Correct ISA requirements for floating-point instructions:
* the CU3 exception signifies a real COP3 instruction in MIPS I & II,
* the BC1FL and BC1TL instructions are not supported in MIPS I,
* the SQRT.fmt instructions are indeed supported in MIPS II,
* the LDC1 and SDC1 instructions are indeed supported in MIPS32r1,
* the CEIL.W.fmt, FLOOR.W.fmt, ROUND.W.fmt and TRUNC.W.fmt instructions
are indeed supported in MIPS32,
* the CVT.L.fmt and CVT.fmt.L instructions are indeed supported in
MIPS32r2 and MIPS32r6,
* the CEIL.L.fmt, FLOOR.L.fmt, ROUND.L.fmt and TRUNC.L.fmt instructions
are indeed supported in MIPS32r2 and MIPS32r6,
* the RSQRT.fmt and RECIP.fmt instructions are indeed supported in
MIPS64r1,
Also simplify conditionals for MIPS III and MIPS IV FPU instructions and
the handling of the MOVCI minor opcode.
Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxxxxx>
---
linux-mips-emu-isa.diff
Index: linux/arch/mips/include/asm/cpu-features.h
===================================================================
--- linux.orig/arch/mips/include/asm/cpu-features.h 2015-04-02 20:27:56.252205000 +0100
+++ linux/arch/mips/include/asm/cpu-features.h 2015-04-02 20:27:57.478232000 +0100
@@ -221,8 +221,11 @@
#define cpu_has_mips_4_5_r (cpu_has_mips_4 | cpu_has_mips_5_r)
#define cpu_has_mips_5_r (cpu_has_mips_5 | cpu_has_mips_r)
-#define cpu_has_mips_4_5_r2_r6 (cpu_has_mips_4_5 | cpu_has_mips_r2 | \
- cpu_has_mips_r6)
+#define cpu_has_mips_3_4_5_64_r2_r6 \
+ (cpu_has_mips_3 | cpu_has_mips_4_5_64_r2_r6)
+#define cpu_has_mips_4_5_64_r2_r6 \
+ (cpu_has_mips_4_5 | cpu_has_mips64r1 | \
+ cpu_has_mips_r2 | cpu_has_mips_r6)
#define cpu_has_mips32 (cpu_has_mips32r1 | cpu_has_mips32r2 | cpu_has_mips32r6)
#define cpu_has_mips64 (cpu_has_mips64r1 | cpu_has_mips64r2 | cpu_has_mips64r6)
Index: linux/arch/mips/kernel/traps.c
===================================================================
--- linux.orig/arch/mips/kernel/traps.c 2015-04-02 20:27:56.948213000 +0100
+++ linux/arch/mips/kernel/traps.c 2015-04-02 20:27:57.489216000 +0100
@@ -1349,19 +1349,18 @@ asmlinkage void do_cpu(struct pt_regs *r
case 3:
/*
- * Old (MIPS I and MIPS II) processors will set this code
- * for COP1X opcode instructions that replaced the original
- * COP3 space. We don't limit COP1 space instructions in
- * the emulator according to the CPU ISA, so we want to
- * treat COP1X instructions consistently regardless of which
- * code the CPU chose. Therefore we redirect this trap to
- * the FP emulator too.
- *
- * Then some newer FPU-less processors use this code
- * erroneously too, so they are covered by this choice
- * as well.
+ * The COP3 opcode space and consequently the CP0.Status.CU3
+ * bit and the CP0.Cause.CE=3 encoding have been removed as
+ * of the MIPS III ISA. From the MIPS IV and MIPS32r2 ISAs
+ * up the space has been reused for COP1X instructions, that
+ * are enabled by the CP0.Status.CU1 bit and consequently
+ * use the CP0.Cause.CE=1 encoding for Coprocessor Unusable
+ * exceptions. Some FPU-less processors that implement one
+ * of these ISAs however use this code erroneously for COP1X
+ * instructions. Therefore we redirect this trap to the FP
+ * emulator too.
*/
- if (raw_cpu_has_fpu) {
+ if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) {
force_sig(SIGILL, current);
break;
}
Index: linux/arch/mips/math-emu/cp1emu.c
===================================================================
--- linux.orig/arch/mips/math-emu/cp1emu.c 2015-04-02 20:27:54.459192000 +0100
+++ linux/arch/mips/math-emu/cp1emu.c 2015-04-02 20:27:57.493218000 +0100
@@ -1115,17 +1115,18 @@ static int cop1Emulate(struct pt_regs *x
likely = 0;
switch (MIPSInst_RT(ir) & 3) {
case bcfl_op:
- likely = 1;
+ if (cpu_has_mips_2_3_4_5_r)
+ likely = 1;
+ /* Fall through */
case bcf_op:
cond = !cond;
break;
case bctl_op:
- likely = 1;
+ if (cpu_has_mips_2_3_4_5_r)
+ likely = 1;
+ /* Fall through */
case bct_op:
break;
- default:
- /* thats an illegal instruction */
- return SIGILL;
}
set_delay_slot(xcp);
@@ -1165,36 +1166,34 @@ static int cop1Emulate(struct pt_regs *x
switch (MIPSInst_OPCODE(ir)) {
case lwc1_op:
- goto emul;
-
case swc1_op:
goto emul;
case ldc1_op:
case sdc1_op:
- if (cpu_has_mips_2_3_4_5 ||
- cpu_has_mips64)
+ if (cpu_has_mips_2_3_4_5_r)
goto emul;
return SIGILL;
- goto emul;
case cop1_op:
goto emul;
case cop1x_op:
- if (cpu_has_mips_4_5 || cpu_has_mips64 || cpu_has_mips32r2)
+ if (cpu_has_mips_4_5_64_r2_r6)
/* its one of ours */
goto emul;
return SIGILL;
case spec_op:
- if (!cpu_has_mips_4_5_r)
- return SIGILL;
+ switch (MIPSInst_FUNC(ir)) {
+ case movc_op:
+ if (cpu_has_mips_4_5_r)
+ goto emul;
- if (MIPSInst_FUNC(ir) == movc_op)
- goto emul;
+ return SIGILL;
+ }
break;
}
@@ -1228,7 +1227,7 @@ static int cop1Emulate(struct pt_regs *x
break;
case cop1x_op:
- if (!cpu_has_mips_4_5 && !cpu_has_mips64 && !cpu_has_mips32r2)
+ if (!cpu_has_mips_4_5_64_r2_r6)
return SIGILL;
sig = fpux_emu(xcp, ctx, ir, fault_addr);
@@ -1561,7 +1560,7 @@ static int fpu_emu(struct pt_regs *xcp,
/* unary ops */
case fsqrt_op:
- if (!cpu_has_mips_4_5_r)
+ if (!cpu_has_mips_2_3_4_5_r)
return SIGILL;
handler.u = ieee754sp_sqrt;
@@ -1573,14 +1572,14 @@ static int fpu_emu(struct pt_regs *xcp,
* achieve full IEEE-754 accuracy - however this emulator does.
*/
case frsqrt_op:
- if (!cpu_has_mips_4_5_r2_r6)
+ if (!cpu_has_mips_4_5_64_r2_r6)
return SIGILL;
handler.u = fpemu_sp_rsqrt;
goto scopuop;
case frecip_op:
- if (!cpu_has_mips_4_5_r2_r6)
+ if (!cpu_has_mips_4_5_64_r2_r6)
return SIGILL;
handler.u = fpemu_sp_recip;
@@ -1682,7 +1681,7 @@ static int fpu_emu(struct pt_regs *xcp,
case ftrunc_op:
case fceil_op:
case ffloor_op:
- if (!cpu_has_mips_2_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_2_3_4_5_r)
return SIGILL;
oldrm = ieee754_csr.rm;
@@ -1694,7 +1693,7 @@ static int fpu_emu(struct pt_regs *xcp,
goto copcsr;
case fcvtl_op:
- if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
SPFROMREG(fs, MIPSInst_FS(ir));
@@ -1706,7 +1705,7 @@ static int fpu_emu(struct pt_regs *xcp,
case ftruncl_op:
case fceill_op:
case ffloorl_op:
- if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
oldrm = ieee754_csr.rm;
@@ -1775,13 +1774,13 @@ static int fpu_emu(struct pt_regs *xcp,
* achieve full IEEE-754 accuracy - however this emulator does.
*/
case frsqrt_op:
- if (!cpu_has_mips_4_5_r2_r6)
+ if (!cpu_has_mips_4_5_64_r2_r6)
return SIGILL;
handler.u = fpemu_dp_rsqrt;
goto dcopuop;
case frecip_op:
- if (!cpu_has_mips_4_5_r2_r6)
+ if (!cpu_has_mips_4_5_64_r2_r6)
return SIGILL;
handler.u = fpemu_dp_recip;
@@ -1871,7 +1870,7 @@ static int fpu_emu(struct pt_regs *xcp,
goto copcsr;
case fcvtl_op:
- if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
DPFROMREG(fs, MIPSInst_FS(ir));
@@ -1883,7 +1882,7 @@ static int fpu_emu(struct pt_regs *xcp,
case ftruncl_op:
case fceill_op:
case ffloorl_op:
- if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
oldrm = ieee754_csr.rm;
@@ -1942,7 +1941,7 @@ static int fpu_emu(struct pt_regs *xcp,
case l_fmt:
- if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
DIFROMREG(bits, MIPSInst_FS(ir));
@@ -2006,7 +2005,7 @@ static int fpu_emu(struct pt_regs *xcp,
SITOREG(rv.w, MIPSInst_FD(ir));
break;
case l_fmt:
- if (!cpu_has_mips_3_4_5 && !cpu_has_mips64)
+ if (!cpu_has_mips_3_4_5_64_r2_r6)
return SIGILL;
DITOREG(rv.l, MIPSInst_FD(ir));
