings() {
 
     public static void initialize(boolean gui) {
         if (!initialized) {
-            memory = Memory.getInstance();  //clients can use Memory.getInstance instead of Globals.memory
+            memory = Memory.getInstance(); //clients can use Memory.getInstance instead of Globals.memory
+            reservationTables = new ReservationTables(harts);
             symbolTable = new SymbolTable("global");
             settings = new Settings(gui);
             instructionSet = new InstructionSet();

src/rars/api/Program.java

@@ -130,6 +130,7 @@ private ErrorList assemble(ArrayList<RISCVprogram> programs) throws AssemblyExce
      */
     public void setup(ArrayList<String> args, String STDIN){
         RegisterFile.resetRegisters();
+        Globals.reservationTables.reset();
         FloatingPointRegisterFile.resetRegisters();
         ControlAndStatusRegisterFile.resetRegisters();
         InterruptController.reset();

src/rars/riscv/BasicInstructionFormat.java

@@ -41,5 +41,5 @@ public enum BasicInstructionFormat {
     S_FORMAT, // 2 src registers + small immediate
     B_FORMAT, // 2 src registers + small immediate shifted left
     U_FORMAT, // 1 dst register  + large immediate
-    J_FORMAT  // 1 dst register  + large immediate for jumping
+    J_FORMAT, // 1 dst register  + large immediate for jumping
 }

src/rars/riscv/hardware/ControlAndStatusRegisterFile.java

@@ -70,13 +70,15 @@ public class ControlAndStatusRegisterFile {
                 null, // cycleh
                 null, // timeh
                 null, // instreth
+                null, // mhartid
         };
         tmp[1] = new LinkedRegister("fflags", 0x001, tmp[3], 0x1F);
         tmp[2] = new LinkedRegister("frm", 0x002, tmp[3], 0xE0);
 
         tmp[14] = new LinkedRegister("cycleh", 0xC80,tmp[11], 0xFFFFFFFF_00000000L);
         tmp[15] = new LinkedRegister("timeh", 0xC81, tmp[12],0xFFFFFFFF_00000000L);
-        tmp[16] = new LinkedRegister("instreth",0xC82, tmp[13],0xFFFFFFFF_00000000L);
+        tmp[16] = new LinkedRegister("instreth", 0xC82, tmp[13], 0xFFFFFFFF_00000000L);
+        tmp[17] = new ReadOnlyRegister("mhartid", 0xF10, 0);
         instance = new RegisterBlock('_', tmp); // prefix not used
     }
 

src/rars/riscv/hardware/ReservationTable.java

@@ -0,0 +1,108 @@
+package rars.riscv.hardware;
+
+import java.util.ArrayList;
+import java.util.function.Predicate;
+
+/*
+Copyright (c) 2021, Siva Chowdeswar Nandipati & Giancarlo Pernudi Segura.
+
+Permission is hereby granted, free of charge, to any person obtaining 
+a copy of this software and associated documentation files (the 
+"Software"), to deal in the Software without restriction, including 
+without limitation the rights to use, copy, modify, merge, publish, 
+distribute, sublicense, and/or sell copies of the Software, and to 
+permit persons to whom the Software is furnished to do so, subject 
+to the following conditions:
+
+The above copyright notice and this permission notice shall be 
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 
+ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 
+CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+(MIT license, http://www.opensource.org/licenses/mit-license.html)
+ */
+
+public class ReservationTable {
+	private ArrayList<ReservationTableEntry> table;
+	public final static int capacity = 8;
+	private final static int doubleAlignMask = ~0x7;
+
+	public enum bitWidth {
+		word,
+		doubleWord
+	}
+
+	protected class ReservationTableEntry {
+		protected Integer address;
+		protected bitWidth width;
+
+		public ReservationTableEntry(Integer address, bitWidth width) {
+			this.address = address;
+			this.width = width;
+		}
+
+		public boolean equals(Object o) {
+			ReservationTableEntry other = (ReservationTableEntry) o;
+			return address.equals(other.address) && width.equals(other.width);
+		}
+	}
+
+	public ReservationTable() {
+		table = new ArrayList<ReservationTableEntry>();
+	}
+
+	public void reserveAddress(int address, bitWidth width) {
+		ReservationTableEntry newEntry = new ReservationTableEntry(address, width);
+		if(table.contains(newEntry))
+			return;
+		if (table.size() == capacity)
+			table.remove(0);
+		table.add(newEntry);
+	}
+
+	public void unreserveAddress(int address, bitWidth width) {
+		Predicate<ReservationTableEntry> filter = entry ->
+				(entry.address == address && entry.width == width)
+				|| ((address & doubleAlignMask) == entry.address && entry.width == bitWidth.doubleWord);
+		table.removeIf(filter);
+	}
+
+	public boolean contains(int address, bitWidth width) {
+		for (ReservationTableEntry entry : table) {
+			if ((entry.address == address && entry.width == width)
+					|| ((address & doubleAlignMask) == entry.address && entry.width == bitWidth.doubleWord))
+				return true;
+		}
+		return false;
+	}
+
+	public Integer[] getAddresses() {
+		Integer[] addresses = new Integer[capacity];
+		for (int i = 0; i < capacity; i++) {
+			try {
+				addresses[i] = this.table.get(i).address;
+			} catch (IndexOutOfBoundsException e) {
+				addresses[i] = 0;
+			}
+		}
+		return addresses;
+	}
+
+	public bitWidth[] getWidths() {
+		bitWidth[] addresses = new bitWidth[capacity];
+		for (int i = 0; i < capacity; i++) {
+			try {
+				addresses[i] = this.table.get(i).width;
+			} catch (IndexOutOfBoundsException e) {
+				addresses[i] = null;
+			}
+		}
+		return addresses;
+	}
+}

src/rars/riscv/hardware/ReservationTables.java

@@ -0,0 +1,129 @@
+package rars.riscv.hardware;
+
+import java.util.Collection;
+import java.util.Observable;
+import java.util.Observer;
+import java.util.Vector;
+
+import rars.SimulationException;
+import rars.riscv.hardware.ReservationTable.bitWidth;
+
+/*
+Copyright (c) 2021, Siva Chowdeswar Nandipati & Giancarlo Pernudi Segura.
+
+Permission is hereby granted, free of charge, to any person obtaining 
+a copy of this software and associated documentation files (the 
+"Software"), to deal in the Software without restriction, including 
+without limitation the rights to use, copy, modify, merge, publish, 
+distribute, sublicense, and/or sell copies of the Software, and to 
+permit persons to whom the Software is furnished to do so, subject 
+to the following conditions:
+
+The above copyright notice and this permission notice shall be 
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 
+ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 
+CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+(MIT license, http://www.opensource.org/licenses/mit-license.html)
+ */
+
+public class ReservationTables extends Observable {
+	private ReservationTable[] reservationTables;
+	public int harts;
+	private Collection<ReservationTablesObservable> observables = new Vector<>();
+
+	public ReservationTables(int harts) {
+		this.harts = harts;
+		reset();
+	}
+
+	public void reset() {
+		reservationTables = new ReservationTable[harts];
+		for (int i = 0; i < reservationTables.length; i++) {
+			reservationTables[i] = new ReservationTable();
+		}
+	}
+
+	public void reserveAddress(int hart, int address, bitWidth width) throws AddressErrorException {
+		int modulo = width == bitWidth.doubleWord ? 8 : 4;
+		if (address % modulo != 0) {
+			throw new AddressErrorException("Reservation address not aligned to word boundary ", SimulationException.LOAD_ADDRESS_MISALIGNED, address);
+		}
+		reservationTables[hart].reserveAddress(address, width);
+	}
+
+	public boolean unreserveAddress(int hart, int address, bitWidth width) throws AddressErrorException {
+		int modulo = width == bitWidth.doubleWord ? 8 : 4;
+		if (address % modulo != 0) {
+			throw new AddressErrorException("Reservation address not aligned to word boundary ", SimulationException.STORE_ADDRESS_MISALIGNED, address);
+		}
+		if (reservationTables[hart].contains(address, width)) {
+			for (ReservationTable reservationTable : reservationTables) {
+				reservationTable.unreserveAddress(address, width);
+			}
+			return true;
+		}
+		return false;
+	}
+
+	public String[][] getAllAddressesAsStrings() {
+		String[][] all = new String[ReservationTable.capacity][harts * 2];
+		char width = '0';
+		for (int i = 0; i < ReservationTable.capacity; i++) {
+			for (int j = 0; j < harts; j++) {
+				Integer[] addresses = reservationTables[j].getAddresses();
+				ReservationTable.bitWidth[] widths = reservationTables[j].getWidths();
+				if (widths[i] == ReservationTable.bitWidth.word) {
+					width = 'w';
+				} else if (widths[i] == ReservationTable.bitWidth.doubleWord) {
+					width = 'd';
+				} else {
+					width = ' ';
+				}
+				all[i][j * 2] = String.format("0x%08x", addresses[i]);
+				all[i][j * 2 + 1] = String.format("%c", width);
+			}
+		}
+		return all;
+	}
+
+	public void addObserver(Observer obs) {
+		observables.add(new ReservationTablesObservable(obs));
+	}
+
+	/**
+	 * Remove specified reservation tables observer
+	 *
+	 * @param obs Observer to be removed
+	 */
+	public void deleteObserver(Observer obs) {
+		for (ReservationTablesObservable o : observables) {
+			o.deleteObserver(obs);
+		}
+	}
+
+	/**
+	 * Remove all reservation tables observers
+	 */
+	public void deleteObservers() {
+		// just drop the collection
+		observables = new Vector<>();
+	}
+
+	private class ReservationTablesObservable extends Observable {
+		public ReservationTablesObservable(Observer obs) {
+			this.addObserver(obs);
+		}
+
+		public void notifyObserver(MemoryAccessNotice notice) {
+			this.setChanged();
+			this.notifyObservers(notice);
+		}
+	}
+}

src/rars/riscv/instructions/AMOADDD.java

@@ -0,0 +1,39 @@
+package rars.riscv.instructions;
+
+/*
+Copyright (c) 2021, Giancarlo Pernudi Segura
+
+Developed by Giancarlo Pernudi Segura at the University of Alberta ([email protected])
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject
+to the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
+ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+(MIT license, http://www.opensource.org/licenses/mit-license.html)
+ */
+
+public class AMOADDD extends AtomicMemoryOperation {
+    public AMOADDD() {
+        super("amoadd.d t0, t1, (t2)", "Loads value at t2 and places it into t0, adds value t1 and t0 (new), and saves at memory location t2.", "00000", true);
+    }
+
+    @Override
+    protected long binaryOperation(long value1, long value2) {
+        return value1 + value2;
+    }
+}