From 73c58e7e14126466701705820c4eb47daddc357d Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Wed, 5 Jul 2023 16:51:42 +0200 Subject: powerpc: Add HOTPLUG_SMT support Add support for HOTPLUG_SMT, which enables the generic sysfs SMT support files in /sys/devices/system/cpu/smt, as well as the "nosmt" boot parameter. Implement the recently added hooks to allow partial SMT states, allow any number of threads per core. Tie the config symbol to HOTPLUG_CPU, which enables it on the major platforms that support SMT. If there are other platforms that want the SMT support that can be tweaked in future. Signed-off-by: Michael Ellerman [ldufour: remove topology_smt_supported] [ldufour: remove topology_smt_threads_supported] [ldufour: select CONFIG_SMT_NUM_THREADS_DYNAMIC] [ldufour: update kernel-parameters.txt] Signed-off-by: Laurent Dufour Link: https://msgid.link/20230705145143.40545-10-ldufour@linux.ibm.com --- Documentation/admin-guide/kernel-parameters.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'Documentation/admin-guide/kernel-parameters.txt') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index a1457995fd41..cac464386779 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3853,10 +3853,10 @@ nosmp [SMP] Tells an SMP kernel to act as a UP kernel, and disable the IO APIC. legacy for "maxcpus=0". - nosmt [KNL,MIPS,S390] Disable symmetric multithreading (SMT). + nosmt [KNL,MIPS,PPC,S390] Disable symmetric multithreading (SMT). Equivalent to smt=1. - [KNL,X86] Disable symmetric multithreading (SMT). + [KNL,X86,PPC] Disable symmetric multithreading (SMT). nosmt=force: Force disable SMT, cannot be undone via the sysfs control file. -- cgit From 0ceef6e99cc3a57f33b84dafc6df5dfb3b28278d Mon Sep 17 00:00:00 2001 From: Vaibhav Jain Date: Fri, 18 Aug 2023 10:37:37 +0530 Subject: powerpc/idle: Add support for nohlt This patch enables config option GENERIC_IDLE_POLL_SETUP for arch powerpc. This adds support for kernel param 'nohlt'. Powerpc kernel also supports another kernel boot-time param called 'powersave' which can also be used to disable all cpu idle-states and forces CPU to an idle-loop similar to what cpu_idle_poll() does. This patch however makes powerpc kernel-parameters better aligned to the generic boot-time parameters. Signed-off-by: Vaibhav Jain Signed-off-by: Michael Ellerman Link: https://msgid.link/20230818050739.827851-1-vaibhav@linux.ibm.com --- Documentation/admin-guide/kernel-parameters.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation/admin-guide/kernel-parameters.txt') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index cac464386779..fd9f21b49582 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3717,7 +3717,7 @@ nohibernate [HIBERNATION] Disable hibernation and resume. - nohlt [ARM,ARM64,MICROBLAZE,MIPS,SH] Forces the kernel to + nohlt [ARM,ARM64,MICROBLAZE,MIPS,PPC,SH] Forces the kernel to busy wait in do_idle() and not use the arch_cpu_idle() implementation; requires CONFIG_GENERIC_IDLE_POLL_SETUP to be effective. This is useful on platforms where the -- cgit