On Tue, Sep 21, 2021 at 06:11:24PM -0300, Daniel Henrique Barboza wrote: > > > On 9/6/21 22:57, David Gibson wrote: > > On Fri, Sep 03, 2021 at 05:31:06PM -0300, Daniel Henrique Barboza wrote: > > > The PMU is already counting cycles by calculating time elapsed in > > > nanoseconds. Counting instructions is a different matter and requires > > > another approach. > > > > > > This patch adds the capability of counting completed instructions > > > (Perf event PM_INST_CMPL) by counting the amount of instructions > > > translated in each translation block right before exiting it. > > > > > > A new pmu_count_insns() helper in translation.c was added to do that. > > > After verifying that the PMU is running (MMCR0_FC bit not set), call > > > helper_insns_inc(). This new helper from power8_pmu.c will add the > > > instructions to the relevant counters. It'll also be responsible for > > > triggering counter negative overflows later on. > > > > > > Signed-off-by: Daniel Henrique Barboza <danielhb...@gmail.com> > > > --- > > > target/ppc/cpu.h | 1 + > > > target/ppc/helper.h | 1 + > > > target/ppc/helper_regs.c | 3 ++ > > > target/ppc/power8_pmu.c | 70 ++++++++++++++++++++++++++++++++++++---- > > > target/ppc/translate.c | 46 ++++++++++++++++++++++++++ > > > 5 files changed, 114 insertions(+), 7 deletions(-) > > > > > > diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h > > > index 74698a3600..4d4886ac74 100644 > > > --- a/target/ppc/cpu.h > > > +++ b/target/ppc/cpu.h > > > @@ -628,6 +628,7 @@ enum { > > > HFLAGS_FP = 13, /* MSR_FP */ > > > HFLAGS_PR = 14, /* MSR_PR */ > > > HFLAGS_PMCCCLEAR = 15, /* PMU MMCR0 PMCC equal to 0b00 */ > > > + HFLAGS_MMCR0FC = 16, /* MMCR0 FC bit */ > > > HFLAGS_VSX = 23, /* MSR_VSX if cpu has VSX */ > > > HFLAGS_VR = 25, /* MSR_VR if cpu has VRE */ > > > diff --git a/target/ppc/helper.h b/target/ppc/helper.h > > > index 5122632784..47dbbe6da1 100644 > > > --- a/target/ppc/helper.h > > > +++ b/target/ppc/helper.h > > > @@ -21,6 +21,7 @@ DEF_HELPER_1(hrfid, void, env) > > > DEF_HELPER_2(store_lpcr, void, env, tl) > > > DEF_HELPER_2(store_pcr, void, env, tl) > > > DEF_HELPER_2(store_mmcr0, void, env, tl) > > > +DEF_HELPER_2(insns_inc, void, env, i32) > > > #endif > > > DEF_HELPER_1(check_tlb_flush_local, void, env) > > > DEF_HELPER_1(check_tlb_flush_global, void, env) > > > diff --git a/target/ppc/helper_regs.c b/target/ppc/helper_regs.c > > > index 4c1d9575ac..27d139edd8 100644 > > > --- a/target/ppc/helper_regs.c > > > +++ b/target/ppc/helper_regs.c > > > @@ -109,6 +109,9 @@ static uint32_t hreg_compute_hflags_value(CPUPPCState > > > *env) > > > if (((env->spr[SPR_POWER_MMCR0] & MMCR0_PMCC) >> 18) == 0) { > > > hflags |= 1 << HFLAGS_PMCCCLEAR; > > > } > > > + if (env->spr[SPR_POWER_MMCR0] & MMCR0_FC) { > > > + hflags |= 1 << HFLAGS_MMCR0FC; > > > + } > > > #ifndef CONFIG_USER_ONLY > > > if (!env->has_hv_mode || (msr & (1ull << MSR_HV))) { > > > diff --git a/target/ppc/power8_pmu.c b/target/ppc/power8_pmu.c > > > index 3f7b305f4f..9769c0ff35 100644 > > > --- a/target/ppc/power8_pmu.c > > > +++ b/target/ppc/power8_pmu.c > > > @@ -31,10 +31,13 @@ static void update_PMC_PM_CYC(CPUPPCState *env, int > > > sprn, > > > env->spr[sprn] += time_delta; > > > } > > > -static void update_programmable_PMC_reg(CPUPPCState *env, int sprn, > > > - uint64_t time_delta) > > > +static uint8_t get_PMC_event(CPUPPCState *env, int sprn) > > > > I like the idea of splitting out a helper to get the selected event > > (might even make sense to move that to the earlier patch). What would > > be even nicer is if it also included handling of the fact that some > > events are specific to particular PMCs (like 0xF0 for PMC1). That > > means that all the event selection logic will be here, rather than > > having to check the PMC number again in the caller. Obviously to do > > that you'll need some special "bad event" return value, which might > > mean changing the return type. > > The initial idea of this function was to be a simple event extractor > returning 0 if MMCR1 is blank. In the end of the series there are 3 callers > of this function that will execute a specific action based on the event > returned by it. > > I suppose that we can use the return value 0 as a 'bad value' based on the > PMC events we're going to support, but that will not prevent the callers > from doing a 'switch()' like logic, rechecking the PMC, to see which action > is supposed to be taken. > > IIUC, your idea would require an additional layer of abstraction, e.g. a > PMCEvent object, that would tie together PMC + event. Then get_PMC_event() > would return a PMCEvent object and the caller wouldn't need to re-check the > PMC again.
More-or-less, yes. I don't think the "object" would need to be anything more than an enum though: "cycles", "instructions" or "invalid". > I'll see how hard it would be to introduce this new concept in this existing > series. If it ends up being too much rework I'll suggest to do this in a > follow-up. > > > > Thanks, > > > Daniel > > > > > > { > > > - uint8_t event, evt_extr; > > > + uint8_t evt_extr = 0; > > > + > > > + if (env->spr[SPR_POWER_MMCR1] == 0) { > > > + return 0; > > > + } > > > switch (sprn) { > > > case SPR_POWER_PMC1: > > > @@ -50,10 +53,16 @@ static void update_programmable_PMC_reg(CPUPPCState > > > *env, int sprn, > > > evt_extr = MMCR1_PMC4EVT_EXTR; > > > break; > > > default: > > > - return; > > > + return 0; > > > } > > > - event = extract64(env->spr[SPR_POWER_MMCR1], evt_extr, > > > MMCR1_EVT_SIZE); > > > + return extract64(env->spr[SPR_POWER_MMCR1], evt_extr, > > > MMCR1_EVT_SIZE); > > > +} > > > + > > > +static void update_programmable_PMC_reg(CPUPPCState *env, int sprn, > > > + uint64_t time_delta) > > > +{ > > > + uint8_t event = get_PMC_event(env, sprn); > > > /* > > > * MMCR0_PMC1SEL = 0xF0 is the architected PowerISA v3.1 event > > > @@ -99,8 +108,9 @@ void helper_store_mmcr0(CPUPPCState *env, target_ulong > > > value) > > > env->spr[SPR_POWER_MMCR0] = value; > > > - /* MMCR0 writes can change HFLAGS_PMCCCLEAR */ > > > - if ((curr_value & MMCR0_PMCC) != (value & MMCR0_PMCC)) { > > > + /* MMCR0 writes can change HFLAGS_PMCCCLEAR and HFLAGS_MMCR0FC */ > > > + if (((curr_value & MMCR0_PMCC) != (value & MMCR0_PMCC)) || > > > + (curr_FC != new_FC)) { > > > hreg_compute_hflags(env); > > > } > > > @@ -123,4 +133,50 @@ void helper_store_mmcr0(CPUPPCState *env, > > > target_ulong value) > > > } > > > } > > > +static bool pmc_counting_insns(CPUPPCState *env, int sprn) > > > +{ > > > + bool ret = false; > > > + uint8_t event; > > > + > > > + if (sprn == SPR_POWER_PMC5) { > > > + return true; > > > + } > > > + > > > + event = get_PMC_event(env, sprn); > > > + > > > + /* > > > + * Event 0x2 is an implementation-dependent event that IBM > > > + * POWER chips implement (at least since POWER8) that is > > > + * equivalent to PM_INST_CMPL. Let's support this event on > > > + * all programmable PMCs. > > > + * > > > + * Event 0xFE is the PowerISA v3.1 architected event to > > > + * sample PM_INST_CMPL using PMC1. > > > + */ > > > + switch (sprn) { > > > + case SPR_POWER_PMC1: > > > + return event == 0x2 || event == 0xFE; > > > + case SPR_POWER_PMC2: > > > + case SPR_POWER_PMC3: > > > + case SPR_POWER_PMC4: > > > + return event == 0x2; > > > + default: > > > + break; > > > + } > > > + > > > + return ret; > > > +} > > > + > > > +/* This helper assumes that the PMC is running. */ > > > +void helper_insns_inc(CPUPPCState *env, uint32_t num_insns) > > > +{ > > > + int sprn; > > > + > > > + for (sprn = SPR_POWER_PMC1; sprn <= SPR_POWER_PMC5; sprn++) { > > > + if (pmc_counting_insns(env, sprn)) { > > > + env->spr[sprn] += num_insns; > > > + } > > > + } > > > +} > > > + > > > #endif /* defined(TARGET_PPC64) && !defined(CONFIG_USER_ONLY) */ > > > diff --git a/target/ppc/translate.c b/target/ppc/translate.c > > > index c3e2e3d329..b7235a2be0 100644 > > > --- a/target/ppc/translate.c > > > +++ b/target/ppc/translate.c > > > @@ -176,6 +176,7 @@ struct DisasContext { > > > bool tm_enabled; > > > bool gtse; > > > bool pmcc_clear; > > > + bool pmu_frozen; > > > ppc_spr_t *spr_cb; /* Needed to check rights for mfspr/mtspr */ > > > int singlestep_enabled; > > > uint32_t flags; > > > @@ -411,6 +412,12 @@ void spr_write_MMCR0(DisasContext *ctx, int sprn, > > > int gprn) > > > */ > > > gen_icount_io_start(ctx); > > > gen_helper_store_mmcr0(cpu_env, cpu_gpr[gprn]); > > > + > > > + /* > > > + * End the translation block because MMCR0 writes can change > > > + * ctx->pmu_frozen. > > > + */ > > > + ctx->base.is_jmp = DISAS_EXIT_UPDATE; > > > } > > > #else > > > void spr_write_MMCR0(DisasContext *ctx, int sprn, int gprn) > > > @@ -4407,6 +4414,22 @@ static inline void gen_update_cfar(DisasContext > > > *ctx, target_ulong nip) > > > #endif > > > } > > > +#if defined(TARGET_PPC64) && !defined(CONFIG_USER_ONLY) > > > +static void pmu_count_insns(DisasContext *ctx) > > > +{ > > > + /* Do not bother calling the helper if the PMU is frozen */ > > > + if (ctx->pmu_frozen) { > > > + return; > > > + } > > > + > > > + gen_helper_insns_inc(cpu_env, tcg_constant_i32(ctx->base.num_insns)); > > > +} > > > +#else > > > +static void pmu_count_insns(DisasContext *ctx) > > > +{ > > > + return; > > > +} > > > +#endif > > > static inline bool use_goto_tb(DisasContext *ctx, target_ulong dest) > > > { > > > return translator_use_goto_tb(&ctx->base, dest); > > > @@ -4421,9 +4444,17 @@ static void gen_lookup_and_goto_ptr(DisasContext > > > *ctx) > > > } else if (sse & (CPU_SINGLE_STEP | CPU_BRANCH_STEP)) { > > > gen_helper_raise_exception(cpu_env, > > > tcg_constant_i32(gen_prep_dbgex(ctx))); > > > } else { > > > + pmu_count_insns(ctx); > > > tcg_gen_exit_tb(NULL, 0); > > > } > > > } else { > > > + /* > > > + * tcg_gen_lookup_and_goto_ptr will exit the TB if > > > + * CF_NO_GOTO_PTR is set. Count insns now. > > > + */ > > > + if (ctx->base.tb->flags & CF_NO_GOTO_PTR) { > > > + pmu_count_insns(ctx); > > > + } > > > tcg_gen_lookup_and_goto_ptr(); > > > } > > > } > > > @@ -4435,6 +4466,8 @@ static void gen_goto_tb(DisasContext *ctx, int n, > > > target_ulong dest) > > > dest = (uint32_t) dest; > > > } > > > if (use_goto_tb(ctx, dest)) { > > > + pmu_count_insns(ctx); > > > + > > > tcg_gen_goto_tb(n); > > > tcg_gen_movi_tl(cpu_nip, dest & ~3); > > > tcg_gen_exit_tb(ctx->base.tb, n); > > > @@ -8648,6 +8681,7 @@ static void > > > ppc_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs) > > > ctx->tm_enabled = (hflags >> HFLAGS_TM) & 1; > > > ctx->gtse = (hflags >> HFLAGS_GTSE) & 1; > > > ctx->pmcc_clear = (hflags >> HFLAGS_PMCCCLEAR) & 1; > > > + ctx->pmu_frozen = (hflags >> HFLAGS_MMCR0FC) & 1; > > > ctx->singlestep_enabled = 0; > > > if ((hflags >> HFLAGS_SE) & 1) { > > > @@ -8767,6 +8801,8 @@ static void ppc_tr_tb_stop(DisasContextBase > > > *dcbase, CPUState *cs) > > > switch (is_jmp) { > > > case DISAS_TOO_MANY: > > > if (use_goto_tb(ctx, nip)) { > > > + pmu_count_insns(ctx); > > > + > > > tcg_gen_goto_tb(0); > > > gen_update_nip(ctx, nip); > > > tcg_gen_exit_tb(ctx->base.tb, 0); > > > @@ -8777,6 +8813,14 @@ static void ppc_tr_tb_stop(DisasContextBase > > > *dcbase, CPUState *cs) > > > gen_update_nip(ctx, nip); > > > /* fall through */ > > > case DISAS_CHAIN: > > > + /* > > > + * tcg_gen_lookup_and_goto_ptr will exit the TB if > > > + * CF_NO_GOTO_PTR is set. Count insns now. > > > + */ > > > + if (ctx->base.tb->flags & CF_NO_GOTO_PTR) { > > > + pmu_count_insns(ctx); > > > + } > > > + > > > tcg_gen_lookup_and_goto_ptr(); > > > break; > > > @@ -8784,6 +8828,8 @@ static void ppc_tr_tb_stop(DisasContextBase > > > *dcbase, CPUState *cs) > > > gen_update_nip(ctx, nip); > > > /* fall through */ > > > case DISAS_EXIT: > > > + pmu_count_insns(ctx); > > > + > > > tcg_gen_exit_tb(NULL, 0); > > > break; > > > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson
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