Re: [RFC v3 08/10] target/mips: Add support for native library calls

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 25/6/23 23:27, Yeqi Fu wrote:
> Upon encountering specialized instructions reserved for native calls,
> store the function id and argument types, then invoke helper.
> 
> Signed-off-by: Yeqi Fu <fufuyqqqqqq@gmail.com>
> ---
>   target/mips/tcg/translate.c | 26 ++++++++++++++++++++++++++
>   target/mips/tcg/translate.h |  2 ++
>   2 files changed, 28 insertions(+)
> 
> diff --git a/target/mips/tcg/translate.c b/target/mips/tcg/translate.c
> index a6ca2e5a3b..15ab889dca 100644
> --- a/target/mips/tcg/translate.c
> +++ b/target/mips/tcg/translate.c
> @@ -36,6 +36,7 @@
>   #include "qemu/qemu-print.h"
>   #include "fpu_helper.h"
>   #include "translate.h"
> +#include "native/native-defs.h"
>   
>   /*
>    * Many sysemu-only helpers are not reachable for user-only.
> @@ -13592,6 +13593,31 @@ static void decode_opc_special(CPUMIPSState *env, DisasContext *ctx)
>   #endif
>           break;
>       case OPC_SYSCALL:
> +        uint32_t sig = (ctx->opcode) >> 6;

            if (native_call_enabled() && sig) {
                if (ctx->native_call_status) {
                    ...
                } else {
                    ...
                }
                break;
            }

> +        if (native_call_enabled() && (!ctx->native_call_status) && sig) {
> +            ctx->native_call_status = true;
> +            ctx->native_call_id = sig;
> +            break;
> +        } else if (native_call_enabled() && (ctx->native_call_status) && sig) {
> +            TCGv arg1 = tcg_temp_new();
> +            TCGv arg2 = tcg_temp_new();
> +            TCGv arg3 = tcg_temp_new();
> +
> +            tcg_gen_mov_tl(arg1, cpu_gpr[4]);
> +            tcg_gen_mov_tl(arg2, cpu_gpr[5]);
> +            tcg_gen_mov_tl(arg3, cpu_gpr[6]);
> +
> +            TCGv_i32 abi_map = tcg_constant_i32(sig);
> +            TCGv_i32 func_id = tcg_constant_i32(ctx->native_call_id);
> +            TCGv res = tcg_temp_new();
> +            TCGv_i32 mmu_idx = tcg_constant_i32(MMU_USER_IDX);
> +            gen_helper_native_call(res, cpu_env, arg1, arg2, arg3,
> +                                    abi_map, func_id, mmu_idx);
> +            tcg_gen_mov_tl(cpu_gpr[2], res);
> +            ctx->native_call_status = false;
> +            ctx->native_call_id = 0;
> +            break;
> +        }
>           generate_exception_end(ctx, EXCP_SYSCALL);
>           break;
>       case OPC_BREAK: