Anup Patel 於 2021年12月30日 週四 下午8:38寫道： > From: Anup Patel > > The AIA spec defines programmable 8-bit priority for each local interrupt > at M-level, S-level and VS-level so we extend local interrupt processing > to consider AIA interrupt priorities. The AIA CSRs which help software > configure local interrupt priorities will be added by subsequent patches. > > Signed-off-by: Anup Patel > Signed-off-by: Anup Patel > Reviewed-by: Alistair Francis > --- > target/riscv/cpu.c | 19 ++++ > target/riscv/cpu.h | 12 ++ > target/riscv/cpu_helper.c | 231 ++++++++++++++++++++++++++++++++++---- > target/riscv/machine.c | 3 + > 4 files changed, 244 insertions(+), 21 deletions(-) > > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c > index 9f1a4d1088..9ad26035e1 100644 > --- a/target/riscv/cpu.c > +++ b/target/riscv/cpu.c > @@ -348,6 +348,10 @@ void restore_state_to_opc(CPURISCVState *env, > TranslationBlock *tb, > > static void riscv_cpu_reset(DeviceState *dev) > { > +#ifndef CONFIG_USER_ONLY > + uint8_t iprio; > + int i, irq, rdzero; > +#endif > CPUState *cs = CPU(dev); > RISCVCPU *cpu = RISCV_CPU(cs); > RISCVCPUClass *mcc = RISCV_CPU_GET_CLASS(cpu); > @@ -370,6 +374,21 @@ static void riscv_cpu_reset(DeviceState *dev) > env->miclaim = MIP_SGEIP; > env->pc = env->resetvec; > env->two_stage_lookup = false; > + > + /* Initialized default priorities of local interrupts. */ > + for (i = 0; i < ARRAY_SIZE(env->miprio); i++) { > + iprio = riscv_cpu_default_priority(i); > + env->miprio[i] = (i == IRQ_M_EXT) ? 0 : iprio; > + env->siprio[i] = (i == IRQ_S_EXT) ? 0 : iprio; > + env->hviprio[i] = 0; > + } > + i = 0; > + while (!riscv_cpu_hviprio_index2irq(i, &irq, &rdzero)) { > + if (!rdzero) { > + env->hviprio[irq] = env->miprio[irq]; > + } > + i++; > + } > /* mmte is supposed to have pm.current hardwired to 1 */ > env->mmte |= (PM_EXT_INITIAL | MMTE_M_PM_CURRENT); > #endif > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h > index 02f3ef2c3c..140fabfdf9 100644 > --- a/target/riscv/cpu.h > +++ b/target/riscv/cpu.h > @@ -182,6 +182,10 @@ struct CPURISCVState { > target_ulong mcause; > target_ulong mtval; /* since: priv-1.10.0 */ > > + /* Machine and Supervisor interrupt priorities */ > + uint8_t miprio[64]; > + uint8_t siprio[64]; > + > /* Hypervisor CSRs */ > target_ulong hstatus; > target_ulong hedeleg; > @@ -194,6 +198,9 @@ struct CPURISCVState { > target_ulong hgeip; > uint64_t htimedelta; > > + /* Hypervisor controlled virtual interrupt priorities */ > + uint8_t hviprio[64]; > + > /* Virtual CSRs */ > /* > * For RV32 this is 32-bit vsstatus and 32-bit vsstatush. > @@ -379,6 +386,11 @@ int riscv_cpu_write_elf32_note(WriteCoreDumpFunction > f, CPUState *cs, > int cpuid, void *opaque); > int riscv_cpu_gdb_read_register(CPUState *cpu, GByteArray *buf, int reg); > int riscv_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg); > +int riscv_cpu_hviprio_index2irq(int index, int *out_irq, int *out_rdzero); > +uint8_t riscv_cpu_default_priority(int irq); > +int riscv_cpu_mirq_pending(CPURISCVState *env); > +int riscv_cpu_sirq_pending(CPURISCVState *env); > +int riscv_cpu_vsirq_pending(CPURISCVState *env); > bool riscv_cpu_fp_enabled(CPURISCVState *env); > target_ulong riscv_cpu_get_geilen(CPURISCVState *env); > void riscv_cpu_set_geilen(CPURISCVState *env, target_ulong geilen); > diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c > index f94a36fa89..e3532de4cf 100644 > --- a/target/riscv/cpu_helper.c > +++ b/target/riscv/cpu_helper.c > @@ -151,36 +151,225 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, > target_ulong *pc, > } > > #ifndef CONFIG_USER_ONLY > -static int riscv_cpu_local_irq_pending(CPURISCVState *env) > + > +/* > + * The HS-mode is allowed to configure priority only for the > + * following VS-mode local interrupts: > + * > + * 0 (Reserved interrupt, reads as zero) > + * 1 Supervisor software interrupt > + * 4 (Reserved interrupt, reads as zero) > + * 5 Supervisor timer interrupt > + * 8 (Reserved interrupt, reads as zero) > + * 13 (Reserved interrupt) > + * 14 " > + * 15 " > + * 16 " > + * 18 Debug/trace interrupt > + * 20 (Reserved interrupt) > + * 22 " > + * 24 " > + * 26 " > + * 28 " > + * 30 (Reserved for standard reporting of bus or system errors) > + */ > + > +static int hviprio_index2irq[] = > + { 0, 1, 4, 5, 8, 13, 14, 15, 16, 18, 20, 22, 24, 26, 28, 30 }; > +static int hviprio_index2rdzero[] = > + { 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; > + > +int riscv_cpu_hviprio_index2irq(int index, int *out_irq, int *out_rdzero) > { > - target_ulong virt_enabled = riscv_cpu_virt_enabled(env); > + if (index < 0 || ARRAY_SIZE(hviprio_index2irq) <= index) { > + return -EINVAL; > + } > + > + if (out_irq) { > + *out_irq = hviprio_index2irq[index]; > + } > > - target_ulong mstatus_mie = get_field(env->mstatus, MSTATUS_MIE); > - target_ulong mstatus_sie = get_field(env->mstatus, MSTATUS_SIE); > + if (out_rdzero) { > + *out_rdzero = hviprio_index2rdzero[index]; > + } > > - target_ulong vsgemask = > - (target_ulong)1 << get_field(env->hstatus, HSTATUS_VGEIN); > - target_ulong vsgein = (env->hgeip & vsgemask) ? MIP_VSEIP : 0; > + return 0; > +} > > - target_ulong pending = (env->mip | vsgein) & env->mie; > +uint8_t riscv_cpu_default_priority(int irq) > +{ > + int u, l; > + uint8_t iprio = IPRIO_MMAXIPRIO; > > - target_ulong mie = env->priv < PRV_M || > - (env->priv == PRV_M && mstatus_mie); > - target_ulong sie = env->priv < PRV_S || > - (env->priv == PRV_S && mstatus_sie); > - target_ulong hsie = virt_enabled || sie; > - target_ulong vsie = virt_enabled && sie; > + if (irq < 0 || irq > 63) { > + return iprio; > + } > > - target_ulong irqs = > - (pending & ~env->mideleg & -mie) | > - (pending & env->mideleg & ~env->hideleg & -hsie) | > - (pending & env->mideleg & env->hideleg & -vsie); > + /* > + * Default priorities of local interrupts are defined in the > + * RISC-V Advanced Interrupt Architecture specification. > + * > + * ---------------------------------------------------------------- > + * Default | > + * Priority | Major Interrupt Numbers > + * ---------------------------------------------------------------- > + * Highest | 63 (3f), 62 (3e), 31 (1f), 30 (1e), 61 (3d), 60 (3c), > + * | 59 (3b), 58 (3a), 29 (1d), 28 (1c), 57 (39), 56 (38), > + * | 55 (37), 54 (36), 27 (1b), 26 (1a), 53 (35), 52 (34), > + * | 51 (33), 50 (32), 25 (19), 24 (18), 49 (31), 48 (30) > + * | > + * | 11 (0b), 3 (03), 7 (07) > + * | 9 (09), 1 (01), 5 (05) > + * | 12 (0c) > + * | 10 (0a), 2 (02), 6 (06) > + * | > + * | 47 (2f), 46 (2e), 23 (17), 22 (16), 45 (2d), 44 (2c), > + * | 43 (2b), 42 (2a), 21 (15), 20 (14), 41 (29), 40 (28), > + * | 39 (27), 38 (26), 19 (13), 18 (12), 37 (25), 36 (24), > + * Lowest | 35 (23), 34 (22), 17 (11), 16 (10), 33 (21), 32 (20) > + * ---------------------------------------------------------------- > + */ > > - if (irqs) { > - return ctz64(irqs); /* since non-zero */ > + u = IPRIO_DEFAULT_U(irq); > + l = IPRIO_DEFAULT_L(irq); > + if (u == 0) { > + if (irq == IRQ_VS_EXT || irq == IRQ_VS_TIMER || > + irq == IRQ_VS_SOFT) { > + iprio = IPRIO_DEFAULT_VS; > + } else if (irq == IRQ_S_GEXT) { > + iprio = IPRIO_DEFAULT_SGEXT; > + } else if (irq == IRQ_S_EXT || irq == IRQ_S_TIMER || > + irq == IRQ_S_SOFT) { > + iprio = IPRIO_DEFAULT_S; > + } else if (irq == IRQ_M_EXT || irq == IRQ_M_TIMER || > + irq == IRQ_M_SOFT) { > + iprio = IPRIO_DEFAULT_M; > + } else { > + iprio = IPRIO_DEFAULT_VS; > + } > + } else if (u == 1) { > + if (l < 8) { > + iprio = IPRIO_DEFAULT_16_23(irq); > + } else { > + iprio = IPRIO_DEFAULT_24_31(irq); > + } > + } else if (u == 2) { > + iprio = IPRIO_DEFAULT_32_47(irq); > + } else if (u == 3) { > + iprio = IPRIO_DEFAULT_48_63(irq); > + } > + > + return iprio; > +} > + > +static int riscv_cpu_pending_to_irq(CPURISCVState *env, > + uint64_t pending, uint8_t *iprio) > +{ > + int irq, best_irq = RISCV_EXCP_NONE; > + unsigned int prio, best_prio = UINT_MAX; > + > + if (!pending) { > + return RISCV_EXCP_NONE; > + } > + > + irq = ctz64(pending); > + if (!riscv_feature(env, RISCV_FEATURE_AIA)) { > + return irq; > + } > + > + pending = pending >> irq; > + while (pending) { > + prio = iprio[irq]; > + if (!prio) { > + prio = (riscv_cpu_default_priority(irq) < IPRIO_DEFAULT_M) ? > + 1 : IPRIO_MMAXIPRIO; > Hi Anup, I have a question regarding configuring priorities of major interrupts. riscv_cpu_default_priority() for M-mode external interrupt would return IPRIO_DEFAULT_M (8). but the comparison here is < IPRIO_DEFAULT_M, so if M-mode external interrupt is pending, the prio would be assigned to IPRIO_MMAXIPRIO (255). Is this the expected behavior? Also, why is IPRIO_DEFAULT_M been compared? Should IPRIO_DEFAULT_S and IPRIO_DEFAULT_VS be used for S-mode and VS-mode interrupts? > + } > + if ((pending & 0x1) && (prio < best_prio)) { > If both interrupt 63 and 62 are pending-and-enabled, with their iprio values both assigned to zero. Interrupt 62 would be picked, because best_prio will be 1 when interrupt 62 is been checked. As the default priority order for interrupt 63 is also less than IPRIO_DEFAULT_M (8), so prio would be assigned to 1 as well. But as prio is not less than best_prio, so best_irq would still be interrupt 62. However, according to the default priority table in AIA spec, interrupt 63 should have a higher priority than interrupt 62: Interrupt 63 has the highest default priority, and interrupt 32 has the lowest default priority. > + best_irq = irq; > + best_prio = prio; > + } > + irq++; > + pending = pending >> 1; > + } > + > + return best_irq; > +} > Yet I have another question for major interrupts priorities. According to AIA spec (v0.2-draft.28): ========== The priority number for a machine-level external interrupt (bits 31:24 of register iprio2) must also be read-only zero. When an interrupt’s priority number in the array is zero (either read-only zero or set to zero), its priority is the default order from Section 6.1. Setting an interrupt’s priority number instead to a nonzero value p gives that interrupt nominally the same priority as a machine-level external interrupt with priority number p. For a major interrupt that defaults to a higher priority than machine external interrupts, setting its priority number to a nonzero value lowers its priority. For a major interrupt that defaults to a lower priority than machine external interrupts, setting its priority number to a nonzero value raises its priority. ========== From the above sentences, The M-mode external interrupt has iprio value of 0, so the default priority order is applied. What are the priorities for the major interrupt interrupts which are higher/lower than M-mode external interrupt when their iprio values are not 0? Which interrupt will be picked when: M-mode external interrupt is pending-and-enabled, Interrupt with higher default priority than M-mode external interrupt is pending-and-enabled, and Interrupt with lower default priority than M-mode external interrupt is pending-and-enabled/ From the above riscv_cpu_pending_to_irq(), If both interrupt 63 and interrupt 18's iprio values are assigned to the value of 10, and interrupt 63, interrupt 18 and M-mode external interrupts are pending-and-enabled. Interrupt 18 would be picked. Is this the correct expectation? I'm a bit confused with the correct priority order of the interrupts with/without non-zero value iprio and the default priority. Thanks, Frank Chang > + > +static uint64_t riscv_cpu_all_pending(CPURISCVState *env) > +{ > + uint32_t gein = get_field(env->hstatus, HSTATUS_VGEIN); > + uint64_t vsgein = (env->hgeip & (1ULL << gein)) ? MIP_VSEIP : 0; > + > + return (env->mip | vsgein) & env->mie; > +} > + > +int riscv_cpu_mirq_pending(CPURISCVState *env) > +{ > + uint64_t irqs = riscv_cpu_all_pending(env) & ~env->mideleg & > + ~(MIP_SGEIP | MIP_VSSIP | MIP_VSTIP | MIP_VSEIP); > + > + return riscv_cpu_pending_to_irq(env, irqs, env->miprio); > +} > + > +int riscv_cpu_sirq_pending(CPURISCVState *env) > +{ > + uint64_t irqs = riscv_cpu_all_pending(env) & env->mideleg & > + ~(MIP_VSSIP | MIP_VSTIP | MIP_VSEIP); > + > + return riscv_cpu_pending_to_irq(env, irqs, env->siprio); > +} > + > +int riscv_cpu_vsirq_pending(CPURISCVState *env) > +{ > + uint64_t irqs = riscv_cpu_all_pending(env) & env->mideleg & > + (MIP_VSSIP | MIP_VSTIP | MIP_VSEIP); > + > + return riscv_cpu_pending_to_irq(env, irqs >> 1, env->hviprio); > +} > + > +static int riscv_cpu_local_irq_pending(CPURISCVState *env) > +{ > + int virq; > + uint64_t irqs, pending, mie, hsie, vsie; > + > + /* Determine interrupt enable state of all privilege modes */ > + if (riscv_cpu_virt_enabled(env)) { > + mie = 1; > + hsie = 1; > + vsie = (env->priv < PRV_S) || > + (env->priv == PRV_S && get_field(env->mstatus, > MSTATUS_SIE)); > } else { > - return RISCV_EXCP_NONE; /* indicates no pending interrupt */ > + mie = (env->priv < PRV_M) || > + (env->priv == PRV_M && get_field(env->mstatus, > MSTATUS_MIE)); > + hsie = (env->priv < PRV_S) || > + (env->priv == PRV_S && get_field(env->mstatus, > MSTATUS_SIE)); > + vsie = 0; > } > + > + /* Determine all pending interrupts */ > + pending = riscv_cpu_all_pending(env); > + > + /* Check M-mode interrupts */ > + irqs = pending & ~env->mideleg & -mie; > + if (irqs) { > + return riscv_cpu_pending_to_irq(env, irqs, env->miprio); > + } > + > + /* Check HS-mode interrupts */ > + irqs = pending & env->mideleg & ~env->hideleg & -hsie; > + if (irqs) { > + return riscv_cpu_pending_to_irq(env, irqs, env->siprio); > + } > + > + /* Check VS-mode interrupts */ > + irqs = pending & env->mideleg & env->hideleg & -vsie; > + if (irqs) { > + virq = riscv_cpu_pending_to_irq(env, irqs >> 1, env->hviprio); > + return (virq <= 0) ? virq : virq + 1; > + } > + > + /* Indicate no pending interrupt */ > + return RISCV_EXCP_NONE; > } > > bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request) > diff --git a/target/riscv/machine.c b/target/riscv/machine.c > index 76dd0d415c..cffc444969 100644 > --- a/target/riscv/machine.c > +++ b/target/riscv/machine.c > @@ -92,6 +92,7 @@ static const VMStateDescription vmstate_hyper = { > VMSTATE_UINTTL(env.hgeie, RISCVCPU), > VMSTATE_UINTTL(env.hgeip, RISCVCPU), > VMSTATE_UINT64(env.htimedelta, RISCVCPU), > + VMSTATE_UINT8_ARRAY(env.hviprio, RISCVCPU, 64), > > VMSTATE_UINT64(env.vsstatus, RISCVCPU), > VMSTATE_UINTTL(env.vstvec, RISCVCPU), > @@ -173,6 +174,8 @@ const VMStateDescription vmstate_riscv_cpu = { > .fields = (VMStateField[]) { > VMSTATE_UINTTL_ARRAY(env.gpr, RISCVCPU, 32), > VMSTATE_UINT64_ARRAY(env.fpr, RISCVCPU, 32), > + VMSTATE_UINT8_ARRAY(env.miprio, RISCVCPU, 64), > + VMSTATE_UINT8_ARRAY(env.siprio, RISCVCPU, 64), > VMSTATE_UINTTL(env.pc, RISCVCPU), > VMSTATE_UINTTL(env.load_res, RISCVCPU), > VMSTATE_UINTTL(env.load_val, RISCVCPU), > -- > 2.25.1 > > >