1 files changed, 5 insertions, 21 deletions

diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 485204f58cda..c08d1ff12b7c 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -214,6 +214,7 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
 
         task_user_gs(p) = get_user_gs(regs);
 
+        p->fpu_counter = 0;
         p->thread.io_bitmap_ptr = NULL;
         tsk = current;
         err = -ENOMEM;
@@ -299,22 +300,11 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
                                  *next = &next_p->thread;
         int cpu = smp_processor_id();
         struct tss_struct *tss = &per_cpu(init_tss, cpu);
-        bool preload_fpu;
+        fpu_switch_t fpu;
 
         /* never put a printk in __switch_to... printk() calls wake_up*() indirectly */
 
-        /*
-         * 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
-         */
-        preload_fpu = tsk_used_math(next_p) && next_p->fpu_counter > 5;
-
-        __unlazy_fpu(prev_p);
-
-        /* we're going to use this soon, after a few expensive things */
-        if (preload_fpu)
-                prefetch(next->fpu.state);
+        fpu = switch_fpu_prepare(prev_p, next_p, cpu);
 
         /*
          * Reload esp0.
@@ -354,11 +344,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
                      task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT))
                 __switch_to_xtra(prev_p, next_p, tss);
 
-        /* If we're going to preload the fpu context, make sure clts
-           is run while we're batching the cpu state updates. */
-        if (preload_fpu)
-                clts();
-
         /*
          * Leave lazy mode, flushing any hypercalls made here.
          * This must be done before restoring TLS segments so
@@ -368,15 +353,14 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
          */
         arch_end_context_switch(next_p);
 
-        if (preload_fpu)
-                __math_state_restore();
-
         /*
          * Restore %gs if needed (which is common)
          */
         if (prev->gs | next->gs)
                 lazy_load_gs(next->gs);
 
+        switch_fpu_finish(next_p, fpu);
+
         percpu_write(current_task, next_p);
 
         return prev_p;