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| author | Greg Kurz <gkurz@linux.vnet.ibm.com> | 2014-12-12 12:37:40 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2014-12-18 19:59:21 +1100 |
| commit | d70a54e2d08510a99b1f10eceeae6f2f7086e226 (patch) | |
| tree | 2609a216f280aecc8684a9dac4555830d1f794df /arch | |
| parent | 505e428374bc17a2c0bd388c2e8d892e9cd8eef2 (diff) | |
| download | linux-d70a54e2d08510a99b1f10eceeae6f2f7086e226.tar.bz2 | |
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: Greg Kurz <gkurz@linux.vnet.ibm.com>
[mpe: Update comment and change log to be more precise]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/platforms/powernv/smp.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/powernv/smp.c b/arch/powerpc/platforms/powernv/smp.c index 6c551a28e899..fc34025ef822 100644 --- a/arch/powerpc/platforms/powernv/smp.c +++ b/arch/powerpc/platforms/powernv/smp.c @@ -209,13 +209,27 @@ static void pnv_smp_cpu_kill_self(void) #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 = { .message_pass = smp_muxed_ipi_message_pass, .cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */ .probe = xics_smp_probe, .kick_cpu = pnv_smp_kick_cpu, .setup_cpu = pnv_smp_setup_cpu, - .cpu_bootable = smp_generic_cpu_bootable, + .cpu_bootable = pnv_cpu_bootable, #ifdef CONFIG_HOTPLUG_CPU .cpu_disable = pnv_smp_cpu_disable, .cpu_die = generic_cpu_die, |