diff options
| -rw-r--r-- | model/riscv_insts_aext.sail | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/model/riscv_insts_aext.sail b/model/riscv_insts_aext.sail index 55727b8..7b40985 100644 --- a/model/riscv_insts_aext.sail +++ b/model/riscv_insts_aext.sail @@ -20,11 +20,24 @@ function lrsc_width_str(width : word_width) -> string = DOUBLE => ".d" } +/** + * RISC-V only appears to define LR / SC / AMOs for word and double, although + * there seem to be encodings reserved for other widths. + */ +function amo_width_valid(size : word_width) -> bool = { + match(size) { + WORD => true, + DOUBLE => sizeof(xlen) >= 64, + _ => false + } +} + /* ****************************************************************** */ union clause ast = LOADRES : (bool, bool, regidx, word_width, regidx) -mapping clause encdec = LOADRES(aq, rl, rs1, size, rd) if word_width_bytes(size) <= sizeof(xlen_bytes) - <-> 0b00010 @ bool_bits(aq) @ bool_bits(rl) @ 0b00000 @ rs1 @ 0b0 @ size_bits(size) @ rd @ 0b0101111 if word_width_bytes(size) <= sizeof(xlen_bytes) +mapping clause encdec = LOADRES(aq, rl, rs1, size, rd) if amo_width_valid(size) + <-> 0b00010 @ bool_bits(aq) @ bool_bits(rl) @ 0b00000 @ rs1 @ 0b0 @ size_bits(size) @ rd @ 0b0101111 if amo_width_valid(size) + /* We could set load-reservations on physical or virtual addresses. * For now we set them on virtual addresses, since it makes the @@ -85,8 +98,8 @@ mapping clause assembly = LOADRES(aq, rl, rs1, size, rd) /* ****************************************************************** */ union clause ast = STORECON : (bool, bool, regidx, regidx, word_width, regidx) -mapping clause encdec = STORECON(aq, rl, rs2, rs1, size, rd) if word_width_bytes(size) <= sizeof(xlen_bytes) - <-> 0b00011 @ bool_bits(aq) @ bool_bits(rl) @ rs2 @ rs1 @ 0b0 @ size_bits(size) @ rd @ 0b0101111 if word_width_bytes(size) <= sizeof(xlen_bytes) +mapping clause encdec = STORECON(aq, rl, rs2, rs1, size, rd) if amo_width_valid(size) + <-> 0b00011 @ bool_bits(aq) @ bool_bits(rl) @ rs2 @ rs1 @ 0b0 @ size_bits(size) @ rd @ 0b0101111 if amo_width_valid(size) /* NOTE: Currently, we only EA if address translation is successful. This may need revisiting. */ function clause execute (STORECON(aq, rl, rs2, rs1, width, rd)) = { @@ -179,8 +192,8 @@ mapping encdec_amoop : amoop <-> bits(5) = { AMOMAXU <-> 0b11100 } -mapping clause encdec = AMO(op, aq, rl, rs2, rs1, size, rd) if word_width_bytes(size) <= sizeof(xlen_bytes) - <-> encdec_amoop(op) @ bool_bits(aq) @ bool_bits(rl) @ rs2 @ rs1 @ 0b0 @ size_bits(size) @ rd @ 0b0101111 if word_width_bytes(size) <= sizeof(xlen_bytes) +mapping clause encdec = AMO(op, aq, rl, rs2, rs1, size, rd) if amo_width_valid(size) + <-> encdec_amoop(op) @ bool_bits(aq) @ bool_bits(rl) @ rs2 @ rs1 @ 0b0 @ size_bits(size) @ rd @ 0b0101111 if amo_width_valid(size) /* NOTE: Currently, we only EA if address translation is successful. This may need revisiting. */ |