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Diffstat (limited to 'arch/s390/include/asm/switch_to.h')
-rw-r--r--arch/s390/include/asm/switch_to.h27
1 files changed, 13 insertions, 14 deletions
diff --git a/arch/s390/include/asm/switch_to.h b/arch/s390/include/asm/switch_to.h
index ec7b476c1ac5..c61b2cc1a8a8 100644
--- a/arch/s390/include/asm/switch_to.h
+++ b/arch/s390/include/asm/switch_to.h
@@ -30,21 +30,20 @@ static inline void restore_access_regs(unsigned int *acrs)
asm volatile("lam 0,15,%0" : : "Q" (*(acrstype *)acrs));
}
-#define switch_to(prev,next,last) do { \
- if (prev->mm) { \
- save_fpu_regs(); \
- save_access_regs(&prev->thread.acrs[0]); \
- save_ri_cb(prev->thread.ri_cb); \
- save_gs_cb(prev->thread.gs_cb); \
- } \
+#define switch_to(prev, next, last) do { \
+ /* save_fpu_regs() sets the CIF_FPU flag, which enforces \
+ * a restore of the floating point / vector registers as \
+ * soon as the next task returns to user space \
+ */ \
+ save_fpu_regs(); \
+ save_access_regs(&prev->thread.acrs[0]); \
+ save_ri_cb(prev->thread.ri_cb); \
+ save_gs_cb(prev->thread.gs_cb); \
update_cr_regs(next); \
- if (next->mm) { \
- set_cpu_flag(CIF_FPU); \
- restore_access_regs(&next->thread.acrs[0]); \
- restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb); \
- restore_gs_cb(next->thread.gs_cb); \
- } \
- prev = __switch_to(prev,next); \
+ restore_access_regs(&next->thread.acrs[0]); \
+ restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb); \
+ restore_gs_cb(next->thread.gs_cb); \
+ prev = __switch_to(prev, next); \
} while (0)
#endif /* __ASM_SWITCH_TO_H */