Re: [PATCH v2 5/8] target/riscv: debug: Introduce tinfo CSR

[LIU Zhiwei]

Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>

Zhiwei

On 2022/9/9 21:42, Bin Meng wrote:
> From: Frank Chang <frank.chang@sifive.com>
>
> 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 <frank.chang@sifive.com>
> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
> ---
>
> (no changes since v1)
>
>   target/riscv/cpu_bits.h |  1 +
>   target/riscv/debug.h    |  2 ++
>   target/riscv/csr.c      |  8 ++++++++
>   target/riscv/debug.c    | 10 +++++++---
>   4 files changed, 18 insertions(+), 3 deletions(-)
>
> diff --git a/target/riscv/cpu_bits.h b/target/riscv/cpu_bits.h
> index 7be12cac2e..1972aee3bb 100644
> --- a/target/riscv/cpu_bits.h
> +++ b/target/riscv/cpu_bits.h
> @@ -321,6 +321,7 @@
>   #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/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);
> diff --git a/target/riscv/csr.c b/target/riscv/csr.c
> index 3d0d8e0340..e66019048d 100644
> --- a/target/riscv/csr.c
> +++ b/target/riscv/csr.c
> @@ -3089,6 +3089,13 @@ 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
> @@ -3893,6 +3900,7 @@ 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 d6666164cd..7d546ace42 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:
>    *
> @@ -372,6 +370,12 @@ 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);