Commit d70a54e2 authored by Greg Kurz's avatar Greg Kurz Committed by Michael Ellerman

powerpc/powernv: Ignore smt-enabled on Power8 and later

Starting with POWER8, the subcore logic relies on all threads of a core
being booted so that they can participate in split mode switches. So on
those machines we ignore the smt_enabled_at_boot setting (smt-enabled on
the kernel command line).
Signed-off-by: default avatarGreg Kurz <gkurz@linux.vnet.ibm.com>
[mpe: Update comment and change log to be more precise]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 505e4283
...@@ -209,13 +209,27 @@ static void pnv_smp_cpu_kill_self(void) ...@@ -209,13 +209,27 @@ static void pnv_smp_cpu_kill_self(void)
#endif /* CONFIG_HOTPLUG_CPU */ #endif /* CONFIG_HOTPLUG_CPU */
static int pnv_cpu_bootable(unsigned int nr)
{
/*
* Starting with POWER8, the subcore logic relies on all threads of a
* core being booted so that they can participate in split mode
* switches. So on those machines we ignore the smt_enabled_at_boot
* setting (smt-enabled on the kernel command line).
*/
if (cpu_has_feature(CPU_FTR_ARCH_207S))
return 1;
return smp_generic_cpu_bootable(nr);
}
static struct smp_ops_t pnv_smp_ops = { static struct smp_ops_t pnv_smp_ops = {
.message_pass = smp_muxed_ipi_message_pass, .message_pass = smp_muxed_ipi_message_pass,
.cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */ .cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */
.probe = xics_smp_probe, .probe = xics_smp_probe,
.kick_cpu = pnv_smp_kick_cpu, .kick_cpu = pnv_smp_kick_cpu,
.setup_cpu = pnv_smp_setup_cpu, .setup_cpu = pnv_smp_setup_cpu,
.cpu_bootable = smp_generic_cpu_bootable, .cpu_bootable = pnv_cpu_bootable,
#ifdef CONFIG_HOTPLUG_CPU #ifdef CONFIG_HOTPLUG_CPU
.cpu_disable = pnv_smp_cpu_disable, .cpu_disable = pnv_smp_cpu_disable,
.cpu_die = generic_cpu_die, .cpu_die = generic_cpu_die,
......
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