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ppc/pnv: use class attribute to limit SMT threads for different machines

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Use a class attribute to specify the number of SMT threads per core
permitted for different machines, 8 for powernv8 and 4 for powernv9/10.

Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
This commit is contained in:
Nicholas Piggin 2024-05-24 15:52:04 +10:00
parent 60d30cff84
commit d76cb5a53b
2 changed files with 10 additions and 3 deletions
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12
hw/ppc/pnv.c
View File

@ -899,6 +899,7 @@ static void pnv_init(MachineState *machine)
PnvMachineState *pnv = PNV_MACHINE(machine);
MachineClass *mc = MACHINE_GET_CLASS(machine);
PnvMachineClass *pmc = PNV_MACHINE_GET_CLASS(machine);
int max_smt_threads = pmc->max_smt_threads;
char *fw_filename;
long fw_size;
uint64_t chip_ram_start = 0;
@ -997,17 +998,19 @@ static void pnv_init(MachineState *machine)
pnv->num_chips =
machine->smp.max_cpus / (machine->smp.cores * machine->smp.threads);
if (machine->smp.threads > 8) {
error_report("Cannot support more than 8 threads/core "
"on a powernv machine");
if (machine->smp.threads > max_smt_threads) {
error_report("Cannot support more than %d threads/core "
"on %s machine", max_smt_threads, mc->desc);
exit(1);
}
if (!is_power_of_2(machine->smp.threads)) {
error_report("Cannot support %d threads/core on a powernv"
"machine because it must be a power of 2",
machine->smp.threads);
exit(1);
}
/*
* TODO: should we decide on how many chips we can create based
* on #cores and Venice vs. Murano vs. Naples chip type etc...,
@ -2490,6 +2493,7 @@ static void pnv_machine_power8_class_init(ObjectClass *oc, void *data)
pmc->compat = compat;
pmc->compat_size = sizeof(compat);
pmc->max_smt_threads = 8;
machine_class_allow_dynamic_sysbus_dev(mc, TYPE_PNV_PHB);
}
@ -2514,6 +2518,7 @@ static void pnv_machine_power9_class_init(ObjectClass *oc, void *data)
pmc->compat = compat;
pmc->compat_size = sizeof(compat);
pmc->max_smt_threads = 4;
pmc->dt_power_mgt = pnv_dt_power_mgt;
machine_class_allow_dynamic_sysbus_dev(mc, TYPE_PNV_PHB);
@ -2538,6 +2543,7 @@ static void pnv_machine_p10_common_class_init(ObjectClass *oc, void *data)
pmc->compat = compat;
pmc->compat_size = sizeof(compat);
pmc->max_smt_threads = 4;
pmc->dt_power_mgt = pnv_dt_power_mgt;
xfc->match_nvt = pnv10_xive_match_nvt;

1
include/hw/ppc/pnv.h
View File

@ -76,6 +76,7 @@ struct PnvMachineClass {
/*< public >*/
const char *compat;
int compat_size;
int max_smt_threads;
void (*dt_power_mgt)(PnvMachineState *pnv, void *fdt);
void (*i2c_init)(PnvMachineState *pnv);