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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt4
-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/include/asm/topology.h6
-rw-r--r--arch/s390/kernel/smp.c8
4 files changed, 10 insertions, 9 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 5e351ac52cca..0d97f811d8b1 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4236,10 +4236,10 @@
nosmp [SMP,EARLY] Tells an SMP kernel to act as a UP kernel,
and disable the IO APIC. legacy for "maxcpus=0".
- nosmt [KNL,MIPS,PPC,S390,EARLY] Disable symmetric multithreading (SMT).
+ nosmt [KNL,MIPS,PPC,EARLY] Disable symmetric multithreading (SMT).
Equivalent to smt=1.
- [KNL,X86,PPC] Disable symmetric multithreading (SMT).
+ [KNL,X86,PPC,S390] Disable symmetric multithreading (SMT).
nosmt=force: Force disable SMT, cannot be undone
via the sysfs control file.
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 6412e39a795d..e220589dae11 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -239,6 +239,7 @@ config S390
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_VIRT_CPU_ACCOUNTING
select HAVE_VIRT_CPU_ACCOUNTING_IDLE
+ select HOTPLUG_SMT
select IOMMU_HELPER if PCI
select IOMMU_SUPPORT if PCI
select KASAN_VMALLOC if KASAN
diff --git a/arch/s390/include/asm/topology.h b/arch/s390/include/asm/topology.h
index cef06bffad80..44110847342a 100644
--- a/arch/s390/include/asm/topology.h
+++ b/arch/s390/include/asm/topology.h
@@ -61,6 +61,12 @@ static inline void topology_expect_change(void) { }
#endif /* CONFIG_SCHED_TOPOLOGY */
+static inline bool topology_is_primary_thread(unsigned int cpu)
+{
+ return smp_get_base_cpu(cpu) == cpu;
+}
+#define topology_is_primary_thread topology_is_primary_thread
+
#define POLARIZATION_UNKNOWN (-1)
#define POLARIZATION_HRZ (0)
#define POLARIZATION_VL (1)
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index f9908a41bfe8..63f41dfaba85 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -99,13 +99,6 @@ __vector128 __initdata boot_cpu_vector_save_area[__NUM_VXRS];
static unsigned int smp_max_threads __initdata = -1U;
cpumask_t cpu_setup_mask;
-static int __init early_nosmt(char *s)
-{
- smp_max_threads = 1;
- return 0;
-}
-early_param("nosmt", early_nosmt);
-
static int __init early_smt(char *s)
{
get_option(&s, &smp_max_threads);
@@ -808,6 +801,7 @@ void __init smp_detect_cpus(void)
mtid = boot_core_type ? sclp.mtid : sclp.mtid_cp;
mtid = (mtid < smp_max_threads) ? mtid : smp_max_threads - 1;
pcpu_set_smt(mtid);
+ cpu_smt_set_num_threads(smp_cpu_mtid + 1, smp_cpu_mtid + 1);
/* Print number of CPUs */
c_cpus = s_cpus = 0;