Commit 15f63e30 authored by Michael Ellerman's avatar Michael Ellerman
Browse files

Merge branch 'topic/cpu-smt' into next 

Merge SMT changes we are sharing with the tip tree.
parents 7f965394 d1099e22

Documentation/ABI/testing/sysfs-devices-system-cpu

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@@ -555,6 +555,7 @@ Description: Control Symmetric Multi Threading (SMT) 
			 ================ =========================================

			 "on"		  SMT is enabled

			 "off"		  SMT is disabled

			 "<N>"		  SMT is enabled with N threads per core.

			 "forceoff"	  SMT is force disabled. Cannot be changed.

			 "notsupported"   SMT is not supported by the CPU

			 "notimplemented" SMT runtime toggling is not

Documentation/admin-guide/kernel-parameters.txt

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@@ -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.

arch/Kconfig

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@@ -34,6 +34,9 @@ config ARCH_HAS_SUBPAGE_FAULTS 
config HOTPLUG_SMT

	bool



config SMT_NUM_THREADS_DYNAMIC

	bool



# Selected by HOTPLUG_CORE_SYNC_DEAD or HOTPLUG_CORE_SYNC_FULL

config HOTPLUG_CORE_SYNC

	bool

arch/powerpc/Kconfig

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@@ -272,6 +272,8 @@ config PPC 
	select HAVE_SYSCALL_TRACEPOINTS

	select HAVE_VIRT_CPU_ACCOUNTING

	select HAVE_VIRT_CPU_ACCOUNTING_GEN

	select HOTPLUG_SMT			if HOTPLUG_CPU

	select SMT_NUM_THREADS_DYNAMIC

	select HUGETLB_PAGE_SIZE_VARIABLE	if PPC_BOOK3S_64 && HUGETLB_PAGE

	select IOMMU_HELPER			if PPC64

	select IRQ_DOMAIN

arch/powerpc/include/asm/topology.h

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@@ -143,5 +143,20 @@ static inline int cpu_to_coregroup_id(int cpu) 
#endif

#endif



#ifdef CONFIG_HOTPLUG_SMT

#include <linux/cpu_smt.h>

#include <asm/cputhreads.h>



static inline bool topology_is_primary_thread(unsigned int cpu)

{

	return cpu == cpu_first_thread_sibling(cpu);

}



static inline bool topology_smt_thread_allowed(unsigned int cpu)

{

	return cpu_thread_in_core(cpu) < cpu_smt_num_threads;

}

#endif



#endif /* __KERNEL__ */

#endif	/* _ASM_POWERPC_TOPOLOGY_H */