4.18-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Gleixner tglx@linutronix.de
Provide information whether SMT is supoorted by the CPUs. Preparatory patch for SMT control mechanism.
Suggested-by: Dave Hansen dave.hansen@intel.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/include/asm/topology.h | 2 ++ arch/x86/kernel/smpboot.c | 8 ++++++++ 2 files changed, 10 insertions(+)
--- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h @@ -125,6 +125,7 @@ static inline int topology_max_smt_threa int topology_update_package_map(unsigned int apicid, unsigned int cpu); int topology_phys_to_logical_pkg(unsigned int pkg); bool topology_is_primary_thread(unsigned int cpu); +bool topology_smt_supported(void); #else #define topology_max_packages() (1) static inline int @@ -132,6 +133,7 @@ topology_update_package_map(unsigned int static inline int topology_phys_to_logical_pkg(unsigned int pkg) { return 0; } static inline int topology_max_smt_threads(void) { return 1; } static inline bool topology_is_primary_thread(unsigned int cpu) { return true; } +static inline bool topology_smt_supported(void) { return false; } #endif
static inline void arch_fix_phys_package_id(int num, u32 slot) --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -280,6 +280,14 @@ bool topology_is_primary_thread(unsigned }
/** + * topology_smt_supported - Check whether SMT is supported by the CPUs + */ +bool topology_smt_supported(void) +{ + return smp_num_siblings > 1; +} + +/** * topology_phys_to_logical_pkg - Map a physical package id to a logical * * Returns logical package id or -1 if not found