Merge branch 'linus' into timers/nohz

[firefly-linux-kernel-4.4.55.git] / arch / x86 / kernel / process_32.c

diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 1f5fa1cf16ddff5a1957e649847ef7e010187fb0..53bc653ed5ca52bab902dde3d9efbc0e1630eb6c 100644 (file)
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -58,11 +58,6 @@
 
 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 
-static int hlt_counter;
-
-unsigned long boot_option_idle_override = 0;
-EXPORT_SYMBOL(boot_option_idle_override);
-
 DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
 EXPORT_PER_CPU_SYMBOL(current_task);
 
@@ -77,57 +72,24 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
        return ((unsigned long *)tsk->thread.sp)[3];
 }
 
-/*
- * Powermanagement idle function, if any..
- */
-void (*pm_idle)(void);
-EXPORT_SYMBOL(pm_idle);
+#ifdef CONFIG_HOTPLUG_CPU
+#include <asm/nmi.h>
 
-void disable_hlt(void)
+static void cpu_exit_clear(void)
 {
-       hlt_counter++;
-}
+       int cpu = raw_smp_processor_id();
 
-EXPORT_SYMBOL(disable_hlt);
+       idle_task_exit();
 
-void enable_hlt(void)
-{
-       hlt_counter--;
-}
+       cpu_uninit();
+       irq_ctx_exit(cpu);
 
-EXPORT_SYMBOL(enable_hlt);
+       cpu_clear(cpu, cpu_callout_map);
+       cpu_clear(cpu, cpu_callin_map);
 
-/*
- * We use this if we don't have any better
- * idle routine..
- */
-void default_idle(void)
-{
-       if (!hlt_counter && boot_cpu_data.hlt_works_ok) {
-               current_thread_info()->status &= ~TS_POLLING;
-               /*
-                * TS_POLLING-cleared state must be visible before we
-                * test NEED_RESCHED:
-                */
-               smp_mb();
-
-               if (!need_resched())
-                       safe_halt();    /* enables interrupts racelessly */
-               else
-                       local_irq_enable();
-               current_thread_info()->status |= TS_POLLING;
-       } else {
-               local_irq_enable();
-               /* loop is done by the caller */
-               cpu_relax();
-       }
+       numa_remove_cpu(cpu);
 }
-#ifdef CONFIG_APM_MODULE
-EXPORT_SYMBOL(default_idle);
-#endif
 
-#ifdef CONFIG_HOTPLUG_CPU
-#include <asm/nmi.h>
 /* We don't actually take CPU down, just spin without interrupts. */
 static inline void play_dead(void)
 {
@@ -168,24 +130,22 @@ void cpu_idle(void)
        while (1) {
                tick_nohz_stop_sched_tick(1);
                while (!need_resched()) {
-                       void (*idle)(void);
 
                        check_pgt_cache();
                        rmb();
-                       idle = pm_idle;
 
                        if (rcu_pending(cpu))
                                rcu_check_callbacks(cpu, 0);
 
-                       if (!idle)
-                               idle = default_idle;
-
                        if (cpu_is_offline(cpu))
                                play_dead();
 
                        local_irq_disable();
                        __get_cpu_var(irq_stat).idle_timestamp = jiffies;
-                       idle();
+                       /* Don't trace irqs off for idle */
+                       stop_critical_timings();
+                       pm_idle();
+                       start_critical_timings();
                }
                tick_nohz_restart_sched_tick();
                preempt_enable_no_resched();
@@ -333,6 +293,7 @@ void flush_thread(void)
        /*
         * Forget coprocessor state..
         */
+       tsk->fpu_counter = 0;
        clear_fpu(tsk);
        clear_used_math();
 }
@@ -649,8 +610,11 @@ struct task_struct * __switch_to(struct task_struct *prev_p, struct task_struct
        /* If the task has used fpu the last 5 timeslices, just do a full
         * restore of the math state immediately to avoid the trap; the
         * chances of needing FPU soon are obviously high now
+        *
+        * tsk_used_math() checks prevent calling math_state_restore(),
+        * which can sleep in the case of !tsk_used_math()
         */
-       if (next_p->fpu_counter > 5)
+       if (tsk_used_math(next_p) && next_p->fpu_counter > 5)
                math_state_restore();
 
        /*