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| author | Michael Ellerman <mpe@ellerman.id.au> | 2023-07-05 16:51:42 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-08-02 22:49:43 +1000 |
| commit | 73c58e7e14126466701705820c4eb47daddc357d (patch) | |
| tree | d07ae0e1b3836a96e7d4477fa7cfb6b8bf23059c /arch/powerpc/kernel/smp.c | |
| parent | 3b3a4d0fe542b8c2295cf934305b45a14e224beb (diff) | |
| download | linux-73c58e7e14126466701705820c4eb47daddc357d.tar.gz | |
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 <mpe@ellerman.id.au>
[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 <ldufour@linux.ibm.com>
Link: https://msgid.link/20230705145143.40545-10-ldufour@linux.ibm.com
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index fbbb695bae3d25..b9f0f8f11c3768 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -1087,7 +1087,7 @@ static int __init init_big_cores(void) void __init smp_prepare_cpus(unsigned int max_cpus) { - unsigned int cpu; + unsigned int cpu, num_threads; DBG("smp_prepare_cpus\n"); @@ -1154,6 +1154,12 @@ void __init smp_prepare_cpus(unsigned int max_cpus) if (smp_ops && smp_ops->probe) smp_ops->probe(); + + // Initalise the generic SMT topology support + num_threads = 1; + if (smt_enabled_at_boot) + num_threads = smt_enabled_at_boot; + cpu_smt_set_num_threads(num_threads, threads_per_core); } void smp_prepare_boot_cpu(void) |