Add Zaamo instructions.

arch/ext/I.yaml

@@ -109,10 +109,47 @@ I:
         maximum: 127
     MISALIGNED_LDST:
       description: |
-        Whether or not the implementation supports misaligned loads and stores in
+        Whether or not the implementation supports non-atomic misaligned loads and stores in
         main memory (does *not* affect misaligned support to device memory)
       schema:
         type: boolean
+    MISALIGNED_LDST_EXCEPTION_PRIORITY:
+      description: |
+        The relative priority of a load/store/AMO exception vs. load/store/AMO page-fault
+        or access-fault exceptions.
+
+        May be one of:
+
+        [separator="!"]
+        !===
+        ! high ! Misaligned load/store/AMO exceptions are always higher priority than load/store/AMO page-fault and access-fault exceptions.
+        ! low  ! Misaligned load/store/AMO exceptions are always lower priority than load/store/AMO page-fault and access-fault exceptions.
+        !===
+
+        MISALIGNED_LDST_EXCEPTION_PRIORITY cannot be "high" when MAX_MISALIGNED_ATOMICITY_GRANULE_SIZE
+        is non-zero, since the atomicity of an access cannot be determined in that case until after
+        address translation.
+      schema:
+        type: string
+        enum: ["high", "low"]
+        extra_validation: |
+          assert (MISALIGNED_LDST_EXCEPTION_PRIORITY == "low") if MAX_MISALIGNED_ATOMICITY_GRANULE_SIZE.positive?
+    MAX_MISALIGNED_ATOMICITY_GRANULE_SIZE:
+      description: |
+        The maximum granule size, in bytes, that the hart can atomically perform a
+        misligned load/store/AMO without raising a Misaligned exception. When MAX_MISALIGNED_ATOMICITY_GRANULE_SIZE is 0, the hart
+        cannot atomically perform a misaligned load/store/AMO. When a power of two, the hart can
+        atomically load/store/AMO a misaligned access that is fully contained in a
+        MAX_MISALIGNED_ATOMICITY_GRANULE_SIZE-aligned region.
+
+        [NOTE]
+        Even if the hart is capable of performing a misligned load/store/AMO atomically,
+        a misaligned exception may still occur if the access does not have the appropriate
+        Misaligned Atomicity Granule PMA set.
+      schema:
+        type: integer
+        # can't be larger than a page, since there is no way to reconcile that with virtual memory
+        enum: [0, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096]
     MISALIGNED_SPLIT_STRATEGY:
       description: |
         when misaligned accesses are supported, this determines the *order* in the implementation appears

arch/inst/A/amoadd.d.yaml

@@ -0,0 +1,40 @@
+# yaml-language-server: $schema=../../../schemas/inst_schema.json
+
+amoadd.d:
+  long_name: Atomic fetch-and-add doubleword
+  description: |
+     Atomically:
+
+       * Load the doubleword at address _rs1_
+       * Write the loaded value into _rd_
+       * Add the value of register _rs2_ to the loaded value
+       * Write the sum to the address in _rs1_
+  definedBy: [A, Zaamo]
+  base: 64
+  assembly: xd, xs2, (xrs1)
+  encoding:
+    match: 00000------------011-----0101111
+    variables:
+    - name: aq
+      location: 26
+    - name: rl
+      location: 27
+    - name: rs2
+      location: 24-20
+    - name: rs1
+      location: 19-15
+    - name: rd
+      location: 11-7
+  access:
+    s: always
+    u: always
+    vs: always
+    vu: always
+  operation(): |
+    if (implemented?(ExtensionName::A) && (CSR[misa].A == 1'b0)) {
+      raise (ExceptionCode::IllegalInstruction, $encoding);
+    }
+
+    XReg virtual_address = X[rs1];
+
+    X[rd] = amo<64>(virtual_address, X[rs2], AmoOperation::Add, aq, rl);

arch/inst/A/amoadd.w.yaml

@@ -0,0 +1,39 @@
+# yaml-language-server: $schema=../../../schemas/inst_schema.json
+
+amoadd.w:
+  long_name: Atomic fetch-and-add word
+  description: |
+     Atomically:
+
+       * Load the word at address _rs1_
+       * Write the sign-extended value into _rd_
+       * Add the least-significant word of register _rs2_ to the loaded value
+       * Write the sum to the address in _rs1_
+  definedBy: [A, Zaamo]
+  assembly: xd, xs2, (xrs1)
+  encoding:
+    match: 00000------------010-----0101111
+    variables:
+    - name: aq
+      location: 26
+    - name: rl
+      location: 27
+    - name: rs2
+      location: 24-20
+    - name: rs1
+      location: 19-15
+    - name: rd
+      location: 11-7
+  access:
+    s: always
+    u: always
+    vs: always
+    vu: always
+  operation(): |
+    if (implemented?(ExtensionName::A) && (CSR[misa].A == 1'b0)) {
+      raise (ExceptionCode::IllegalInstruction, $encoding);
+    }
+
+    XReg virtual_address = X[rs1];
+
+    X[rd] = amo<32>(virtual_address, X[rs2][31:0], AmoOperation::Add, aq, rl);

arch/inst/A/amoand.d.yaml

@@ -0,0 +1,40 @@
+# yaml-language-server: $schema=../../../schemas/inst_schema.json
+
+amoand.d:
+  long_name: Atomic fetch-and-and doubleword
+  description: |
+     Atomically:
+
+       * Load the doubleword at address _rs1_
+       * Write the loaded value into _rd_
+       * AND the value of register _rs2_ to the loaded value
+       * Write the result to the address in _rs1_
+  definedBy: [A, Zaamo]
+  base: 64
+  assembly: xd, xs2, (xrs1)
+  encoding:
+    match: 01100------------011-----0101111
+    variables:
+    - name: aq
+      location: 26
+    - name: rl
+      location: 27
+    - name: rs2
+      location: 24-20
+    - name: rs1
+      location: 19-15
+    - name: rd
+      location: 11-7
+  access:
+    s: always
+    u: always
+    vs: always
+    vu: always
+  operation(): |
+    if (implemented?(ExtensionName::A) && (CSR[misa].A == 1'b0)) {
+      raise (ExceptionCode::IllegalInstruction, $encoding);
+    }
+
+    XReg virtual_address = X[rs1];
+
+    X[rd] = amo<64>(virtual_address, X[rs2], AmoOperation::And, aq, rl);

arch/inst/A/amoand.w.yaml

@@ -0,0 +1,39 @@
+# yaml-language-server: $schema=../../../schemas/inst_schema.json
+
+amoand.w:
+  long_name: Atomic fetch-and-and word
+  description: |
+     Atomically:
+
+       * Load the word at address _rs1_
+       * Write the sign-extended value into _rd_
+       * AND the least-significant word of register _rs2_ to the loaded value
+       * Write the result to the address in _rs1_
+  definedBy: [A, Zaamo]
+  assembly: xd, xs2, (xrs1)
+  encoding:
+    match: 01100------------010-----0101111
+    variables:
+    - name: aq
+      location: 26
+    - name: rl
+      location: 27
+    - name: rs2
+      location: 24-20
+    - name: rs1
+      location: 19-15
+    - name: rd
+      location: 11-7
+  access:
+    s: always
+    u: always
+    vs: always
+    vu: always
+  operation(): |
+    if (implemented?(ExtensionName::A) && (CSR[misa].A == 1'b0)) {
+      raise (ExceptionCode::IllegalInstruction, $encoding);
+    }
+
+    XReg virtual_address = X[rs1];
+
+    X[rd] = amo<32>(virtual_address, X[rs2][31:0], AmoOperation::And, aq, rl);

arch/inst/A/amomax.d.yaml

@@ -0,0 +1,40 @@
+# yaml-language-server: $schema=../../../schemas/inst_schema.json
+
+amomax.d:
+  long_name: Atomic MAX doubleword
+  description: |
+     Atomically:
+
+       * Load the doubleword at address _rs1_
+       * Write the loaded value into _rd_
+       * Signed compare the value of register _rs2_ to the loaded value, and select the maximum value
+       * Write the maximum to the address in _rs1_
+  definedBy: [A, Zaamo]
+  base: 64
+  assembly: xd, xs2, (xrs1)
+  encoding:
+    match: 10100------------011-----0101111
+    variables:
+    - name: aq
+      location: 26
+    - name: rl
+      location: 27
+    - name: rs2
+      location: 24-20
+    - name: rs1
+      location: 19-15
+    - name: rd
+      location: 11-7
+  access:
+    s: always
+    u: always
+    vs: always
+    vu: always
+  operation(): |
+    if (implemented?(ExtensionName::A) && (CSR[misa].A == 1'b0)) {
+      raise (ExceptionCode::IllegalInstruction, $encoding);
+    }
+
+    XReg virtual_address = X[rs1];
+
+    X[rd] = amo<64>(virtual_address, X[rs2], AmoOperation::Max, aq, rl);

arch/inst/A/amomax.w.yaml

@@ -0,0 +1,39 @@
+# yaml-language-server: $schema=../../../schemas/inst_schema.json
+
+amomax.w:
+  long_name: Atomic MAX word
+  description: |
+     Atomically:
+
+       * Load the word at address _rs1_
+       * Write the sign-extended value into _rd_
+       * Signed compare the least-significant word of register _rs2_ to the loaded value, and select the maximum value
+       * Write the maximum to the address in _rs1_
+  definedBy: [A, Zaamo]
+  assembly: xd, xs2, (xrs1)
+  encoding:
+    match: 10100------------010-----0101111
+    variables:
+    - name: aq
+      location: 26
+    - name: rl
+      location: 27
+    - name: rs2
+      location: 24-20
+    - name: rs1
+      location: 19-15
+    - name: rd
+      location: 11-7
+  access:
+    s: always
+    u: always
+    vs: always
+    vu: always
+  operation(): |
+    if (implemented?(ExtensionName::A) && (CSR[misa].A == 1'b0)) {
+      raise (ExceptionCode::IllegalInstruction, $encoding);
+    }
+
+    XReg virtual_address = X[rs1];
+
+    X[rd] = amo<32>(virtual_address, X[rs2][31:0], AmoOperation::Max, aq, rl);

arch/inst/A/amomaxu.d.yaml

@@ -0,0 +1,40 @@
+# yaml-language-server: $schema=../../../schemas/inst_schema.json
+
+amomaxu.d:
+  long_name: Atomic MAX unsigned doubleword
+  description: |
+     Atomically:
+
+       * Load the doubleword at address _rs1_
+       * Write the loaded value into _rd_
+       * Unsigned compare the value of register _rs2_ to the loaded value, and select the maximum value
+       * Write the maximum to the address in _rs1_
+  definedBy: [A, Zaamo]
+  base: 64
+  assembly: xd, xs2, (xrs1)
+  encoding:
+    match: 11100------------011-----0101111
+    variables:
+    - name: aq
+      location: 26
+    - name: rl
+      location: 27
+    - name: rs2
+      location: 24-20
+    - name: rs1
+      location: 19-15
+    - name: rd
+      location: 11-7
+  access:
+    s: always
+    u: always
+    vs: always
+    vu: always
+  operation(): |
+    if (implemented?(ExtensionName::A) && (CSR[misa].A == 1'b0)) {
+      raise (ExceptionCode::IllegalInstruction, $encoding);
+    }
+
+    XReg virtual_address = X[rs1];
+
+    X[rd] = amo<64>(virtual_address, X[rs2], AmoOperation::Maxu, aq, rl);

arch/inst/A/amomaxu.w.yaml

@@ -0,0 +1,39 @@
+# yaml-language-server: $schema=../../../schemas/inst_schema.json
+
+amomaxu.w:
+  long_name: Atomic MAX unsigned word
+  description: |
+     Atomically:
+
+       * Load the word at address _rs1_
+       * Write the sign-extended value into _rd_
+       * Unsigned compare the least-significant word of register _rs2_ to the loaded value, and select the maximum value
+       * Write the maximum to the address in _rs1_
+  definedBy: [A, Zaamo]
+  assembly: xd, xs2, (xrs1)
+  encoding:
+    match: 11100------------010-----0101111
+    variables:
+    - name: aq
+      location: 26
+    - name: rl
+      location: 27
+    - name: rs2
+      location: 24-20
+    - name: rs1
+      location: 19-15
+    - name: rd
+      location: 11-7
+  access:
+    s: always
+    u: always
+    vs: always
+    vu: always
+  operation(): |
+    if (implemented?(ExtensionName::A) && (CSR[misa].A == 1'b0)) {
+      raise (ExceptionCode::IllegalInstruction, $encoding);
+    }
+
+    XReg virtual_address = X[rs1];
+
+    X[rd] = amo<32>(virtual_address, X[rs2][31:0], AmoOperation::Maxu, aq, rl);