| Message ID | 20220509212827.2057822-3-atishp@rivosinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Implement Sstc extension | expand |
On Tue, May 10, 2022 at 3:03 AM Atish Patra <atishp@rivosinc.com> wrote: > > stimecmp allows the supervisor mode to update stimecmp CSR directly > to program the next timer interrupt. This CSR is part of the Sstc > extension which was ratified recently. > > Signed-off-by: Atish Patra <atishp@rivosinc.com> > --- > target/riscv/cpu.c | 8 ++++ > target/riscv/cpu.h | 7 +++ > target/riscv/cpu_bits.h | 4 ++ > target/riscv/csr.c | 92 +++++++++++++++++++++++++++++++++++ > target/riscv/machine.c | 1 + > target/riscv/meson.build | 3 +- > target/riscv/time_helper.c | 98 ++++++++++++++++++++++++++++++++++++++ > target/riscv/time_helper.h | 30 ++++++++++++ > 8 files changed, 242 insertions(+), 1 deletion(-) > create mode 100644 target/riscv/time_helper.c > create mode 100644 target/riscv/time_helper.h > > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c > index 19f4e8294042..d58dd2f857a7 100644 > --- a/target/riscv/cpu.c > +++ b/target/riscv/cpu.c > @@ -23,6 +23,7 @@ > #include "qemu/log.h" > #include "cpu.h" > #include "internals.h" > +#include "time_helper.h" > #include "exec/exec-all.h" > #include "qapi/error.h" > #include "qemu/error-report.h" > @@ -779,7 +780,12 @@ static void riscv_cpu_init(Object *obj) > #ifndef CONFIG_USER_ONLY > qdev_init_gpio_in(DEVICE(cpu), riscv_cpu_set_irq, > IRQ_LOCAL_MAX + IRQ_LOCAL_GUEST_MAX); > + > + if (cpu->cfg.ext_sstc) { > + riscv_timer_init(cpu); > + } > #endif /* CONFIG_USER_ONLY */ > + > } > > static Property riscv_cpu_properties[] = { > @@ -806,6 +812,7 @@ static Property riscv_cpu_properties[] = { > DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true), > DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true), > DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true), > + DEFINE_PROP_BOOL("sstc", RISCVCPU, cfg.ext_sstc, true), > > DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec), > DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec), > @@ -965,6 +972,7 @@ static void riscv_isa_string_ext(RISCVCPU *cpu, char **isa_str, int max_str_len) > ISA_EDATA_ENTRY(zbs, ext_zbs), > ISA_EDATA_ENTRY(zve32f, ext_zve32f), > ISA_EDATA_ENTRY(zve64f, ext_zve64f), > + ISA_EDATA_ENTRY(sstc, ext_sstc), > ISA_EDATA_ENTRY(svinval, ext_svinval), > ISA_EDATA_ENTRY(svnapot, ext_svnapot), > ISA_EDATA_ENTRY(svpbmt, ext_svpbmt), > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h > index 1119d5201066..9a01e6d0f587 100644 > --- a/target/riscv/cpu.h > +++ b/target/riscv/cpu.h > @@ -276,6 +276,11 @@ struct CPUArchState { > uint64_t mfromhost; > uint64_t mtohost; > > + /* Sstc CSRs */ > + uint64_t stimecmp; > + /* For RV32 only */ > + uint8_t stimecmp_wr_done; > + > /* physical memory protection */ > pmp_table_t pmp_state; > target_ulong mseccfg; > @@ -329,6 +334,7 @@ struct CPUArchState { > float_status fp_status; > > /* Fields from here on are preserved across CPU reset. */ > + QEMUTimer *stimer; /* Internal timer for S-mode interrupt */ > > hwaddr kernel_addr; > hwaddr fdt_addr; > @@ -379,6 +385,7 @@ struct RISCVCPUConfig { > bool ext_counters; > bool ext_ifencei; > bool ext_icsr; > + bool ext_sstc; > bool ext_svinval; > bool ext_svnapot; > bool ext_svpbmt; > diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h > index 4e5b630f5965..29d0e4a1be01 100644 > --- a/target/riscv/cpu_bits.h > +++ b/target/riscv/cpu_bits.h > @@ -215,6 +215,10 @@ > #define CSR_STVAL 0x143 > #define CSR_SIP 0x144 > > +/* Sstc supervisor CSRs */ > +#define CSR_STIMECMP 0x14D > +#define CSR_STIMECMPH 0x15D > + > /* Supervisor Protection and Translation */ > #define CSR_SPTBR 0x180 > #define CSR_SATP 0x180 > diff --git a/target/riscv/csr.c b/target/riscv/csr.c > index 245f007e66e1..8952d1308008 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 "time_helper.h" > #include "qemu/main-loop.h" > #include "exec/exec-all.h" > #include "sysemu/cpu-timers.h" > @@ -537,6 +538,87 @@ static RISCVException read_timeh(CPURISCVState *env, int csrno, > return RISCV_EXCP_NONE; > } > > +static RISCVException sstc(CPURISCVState *env, int csrno) > +{ > + CPUState *cs = env_cpu(env); > + RISCVCPU *cpu = RISCV_CPU(cs); > + > + if (!cpu->cfg.ext_sstc || !env->rdtime_fn) { > + return RISCV_EXCP_ILLEGAL_INST; > + } > + > + if (env->priv == PRV_M) { > + return RISCV_EXCP_NONE; > + } > + > + if (env->priv != PRV_S) { > + return RISCV_EXCP_ILLEGAL_INST; > + } > + > + /* > + * No need of separate function for rv32 as menvcfg stores both menvcfg > + * menvcfgh for RV32. > + */ > + if (!(get_field(env->mcounteren, COUNTEREN_TM) && > + get_field(env->menvcfg, MENVCFG_STCE))) { > + return RISCV_EXCP_ILLEGAL_INST; > + } > + > + return RISCV_EXCP_NONE; > +} > + > +static RISCVException read_stimecmp(CPURISCVState *env, int csrno, > + target_ulong *val) > +{ > + *val = env->stimecmp; > + return RISCV_EXCP_NONE; > +} > + > +static RISCVException read_stimecmph(CPURISCVState *env, int csrno, > + target_ulong *val) > +{ > + *val = env->stimecmp >> 32; > + return RISCV_EXCP_NONE; > +} > + > +static RISCVException write_stimecmp(CPURISCVState *env, int csrno, > + target_ulong val) > +{ > + RISCVCPU *cpu = env_archcpu(env); > + > + if (riscv_cpu_mxl(env) == MXL_RV32) { > + env->stimecmp = deposit64(env->stimecmp, 0, 32, (uint64_t)val); > + env->stimecmp_wr_done |= 0x01; > + if (env->stimecmp_wr_done != 0x03) { > + return RISCV_EXCP_NONE; > + } else { > + env->stimecmp_wr_done = 0; > + } > + } else { > + env->stimecmp = val; > + } > + > + riscv_timer_write_timecmp(cpu, env->stimer, env->stimecmp, 0, MIP_STIP); > + > + return RISCV_EXCP_NONE; > +} > + > +static RISCVException write_stimecmph(CPURISCVState *env, int csrno, > + target_ulong val) > +{ > + RISCVCPU *cpu = env_archcpu(env); > + > + env->stimecmp = deposit64(env->stimecmp, 32, 32, (uint64_t)val); > + env->stimecmp_wr_done |= 0x02; > + if (env->stimecmp_wr_done != 0x03) { > + return RISCV_EXCP_NONE; > + } > + env->stimecmp_wr_done = 0; > + riscv_timer_write_timecmp(cpu, env->stimer, env->stimecmp, 0, MIP_STIP); > + > + return RISCV_EXCP_NONE; > +} > + > /* Machine constants */ > > #define M_MODE_INTERRUPTS ((uint64_t)(MIP_MSIP | MIP_MTIP | MIP_MEIP)) > @@ -1515,6 +1597,12 @@ static RISCVException rmw_mip64(CPURISCVState *env, int csrno, > new_val |= env->external_seip * MIP_SEIP; > } > > + if (cpu->cfg.ext_sstc && (env->priv == PRV_M) && > + get_field(env->menvcfg, MENVCFG_STCE)) { > + /* sstc extension forbids STIP & VSTIP to be writeable in mip */ > + mask = mask & ~(MIP_STIP | MIP_VSTIP); > + } > + > if (mask) { > old_mip = riscv_cpu_update_mip(cpu, mask, (new_val & mask)); > } else { > @@ -3341,6 +3429,10 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = { > [CSR_SCAUSE] = { "scause", smode, read_scause, write_scause }, > [CSR_STVAL] = { "stval", smode, read_stval, write_stval }, > [CSR_SIP] = { "sip", smode, NULL, NULL, rmw_sip }, > + [CSR_STIMECMP] = { "stimecmp", sstc, read_stimecmp, write_stimecmp, > + .min_priv_ver = PRIV_VERSION_1_12_0 }, > + [CSR_STIMECMPH] = { "stimecmph", sstc, read_stimecmph, write_stimecmph, > + .min_priv_ver = PRIV_VERSION_1_12_0 }, > > /* Supervisor Protection and Translation */ > [CSR_SATP] = { "satp", smode, read_satp, write_satp }, > diff --git a/target/riscv/machine.c b/target/riscv/machine.c > index 7d85de0b1d49..ee02bfc18916 100644 > --- a/target/riscv/machine.c > +++ b/target/riscv/machine.c > @@ -334,6 +334,7 @@ const VMStateDescription vmstate_riscv_cpu = { > VMSTATE_UINTTL(env.mscratch, RISCVCPU), > VMSTATE_UINT64(env.mfromhost, RISCVCPU), > VMSTATE_UINT64(env.mtohost, RISCVCPU), > + VMSTATE_UINT64(env.stimecmp, RISCVCPU), Please add stimecmp_wr_done to vmstate_riscv_cpu > > VMSTATE_END_OF_LIST() > }, > diff --git a/target/riscv/meson.build b/target/riscv/meson.build > index 2c20f3dd8e9c..1243d019148e 100644 > --- a/target/riscv/meson.build > +++ b/target/riscv/meson.build > @@ -29,7 +29,8 @@ riscv_softmmu_ss.add(files( > 'pmp.c', > 'debug.c', > 'monitor.c', > - 'machine.c' > + 'machine.c', > + 'time_helper.c' > )) > > target_arch += {'riscv': riscv_ss} > diff --git a/target/riscv/time_helper.c b/target/riscv/time_helper.c > new file mode 100644 > index 000000000000..f3fb5eac7b7b > --- /dev/null > +++ b/target/riscv/time_helper.c > @@ -0,0 +1,98 @@ > +/* > + * RISC-V timer helper implementation. > + * > + * Copyright (c) 2022 Rivos Inc. > + * > + * 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 <http://www.gnu.org/licenses/>. > + */ > + > +#include "qemu/osdep.h" > +#include "qemu/log.h" > +#include "cpu_bits.h" > +#include "time_helper.h" > +#include "hw/intc/riscv_aclint.h" > + > +static void riscv_stimer_cb(void *opaque) > +{ > + RISCVCPU *cpu = opaque; > + riscv_cpu_update_mip(cpu, MIP_STIP, BOOL_TO_MASK(1)); > +} > + > +/* > + * Called when timecmp is written to update the QEMU timer or immediately > + * trigger timer interrupt if mtimecmp <= current timer value. > + */ > +void riscv_timer_write_timecmp(RISCVCPU *cpu, QEMUTimer *timer, > + uint64_t timecmp, uint64_t delta, > + uint32_t timer_irq) > +{ > + uint64_t diff, ns_diff, next; > + CPURISCVState *env = &cpu->env; > + RISCVAclintMTimerState *mtimer = env->rdtime_fn_arg; > + uint32_t timebase_freq = mtimer->timebase_freq; > + uint64_t rtc_r = env->rdtime_fn(env->rdtime_fn_arg) + delta; > + > + if (timecmp <= rtc_r) { > + /* > + * If we're setting an stimecmp value in the "past", > + * immediately raise the timer interrupt > + */ > + riscv_cpu_update_mip(cpu, timer_irq, BOOL_TO_MASK(1)); > + return; > + } > + > + /* Clear the [V]STIP bit in mip */ > + riscv_cpu_update_mip(cpu, timer_irq, BOOL_TO_MASK(0)); > + > + /* otherwise, set up the future timer interrupt */ > + diff = timecmp - rtc_r; > + /* back to ns (note args switched in muldiv64) */ > + ns_diff = muldiv64(diff, NANOSECONDS_PER_SECOND, timebase_freq); > + > + /* > + * check if ns_diff overflowed and check if the addition would potentially > + * overflow > + */ > + if ((NANOSECONDS_PER_SECOND > timebase_freq && ns_diff < diff) || > + ns_diff > INT64_MAX) { > + next = INT64_MAX; > + } else { > + /* > + * as it is very unlikely qemu_clock_get_ns will return a value > + * greater than INT64_MAX, no additional check is needed for an > + * unsigned integer overflow. > + */ > + next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + ns_diff; > + /* > + * if ns_diff is INT64_MAX next may still be outside the range > + * of a signed integer. > + */ > + next = MIN(next, INT64_MAX); > + } > + > + timer_mod(timer, next); > +} > + > +void riscv_timer_init(RISCVCPU *cpu) > +{ > + CPURISCVState *env; > + > + if (!cpu) { > + return; > + } > + > + env = &cpu->env; > + env->stimer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &riscv_stimer_cb, cpu); > + env->stimecmp = 0; > + > +} > diff --git a/target/riscv/time_helper.h b/target/riscv/time_helper.h > new file mode 100644 > index 000000000000..7b3cdcc35020 > --- /dev/null > +++ b/target/riscv/time_helper.h > @@ -0,0 +1,30 @@ > +/* > + * RISC-V timer header file. > + * > + * Copyright (c) 2022 Rivos Inc. > + * > + * 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 <http://www.gnu.org/licenses/>. > + */ > + > +#ifndef RISCV_TIME_HELPER_H > +#define RISCV_TIME_HELPER_H > + > +#include "cpu.h" > +#include "qemu/timer.h" > + > +void riscv_timer_write_timecmp(RISCVCPU *cpu, QEMUTimer *timer, > + uint64_t timecmp, uint64_t delta, > + uint32_t timer_irq); > +void riscv_timer_init(RISCVCPU *cpu); > + > +#endif > -- > 2.25.1 > > Regards, Anup
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c index 19f4e8294042..d58dd2f857a7 100644 --- a/target/riscv/cpu.c +++ b/target/riscv/cpu.c @@ -23,6 +23,7 @@ #include "qemu/log.h" #include "cpu.h" #include "internals.h" +#include "time_helper.h" #include "exec/exec-all.h" #include "qapi/error.h" #include "qemu/error-report.h" @@ -779,7 +780,12 @@ static void riscv_cpu_init(Object *obj) #ifndef CONFIG_USER_ONLY qdev_init_gpio_in(DEVICE(cpu), riscv_cpu_set_irq, IRQ_LOCAL_MAX + IRQ_LOCAL_GUEST_MAX); + + if (cpu->cfg.ext_sstc) { + riscv_timer_init(cpu); + } #endif /* CONFIG_USER_ONLY */ + } static Property riscv_cpu_properties[] = { @@ -806,6 +812,7 @@ static Property riscv_cpu_properties[] = { DEFINE_PROP_BOOL("mmu", RISCVCPU, cfg.mmu, true), DEFINE_PROP_BOOL("pmp", RISCVCPU, cfg.pmp, true), DEFINE_PROP_BOOL("debug", RISCVCPU, cfg.debug, true), + DEFINE_PROP_BOOL("sstc", RISCVCPU, cfg.ext_sstc, true), DEFINE_PROP_STRING("priv_spec", RISCVCPU, cfg.priv_spec), DEFINE_PROP_STRING("vext_spec", RISCVCPU, cfg.vext_spec), @@ -965,6 +972,7 @@ static void riscv_isa_string_ext(RISCVCPU *cpu, char **isa_str, int max_str_len) ISA_EDATA_ENTRY(zbs, ext_zbs), ISA_EDATA_ENTRY(zve32f, ext_zve32f), ISA_EDATA_ENTRY(zve64f, ext_zve64f), + ISA_EDATA_ENTRY(sstc, ext_sstc), ISA_EDATA_ENTRY(svinval, ext_svinval), ISA_EDATA_ENTRY(svnapot, ext_svnapot), ISA_EDATA_ENTRY(svpbmt, ext_svpbmt), diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index 1119d5201066..9a01e6d0f587 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -276,6 +276,11 @@ struct CPUArchState { uint64_t mfromhost; uint64_t mtohost; + /* Sstc CSRs */ + uint64_t stimecmp; + /* For RV32 only */ + uint8_t stimecmp_wr_done; + /* physical memory protection */ pmp_table_t pmp_state; target_ulong mseccfg; @@ -329,6 +334,7 @@ struct CPUArchState { float_status fp_status; /* Fields from here on are preserved across CPU reset. */ + QEMUTimer *stimer; /* Internal timer for S-mode interrupt */ hwaddr kernel_addr; hwaddr fdt_addr; @@ -379,6 +385,7 @@ struct RISCVCPUConfig { bool ext_counters; bool ext_ifencei; bool ext_icsr; + bool ext_sstc; bool ext_svinval; bool ext_svnapot; bool ext_svpbmt; diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h index 4e5b630f5965..29d0e4a1be01 100644 --- a/target/riscv/cpu_bits.h +++ b/target/riscv/cpu_bits.h @@ -215,6 +215,10 @@ #define CSR_STVAL 0x143 #define CSR_SIP 0x144 +/* Sstc supervisor CSRs */ +#define CSR_STIMECMP 0x14D +#define CSR_STIMECMPH 0x15D + /* Supervisor Protection and Translation */ #define CSR_SPTBR 0x180 #define CSR_SATP 0x180 diff --git a/target/riscv/csr.c b/target/riscv/csr.c index 245f007e66e1..8952d1308008 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 "time_helper.h" #include "qemu/main-loop.h" #include "exec/exec-all.h" #include "sysemu/cpu-timers.h" @@ -537,6 +538,87 @@ static RISCVException read_timeh(CPURISCVState *env, int csrno, return RISCV_EXCP_NONE; } +static RISCVException sstc(CPURISCVState *env, int csrno) +{ + CPUState *cs = env_cpu(env); + RISCVCPU *cpu = RISCV_CPU(cs); + + if (!cpu->cfg.ext_sstc || !env->rdtime_fn) { + return RISCV_EXCP_ILLEGAL_INST; + } + + if (env->priv == PRV_M) { + return RISCV_EXCP_NONE; + } + + if (env->priv != PRV_S) { + return RISCV_EXCP_ILLEGAL_INST; + } + + /* + * No need of separate function for rv32 as menvcfg stores both menvcfg + * menvcfgh for RV32. + */ + if (!(get_field(env->mcounteren, COUNTEREN_TM) && + get_field(env->menvcfg, MENVCFG_STCE))) { + return RISCV_EXCP_ILLEGAL_INST; + } + + return RISCV_EXCP_NONE; +} + +static RISCVException read_stimecmp(CPURISCVState *env, int csrno, + target_ulong *val) +{ + *val = env->stimecmp; + return RISCV_EXCP_NONE; +} + +static RISCVException read_stimecmph(CPURISCVState *env, int csrno, + target_ulong *val) +{ + *val = env->stimecmp >> 32; + return RISCV_EXCP_NONE; +} + +static RISCVException write_stimecmp(CPURISCVState *env, int csrno, + target_ulong val) +{ + RISCVCPU *cpu = env_archcpu(env); + + if (riscv_cpu_mxl(env) == MXL_RV32) { + env->stimecmp = deposit64(env->stimecmp, 0, 32, (uint64_t)val); + env->stimecmp_wr_done |= 0x01; + if (env->stimecmp_wr_done != 0x03) { + return RISCV_EXCP_NONE; + } else { + env->stimecmp_wr_done = 0; + } + } else { + env->stimecmp = val; + } + + riscv_timer_write_timecmp(cpu, env->stimer, env->stimecmp, 0, MIP_STIP); + + return RISCV_EXCP_NONE; +} + +static RISCVException write_stimecmph(CPURISCVState *env, int csrno, + target_ulong val) +{ + RISCVCPU *cpu = env_archcpu(env); + + env->stimecmp = deposit64(env->stimecmp, 32, 32, (uint64_t)val); + env->stimecmp_wr_done |= 0x02; + if (env->stimecmp_wr_done != 0x03) { + return RISCV_EXCP_NONE; + } + env->stimecmp_wr_done = 0; + riscv_timer_write_timecmp(cpu, env->stimer, env->stimecmp, 0, MIP_STIP); + + return RISCV_EXCP_NONE; +} + /* Machine constants */ #define M_MODE_INTERRUPTS ((uint64_t)(MIP_MSIP | MIP_MTIP | MIP_MEIP)) @@ -1515,6 +1597,12 @@ static RISCVException rmw_mip64(CPURISCVState *env, int csrno, new_val |= env->external_seip * MIP_SEIP; } + if (cpu->cfg.ext_sstc && (env->priv == PRV_M) && + get_field(env->menvcfg, MENVCFG_STCE)) { + /* sstc extension forbids STIP & VSTIP to be writeable in mip */ + mask = mask & ~(MIP_STIP | MIP_VSTIP); + } + if (mask) { old_mip = riscv_cpu_update_mip(cpu, mask, (new_val & mask)); } else { @@ -3341,6 +3429,10 @@ riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = { [CSR_SCAUSE] = { "scause", smode, read_scause, write_scause }, [CSR_STVAL] = { "stval", smode, read_stval, write_stval }, [CSR_SIP] = { "sip", smode, NULL, NULL, rmw_sip }, + [CSR_STIMECMP] = { "stimecmp", sstc, read_stimecmp, write_stimecmp, + .min_priv_ver = PRIV_VERSION_1_12_0 }, + [CSR_STIMECMPH] = { "stimecmph", sstc, read_stimecmph, write_stimecmph, + .min_priv_ver = PRIV_VERSION_1_12_0 }, /* Supervisor Protection and Translation */ [CSR_SATP] = { "satp", smode, read_satp, write_satp }, diff --git a/target/riscv/machine.c b/target/riscv/machine.c index 7d85de0b1d49..ee02bfc18916 100644 --- a/target/riscv/machine.c +++ b/target/riscv/machine.c @@ -334,6 +334,7 @@ const VMStateDescription vmstate_riscv_cpu = { VMSTATE_UINTTL(env.mscratch, RISCVCPU), VMSTATE_UINT64(env.mfromhost, RISCVCPU), VMSTATE_UINT64(env.mtohost, RISCVCPU), + VMSTATE_UINT64(env.stimecmp, RISCVCPU), VMSTATE_END_OF_LIST() }, diff --git a/target/riscv/meson.build b/target/riscv/meson.build index 2c20f3dd8e9c..1243d019148e 100644 --- a/target/riscv/meson.build +++ b/target/riscv/meson.build @@ -29,7 +29,8 @@ riscv_softmmu_ss.add(files( 'pmp.c', 'debug.c', 'monitor.c', - 'machine.c' + 'machine.c', + 'time_helper.c' )) target_arch += {'riscv': riscv_ss} diff --git a/target/riscv/time_helper.c b/target/riscv/time_helper.c new file mode 100644 index 000000000000..f3fb5eac7b7b --- /dev/null +++ b/target/riscv/time_helper.c @@ -0,0 +1,98 @@ +/* + * RISC-V timer helper implementation. + * + * Copyright (c) 2022 Rivos Inc. + * + * 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 <http://www.gnu.org/licenses/>. + */ + +#include "qemu/osdep.h" +#include "qemu/log.h" +#include "cpu_bits.h" +#include "time_helper.h" +#include "hw/intc/riscv_aclint.h" + +static void riscv_stimer_cb(void *opaque) +{ + RISCVCPU *cpu = opaque; + riscv_cpu_update_mip(cpu, MIP_STIP, BOOL_TO_MASK(1)); +} + +/* + * Called when timecmp is written to update the QEMU timer or immediately + * trigger timer interrupt if mtimecmp <= current timer value. + */ +void riscv_timer_write_timecmp(RISCVCPU *cpu, QEMUTimer *timer, + uint64_t timecmp, uint64_t delta, + uint32_t timer_irq) +{ + uint64_t diff, ns_diff, next; + CPURISCVState *env = &cpu->env; + RISCVAclintMTimerState *mtimer = env->rdtime_fn_arg; + uint32_t timebase_freq = mtimer->timebase_freq; + uint64_t rtc_r = env->rdtime_fn(env->rdtime_fn_arg) + delta; + + if (timecmp <= rtc_r) { + /* + * If we're setting an stimecmp value in the "past", + * immediately raise the timer interrupt + */ + riscv_cpu_update_mip(cpu, timer_irq, BOOL_TO_MASK(1)); + return; + } + + /* Clear the [V]STIP bit in mip */ + riscv_cpu_update_mip(cpu, timer_irq, BOOL_TO_MASK(0)); + + /* otherwise, set up the future timer interrupt */ + diff = timecmp - rtc_r; + /* back to ns (note args switched in muldiv64) */ + ns_diff = muldiv64(diff, NANOSECONDS_PER_SECOND, timebase_freq); + + /* + * check if ns_diff overflowed and check if the addition would potentially + * overflow + */ + if ((NANOSECONDS_PER_SECOND > timebase_freq && ns_diff < diff) || + ns_diff > INT64_MAX) { + next = INT64_MAX; + } else { + /* + * as it is very unlikely qemu_clock_get_ns will return a value + * greater than INT64_MAX, no additional check is needed for an + * unsigned integer overflow. + */ + next = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + ns_diff; + /* + * if ns_diff is INT64_MAX next may still be outside the range + * of a signed integer. + */ + next = MIN(next, INT64_MAX); + } + + timer_mod(timer, next); +} + +void riscv_timer_init(RISCVCPU *cpu) +{ + CPURISCVState *env; + + if (!cpu) { + return; + } + + env = &cpu->env; + env->stimer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &riscv_stimer_cb, cpu); + env->stimecmp = 0; + +} diff --git a/target/riscv/time_helper.h b/target/riscv/time_helper.h new file mode 100644 index 000000000000..7b3cdcc35020 --- /dev/null +++ b/target/riscv/time_helper.h @@ -0,0 +1,30 @@ +/* + * RISC-V timer header file. + * + * Copyright (c) 2022 Rivos Inc. + * + * 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 <http://www.gnu.org/licenses/>. + */ + +#ifndef RISCV_TIME_HELPER_H +#define RISCV_TIME_HELPER_H + +#include "cpu.h" +#include "qemu/timer.h" + +void riscv_timer_write_timecmp(RISCVCPU *cpu, QEMUTimer *timer, + uint64_t timecmp, uint64_t delta, + uint32_t timer_irq); +void riscv_timer_init(RISCVCPU *cpu); + +#endif
stimecmp allows the supervisor mode to update stimecmp CSR directly to program the next timer interrupt. This CSR is part of the Sstc extension which was ratified recently. Signed-off-by: Atish Patra <atishp@rivosinc.com> --- target/riscv/cpu.c | 8 ++++ target/riscv/cpu.h | 7 +++ target/riscv/cpu_bits.h | 4 ++ target/riscv/csr.c | 92 +++++++++++++++++++++++++++++++++++ target/riscv/machine.c | 1 + target/riscv/meson.build | 3 +- target/riscv/time_helper.c | 98 ++++++++++++++++++++++++++++++++++++++ target/riscv/time_helper.h | 30 ++++++++++++ 8 files changed, 242 insertions(+), 1 deletion(-) create mode 100644 target/riscv/time_helper.c create mode 100644 target/riscv/time_helper.h