x86/topology: Provide topology_smt_supported()
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>
diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index e5e6c02c..1fbb174 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -131,6 +131,7 @@
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 @@
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)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index e230c47..168cc3b 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -305,6 +305,14 @@
}
/**
+ * 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