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Re: [RFC PATCH 07/10] target/ppc: Add helpers to check for SMT sibling t
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From: |
Nicholas Piggin |
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Subject: |
Re: [RFC PATCH 07/10] target/ppc: Add helpers to check for SMT sibling threads |
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Date: |
Wed, 29 May 2024 10:31:23 +1000 |
On Tue May 28, 2024 at 7:16 PM AEST, Harsh Prateek Bora wrote:
>
>
> On 5/26/24 17:56, Nicholas Piggin wrote:
> > Add helpers for TCG code to determine if there are SMT siblings
> > sharing per-core and per-lpar registers. This simplifies the
> > callers and makes SMT register topology simpler to modify with
> > later changes.
> >
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> > ---
> > target/ppc/cpu.h | 7 +++++++
> > target/ppc/cpu_init.c | 2 +-
> > target/ppc/excp_helper.c | 16 +++++++---------
> > target/ppc/misc_helper.c | 27 ++++++---------------------
> > target/ppc/timebase_helper.c | 20 +++++++-------------
> > 5 files changed, 28 insertions(+), 44 deletions(-)
> >
> > diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> > index 9a89083932..8fd6ade471 100644
> > --- a/target/ppc/cpu.h
> > +++ b/target/ppc/cpu.h
> > @@ -1406,6 +1406,13 @@ struct CPUArchState {
> > uint64_t pmu_base_time;
> > };
> >
> > +#define PPC_CPU_HAS_CORE_SIBLINGS(cs) \
> > + (cs->nr_threads > 1)
> > +
> > +#define PPC_CPU_HAS_LPAR_SIBLINGS(cs) \
> > + ((POWERPC_CPU(cs)->env.flags & POWERPC_FLAG_SMT_1LPAR) && \
> > + PPC_CPU_HAS_CORE_SIBLINGS(cs))
> > +
> > #define _CORE_ID(cs) \
> > (POWERPC_CPU(cs)->env.core_index)
> >
> > diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
> > index ae483e20c4..e71ee008ed 100644
> > --- a/target/ppc/cpu_init.c
> > +++ b/target/ppc/cpu_init.c
> > @@ -6975,7 +6975,7 @@ static void ppc_cpu_realize(DeviceState *dev, Error
> > **errp)
> >
> > pcc->parent_realize(dev, errp);
> >
> > - if (env_cpu(env)->nr_threads > 1) {
> > + if (PPC_CPU_HAS_CORE_SIBLINGS(cs)) {
> > env->flags |= POWERPC_FLAG_SMT;
> > }
> >
> > diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
> > index 0cd542675f..fd45da0f2b 100644
> > --- a/target/ppc/excp_helper.c
> > +++ b/target/ppc/excp_helper.c
> > @@ -3029,7 +3029,7 @@ void helper_book3s_msgsnd(CPUPPCState *env,
> > target_ulong rb)
> > brdcast = true;
> > }
> >
> > - if (cs->nr_threads == 1 || !brdcast) {
> > + if (!PPC_CPU_HAS_CORE_SIBLINGS(cs) || !brdcast) {
>
> Since there are multiple usage of above macro in negation below as well,
> we may probably want to introduce another macro PPC_CPU_HAS_SINGLE_CORE
Ah, you mean SINGLE_THREAD. Yes it would read a bit better.
Thanks,
Nick
> which checks only for nr_threads == 1. Anyways,
>
> Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
>
>
> > ppc_set_irq(cpu, PPC_INTERRUPT_HDOORBELL, 1);
> > return;
> > }
> > @@ -3067,21 +3067,19 @@ void helper_book3s_msgsndp(CPUPPCState *env,
> > target_ulong rb)
> > CPUState *cs = env_cpu(env);
> > PowerPCCPU *cpu = env_archcpu(env);
> > CPUState *ccs;
> > - uint32_t nr_threads = cs->nr_threads;
> > int ttir = rb & PPC_BITMASK(57, 63);
> >
> > helper_hfscr_facility_check(env, HFSCR_MSGP, "msgsndp",
> > HFSCR_IC_MSGP);
> >
> > - if (!(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
> > - nr_threads = 1; /* msgsndp behaves as 1-thread in LPAR-per-thread
> > mode*/
> > - }
> > -
> > - if (!dbell_type_server(rb) || ttir >= nr_threads) {
> > + if (!dbell_type_server(rb)) {
> > return;
> > }
> >
> > - if (nr_threads == 1) {
> > - ppc_set_irq(cpu, PPC_INTERRUPT_DOORBELL, 1);
> > + /* msgsndp behaves as 1-thread in LPAR-per-thread mode*/
> > + if (!PPC_CPU_HAS_LPAR_SIBLINGS(cs)) {
> > + if (ttir == 0) {
> > + ppc_set_irq(cpu, PPC_INTERRUPT_DOORBELL, 1);
> > + }
> > return;
> > }
> >
> > diff --git a/target/ppc/misc_helper.c b/target/ppc/misc_helper.c
> > index 46ba3a5584..598c956cdd 100644
> > --- a/target/ppc/misc_helper.c
> > +++ b/target/ppc/misc_helper.c
> > @@ -49,9 +49,8 @@ void helper_spr_core_write_generic(CPUPPCState *env,
> > uint32_t sprn,
> > {
> > CPUState *cs = env_cpu(env);
> > CPUState *ccs;
> > - uint32_t nr_threads = cs->nr_threads;
> >
> > - if (nr_threads == 1) {
> > + if (!PPC_CPU_HAS_CORE_SIBLINGS(cs)) {
> > env->spr[sprn] = val;
> > return;
> > }
> > @@ -196,7 +195,7 @@ void helper_store_ptcr(CPUPPCState *env, target_ulong
> > val)
> > return;
> > }
> >
> > - if (cs->nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR))
> > {
> > + if (!PPC_CPU_HAS_LPAR_SIBLINGS(cs)) {
> > env->spr[SPR_PTCR] = val;
> > tlb_flush(cs);
> > } else {
> > @@ -243,16 +242,12 @@ target_ulong helper_load_dpdes(CPUPPCState *env)
> > {
> > CPUState *cs = env_cpu(env);
> > CPUState *ccs;
> > - uint32_t nr_threads = cs->nr_threads;
> > target_ulong dpdes = 0;
> >
> > helper_hfscr_facility_check(env, HFSCR_MSGP, "load DPDES",
> > HFSCR_IC_MSGP);
> >
> > - if (!(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
> > - nr_threads = 1; /* DPDES behaves as 1-thread in LPAR-per-thread
> > mode */
> > - }
> > -
> > - if (nr_threads == 1) {
> > + /* DPDES behaves as 1-thread in LPAR-per-thread mode */
> > + if (!PPC_CPU_HAS_LPAR_SIBLINGS(cs)) {
> > if (env->pending_interrupts & PPC_INTERRUPT_DOORBELL) {
> > dpdes = 1;
> > }
> > @@ -279,21 +274,11 @@ void helper_store_dpdes(CPUPPCState *env,
> > target_ulong val)
> > PowerPCCPU *cpu = env_archcpu(env);
> > CPUState *cs = env_cpu(env);
> > CPUState *ccs;
> > - uint32_t nr_threads = cs->nr_threads;
> >
> > helper_hfscr_facility_check(env, HFSCR_MSGP, "store DPDES",
> > HFSCR_IC_MSGP);
> >
> > - if (!(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
> > - nr_threads = 1; /* DPDES behaves as 1-thread in LPAR-per-thread
> > mode */
> > - }
> > -
> > - if (val & ~(nr_threads - 1)) {
> > - qemu_log_mask(LOG_GUEST_ERROR, "Invalid DPDES register value "
> > - TARGET_FMT_lx"\n", val);
> > - val &= (nr_threads - 1); /* Ignore the invalid bits */
> > - }
> > -
> > - if (nr_threads == 1) {
> > + /* DPDES behaves as 1-thread in LPAR-per-thread mode */
> > + if (!PPC_CPU_HAS_LPAR_SIBLINGS(cs)) {
> > ppc_set_irq(cpu, PPC_INTERRUPT_DOORBELL, val & 0x1);
> > return;
> > }
> > diff --git a/target/ppc/timebase_helper.c b/target/ppc/timebase_helper.c
> > index 788c498d63..abe7b95696 100644
> > --- a/target/ppc/timebase_helper.c
> > +++ b/target/ppc/timebase_helper.c
> > @@ -63,9 +63,8 @@ void helper_store_purr(CPUPPCState *env, target_ulong val)
> > {
> > CPUState *cs = env_cpu(env);
> > CPUState *ccs;
> > - uint32_t nr_threads = cs->nr_threads;
> >
> > - if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
> > + if (!PPC_CPU_HAS_LPAR_SIBLINGS(cs)) {
> > cpu_ppc_store_purr(env, val);
> > return;
> > }
> > @@ -82,9 +81,8 @@ void helper_store_tbl(CPUPPCState *env, target_ulong val)
> > {
> > CPUState *cs = env_cpu(env);
> > CPUState *ccs;
> > - uint32_t nr_threads = cs->nr_threads;
> >
> > - if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
> > + if (!PPC_CPU_HAS_LPAR_SIBLINGS(cs)) {
> > cpu_ppc_store_tbl(env, val);
> > return;
> > }
> > @@ -99,9 +97,8 @@ void helper_store_tbu(CPUPPCState *env, target_ulong val)
> > {
> > CPUState *cs = env_cpu(env);
> > CPUState *ccs;
> > - uint32_t nr_threads = cs->nr_threads;
> >
> > - if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
> > + if (!PPC_CPU_HAS_LPAR_SIBLINGS(cs)) {
> > cpu_ppc_store_tbu(env, val);
> > return;
> > }
> > @@ -141,9 +138,8 @@ void helper_store_hdecr(CPUPPCState *env, target_ulong
> > val)
> > {
> > CPUState *cs = env_cpu(env);
> > CPUState *ccs;
> > - uint32_t nr_threads = cs->nr_threads;
> >
> > - if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
> > + if (!PPC_CPU_HAS_LPAR_SIBLINGS(cs)) {
> > cpu_ppc_store_hdecr(env, val);
> > return;
> > }
> > @@ -158,9 +154,8 @@ void helper_store_vtb(CPUPPCState *env, target_ulong
> > val)
> > {
> > CPUState *cs = env_cpu(env);
> > CPUState *ccs;
> > - uint32_t nr_threads = cs->nr_threads;
> >
> > - if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
> > + if (!PPC_CPU_HAS_LPAR_SIBLINGS(cs)) {
> > cpu_ppc_store_vtb(env, val);
> > return;
> > }
> > @@ -175,9 +170,8 @@ void helper_store_tbu40(CPUPPCState *env, target_ulong
> > val)
> > {
> > CPUState *cs = env_cpu(env);
> > CPUState *ccs;
> > - uint32_t nr_threads = cs->nr_threads;
> >
> > - if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
> > + if (!PPC_CPU_HAS_LPAR_SIBLINGS(cs)) {
> > cpu_ppc_store_tbu40(env, val);
> > return;
> > }
> > @@ -288,7 +282,7 @@ static void write_tfmr(CPUPPCState *env, target_ulong
> > val)
> > {
> > CPUState *cs = env_cpu(env);
> >
> > - if (cs->nr_threads == 1) {
> > + if (!PPC_CPU_HAS_CORE_SIBLINGS(cs)) {
> > env->spr[SPR_TFMR] = val;
> > } else {
> > CPUState *ccs;
- Re: [RFC PATCH 05/10] ppc/pnv: Extend chip_pir class method to TIR as well, (continued)
[RFC PATCH 06/10] ppc: Add a core_index to CPUPPCState for SMT vCPUs, Nicholas Piggin, 2024/05/26
[RFC PATCH 07/10] target/ppc: Add helpers to check for SMT sibling threads, Nicholas Piggin, 2024/05/26
[RFC PATCH 08/10] ppc/pnv: Invert the design for big-core machine modelling, Nicholas Piggin, 2024/05/26
Re: [RFC PATCH 08/10] ppc/pnv: Invert the design for big-core machine modelling, Harsh Prateek Bora, 2024/05/29
[RFC PATCH 09/10] ppc/pnv: Implement POWER10 PC xscom registers for direct controls, Nicholas Piggin, 2024/05/26