diff mbox series

[2/3] target/m68k: Implement TRAPcc

Message ID 20211130103752.72099-3-richard.henderson@linaro.org
State New
Headers show
Series target/m68k: Implement conditional traps | expand

Commit Message

Richard Henderson Nov. 30, 2021, 10:37 a.m. UTC
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/754
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/m68k/cpu.h       |  2 ++
 target/m68k/cpu.c       |  1 +
 target/m68k/translate.c | 21 +++++++++++++++++++++
 3 files changed, 24 insertions(+)

Comments

Laurent Vivier Nov. 30, 2021, 11:57 a.m. UTC | #1
Le 30/11/2021 à 11:37, Richard Henderson a écrit :
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/754
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   target/m68k/cpu.h       |  2 ++
>   target/m68k/cpu.c       |  1 +
>   target/m68k/translate.c | 21 +++++++++++++++++++++
>   3 files changed, 24 insertions(+)
> 
> diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h
> index a3423729ef..03f600f7e7 100644
> --- a/target/m68k/cpu.h
> +++ b/target/m68k/cpu.h
> @@ -527,6 +527,8 @@ enum m68k_features {
>       M68K_FEATURE_MOVEC,
>       /* Unaligned data accesses (680[2346]0) */
>       M68K_FEATURE_UNALIGNED_DATA,
> +    /* TRAPCC insn. (680[2346]0, and CPU32) */
> +    M68K_FEATURE_TRAPCC,
>   };
>   
>   static inline int m68k_feature(CPUM68KState *env, int feature)
> diff --git a/target/m68k/cpu.c b/target/m68k/cpu.c
> index c7aeb7da9c..5f778773d1 100644
> --- a/target/m68k/cpu.c
> +++ b/target/m68k/cpu.c
> @@ -162,6 +162,7 @@ static void m68020_cpu_initfn(Object *obj)
>       m68k_set_feature(env, M68K_FEATURE_CHK2);
>       m68k_set_feature(env, M68K_FEATURE_MSP);
>       m68k_set_feature(env, M68K_FEATURE_UNALIGNED_DATA);
> +    m68k_set_feature(env, M68K_FEATURE_TRAPCC);
>   }
>   
>   /*
> diff --git a/target/m68k/translate.c b/target/m68k/translate.c
> index 858ba761fc..cf29f35d91 100644
> --- a/target/m68k/translate.c
> +++ b/target/m68k/translate.c
> @@ -4879,6 +4879,26 @@ DISAS_INSN(trapv)
>       do_trapcc(s, 9); /* VS */
>   }
>   
> +DISAS_INSN(trapcc)
> +{
> +    /* Consume and discard the immediate operand. */
> +    switch (extract32(insn, 0, 3)) {
> +    case 2: /* trapcc.w */
> +        (void)read_im16(env, s);
> +        break;
> +    case 3: /* trapcc.l */
> +        (void)read_im32(env, s);
> +        break;

Do we need to actually read the memory to trigger a fault if needed or can we only increase the PC?

Normally these values are for the trap handler.

> +    case 4: /* trapcc (no operand) */
> +        break;
> +    default:
> +        /* Illegal insn */
> +        disas_undef(env, s, insn);
> +        return;
> +    }
> +    do_trapcc(s, extract32(insn, 8, 4));
> +}

Do we need to change something in m68k_interrupt_all()?

     if (!is_hw) {
         switch (cs->exception_index) {
         case EXCP_RTE:
             /* Return from an exception.  */
             m68k_rte(env);
             return;
         case EXCP_TRAP0 ...  EXCP_TRAP15:
             /* Move the PC after the trap instruction.  */
             retaddr += 2;
             break;
         }
     }

Thanks,
Laurent

> +
>   static void gen_load_fcr(DisasContext *s, TCGv res, int reg)
>   {
>       switch (reg) {
> @@ -6051,6 +6071,7 @@ void register_m68k_insns (CPUM68KState *env)
>       INSN(scc,       50c0, f0f8, CF_ISA_A); /* Scc.B Dx   */
>       INSN(scc,       50c0, f0c0, M68000);   /* Scc.B <EA> */
>       INSN(dbcc,      50c8, f0f8, M68000);
> +    INSN(trapcc,    50f8, f0f8, TRAPCC);
>       INSN(tpf,       51f8, fff8, CF_ISA_A);
>   
>       /* Branch instructions.  */
>
Richard Henderson Nov. 30, 2021, 12:34 p.m. UTC | #2
On 11/30/21 12:57 PM, Laurent Vivier wrote:
>> +DISAS_INSN(trapcc)
>> +{
>> +    /* Consume and discard the immediate operand. */
>> +    switch (extract32(insn, 0, 3)) {
>> +    case 2: /* trapcc.w */
>> +        (void)read_im16(env, s);
>> +        break;
>> +    case 3: /* trapcc.l */
>> +        (void)read_im32(env, s);
>> +        break;
> 
> Do we need to actually read the memory to trigger a fault if needed or can we only 
> increase the PC?

Yes, and to pass the entire instruction to plugins.

>> +    case 4: /* trapcc (no operand) */
>> +        break;
>> +    default:
>> +        /* Illegal insn */
>> +        disas_undef(env, s, insn);
>> +        return;
>> +    }
>> +    do_trapcc(s, extract32(insn, 8, 4));
>> +}
> 
> Do we need to change something in m68k_interrupt_all()?

Yes, and cpu_loop.  Thanks,


r~
diff mbox series

Patch

diff --git a/target/m68k/cpu.h b/target/m68k/cpu.h
index a3423729ef..03f600f7e7 100644
--- a/target/m68k/cpu.h
+++ b/target/m68k/cpu.h
@@ -527,6 +527,8 @@  enum m68k_features {
     M68K_FEATURE_MOVEC,
     /* Unaligned data accesses (680[2346]0) */
     M68K_FEATURE_UNALIGNED_DATA,
+    /* TRAPCC insn. (680[2346]0, and CPU32) */
+    M68K_FEATURE_TRAPCC,
 };
 
 static inline int m68k_feature(CPUM68KState *env, int feature)
diff --git a/target/m68k/cpu.c b/target/m68k/cpu.c
index c7aeb7da9c..5f778773d1 100644
--- a/target/m68k/cpu.c
+++ b/target/m68k/cpu.c
@@ -162,6 +162,7 @@  static void m68020_cpu_initfn(Object *obj)
     m68k_set_feature(env, M68K_FEATURE_CHK2);
     m68k_set_feature(env, M68K_FEATURE_MSP);
     m68k_set_feature(env, M68K_FEATURE_UNALIGNED_DATA);
+    m68k_set_feature(env, M68K_FEATURE_TRAPCC);
 }
 
 /*
diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index 858ba761fc..cf29f35d91 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -4879,6 +4879,26 @@  DISAS_INSN(trapv)
     do_trapcc(s, 9); /* VS */
 }
 
+DISAS_INSN(trapcc)
+{
+    /* Consume and discard the immediate operand. */
+    switch (extract32(insn, 0, 3)) {
+    case 2: /* trapcc.w */
+        (void)read_im16(env, s);
+        break;
+    case 3: /* trapcc.l */
+        (void)read_im32(env, s);
+        break;
+    case 4: /* trapcc (no operand) */
+        break;
+    default:
+        /* Illegal insn */
+        disas_undef(env, s, insn);
+        return;
+    }
+    do_trapcc(s, extract32(insn, 8, 4));
+}
+
 static void gen_load_fcr(DisasContext *s, TCGv res, int reg)
 {
     switch (reg) {
@@ -6051,6 +6071,7 @@  void register_m68k_insns (CPUM68KState *env)
     INSN(scc,       50c0, f0f8, CF_ISA_A); /* Scc.B Dx   */
     INSN(scc,       50c0, f0c0, M68000);   /* Scc.B <EA> */
     INSN(dbcc,      50c8, f0f8, M68000);
+    INSN(trapcc,    50f8, f0f8, TRAPCC);
     INSN(tpf,       51f8, fff8, CF_ISA_A);
 
     /* Branch instructions.  */