diff options
Diffstat (limited to 'arch/mips/math-emu/cp1emu.c')
| -rw-r--r-- | arch/mips/math-emu/cp1emu.c | 15 |
1 files changed, 11 insertions, 4 deletions
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; |