In commit d70a54e2d085 ("powerpc/powernv: Ignore smt-enabled on Power8
and later") we disabled smt-enabled=off on Power8 and later CPUs
because the subcore logic required all CPUs to be booted.
However Power9 doesn't support subcore, so we can support
smt-enabled=off on Power9. Fix the code to do that.
Fixes: c3ab300ea555 ("powerpc: Add POWER9 cputable entry")
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
---
arch/powerpc/platforms/powernv/smp.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/smp.c
b/arch/powerpc/platforms/powernv/smp.c
index 0d354e19ef92..3ab5755eb09f 100644
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
@@ -254,12 +254,12 @@ static void pnv_smp_cpu_kill_self(void)
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).
+ * On 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))
+ if (cpu_has_feature(CPU_FTR_ARCH_207S) &&
!cpu_has_feature(CPU_FTR_ARCH_300))
return 1;
return smp_generic_cpu_bootable(nr);
--
2.20.1
