target/microblaze: Add the div-zero-exception property

Add the div-zero-exception property to control if the core
traps divizions by zero.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Luc Michel <luc.michel@greensocs.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>

diff --git a/target/microblaze/cpu.c b/target/microblaze/cpu.c
index 2cc6b1513cdd817232f74ea82a75cb6f437aede0..4211f50c112027253fb1ee7e5141e936698222e2 100644 (file)
--- a/target/microblaze/cpu.c
+++ b/target/microblaze/cpu.c
@@ -207,6 +207,8 @@ static void mb_cpu_realizefn(DeviceState *dev, Error **errp)
                                                  PVR2_DOPB_BUS_EXC_MASK : 0) |
                         (cpu->cfg.iopb_bus_exception ?
                                                  PVR2_IOPB_BUS_EXC_MASK : 0) |
+                        (cpu->cfg.div_zero_exception ?
+                                                 PVR2_DIV_ZERO_EXC_MASK : 0) |
                         (cpu->cfg.illegal_opcode_exception ?
                                                 PVR2_ILL_OPCODE_EXC_MASK : 0) |
                         (cpu->cfg.opcode_0_illegal ?
@@ -280,6 +282,8 @@ static Property mb_properties[] = {
                      cfg.iopb_bus_exception, false),
     DEFINE_PROP_BOOL("ill-opcode-exception", MicroBlazeCPU,
                      cfg.illegal_opcode_exception, false),
+    DEFINE_PROP_BOOL("div-zero-exception", MicroBlazeCPU,
+                     cfg.div_zero_exception, false),
     DEFINE_PROP_BOOL("opcode-0x0-illegal", MicroBlazeCPU,
                      cfg.opcode_0_illegal, false),
     DEFINE_PROP_STRING("version", MicroBlazeCPU, cfg.version),

diff --git a/target/microblaze/cpu.h b/target/microblaze/cpu.h
index 71d7317a58a1925ce11beab6be052a2d66405fff..3c07f9b3f76fd70283125c3af8609ff0a1192070 100644 (file)
--- a/target/microblaze/cpu.h
+++ b/target/microblaze/cpu.h
@@ -305,6 +305,7 @@ struct MicroBlazeCPU {
         bool iopb_bus_exception;
         bool illegal_opcode_exception;
         bool opcode_0_illegal;
+        bool div_zero_exception;
         char *version;
         uint8_t pvr;
     } cfg;

diff --git a/target/microblaze/op_helper.c b/target/microblaze/op_helper.c
index 18677ddfca5b02c3ab650cdb28c2f994330c8eb6..f3b17a95b304940c8d7b4b0d0678c2196d7b94ad 100644 (file)
--- a/target/microblaze/op_helper.c
+++ b/target/microblaze/op_helper.c
@@ -132,11 +132,12 @@ uint32_t helper_carry(uint32_t a, uint32_t b, uint32_t cf)
 
 static inline int div_prepare(CPUMBState *env, uint32_t a, uint32_t b)
 {
+    MicroBlazeCPU *cpu = env_archcpu(env);
+
     if (b == 0) {
         env->sregs[SR_MSR] |= MSR_DZ;
 
-        if ((env->sregs[SR_MSR] & MSR_EE)
-            && !(env->pvr.regs[2] & PVR2_DIV_ZERO_EXC_MASK)) {
+        if ((env->sregs[SR_MSR] & MSR_EE) && cpu->cfg.div_zero_exception) {
             env->sregs[SR_ESR] = ESR_EC_DIVZERO;
             helper_raise_exception(env, EXCP_HW_EXCP);
         }