Re: [PATCH] target/riscv: Add Tenstorrent Ascalon CPU

[Daniel Henrique Barboza]

Hi,

On 11/8/24 8:07 PM, Anton Blanchard wrote:
> Add a CPU entry for the Tenstorrent Ascalon CPU, a series of 2 wide to
> 8 wide RV64 cores.

As Phil mentioned, it would be nice to have a reference of the CPU you're
adding. The link you gave in the reply (https://tenstorrent.com/ip/tt-ascalon)
is enough.

> Signed-off-by: Anton Blanchard <antonb@tenstorrent.com>
> ---
>   target/riscv/cpu-qom.h |  1 +
>   target/riscv/cpu.c     | 67 ++++++++++++++++++++++++++++++++++++++++++
>   2 files changed, 68 insertions(+)
>
> diff --git a/target/riscv/cpu-qom.h b/target/riscv/cpu-qom.h
> index 62115375cd..6547642287 100644
> --- a/target/riscv/cpu-qom.h
> +++ b/target/riscv/cpu-qom.h
> @@ -49,6 +49,7 @@
>   #define TYPE_RISCV_CPU_SIFIVE_U54       RISCV_CPU_TYPE_NAME("sifive-u54")
>   #define TYPE_RISCV_CPU_THEAD_C906       RISCV_CPU_TYPE_NAME("thead-c906")
>   #define TYPE_RISCV_CPU_VEYRON_V1        RISCV_CPU_TYPE_NAME("veyron-v1")
> +#define TYPE_RISCV_CPU_TT_ASCALON       RISCV_CPU_TYPE_NAME("tt-ascalon")
>   #define TYPE_RISCV_CPU_HOST             RISCV_CPU_TYPE_NAME("host")
>   
>   OBJECT_DECLARE_CPU_TYPE(RISCVCPU, RISCVCPUClass, RISCV_CPU)
> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> index f219f0c3b5..8447ad0dfb 100644
> --- a/target/riscv/cpu.c
> +++ b/target/riscv/cpu.c
> @@ -579,6 +579,72 @@ static void rv64_veyron_v1_cpu_init(Object *obj)
>   #endif
>   }
>   
> +/* Tenstorrent Ascalon */
> +static void rv64_tt_ascalon_cpu_init(Object *obj)
> +{
> +    CPURISCVState *env = &RISCV_CPU(obj)->env;
> +    RISCVCPU *cpu = RISCV_CPU(obj);
> +
> +    riscv_cpu_set_misa_ext(env, RVG | RVC | RVS | RVU | RVH | RVV);
> +    env->priv_ver = PRIV_VERSION_1_13_0;
> +
> +    /* Enable ISA extensions */
> +    cpu->cfg.mmu = true;
> +    cpu->cfg.vlenb = 256 >> 3;
> +    cpu->cfg.elen = 64;
> +    cpu->env.vext_ver = VEXT_VERSION_1_00_0;
> +    cpu->cfg.rvv_ma_all_1s = true;
> +    cpu->cfg.rvv_ta_all_1s = true;
> +    cpu->cfg.misa_w = true;
> +    cpu->cfg.pmp = true;
> +    cpu->cfg.cbom_blocksize = 64;
> +    cpu->cfg.cbop_blocksize = 64;
> +    cpu->cfg.cboz_blocksize = 64;
> +    cpu->cfg.ext_zic64b = true;
> +    cpu->cfg.ext_zicbom = true;
> +    cpu->cfg.ext_zicbop = true;
> +    cpu->cfg.ext_zicboz = true;
> +    cpu->cfg.ext_zicntr = true;
> +    cpu->cfg.ext_zicond = true;
> +    cpu->cfg.ext_zicsr = true;
> +    cpu->cfg.ext_zifencei = true;
> +    cpu->cfg.ext_zihintntl = true;
> +    cpu->cfg.ext_zihintpause = true;
> +    cpu->cfg.ext_zihpm = true;
> +    cpu->cfg.ext_zimop = true;
> +    cpu->cfg.ext_zawrs = true;
> +    cpu->cfg.ext_zfa = true;
> +    cpu->cfg.ext_zfbfmin = true;
> +    cpu->cfg.ext_zfh = true;
> +    cpu->cfg.ext_zfhmin = true;
> +    cpu->cfg.ext_zcb = true;
> +    cpu->cfg.ext_zcmop = true;
> +    cpu->cfg.ext_zba = true;
> +    cpu->cfg.ext_zbb = true;
> +    cpu->cfg.ext_zbs = true;
> +    cpu->cfg.ext_zkt = true;
> +    cpu->cfg.ext_zvbb = true;
> +    cpu->cfg.ext_zvbc = true;
> +    cpu->cfg.ext_zvfbfmin = true;
> +    cpu->cfg.ext_zvfbfwma = true;
> +    cpu->cfg.ext_zvfh = true;
> +    cpu->cfg.ext_zvfhmin = true;
> +    cpu->cfg.ext_zvkng = true;
> +    cpu->cfg.ext_smaia = true;
> +    cpu->cfg.ext_smstateen = true;
> +    cpu->cfg.ext_ssaia = true;
> +    cpu->cfg.ext_sscofpmf = true;
> +    cpu->cfg.ext_sstc = true;
> +    cpu->cfg.ext_svade = true;
> +    cpu->cfg.ext_svinval = true;
> +    cpu->cfg.ext_svnapot = true;
> +    cpu->cfg.ext_svpbmt = true;
> +
> +#ifndef CONFIG_USER_ONLY
> +    set_satp_mode_max_supported(cpu, VM_1_10_SV57);
> +#endif

Patch looks good. One thing to consider is to set mvendorid/marchid/mimpid in 
case
the CPU defines specific IDs. These IDs can be read later by software to 
determine
if a certain vendor CPU is being used (and then vendor specific drivers can be
used, for example). See rv64_veryon_v1_cpu_init() for an example.

This is optional though. Feel free to leave it as is. Thanks,


Daniel



> +}
> +
>   #ifdef CONFIG_TCG
>   static void rv128_base_cpu_init(Object *obj)
>   {
> @@ -2982,6 +3048,7 @@ static const TypeInfo riscv_cpu_type_infos[] = {
>       DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_SIFIVE_U54, MXL_RV64,  
> rv64_sifive_u_cpu_init),
>       DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_SHAKTI_C,   MXL_RV64,  
> rv64_sifive_u_cpu_init),
>       DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_THEAD_C906, MXL_RV64,  
> rv64_thead_c906_cpu_init),
> +    DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_TT_ASCALON, MXL_RV64,  
> rv64_tt_ascalon_cpu_init),
>       DEFINE_VENDOR_CPU(TYPE_RISCV_CPU_VEYRON_V1,  MXL_RV64,  
> rv64_veyron_v1_cpu_init),
>   #ifdef CONFIG_TCG
>       DEFINE_DYNAMIC_CPU(TYPE_RISCV_CPU_BASE128,   MXL_RV128, 
> rv128_base_cpu_init),