MIPS: math-emu: Fix prefx detection and COP1X function field definition

When running applications which contain the instruction "prefx" on FPU-less CPUs, a message "Illegal instruction" will be seen. This instruction is supposed to be ignored by the FPU emulator. However, its current detection and function field encoding are incorrect. This patch fix the issue. Signed-off-by: Deng-Cheng Zhu <[email protected]> Reviewed-by: Leonid Yegoshin <[email protected]> Reviewed-by: Paul Burton <[email protected]> Acked-by: David Daney <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/6608/ Signed-off-by: Ralf Baechle <[email protected]>
ddstreet · Mar 11, 2014 · 51061b8 · 51061b8
1 parent 031365b
commit 51061b8
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Showing 2 changed files with 5 additions and 5 deletions.
diff --git a/arch/mips/include/uapi/asm/inst.h b/arch/mips/include/uapi/asm/inst.h
@@ -163,8 +163,8 @@ enum cop1_sdw_func {
  */
 enum cop1x_func {
 	lwxc1_op     =	0x00, ldxc1_op	   =  0x01,
-	pfetch_op    =	0x07, swxc1_op	   =  0x08,
-	sdxc1_op     =	0x09, madd_s_op	   =  0x20,
+	swxc1_op     =  0x08, sdxc1_op	   =  0x09,
+	pfetch_op    =	0x0f, madd_s_op	   =  0x20,
 	madd_d_op    =	0x21, madd_e_op	   =  0x22,
 	msub_s_op    =	0x28, msub_d_op	   =  0x29,
 	msub_e_op    =	0x2a, nmadd_s_op   =  0x30,

diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
@@ -1538,10 +1538,10 @@ static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 		break;
 	}
 
-	case 0x7:		/* 7 */
-		if (MIPSInst_FUNC(ir) != pfetch_op) {
+	case 0x3:
+		if (MIPSInst_FUNC(ir) != pfetch_op)
 			return SIGILL;
-		}
+
 		/* ignore prefx operation */
 		break;