diff mbox series

[v1,3/6] target/microblaze: Add the div-zero-exception property

Message ID 20200417191022.5247-4-edgar.iglesias@gmail.com (mailing list archive)
State New, archived
Headers show
Series target-microblaze: Misc configurability #2 | expand

Commit Message

Edgar E. Iglesias April 17, 2020, 7:10 p.m. UTC 
From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>

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

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
---
 target/microblaze/cpu.c       | 2 ++
 target/microblaze/cpu.h       | 1 +
 target/microblaze/op_helper.c | 5 +++--
 3 files changed, 6 insertions(+), 2 deletions(-)

Comments

Alistair Francis April 17, 2020, 9:35 p.m. UTC | #1 
On Fri, Apr 17, 2020 at 12:15 PM Edgar E. Iglesias
<edgar.iglesias@gmail.com> wrote:
>
> From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>
>
> Add the div-zero-exception property to control if the core
> traps divizions by zero.
>
> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  target/microblaze/cpu.c       | 2 ++
>  target/microblaze/cpu.h       | 1 +
>  target/microblaze/op_helper.c | 5 +++--
>  3 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/target/microblaze/cpu.c b/target/microblaze/cpu.c
> index 36c20d9724..7a40e2fbad 100644
> --- a/target/microblaze/cpu.c
> +++ b/target/microblaze/cpu.c
> @@ -280,6 +280,8 @@ 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 71d7317a58..3c07f9b3f7 100644
> --- 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 18677ddfca..f3b17a95b3 100644
> --- 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);
>          }
> --
> 2.20.1
>
>
Luc Michel April 19, 2020, 7:25 p.m. UTC | #2 
Hi Edgar,

On 4/17/20 9:10 PM, Edgar E. Iglesias wrote:
> From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>
> 
> Add the div-zero-exception property to control if the core
> traps divizions by zero.
> 
> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
> ---
>  target/microblaze/cpu.c       | 2 ++
>  target/microblaze/cpu.h       | 1 +
>  target/microblaze/op_helper.c | 5 +++--
>  3 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/target/microblaze/cpu.c b/target/microblaze/cpu.c
> index 36c20d9724..7a40e2fbad 100644
> --- a/target/microblaze/cpu.c
> +++ b/target/microblaze/cpu.c
> @@ -280,6 +280,8 @@ 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 71d7317a58..3c07f9b3f7 100644
> --- 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 18677ddfca..f3b17a95b3 100644
> --- 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);
>          }
> 

I don't know the Microblaze but don't you need to set pvr.regs[2] in
mb_cpu_realizefn as you do in previous patches?

Something like:

env->pvr.regs[2] |=
                    ...
                    (cpu->cfg.div_zero_exception ?
                         PVR2_DIV_ZERO_EXC_MASK : 0) |
                    ...
Edgar E. Iglesias April 20, 2020, 5:20 p.m. UTC | #3 
On Sun, Apr 19, 2020 at 09:25:28PM +0200, Luc Michel wrote:
> Hi Edgar,
> 
> On 4/17/20 9:10 PM, Edgar E. Iglesias wrote:
> > From: "Edgar E. Iglesias" <edgar.iglesias@xilinx.com>
> > 
> > Add the div-zero-exception property to control if the core
> > traps divizions by zero.
> > 
> > Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
> > ---

...

> >          }
> > 
> 
> I don't know the Microblaze but don't you need to set pvr.regs[2] in
> mb_cpu_realizefn as you do in previous patches?
> 
> Something like:
> 
> env->pvr.regs[2] |=
>                     ...
>                     (cpu->cfg.div_zero_exception ?
>                          PVR2_DIV_ZERO_EXC_MASK : 0) |
>                     ...


Yes you're right Luc. I'll post a v2 shortly.

Thanks,
Edgar
diff mbox series

Patch

diff --git a/target/microblaze/cpu.c b/target/microblaze/cpu.c
index 36c20d9724..7a40e2fbad 100644
--- a/target/microblaze/cpu.c
+++ b/target/microblaze/cpu.c
@@ -280,6 +280,8 @@  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 71d7317a58..3c07f9b3f7 100644
--- 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 18677ddfca..f3b17a95b3 100644
--- 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);
         }