#if defined(CONFIG_SMP) && defined(CONFIG_HOTPLUG_SMT)
extern enum cpuhp_smt_control cpu_smt_control;
+extern unsigned int cpu_smt_num_threads;
extern void cpu_smt_disable(bool force);
-extern void cpu_smt_check_topology(void);
+extern void cpu_smt_set_num_threads(unsigned int num_threads,
+ unsigned int max_threads);
extern bool cpu_smt_possible(void);
extern int cpuhp_smt_enable(void);
extern int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval);
#else
# define cpu_smt_control (CPU_SMT_NOT_IMPLEMENTED)
+# define cpu_smt_num_threads 1
static inline void cpu_smt_disable(bool force) { }
-static inline void cpu_smt_check_topology(void) { }
+static inline void cpu_smt_set_num_threads(unsigned int num_threads,
+ unsigned int max_threads) { }
static inline bool cpu_smt_possible(void) { return false; }
static inline int cpuhp_smt_enable(void) { return 0; }
static inline int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { return 0; }
#ifdef CONFIG_HOTPLUG_SMT
enum cpuhp_smt_control cpu_smt_control __read_mostly = CPU_SMT_ENABLED;
+static unsigned int cpu_smt_max_threads __ro_after_init;
+unsigned int cpu_smt_num_threads __read_mostly = UINT_MAX;
void __init cpu_smt_disable(bool force)
{
pr_info("SMT: disabled\n");
cpu_smt_control = CPU_SMT_DISABLED;
}
+ cpu_smt_num_threads = 1;
}
/*
* The decision whether SMT is supported can only be done after the full
* CPU identification. Called from architecture code.
*/
-void __init cpu_smt_check_topology(void)
+void __init cpu_smt_set_num_threads(unsigned int num_threads,
+ unsigned int max_threads)
{
+ WARN_ON(!num_threads || (num_threads > max_threads));
+
if (!topology_smt_supported())
cpu_smt_control = CPU_SMT_NOT_SUPPORTED;
+
+ cpu_smt_max_threads = max_threads;
+
+ /*
+ * If SMT has been disabled via the kernel command line or SMT is
+ * not supported, set cpu_smt_num_threads to 1 for consistency.
+ * If enabled, take the architecture requested number of threads
+ * to bring up into account.
+ */
+ if (cpu_smt_control != CPU_SMT_ENABLED)
+ cpu_smt_num_threads = 1;
+ else if (num_threads < cpu_smt_num_threads)
+ cpu_smt_num_threads = num_threads;
}
static int __init smt_cmdline_disable(char *str)