From 3780e33732f88a88b444fa42d56c5938ecd33e21 Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Mon, 20 Jun 2022 16:15:57 -0700 Subject: [PATCH] target/riscv: Support mcycle/minstret write operation mcycle/minstret are actually WARL registers and can be written with any given value. With SBI PMU extension, it will be used to store a initial value provided from supervisor OS. The Qemu also need prohibit the counter increment if mcountinhibit is set. Support mcycle/minstret through generic counter infrastructure. Reviewed-by: Alistair Francis Signed-off-by: Atish Patra Signed-off-by: Atish Patra Message-Id: <20220620231603.2547260-8-atishp@rivosinc.com> Signed-off-by: Alistair Francis --- target/riscv/cpu.h | 23 ++++-- target/riscv/csr.c | 159 ++++++++++++++++++++++++++++----------- target/riscv/machine.c | 25 +++++- target/riscv/meson.build | 3 +- target/riscv/pmu.c | 32 ++++++++ target/riscv/pmu.h | 28 +++++++ 6 files changed, 215 insertions(+), 55 deletions(-) create mode 100644 target/riscv/pmu.c create mode 100644 target/riscv/pmu.h diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index 199d0d570b..5c7acc055a 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -117,7 +117,7 @@ typedef struct CPUArchState CPURISCVState; #endif #define RV_VLEN_MAX 1024 -#define RV_MAX_MHPMEVENTS 29 +#define RV_MAX_MHPMEVENTS 32 #define RV_MAX_MHPMCOUNTERS 32 FIELD(VTYPE, VLMUL, 0, 3) @@ -127,6 +127,18 @@ FIELD(VTYPE, VMA, 7, 1) FIELD(VTYPE, VEDIV, 8, 2) FIELD(VTYPE, RESERVED, 10, sizeof(target_ulong) * 8 - 11) +typedef struct PMUCTRState { + /* Current value of a counter */ + target_ulong mhpmcounter_val; + /* Current value of a counter in RV32*/ + target_ulong mhpmcounterh_val; + /* Snapshot values of counter */ + target_ulong mhpmcounter_prev; + /* Snapshort value of a counter in RV32 */ + target_ulong mhpmcounterh_prev; + bool started; +} PMUCTRState; + struct CPUArchState { target_ulong gpr[32]; target_ulong gprh[32]; /* 64 top bits of the 128-bit registers */ @@ -279,13 +291,10 @@ struct CPUArchState { target_ulong mcountinhibit; - /* PMU counter configured values */ - target_ulong mhpmcounter_val[RV_MAX_MHPMCOUNTERS]; + /* PMU counter state */ + PMUCTRState pmu_ctrs[RV_MAX_MHPMCOUNTERS]; - /* for RV32 */ - target_ulong mhpmcounterh_val[RV_MAX_MHPMCOUNTERS]; - - /* PMU event selector configured values */ + /* PMU event selector configured values. First three are unused*/ target_ulong mhpmevent_val[RV_MAX_MHPMEVENTS]; target_ulong sscratch; diff --git a/target/riscv/csr.c b/target/riscv/csr.c index b931a3970e..d65318dcc6 100644 --- a/target/riscv/csr.c +++ b/target/riscv/csr.c @@ -21,6 +21,7 @@ #include "qemu/log.h" #include "qemu/timer.h" #include "cpu.h" +#include "pmu.h" #include "qemu/main-loop.h" #include "exec/exec-all.h" #include "sysemu/cpu-timers.h" @@ -597,34 +598,28 @@ static int write_vcsr(CPURISCVState *env, int csrno, target_ulong val) } /* User Timers and Counters */ -static RISCVException read_instret(CPURISCVState *env, int csrno, - target_ulong *val) +static target_ulong get_ticks(bool shift) { -#if !defined(CONFIG_USER_ONLY) - if (icount_enabled()) { - *val = icount_get(); - } else { - *val = cpu_get_host_ticks(); - } -#else - *val = cpu_get_host_ticks(); -#endif - return RISCV_EXCP_NONE; -} + int64_t val; + target_ulong result; -static RISCVException read_instreth(CPURISCVState *env, int csrno, - target_ulong *val) -{ #if !defined(CONFIG_USER_ONLY) if (icount_enabled()) { - *val = icount_get() >> 32; + val = icount_get(); } else { - *val = cpu_get_host_ticks() >> 32; + val = cpu_get_host_ticks(); } #else - *val = cpu_get_host_ticks() >> 32; + val = cpu_get_host_ticks(); #endif - return RISCV_EXCP_NONE; + + if (shift) { + result = val >> 32; + } else { + result = val; + } + + return result; } #if defined(CONFIG_USER_ONLY) @@ -642,11 +637,23 @@ static RISCVException read_timeh(CPURISCVState *env, int csrno, return RISCV_EXCP_NONE; } +static int read_hpmcounter(CPURISCVState *env, int csrno, target_ulong *val) +{ + *val = get_ticks(false); + return RISCV_EXCP_NONE; +} + +static int read_hpmcounterh(CPURISCVState *env, int csrno, target_ulong *val) +{ + *val = get_ticks(true); + return RISCV_EXCP_NONE; +} + #else /* CONFIG_USER_ONLY */ static int read_mhpmevent(CPURISCVState *env, int csrno, target_ulong *val) { - int evt_index = csrno - CSR_MHPMEVENT3; + int evt_index = csrno - CSR_MCOUNTINHIBIT; *val = env->mhpmevent_val[evt_index]; @@ -655,7 +662,7 @@ static int read_mhpmevent(CPURISCVState *env, int csrno, target_ulong *val) static int write_mhpmevent(CPURISCVState *env, int csrno, target_ulong val) { - int evt_index = csrno - CSR_MHPMEVENT3; + int evt_index = csrno - CSR_MCOUNTINHIBIT; env->mhpmevent_val[evt_index] = val; @@ -664,55 +671,105 @@ static int write_mhpmevent(CPURISCVState *env, int csrno, target_ulong val) static int write_mhpmcounter(CPURISCVState *env, int csrno, target_ulong val) { - int ctr_index = csrno - CSR_MHPMCOUNTER3 + 3; + int ctr_idx = csrno - CSR_MCYCLE; + PMUCTRState *counter = &env->pmu_ctrs[ctr_idx]; - env->mhpmcounter_val[ctr_index] = val; + counter->mhpmcounter_val = val; + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || + riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { + counter->mhpmcounter_prev = get_ticks(false); + } else { + /* Other counters can keep incrementing from the given value */ + counter->mhpmcounter_prev = val; + } return RISCV_EXCP_NONE; } static int write_mhpmcounterh(CPURISCVState *env, int csrno, target_ulong val) { - int ctr_index = csrno - CSR_MHPMCOUNTER3H + 3; + int ctr_idx = csrno - CSR_MCYCLEH; + PMUCTRState *counter = &env->pmu_ctrs[ctr_idx]; - env->mhpmcounterh_val[ctr_index] = val; + counter->mhpmcounterh_val = val; + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || + riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { + counter->mhpmcounterh_prev = get_ticks(true); + } else { + counter->mhpmcounterh_prev = val; + } + + return RISCV_EXCP_NONE; +} + +static RISCVException riscv_pmu_read_ctr(CPURISCVState *env, target_ulong *val, + bool upper_half, uint32_t ctr_idx) +{ + PMUCTRState counter = env->pmu_ctrs[ctr_idx]; + target_ulong ctr_prev = upper_half ? counter.mhpmcounterh_prev : + counter.mhpmcounter_prev; + target_ulong ctr_val = upper_half ? counter.mhpmcounterh_val : + counter.mhpmcounter_val; + + if (get_field(env->mcountinhibit, BIT(ctr_idx))) { + /** + * Counter should not increment if inhibit bit is set. We can't really + * stop the icount counting. Just return the counter value written by + * the supervisor to indicate that counter was not incremented. + */ + if (!counter.started) { + *val = ctr_val; + return RISCV_EXCP_NONE; + } else { + /* Mark that the counter has been stopped */ + counter.started = false; + } + } + + /** + * The kernel computes the perf delta by subtracting the current value from + * the value it initialized previously (ctr_val). + */ + if (riscv_pmu_ctr_monitor_cycles(env, ctr_idx) || + riscv_pmu_ctr_monitor_instructions(env, ctr_idx)) { + *val = get_ticks(upper_half) - ctr_prev + ctr_val; + } else { + *val = ctr_val; + } return RISCV_EXCP_NONE; } static int read_hpmcounter(CPURISCVState *env, int csrno, target_ulong *val) { - int ctr_index; + uint16_t ctr_index; if (csrno >= CSR_MCYCLE && csrno <= CSR_MHPMCOUNTER31) { - ctr_index = csrno - CSR_MHPMCOUNTER3 + 3; + ctr_index = csrno - CSR_MCYCLE; } else if (csrno >= CSR_CYCLE && csrno <= CSR_HPMCOUNTER31) { - ctr_index = csrno - CSR_HPMCOUNTER3 + 3; + ctr_index = csrno - CSR_CYCLE; } else { return RISCV_EXCP_ILLEGAL_INST; } - *val = env->mhpmcounter_val[ctr_index]; - return RISCV_EXCP_NONE; + return riscv_pmu_read_ctr(env, val, false, ctr_index); } static int read_hpmcounterh(CPURISCVState *env, int csrno, target_ulong *val) { - int ctr_index; + uint16_t ctr_index; if (csrno >= CSR_MCYCLEH && csrno <= CSR_MHPMCOUNTER31H) { - ctr_index = csrno - CSR_MHPMCOUNTER3H + 3; + ctr_index = csrno - CSR_MCYCLEH; } else if (csrno >= CSR_CYCLEH && csrno <= CSR_HPMCOUNTER31H) { - ctr_index = csrno - CSR_HPMCOUNTER3H + 3; + ctr_index = csrno - CSR_CYCLEH; } else { return RISCV_EXCP_ILLEGAL_INST; } - *val = env->mhpmcounterh_val[ctr_index]; - return RISCV_EXCP_NONE; + return riscv_pmu_read_ctr(env, val, true, ctr_index); } - static RISCVException read_time(CPURISCVState *env, int csrno, target_ulong *val) { @@ -1567,11 +1624,23 @@ static RISCVException read_mcountinhibit(CPURISCVState *env, int csrno, static RISCVException write_mcountinhibit(CPURISCVState *env, int csrno, target_ulong val) { + int cidx; + PMUCTRState *counter; + if (env->priv_ver < PRIV_VERSION_1_11_0) { return RISCV_EXCP_ILLEGAL_INST; } env->mcountinhibit = val; + + /* Check if any other counter is also monitoring cycles/instructions */ + for (cidx = 0; cidx < RV_MAX_MHPMCOUNTERS; cidx++) { + if (!get_field(env->mcountinhibit, BIT(cidx))) { + counter = &env->pmu_ctrs[cidx]; + counter->started = true; + } + } + return RISCV_EXCP_NONE; } @@ -3533,10 +3602,10 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = { [CSR_VLENB] = { "vlenb", vs, read_vlenb, .min_priv_ver = PRIV_VERSION_1_12_0 }, /* User Timers and Counters */ - [CSR_CYCLE] = { "cycle", ctr, read_instret }, - [CSR_INSTRET] = { "instret", ctr, read_instret }, - [CSR_CYCLEH] = { "cycleh", ctr32, read_instreth }, - [CSR_INSTRETH] = { "instreth", ctr32, read_instreth }, + [CSR_CYCLE] = { "cycle", ctr, read_hpmcounter }, + [CSR_INSTRET] = { "instret", ctr, read_hpmcounter }, + [CSR_CYCLEH] = { "cycleh", ctr32, read_hpmcounterh }, + [CSR_INSTRETH] = { "instreth", ctr32, read_hpmcounterh }, /* * In privileged mode, the monitor will have to emulate TIME CSRs only if @@ -3550,10 +3619,10 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = { #if !defined(CONFIG_USER_ONLY) /* Machine Timers and Counters */ - [CSR_MCYCLE] = { "mcycle", any, read_instret }, - [CSR_MINSTRET] = { "minstret", any, read_instret }, - [CSR_MCYCLEH] = { "mcycleh", any32, read_instreth }, - [CSR_MINSTRETH] = { "minstreth", any32, read_instreth }, + [CSR_MCYCLE] = { "mcycle", any, read_hpmcounter, write_mhpmcounter}, + [CSR_MINSTRET] = { "minstret", any, read_hpmcounter, write_mhpmcounter}, + [CSR_MCYCLEH] = { "mcycleh", any32, read_hpmcounterh, write_mhpmcounterh}, + [CSR_MINSTRETH] = { "minstreth", any32, read_hpmcounterh, write_mhpmcounterh}, /* Machine Information Registers */ [CSR_MVENDORID] = { "mvendorid", any, read_mvendorid }, diff --git a/target/riscv/machine.c b/target/riscv/machine.c index 99193c85bb..dc182ca811 100644 --- a/target/riscv/machine.c +++ b/target/riscv/machine.c @@ -279,7 +279,28 @@ static const VMStateDescription vmstate_envcfg = { VMSTATE_UINT64(env.menvcfg, RISCVCPU), VMSTATE_UINTTL(env.senvcfg, RISCVCPU), VMSTATE_UINT64(env.henvcfg, RISCVCPU), + VMSTATE_END_OF_LIST() + } +}; +static bool pmu_needed(void *opaque) +{ + RISCVCPU *cpu = opaque; + + return cpu->cfg.pmu_num; +} + +static const VMStateDescription vmstate_pmu_ctr_state = { + .name = "cpu/pmu", + .version_id = 1, + .minimum_version_id = 1, + .needed = pmu_needed, + .fields = (VMStateField[]) { + VMSTATE_UINTTL(mhpmcounter_val, PMUCTRState), + VMSTATE_UINTTL(mhpmcounterh_val, PMUCTRState), + VMSTATE_UINTTL(mhpmcounter_prev, PMUCTRState), + VMSTATE_UINTTL(mhpmcounterh_prev, PMUCTRState), + VMSTATE_BOOL(started, PMUCTRState), VMSTATE_END_OF_LIST() } }; @@ -331,8 +352,8 @@ const VMStateDescription vmstate_riscv_cpu = { VMSTATE_UINTTL(env.scounteren, RISCVCPU), VMSTATE_UINTTL(env.mcounteren, RISCVCPU), VMSTATE_UINTTL(env.mcountinhibit, RISCVCPU), - VMSTATE_UINTTL_ARRAY(env.mhpmcounter_val, RISCVCPU, RV_MAX_MHPMCOUNTERS), - VMSTATE_UINTTL_ARRAY(env.mhpmcounterh_val, RISCVCPU, RV_MAX_MHPMCOUNTERS), + VMSTATE_STRUCT_ARRAY(env.pmu_ctrs, RISCVCPU, RV_MAX_MHPMCOUNTERS, 0, + vmstate_pmu_ctr_state, PMUCTRState), VMSTATE_UINTTL_ARRAY(env.mhpmevent_val, RISCVCPU, RV_MAX_MHPMEVENTS), VMSTATE_UINTTL(env.sscratch, RISCVCPU), VMSTATE_UINTTL(env.mscratch, RISCVCPU), diff --git a/target/riscv/meson.build b/target/riscv/meson.build index 096249f3a3..2c1975e72c 100644 --- a/target/riscv/meson.build +++ b/target/riscv/meson.build @@ -30,7 +30,8 @@ riscv_softmmu_ss.add(files( 'pmp.c', 'debug.c', 'monitor.c', - 'machine.c' + 'machine.c', + 'pmu.c' )) target_arch += {'riscv': riscv_ss} diff --git a/target/riscv/pmu.c b/target/riscv/pmu.c new file mode 100644 index 0000000000..000fe8da45 --- /dev/null +++ b/target/riscv/pmu.c @@ -0,0 +1,32 @@ +/* + * RISC-V PMU file. + * + * Copyright (c) 2021 Western Digital Corporation or its affiliates. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2 or later, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see . + */ + +#include "qemu/osdep.h" +#include "cpu.h" +#include "pmu.h" + +bool riscv_pmu_ctr_monitor_instructions(CPURISCVState *env, + uint32_t target_ctr) +{ + return (target_ctr == 0) ? true : false; +} + +bool riscv_pmu_ctr_monitor_cycles(CPURISCVState *env, uint32_t target_ctr) +{ + return (target_ctr == 2) ? true : false; +} diff --git a/target/riscv/pmu.h b/target/riscv/pmu.h new file mode 100644 index 0000000000..58a5bc3a40 --- /dev/null +++ b/target/riscv/pmu.h @@ -0,0 +1,28 @@ +/* + * RISC-V PMU header file. + * + * Copyright (c) 2021 Western Digital Corporation or its affiliates. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2 or later, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see . + */ + +#include "qemu/osdep.h" +#include "qemu/log.h" +#include "cpu.h" +#include "qemu/main-loop.h" +#include "exec/exec-all.h" + +bool riscv_pmu_ctr_monitor_instructions(CPURISCVState *env, + uint32_t target_ctr); +bool riscv_pmu_ctr_monitor_cycles(CPURISCVState *env, + uint32_t target_ctr);