|
| From: | Matheus K. Ferst |
| Subject: | Re: [RFC PATCH v2 11/29] target/ppc: add power-saving interrupt masking logic to p9_next_unmasked_interrupt |
| Date: | Mon, 3 Oct 2022 12:46:13 -0300 |
| User-agent: | Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 |
On 30/09/2022 15:38, Fabiano Rosas wrote:
Matheus Ferst <matheus.ferst@eldorado.org.br> writes:Export p9_interrupt_powersave and use it in p9_next_unmasked_interrupt. Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br> --- Temporarily putting the prototype in internal.h for lack of a better place, we will un-export p9_interrupt_powersave in future patches. --- target/ppc/cpu_init.c | 2 +- target/ppc/excp_helper.c | 46 ++++++++++++++++++++++++++++------------ target/ppc/internal.h | 4 ++++ 3 files changed, 38 insertions(+), 14 deletions(-) diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c index 1f8f6c6ef2..7889158c52 100644 --- a/target/ppc/cpu_init.c +++ b/target/ppc/cpu_init.c @@ -6351,7 +6351,7 @@ static bool ppc_pvr_match_power9(PowerPCCPUClass *pcc, uint32_t pvr, bool best) return false; } -static int p9_interrupt_powersave(CPUPPCState *env) +int p9_interrupt_powersave(CPUPPCState *env) { /* External Exception */ if ((env->pending_interrupts & PPC_INTERRUPT_EXT) && diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c index 67e73f30ab..5a0d2c11a2 100644 --- a/target/ppc/excp_helper.c +++ b/target/ppc/excp_helper.c @@ -1686,28 +1686,39 @@ void ppc_cpu_do_interrupt(CPUState *cs) static int p9_next_unmasked_interrupt(CPUPPCState *env) { - bool async_deliver; + PowerPCCPU *cpu = env_archcpu(env); + CPUState *cs = CPU(cpu); + /* Ignore MSR[EE] when coming out of some power management states */ + bool msr_ee = FIELD_EX64(env->msr, MSR, EE) || env->resume_as_sreset; assert((env->pending_interrupts & P9_UNUSED_INTERRUPTS) == 0); + if (cs->halted) { + if (env->spr[SPR_PSSCR] & PSSCR_EC) { + /* + * When PSSCR[EC] is set, LPCR[PECE] controls which interrupts can + * wakeup the processor + */ + return p9_interrupt_powersave(env); + } else { + /* + * When it's clear, any system-caused exception exits power-saving + * mode, even the ones that gate on MSR[EE]. + */ + msr_ee = true; + } + } + /* Machine check exception */ if (env->pending_interrupts & PPC_INTERRUPT_MCK) { return PPC_INTERRUPT_MCK; } - /* - * For interrupts that gate on MSR:EE, we need to do something a - * bit more subtle, as we need to let them through even when EE is - * clear when coming out of some power management states (in order - * for them to become a 0x100). - */ - async_deliver = FIELD_EX64(env->msr, MSR, EE) || env->resume_as_sreset; -You could simplify the code below if you bail early here when !msr_ee.
The next interrupts have checks in the form
if (MSR[EE] && some_condition) || (!MSR[HV] && some_other_condition)
so we cannot return yet. We could check twice for these interrupts, e.g.
if ((env->pending_interrupts & PPC_INTERRUPT_EXT) &&
(env->has_hv_mode && !FIELD_EX64_HV(env->msr) && !lpes0)) {
return PPC_INTERRUPT_EXT;
}
/* ... */
if (!msr_ee) {
return 0;
}
/* ... */
if ((env->pending_interrupts & PPC_INTERRUPT_EXT) &&
!(heic && FIELD_EX64_HV(env->msr) && !FIELD_EX64(env->msr, MSR, PR))) {
return PPC_INTERRUPT_EXT;
}
But I'm not sure if it'd be better.
/* Hypervisor decrementer exception */ if (env->pending_interrupts & PPC_INTERRUPT_HDECR) { /* LPCR will be clear when not supported so this will work */ bool hdice = !!(env->spr[SPR_LPCR] & LPCR_HDICE); - if ((async_deliver || !FIELD_EX64_HV(env->msr)) && hdice) { + if ((msr_ee || !FIELD_EX64_HV(env->msr)) && hdice) { /* HDEC clears on delivery */ return PPC_INTERRUPT_HDECR; } @@ -1717,7 +1728,7 @@ static int p9_next_unmasked_interrupt(CPUPPCState *env) if (env->pending_interrupts & PPC_INTERRUPT_HVIRT) { /* LPCR will be clear when not supported so this will work */ bool hvice = !!(env->spr[SPR_LPCR] & LPCR_HVICE); - if ((async_deliver || !FIELD_EX64_HV(env->msr)) && hvice) { + if ((msr_ee || !FIELD_EX64_HV(env->msr)) && hvice) { return PPC_INTERRUPT_HVIRT; } } @@ -1727,13 +1738,13 @@ static int p9_next_unmasked_interrupt(CPUPPCState *env) bool lpes0 = !!(env->spr[SPR_LPCR] & LPCR_LPES0); bool heic = !!(env->spr[SPR_LPCR] & LPCR_HEIC); /* HEIC blocks delivery to the hypervisor */ - if ((async_deliver && !(heic && FIELD_EX64_HV(env->msr) && + if ((msr_ee && !(heic && FIELD_EX64_HV(env->msr) && !FIELD_EX64(env->msr, MSR, PR))) || (env->has_hv_mode && !FIELD_EX64_HV(env->msr) && !lpes0)) { return PPC_INTERRUPT_EXT; } } - if (async_deliver != 0) { + if (msr_ee != 0) { /* Decrementer exception */ if (env->pending_interrupts & PPC_INTERRUPT_DECR) { return PPC_INTERRUPT_DECR; @@ -1895,6 +1906,15 @@ static void p9_deliver_interrupt(CPUPPCState *env, int interrupt) PowerPCCPU *cpu = env_archcpu(env); CPUState *cs = env_cpu(env); + if (cs->halted && !(env->spr[SPR_PSSCR] & PSSCR_EC) && + !FIELD_EX64(env->msr, MSR, EE)) { + /* + * A pending interrupt took us out of power-saving, but MSR[EE] says + * that we should return to NIP+4 instead of delivering it. + */ + return;How will the NIP be advanced in this case?
It's already incremented by the translation code. ppc_tr_translate_insn increments ctx->base.pc_next before calling decode_{insn{32,64},legacy}, and methods that put the CPU to sleep will use gen_exception_nip with this value as the last argument.
+ } + switch (interrupt) { case PPC_INTERRUPT_MCK: /* Machine check exception */ env->pending_interrupts &= ~PPC_INTERRUPT_MCK; diff --git a/target/ppc/internal.h b/target/ppc/internal.h index 337a362205..41e79adfdb 100644 --- a/target/ppc/internal.h +++ b/target/ppc/internal.h @@ -306,4 +306,8 @@ static inline int ger_pack_masks(int pmsk, int ymsk, int xmsk) return msk; } +#if defined(TARGET_PPC64) +int p9_interrupt_powersave(CPUPPCState *env); +#endif + #endif /* PPC_INTERNAL_H */
Thanks, Matheus K. Ferst Instituto de Pesquisas ELDORADO <http://www.eldorado.org.br/> Analista de Software Aviso Legal - Disclaimer <https://www.eldorado.org.br/disclaimer.html>
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