1 files changed, 16 insertions, 0 deletions

diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index 0673c4746be3..aff5fe02e393 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -288,8 +288,14 @@ static void ubc_set_tracing(int asid, unsigned long pc)
 __notrace_funcgraph struct task_struct *
 __switch_to(struct task_struct *prev, struct task_struct *next)
 {
+        struct thread_struct *next_t = &next->thread;
+
 #if defined(CONFIG_SH_FPU)
         unlazy_fpu(prev, task_pt_regs(prev));
+
+        /* we're going to use this soon, after a few expensive things */
+        if (next->fpu_counter > 5)
+                prefetch(&next_t->fpu.hard);
 #endif
 
 #ifdef CONFIG_MMU
@@ -321,6 +327,16 @@ __switch_to(struct task_struct *prev, struct task_struct *next)
 #endif
         }
 
+#if defined(CONFIG_SH_FPU)
+        /* 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
+         */
+        if (next->fpu_counter > 5) {
+                fpu_state_restore(task_pt_regs(next));
+        }
+#endif
+
         return prev;
 }