MIPS: math-emu: Correctly handle NOP emulation

[linux-drm-fsl-dcu.git] / arch / mips / math-emu / dsemul.c

diff --git a/arch/mips/math-emu/dsemul.c b/arch/mips/math-emu/dsemul.c
index cbb36c14b155ad07dae2250550bc4090622180cd..70e4824c64dc8d5065c3fdfbad140d302ad02de2 100644 (file)
--- a/arch/mips/math-emu/dsemul.c
+++ b/arch/mips/math-emu/dsemul.c
@@ -31,18 +31,20 @@ struct emuframe {
        unsigned long           epc;
 };
 
+/*
+ * Set up an emulation frame for instruction IR, from a delay slot of
+ * a branch jumping to CPC.  Return 0 if successful, -1 if no emulation
+ * required, otherwise a signal number causing a frame setup failure.
+ */
 int mips_dsemul(struct pt_regs *regs, mips_instruction ir, unsigned long cpc)
 {
        struct emuframe __user *fr;
        int err;
 
+       /* NOP is easy */
        if ((get_isa16_mode(regs->cp0_epc) && ((ir >> 16) == MM_NOP16)) ||
-               (ir == 0)) {
-               /* NOP is easy */
-               regs->cp0_epc = cpc;
-               clear_delay_slot(regs);
-               return 0;
-       }
+           (ir == 0))
+               return -1;
 
        pr_debug("dsemul %lx %lx\n", regs->cp0_epc, cpc);