[5/9] target/riscv: debug: Introduce tinfo CSR

Commit Message

Frank Chang June 10, 2022, 5:13 a.m. UTC

From: Frank Chang <[e-mail]>

tinfo.info:
  One bit for each possible type enumerated in tdata1.
  If the bit is set, then that type is supported by the currently
  selected trigger.

Signed-off-by: Frank Chang <[e-mail]>
---
 target/riscv/cpu_bits.h |  1 +
 target/riscv/csr.c      |  8 ++++++++
 target/riscv/debug.c    | 10 +++++++---
 target/riscv/debug.h    |  2 ++
 4 files changed, 18 insertions(+), 3 deletions(-)

Comments

Bin Meng June 15, 2022, 12:26 p.m. UTC | #1

On Fri, Jun 10, 2022 at 1:21 PM <[e-mail]> wrote:
>
> From: Frank Chang <[e-mail]>
>
> tinfo.info:
>   One bit for each possible type enumerated in tdata1.
>   If the bit is set, then that type is supported by the currently
>   selected trigger.
>
> Signed-off-by: Frank Chang <[e-mail]>
> ---
>  target/riscv/cpu_bits.h |  1 +
>  target/riscv/csr.c      |  8 ++++++++
>  target/riscv/debug.c    | 10 +++++++---
>  target/riscv/debug.h    |  2 ++
>  4 files changed, 18 insertions(+), 3 deletions(-)
>

Reviewed-by: Bin Meng <[e-mail]>

Patch

diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
index 4d04b20d06..666b4d69ca 100644
--- a/target/riscv/cpu_bits.h
+++ b/target/riscv/cpu_bits.h
@@ -331,6 +331,7 @@ 
 #define CSR_TDATA1          0x7a1
 #define CSR_TDATA2          0x7a2
 #define CSR_TDATA3          0x7a3
+#define CSR_TINFO           0x7a4
 
 /* Debug Mode Registers */
 #define CSR_DCSR            0x7b0
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 005ae31a01..823b6bd520 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -2800,6 +2800,13 @@  static RISCVException write_tdata(CPURISCVState *env, int csrno,
     return RISCV_EXCP_NONE;
 }
 
+static RISCVException read_tinfo(CPURISCVState *env, int csrno,
+                                 target_ulong *val)
+{
+    *val = tinfo_csr_read(env);
+    return RISCV_EXCP_NONE;
+}
+
 /*
  * Functions to access Pointer Masking feature registers
  * We have to check if current priv lvl could modify
@@ -3588,6 +3595,7 @@  riscv_csr_operations csr_ops[CSR_TABLE_SIZE] = {
     [CSR_TDATA1]    =  { "tdata1",  debug, read_tdata,   write_tdata   },
     [CSR_TDATA2]    =  { "tdata2",  debug, read_tdata,   write_tdata   },
     [CSR_TDATA3]    =  { "tdata3",  debug, read_tdata,   write_tdata   },
+    [CSR_TINFO]     =  { "tinfo",   debug, read_tinfo,   write_ignore  },
 
     /* User Pointer Masking */
     [CSR_UMTE]    =    { "umte",    pointer_masking, read_umte,    write_umte    },
diff --git a/target/riscv/debug.c b/target/riscv/debug.c
index 296192ffc4..1668b8abda 100644
--- a/target/riscv/debug.c
+++ b/target/riscv/debug.c
@@ -37,9 +37,7 @@ 
  * - tdata1
  * - tdata2
  * - tdata3
- *
- * We don't support writable 'type' field in the tdata1 register, so there is
- * no need to implement the "tinfo" CSR.
+ * - tinfo
  *
  * The following triggers are implemented:
  *
@@ -369,6 +367,12 @@  void tdata_csr_write(CPURISCVState *env, int tdata_index, target_ulong val)
     }
 }
 
+target_ulong tinfo_csr_read(CPURISCVState *env)
+{
+    /* assume all triggers support the same types of triggers */
+    return BIT(TRIGGER_TYPE_AD_MATCH);
+}
+
 void riscv_cpu_debug_excp_handler(CPUState *cs)
 {
     RISCVCPU *cpu = RISCV_CPU(cs);
diff --git a/target/riscv/debug.h b/target/riscv/debug.h
index 76146f373a..9f69c64591 100644
--- a/target/riscv/debug.h
+++ b/target/riscv/debug.h
@@ -95,6 +95,8 @@  void tselect_csr_write(CPURISCVState *env, target_ulong val);
 target_ulong tdata_csr_read(CPURISCVState *env, int tdata_index);
 void tdata_csr_write(CPURISCVState *env, int tdata_index, target_ulong val);
 
+target_ulong tinfo_csr_read(CPURISCVState *env);
+
 void riscv_cpu_debug_excp_handler(CPUState *cs);
 bool riscv_cpu_debug_check_breakpoint(CPUState *cs);
 bool riscv_cpu_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp);