From 65621a36decedba5b555e5435f1e32287ea641d3 Mon Sep 17 00:00:00 2001 From: Tim Hutt Date: Thu, 21 Dec 2023 15:17:22 +0000 Subject: [PATCH] Add support for HPM counters Implements High Performance Monitoring counters, but only by making the registers available. Their values only change if explicitly written to and all values are legal. All 32 HPM counters are always implemented (the spec says this "should" be the case), and a platform callback `sys_writable_hpm_counters` is added to allow making any of them read-only. I haven't hooked `sys_writable_hpm_counters` up to CLI flags because Codasip does not use the CLI flags and it is quite tedious, and hopefully going to change when riscv-config is used. Finally this adds `menvcfg` and `senvcfg` to the CSR name map which I forgot to do previously. --- c_emulator/riscv_platform.c | 5 + c_emulator/riscv_platform.h | 1 + c_emulator/riscv_platform_impl.c | 1 + c_emulator/riscv_platform_impl.h | 1 + model/prelude.sail | 15 ++- model/riscv_csr_map.sail | 153 ++++++++++++++++++++++++++++++- model/riscv_insts_zicsr.sail | 28 ++++++ model/riscv_sys_control.sail | 42 ++++++--- model/riscv_sys_regs.sail | 51 +++++++++-- ocaml_emulator/platform.ml | 2 + 10 files changed, 274 insertions(+), 25 deletions(-) diff --git a/c_emulator/riscv_platform.c b/c_emulator/riscv_platform.c index 253da353f..f4f35a09b 100644 --- a/c_emulator/riscv_platform.c +++ b/c_emulator/riscv_platform.c @@ -62,6 +62,11 @@ bool sys_enable_writable_misa(unit u) return rv_enable_writable_misa; } +mach_bits sys_writable_hpm_counters(unit u) +{ + return rv_writable_hpm_counters; +} + bool plat_enable_dirty_update(unit u) { return rv_enable_dirty_update; diff --git a/c_emulator/riscv_platform.h b/c_emulator/riscv_platform.h index 38fac2f07..aec32426f 100644 --- a/c_emulator/riscv_platform.h +++ b/c_emulator/riscv_platform.h @@ -8,6 +8,7 @@ bool sys_enable_zfinx(unit); bool sys_enable_writable_misa(unit); bool sys_enable_writable_fiom(unit); bool sys_enable_vext(unit); +mach_bits sys_writable_hpm_counters(unit u); uint64_t sys_pmp_count(unit); uint64_t sys_pmp_grain(unit); diff --git a/c_emulator/riscv_platform_impl.c b/c_emulator/riscv_platform_impl.c index c2ae256ef..e0b511e20 100644 --- a/c_emulator/riscv_platform_impl.c +++ b/c_emulator/riscv_platform_impl.c @@ -12,6 +12,7 @@ bool rv_enable_next = false; bool rv_enable_writable_misa = true; bool rv_enable_fdext = true; bool rv_enable_vext = true; +uint64_t rv_writable_hpm_counters = 0xFFFFFFFF; bool rv_enable_dirty_update = false; bool rv_enable_misaligned = false; diff --git a/c_emulator/riscv_platform_impl.h b/c_emulator/riscv_platform_impl.h index e3e4a9678..2d68a1ad6 100644 --- a/c_emulator/riscv_platform_impl.h +++ b/c_emulator/riscv_platform_impl.h @@ -16,6 +16,7 @@ extern bool rv_enable_rvc; extern bool rv_enable_next; extern bool rv_enable_fdext; extern bool rv_enable_vext; +extern uint64_t rv_writable_hpm_counters; extern bool rv_enable_writable_misa; extern bool rv_enable_dirty_update; extern bool rv_enable_misaligned; diff --git a/model/prelude.sail b/model/prelude.sail index 3edec051d..d3b414497 100644 --- a/model/prelude.sail +++ b/model/prelude.sail @@ -178,22 +178,31 @@ val to_bits : forall 'l, 'l >= 0.(atom('l), int) -> bits('l) function to_bits (l, n) = get_slice_int(l, n, 0) infix 4 <_s +infix 4 >_s +infix 4 <=_s infix 4 >=_s infix 4 <_u -infix 4 >=_u +infix 4 >_u infix 4 <=_u +infix 4 >=_u val operator <_s : forall 'n, 'n > 0. (bits('n), bits('n)) -> bool +val operator >_s : forall 'n, 'n > 0. (bits('n), bits('n)) -> bool +val operator <=_s : forall 'n, 'n > 0. (bits('n), bits('n)) -> bool val operator >=_s : forall 'n, 'n > 0. (bits('n), bits('n)) -> bool val operator <_u : forall 'n. (bits('n), bits('n)) -> bool -val operator >=_u : forall 'n. (bits('n), bits('n)) -> bool +val operator >_u : forall 'n. (bits('n), bits('n)) -> bool val operator <=_u : forall 'n. (bits('n), bits('n)) -> bool +val operator >=_u : forall 'n. (bits('n), bits('n)) -> bool function operator <_s (x, y) = signed(x) < signed(y) +function operator >_s (x, y) = signed(x) > signed(y) +function operator <=_s (x, y) = signed(x) <= signed(y) function operator >=_s (x, y) = signed(x) >= signed(y) function operator <_u (x, y) = unsigned(x) < unsigned(y) -function operator >=_u (x, y) = unsigned(x) >= unsigned(y) +function operator >_u (x, y) = unsigned(x) > unsigned(y) function operator <=_u (x, y) = unsigned(x) <= unsigned(y) +function operator >=_u (x, y) = unsigned(x) >= unsigned(y) infix 7 >> infix 7 << diff --git a/model/riscv_csr_map.sail b/model/riscv_csr_map.sail index dcc865117..71d630a27 100644 --- a/model/riscv_csr_map.sail +++ b/model/riscv_csr_map.sail @@ -94,10 +94,69 @@ mapping clause csr_name_map = 0x015 <-> "seed" mapping clause csr_name_map = 0xC00 <-> "cycle" mapping clause csr_name_map = 0xC01 <-> "time" mapping clause csr_name_map = 0xC02 <-> "instret" +mapping clause csr_name_map = 0xC03 <-> "hpmcounter3" +mapping clause csr_name_map = 0xC04 <-> "hpmcounter4" +mapping clause csr_name_map = 0xC05 <-> "hpmcounter5" +mapping clause csr_name_map = 0xC06 <-> "hpmcounter6" +mapping clause csr_name_map = 0xC07 <-> "hpmcounter7" +mapping clause csr_name_map = 0xC08 <-> "hpmcounter8" +mapping clause csr_name_map = 0xC09 <-> "hpmcounter9" +mapping clause csr_name_map = 0xC0A <-> "hpmcounter10" +mapping clause csr_name_map = 0xC0B <-> "hpmcounter11" +mapping clause csr_name_map = 0xC0C <-> "hpmcounter12" +mapping clause csr_name_map = 0xC0D <-> "hpmcounter13" +mapping clause csr_name_map = 0xC0E <-> "hpmcounter14" +mapping clause csr_name_map = 0xC0F <-> "hpmcounter15" +mapping clause csr_name_map = 0xC10 <-> "hpmcounter16" +mapping clause csr_name_map = 0xC11 <-> "hpmcounter17" +mapping clause csr_name_map = 0xC12 <-> "hpmcounter18" +mapping clause csr_name_map = 0xC13 <-> "hpmcounter19" +mapping clause csr_name_map = 0xC14 <-> "hpmcounter20" +mapping clause csr_name_map = 0xC15 <-> "hpmcounter21" +mapping clause csr_name_map = 0xC16 <-> "hpmcounter22" +mapping clause csr_name_map = 0xC17 <-> "hpmcounter23" +mapping clause csr_name_map = 0xC18 <-> "hpmcounter24" +mapping clause csr_name_map = 0xC19 <-> "hpmcounter25" +mapping clause csr_name_map = 0xC1A <-> "hpmcounter26" +mapping clause csr_name_map = 0xC1B <-> "hpmcounter27" +mapping clause csr_name_map = 0xC1C <-> "hpmcounter28" +mapping clause csr_name_map = 0xC1D <-> "hpmcounter29" +mapping clause csr_name_map = 0xC1E <-> "hpmcounter30" +mapping clause csr_name_map = 0xC1F <-> "hpmcounter31" + mapping clause csr_name_map = 0xC80 <-> "cycleh" mapping clause csr_name_map = 0xC81 <-> "timeh" mapping clause csr_name_map = 0xC82 <-> "instreth" -/* TODO: other hpm counters */ +mapping clause csr_name_map = 0xC83 <-> "hpmcounter3h" +mapping clause csr_name_map = 0xC84 <-> "hpmcounter4h" +mapping clause csr_name_map = 0xC85 <-> "hpmcounter5h" +mapping clause csr_name_map = 0xC86 <-> "hpmcounter6h" +mapping clause csr_name_map = 0xC87 <-> "hpmcounter7h" +mapping clause csr_name_map = 0xC88 <-> "hpmcounter8h" +mapping clause csr_name_map = 0xC89 <-> "hpmcounter9h" +mapping clause csr_name_map = 0xC8A <-> "hpmcounter10h" +mapping clause csr_name_map = 0xC8B <-> "hpmcounter11h" +mapping clause csr_name_map = 0xC8C <-> "hpmcounter12h" +mapping clause csr_name_map = 0xC8D <-> "hpmcounter13h" +mapping clause csr_name_map = 0xC8E <-> "hpmcounter14h" +mapping clause csr_name_map = 0xC8F <-> "hpmcounter15h" +mapping clause csr_name_map = 0xC90 <-> "hpmcounter16h" +mapping clause csr_name_map = 0xC91 <-> "hpmcounter17h" +mapping clause csr_name_map = 0xC92 <-> "hpmcounter18h" +mapping clause csr_name_map = 0xC93 <-> "hpmcounter19h" +mapping clause csr_name_map = 0xC94 <-> "hpmcounter20h" +mapping clause csr_name_map = 0xC95 <-> "hpmcounter21h" +mapping clause csr_name_map = 0xC96 <-> "hpmcounter22h" +mapping clause csr_name_map = 0xC97 <-> "hpmcounter23h" +mapping clause csr_name_map = 0xC98 <-> "hpmcounter24h" +mapping clause csr_name_map = 0xC99 <-> "hpmcounter25h" +mapping clause csr_name_map = 0xC9A <-> "hpmcounter26h" +mapping clause csr_name_map = 0xC9B <-> "hpmcounter27h" +mapping clause csr_name_map = 0xC9C <-> "hpmcounter28h" +mapping clause csr_name_map = 0xC9D <-> "hpmcounter29h" +mapping clause csr_name_map = 0xC9E <-> "hpmcounter30h" +mapping clause csr_name_map = 0xC9F <-> "hpmcounter31h" + /* supervisor trap setup */ mapping clause csr_name_map = 0x100 <-> "sstatus" mapping clause csr_name_map = 0x102 <-> "sedeleg" @@ -113,6 +172,8 @@ mapping clause csr_name_map = 0x143 <-> "stval" mapping clause csr_name_map = 0x144 <-> "sip" /* supervisor protection and translation */ mapping clause csr_name_map = 0x180 <-> "satp" +/* supervisor envcfg */ +mapping clause csr_name_map = 0x10A <-> "senvcfg" /* machine information registers */ mapping clause csr_name_map = 0xF11 <-> "mvendorid" mapping clause csr_name_map = 0xF12 <-> "marchid" @@ -127,6 +188,37 @@ mapping clause csr_name_map = 0x304 <-> "mie" mapping clause csr_name_map = 0x305 <-> "mtvec" mapping clause csr_name_map = 0x306 <-> "mcounteren" mapping clause csr_name_map = 0x320 <-> "mcountinhibit" +mapping clause csr_name_map = 0x323 <-> "mhpmevent3" +mapping clause csr_name_map = 0x324 <-> "mhpmevent4" +mapping clause csr_name_map = 0x325 <-> "mhpmevent5" +mapping clause csr_name_map = 0x326 <-> "mhpmevent6" +mapping clause csr_name_map = 0x327 <-> "mhpmevent7" +mapping clause csr_name_map = 0x328 <-> "mhpmevent8" +mapping clause csr_name_map = 0x329 <-> "mhpmevent9" +mapping clause csr_name_map = 0x32A <-> "mhpmevent10" +mapping clause csr_name_map = 0x32B <-> "mhpmevent11" +mapping clause csr_name_map = 0x32C <-> "mhpmevent12" +mapping clause csr_name_map = 0x32D <-> "mhpmevent13" +mapping clause csr_name_map = 0x32E <-> "mhpmevent14" +mapping clause csr_name_map = 0x32F <-> "mhpmevent15" +mapping clause csr_name_map = 0x330 <-> "mhpmevent16" +mapping clause csr_name_map = 0x331 <-> "mhpmevent17" +mapping clause csr_name_map = 0x332 <-> "mhpmevent18" +mapping clause csr_name_map = 0x333 <-> "mhpmevent19" +mapping clause csr_name_map = 0x334 <-> "mhpmevent20" +mapping clause csr_name_map = 0x335 <-> "mhpmevent21" +mapping clause csr_name_map = 0x336 <-> "mhpmevent22" +mapping clause csr_name_map = 0x337 <-> "mhpmevent23" +mapping clause csr_name_map = 0x338 <-> "mhpmevent24" +mapping clause csr_name_map = 0x339 <-> "mhpmevent25" +mapping clause csr_name_map = 0x33A <-> "mhpmevent26" +mapping clause csr_name_map = 0x33B <-> "mhpmevent27" +mapping clause csr_name_map = 0x33C <-> "mhpmevent28" +mapping clause csr_name_map = 0x33D <-> "mhpmevent29" +mapping clause csr_name_map = 0x33E <-> "mhpmevent30" +mapping clause csr_name_map = 0x33F <-> "mhpmevent31" +/* machine envcfg */ +mapping clause csr_name_map = 0x30A <-> "menvcfg" /* machine trap handling */ mapping clause csr_name_map = 0x340 <-> "mscratch" mapping clause csr_name_map = 0x341 <-> "mepc" @@ -217,9 +309,66 @@ mapping clause csr_name_map = 0x3EF <-> "pmpaddr63" /* machine counters/timers */ mapping clause csr_name_map = 0xB00 <-> "mcycle" mapping clause csr_name_map = 0xB02 <-> "minstret" +mapping clause csr_name_map = 0xB03 <-> "mhpmcounter3" +mapping clause csr_name_map = 0xB04 <-> "mhpmcounter4" +mapping clause csr_name_map = 0xB05 <-> "mhpmcounter5" +mapping clause csr_name_map = 0xB06 <-> "mhpmcounter6" +mapping clause csr_name_map = 0xB07 <-> "mhpmcounter7" +mapping clause csr_name_map = 0xB08 <-> "mhpmcounter8" +mapping clause csr_name_map = 0xB09 <-> "mhpmcounter9" +mapping clause csr_name_map = 0xB0A <-> "mhpmcounter10" +mapping clause csr_name_map = 0xB0B <-> "mhpmcounter11" +mapping clause csr_name_map = 0xB0C <-> "mhpmcounter12" +mapping clause csr_name_map = 0xB0D <-> "mhpmcounter13" +mapping clause csr_name_map = 0xB0E <-> "mhpmcounter14" +mapping clause csr_name_map = 0xB0F <-> "mhpmcounter15" +mapping clause csr_name_map = 0xB10 <-> "mhpmcounter16" +mapping clause csr_name_map = 0xB11 <-> "mhpmcounter17" +mapping clause csr_name_map = 0xB12 <-> "mhpmcounter18" +mapping clause csr_name_map = 0xB13 <-> "mhpmcounter19" +mapping clause csr_name_map = 0xB14 <-> "mhpmcounter20" +mapping clause csr_name_map = 0xB15 <-> "mhpmcounter21" +mapping clause csr_name_map = 0xB16 <-> "mhpmcounter22" +mapping clause csr_name_map = 0xB17 <-> "mhpmcounter23" +mapping clause csr_name_map = 0xB18 <-> "mhpmcounter24" +mapping clause csr_name_map = 0xB19 <-> "mhpmcounter25" +mapping clause csr_name_map = 0xB1A <-> "mhpmcounter26" +mapping clause csr_name_map = 0xB1B <-> "mhpmcounter27" +mapping clause csr_name_map = 0xB1C <-> "mhpmcounter28" +mapping clause csr_name_map = 0xB1D <-> "mhpmcounter29" +mapping clause csr_name_map = 0xB1E <-> "mhpmcounter30" +mapping clause csr_name_map = 0xB1F <-> "mhpmcounter31" mapping clause csr_name_map = 0xB80 <-> "mcycleh" mapping clause csr_name_map = 0xB82 <-> "minstreth" -/* TODO: other hpm counters and events */ +mapping clause csr_name_map = 0xB83 <-> "mhpmcounter3h" +mapping clause csr_name_map = 0xB84 <-> "mhpmcounter4h" +mapping clause csr_name_map = 0xB85 <-> "mhpmcounter5h" +mapping clause csr_name_map = 0xB86 <-> "mhpmcounter6h" +mapping clause csr_name_map = 0xB87 <-> "mhpmcounter7h" +mapping clause csr_name_map = 0xB88 <-> "mhpmcounter8h" +mapping clause csr_name_map = 0xB89 <-> "mhpmcounter9h" +mapping clause csr_name_map = 0xB8A <-> "mhpmcounter10h" +mapping clause csr_name_map = 0xB8B <-> "mhpmcounter11h" +mapping clause csr_name_map = 0xB8C <-> "mhpmcounter12h" +mapping clause csr_name_map = 0xB8D <-> "mhpmcounter13h" +mapping clause csr_name_map = 0xB8E <-> "mhpmcounter14h" +mapping clause csr_name_map = 0xB8F <-> "mhpmcounter15h" +mapping clause csr_name_map = 0xB90 <-> "mhpmcounter16h" +mapping clause csr_name_map = 0xB91 <-> "mhpmcounter17h" +mapping clause csr_name_map = 0xB92 <-> "mhpmcounter18h" +mapping clause csr_name_map = 0xB93 <-> "mhpmcounter19h" +mapping clause csr_name_map = 0xB94 <-> "mhpmcounter20h" +mapping clause csr_name_map = 0xB95 <-> "mhpmcounter21h" +mapping clause csr_name_map = 0xB96 <-> "mhpmcounter22h" +mapping clause csr_name_map = 0xB97 <-> "mhpmcounter23h" +mapping clause csr_name_map = 0xB98 <-> "mhpmcounter24h" +mapping clause csr_name_map = 0xB99 <-> "mhpmcounter25h" +mapping clause csr_name_map = 0xB9A <-> "mhpmcounter26h" +mapping clause csr_name_map = 0xB9B <-> "mhpmcounter27h" +mapping clause csr_name_map = 0xB9C <-> "mhpmcounter28h" +mapping clause csr_name_map = 0xB9D <-> "mhpmcounter29h" +mapping clause csr_name_map = 0xB9E <-> "mhpmcounter30h" +mapping clause csr_name_map = 0xB9F <-> "mhpmcounter31h" /* trigger/debug */ mapping clause csr_name_map = 0x7a0 <-> "tselect" mapping clause csr_name_map = 0x7a1 <-> "tdata1" diff --git a/model/riscv_insts_zicsr.sail b/model/riscv_insts_zicsr.sail index 6aa512ea2..9c5198de9 100644 --- a/model/riscv_insts_zicsr.sail +++ b/model/riscv_insts_zicsr.sail @@ -103,6 +103,9 @@ function readCSR csr : csreg -> xlenbits = { (0x31A, 32) => menvcfg.bits[63 .. 32], (0x320, _) => zero_extend(mcountinhibit.bits), + /* High Performance Monitoring event selection */ + (0b0011001 /* 0x320 */ @ index : bits(5), _) if index >_u 0b00010 => read_mhpmevent(hpmidx_from_bits(index)), + (0x340, _) => mscratch, (0x341, _) => get_xret_target(Machine) & pc_alignment_mask(), (0x342, _) => mcause.bits, @@ -123,6 +126,10 @@ function readCSR csr : csreg -> xlenbits = { (0xB80, 32) => mcycle[63 .. 32], (0xB82, 32) => minstret[63 .. 32], + /* High Performance Monitoring machine mode counters */ + (0b1011000 /* 0xB00 */ @ index : bits(5), _) if index >_u 0b00010 => read_mhpmcounter(hpmidx_from_bits(index)), + (0b1011100 /* 0xB80 */ @ index : bits(5), 32) if index >_u 0b00010 => read_mhpmcounterh(hpmidx_from_bits(index)), + /* vector */ (0x008, _) => zero_extend(vstart), (0x009, _) => zero_extend(vxsat), @@ -158,6 +165,10 @@ function readCSR csr : csreg -> xlenbits = { (0xC81, 32) => mtime[63 .. 32], (0xC82, 32) => minstret[63 .. 32], + /* High Performance Monitoring user mode counters */ + (0b1100000 /* 0xC00 */ @ index : bits(5), _) if index >_u 0b00010 => read_mhpmcounter(hpmidx_from_bits(index)), + (0b1100100 /* 0xC80 */ @ index : bits(5), 32) if index >_u 0b00010 => read_mhpmcounterh(hpmidx_from_bits(index)), + /* user mode: Zkr */ (0x015, _) => read_seed_csr(), @@ -213,6 +224,23 @@ function writeCSR (csr : csreg, value : xlenbits) -> unit = { (0xB80, 32) => { mcycle[63 .. 32] = value; Some(value) }, (0xB82, 32) => { minstret[63 .. 32] = value; minstret_increment = false; Some(value) }, + /* High Performance Monitoring machine mode counters */ + (0b0011001 /* 0x320 */ @ index : bits(5), _) if index >_u 0b00010 => { + let index = hpmidx_from_bits(index); + write_mhpmevent(index, value); + Some(read_mhpmevent(index)) + }, + (0b1011000 /* 0xB00 */ @ index : bits(5), _) if index >_u 0b00010 => { + let index = hpmidx_from_bits(index); + write_mhpmcounter(index, value); + Some(read_mhpmcounter(index)) + }, + (0b1011100 /* 0xB80 */ @ index : bits(5), 32) if index >_u 0b00010 => { + let index = hpmidx_from_bits(index); + write_mhpmcounterh(index, value); + Some(read_mhpmcounterh(index)) + }, + /* trigger/debug */ (0x7a0, _) => { tselect = value; Some(tselect) }, diff --git a/model/riscv_sys_control.sail b/model/riscv_sys_control.sail index 4dfe36539..5f3755f5b 100644 --- a/model/riscv_sys_control.sail +++ b/model/riscv_sys_control.sail @@ -110,12 +110,20 @@ function is_CSR_defined (csr : csreg, p : Privilege) -> bool = 0x3C @ idx : bits(4) => p == Machine & sys_pmp_count() > unsigned(0b01 @ idx), 0x3D @ idx : bits(4) => p == Machine & sys_pmp_count() > unsigned(0b10 @ idx), 0x3E @ idx : bits(4) => p == Machine & sys_pmp_count() > unsigned(0b11 @ idx), + + /* counters */ + 0b0011001 /* 0x320 */ @ index : bits(5) if index >_u 0b00010 => p == Machine, // mhpmevent3..31 + 0xB00 => p == Machine, // mcycle 0xB02 => p == Machine, // minstret + 0b1011000 /* 0xB00 */ @ index : bits(5) if index >_u 0b00010 => p == Machine, // mhpmcounter3..31 + 0xB80 => p == Machine & (sizeof(xlen) == 32), // mcycleh 0xB82 => p == Machine & (sizeof(xlen) == 32), // minstreth + 0b1011100 /* 0xB80 */ @ index : bits(5) if index >_u 0b00010 => p == Machine & (sizeof(xlen) == 32), // mhpmcounterh3..31 + /* disabled trigger/debug module */ 0x7a0 => p == Machine, @@ -143,10 +151,14 @@ function is_CSR_defined (csr : csreg, p : Privilege) -> bool = 0xC01 => haveUsrMode(), // time 0xC02 => haveUsrMode(), // instret + 0b1100000 /* 0xC00 */ @ index : bits(5) if index >_u 0b00010 => haveUsrMode(), // mhpmcounter3..31 + 0xC80 => haveUsrMode() & (sizeof(xlen) == 32), // cycleh 0xC81 => haveUsrMode() & (sizeof(xlen) == 32), // timeh 0xC82 => haveUsrMode() & (sizeof(xlen) == 32), // instreth + 0b1100100 /* 0xC80 */ @ index : bits(5) if index >_u 0b00010 => haveUsrMode() & (sizeof(xlen) == 32), // mhpmcounterh3..31 + /* user mode: Zkr */ 0x015 => haveZkr(), @@ -162,22 +174,24 @@ function check_CSR_access(csrrw, csrpr, p, isWrite) = function check_TVM_SATP(csr : csreg, p : Privilege) -> bool = not(csr == 0x180 & p == Supervisor & mstatus[TVM] == 0b1) -function check_Counteren(csr : csreg, p : Privilege) -> bool = - match(csr, p) { - (0xC00, Supervisor) => mcounteren[CY] == 0b1, - (0xC01, Supervisor) => mcounteren[TM] == 0b1, - (0xC02, Supervisor) => mcounteren[IR] == 0b1, +// There are several features that are controlled by machine/supervisor enable +// bits (m/senvcfg, m/scounteren, etc.). This abstracts that logic. +function mode_bit_enabled(p : Privilege, machine_bit : bit, supervisor_bit : bit) -> bool = match p { + Machine => true, + Supervisor => machine_bit == bitone, + User => machine_bit == bitone & (not(haveSupMode()) | supervisor_bit == bitone), +} - (0xC00, User) => mcounteren[CY] == 0b1 & (not(haveSupMode()) | scounteren[CY] == 0b1), - (0xC01, User) => mcounteren[TM] == 0b1 & (not(haveSupMode()) | scounteren[TM] == 0b1), - (0xC02, User) => mcounteren[IR] == 0b1 & (not(haveSupMode()) | scounteren[IR] == 0b1), - - (_, _) => /* no HPM counters for now */ - if 0xC03 <=_u csr & csr <=_u 0xC1F - then false - else true - } +// Return true if the counter is enabled OR the CSR is not a counter. +function check_Counteren(csr : csreg, p : Privilege) -> bool = { + // Check if it is not a counter. + if csr <_u 0xC00 | csr >_u 0xC1F + then return true; + // Check the relevant bit in m/scounteren. + let index = unsigned(csr[4 .. 0]); + mode_bit_enabled(p, mcounteren.bits()[index], scounteren.bits()[index]) +} /* Seed may only be accessed if we are doing a write, and access has been * allowed in the current priv mode diff --git a/model/riscv_sys_regs.sail b/model/riscv_sys_regs.sail index c98584bc0..406915301 100644 --- a/model/riscv_sys_regs.sail +++ b/model/riscv_sys_regs.sail @@ -160,6 +160,9 @@ val sys_pmp_count = {c: "sys_pmp_count", ocaml: "Platform.pmp_count", _: "sys_pm G=0 -> 4 bytes, G=10 -> 4096 bytes. */ val sys_pmp_grain = {c: "sys_pmp_grain", ocaml: "Platform.pmp_grain", _: "sys_pmp_grain"} : unit -> range(0, 63) +/* Which HPM counters are supported (as a bit mask). Bits [2 .. 0] are ignored. */ +val sys_writable_hpm_counters = {c: "sys_writable_hpm_counters", ocaml: "Platform.writable_hpm_counters", _: "sys_writable_hpm_counters"} : unit -> bits(32) + /* whether misa.v was enabled at boot */ val sys_enable_vext = {c: "sys_enable_vext", ocaml: "Platform.enable_vext", _: "sys_enable_vext"} : unit -> bool @@ -523,24 +526,26 @@ register mcounteren : Counteren register scounteren : Counteren function legalize_mcounteren(c : Counteren, v : xlenbits) -> Counteren = { - /* no HPM counters yet */ - [c with IR = [v[2]], TM = [v[1]], CY = [v[0]]] + let supported_counters = sys_writable_hpm_counters()[31 .. 3] @ 0b111; + Mk_Counteren(v[31 .. 0] & supported_counters) } function legalize_scounteren(c : Counteren, v : xlenbits) -> Counteren = { - /* no HPM counters yet */ - [c with IR = [v[2]], TM = [v[1]], CY = [v[0]]] + let supported_counters = sys_writable_hpm_counters()[31 .. 3] @ 0b111; + Mk_Counteren(v[31 .. 0] & supported_counters) } bitfield Counterin : bits(32) = { - /* no HPM counters yet */ + HPM : 31 .. 3, IR : 2, CY : 0 } register mcountinhibit : Counterin function legalize_mcountinhibit(c : Counterin, v : xlenbits) -> Counterin = { - [c with IR = [v[2]], CY = [v[0]]] + // Note the 0 in 0b101 is because the mtimer counter can't be paused. + let supported_counters = sys_writable_hpm_counters()[31 .. 3] @ 0b101; + Mk_Counterin(v[31 .. 0] & supported_counters) } register mcycle : bits(64) @@ -566,6 +571,40 @@ function retire_instruction() -> unit = { if minstret_increment then minstret = minstret + 1; } +// HPM (High Performance Monitoring) counters. The lowest three values are +// not used but they are defined for simplicity. +register mhpmcounter : vector(32, dec, bits(64)) + +// HPM events selector. These control what the HPM counters measure. The lowest +// three values are not used but they are defined for simplicity. +register mhpmevent : vector(32, dec, xlenbits) + +// Valid HPM counter indices. The lowest three are used for mcycle, mtime and minstret. +type hpmidx = range(3, 31) + +// Convert the lowest 5 bits of a CSR index to an hpmidx. Asserts if it is 0..2. +function hpmidx_from_bits(b : bits(5)) -> hpmidx = { + let index = unsigned(b); + if index >= 3 then index else { + assert(false, "unreachable HPM index"); + undefined + } +} + +function read_mhpmcounter(index : hpmidx) -> xlenbits = mhpmcounter[index][(sizeof(xlen) - 1) .. 0] +function read_mhpmcounterh(index : hpmidx) -> bits(32) = mhpmcounter[index][63 .. 32] +function read_mhpmevent(index : hpmidx) -> xlenbits = mhpmevent[index] + +// Write the HPM CSRs. These return the new value of the CSR, for use in writeCSR. +function write_mhpmcounter(index : hpmidx, value : xlenbits) -> unit = + if sys_writable_hpm_counters()[index] == bitone then mhpmcounter[index][(sizeof(xlen) - 1) .. 0] = value + +function write_mhpmcounterh(index : hpmidx, value : bits(32)) -> unit = + if sys_writable_hpm_counters()[index] == bitone then mhpmcounter[index][63 .. 32] = value + +function write_mhpmevent(index : hpmidx, value : xlenbits) -> unit = + if sys_writable_hpm_counters()[index] == bitone then mhpmevent[index] = value + /* informational registers */ register mvendorid : bits(32) register mimpid : xlenbits diff --git a/ocaml_emulator/platform.ml b/ocaml_emulator/platform.ml index a8bde44d6..b804e71d6 100644 --- a/ocaml_emulator/platform.ml +++ b/ocaml_emulator/platform.ml @@ -17,6 +17,7 @@ let config_pmp_grain = ref Big_int.zero let set_config_pmp_count x = config_pmp_count := Big_int.of_int x let set_config_pmp_grain x = config_pmp_grain := Big_int.of_int x +let config_writable_hpm_counters = ref 0xFFFFFFFF let platform_arch = ref P.RV64 @@ -85,6 +86,7 @@ let enable_rvc () = !config_enable_rvc let enable_next () = !config_enable_next let enable_fdext () = false let enable_vext () = !config_enable_vext +let writable_hpm_counters () = !config_writable_hpm_counters let enable_dirty_update () = !config_enable_dirty_update let enable_misaligned_access () = !config_enable_misaligned_access let mtval_has_illegal_inst_bits () = !config_mtval_has_illegal_inst_bits