diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index 49382d5e891a..c6e3c93ce7c7 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -134,6 +134,12 @@
 #define FPU_CSR_COND6   0x40000000      /* $fcc6 */
 #define FPU_CSR_COND7   0x80000000      /* $fcc7 */
 
+/*
+ * Bits 18 - 20 of the FPU Status Register will be read as 0,
+ * and should be written as zero.
+ */
+#define FPU_CSR_RSVD	0x001c0000
+
 /*
  * X the exception cause indicator
  * E the exception enable
@@ -161,7 +167,8 @@
 #define FPU_CSR_UDF_S   0x00000008
 #define FPU_CSR_INE_S   0x00000004
 
-/* rounding mode */
+/* Bits 0 and 1 of FPU Status Register specify the rounding mode */
+#define FPU_CSR_RM	0x00000003
 #define FPU_CSR_RN      0x0     /* nearest */
 #define FPU_CSR_RZ      0x1     /* towards zero */
 #define FPU_CSR_RU      0x2     /* towards +Infinity */
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 8f2f8e9d8b21..f2338d1c0b48 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -78,6 +78,9 @@ DEFINE_PER_CPU(struct mips_fpu_emulator_stats, fpuemustats);
 #define FPCREG_RID	0	/* $0  = revision id */
 #define FPCREG_CSR	31	/* $31 = csr */
 
+/* Determine rounding mode from the RM bits of the FCSR */
+#define modeindex(v) ((v) & FPU_CSR_RM)
+
 /* Convert Mips rounding mode (0..3) to IEEE library modes. */
 static const unsigned char ieee_rm[4] = {
 	[FPU_CSR_RN] = IEEE754_RN,
@@ -384,10 +387,14 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
 					(void *) (xcp->cp0_epc),
 					MIPSInst_RT(ir), value);
 #endif
-				value &= (FPU_CSR_FLUSH | FPU_CSR_ALL_E | FPU_CSR_ALL_S | 0x03);
-				ctx->fcr31 &= ~(FPU_CSR_FLUSH | FPU_CSR_ALL_E | FPU_CSR_ALL_S | 0x03);
-				/* convert to ieee library modes */
-				ctx->fcr31 |= (value & ~0x3) | ieee_rm[value & 0x3];
+
+				/*
+				 * Don't write reserved bits,
+				 * and convert to ieee library modes
+				 */
+				ctx->fcr31 = (value &
+						~(FPU_CSR_RSVD | FPU_CSR_RM)) |
+						ieee_rm[modeindex(value)];
 			}
 			if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
 				return SIGFPE;