MIPS: Avoid FCSR sanitization when CONFIG_MIPS_FP_SUPPORT=n

When CONFIG_MIPS_FP_SUPPORT=n we don't support floating point, so we
don't need to worry about floating point exceptions pending in the
Floating point Control & Status Register (FCSR) during switch_to(). Stub
out the __sanitize_fcr31() macro in this case.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21010/
Cc: linux-mips@linux-mips.org

diff --git a/arch/mips/include/asm/switch_to.h b/arch/mips/include/asm/switch_to.h
index e610473..0f813bb 100644 (file)
--- a/arch/mips/include/asm/switch_to.h
+++ b/arch/mips/include/asm/switch_to.h
@@ -84,7 +84,8 @@ do {                                                                  \
  * Check FCSR for any unmasked exceptions pending set with `ptrace',
  * clear them and send a signal.
  */
-#define __sanitize_fcr31(next)                                         \
+#ifdef CONFIG_MIPS_FP_SUPPORT
+# define __sanitize_fcr31(next)                                                \
 do {                                                                   \
        unsigned long fcr31 = mask_fcr31_x(next->thread.fpu.fcr31);     \
        void __user *pc;                                                \
@@ -95,6 +96,9 @@ do {                                                                  \
                force_fcr31_sig(fcr31, pc, next);                       \
        }                                                               \
 } while (0)
+#else
+# define __sanitize_fcr31(next)
+#endif
 
 /*
  * For newly created kernel threads switch_to() will return to