| From foo@baz Tue Aug 14 16:14:56 CEST 2018 |
| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Thu, 21 Jun 2018 10:37:20 +0200 |
| Subject: x86/topology: Provide topology_smt_supported() |
| |
| From: Thomas Gleixner <tglx@linutronix.de> |
| |
| commit f048c399e0f7490ab7296bc2c255d37eb14a9675 upstream |
| |
| 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: David Woodhouse <dwmw@amazon.co.uk> |
| 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 |
| @@ -131,6 +131,7 @@ 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 |
| @@ -138,6 +139,7 @@ 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 |
| @@ -305,6 +305,14 @@ 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 |
