[RFC v5 07/10] target/mips: Add support for native library calls

[Yeqi Fu]

This commit introduces support for native library calls on the
mips target. When encountering special instructions reserved
for native calls, this commit extracts the function name and
generates the corresponding native call.

Signed-off-by: Yeqi Fu <fufuyqqq...@gmail.com>
---
 configs/targets/mips-linux-user.mak   |  1 +
 configs/targets/mips64-linux-user.mak |  1 +
 target/mips/tcg/translate.c           | 36 ++++++++++++++++++++++++++-
 3 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/configs/targets/mips-linux-user.mak 
b/configs/targets/mips-linux-user.mak
index b4569a9893..fa005d487a 100644
--- a/configs/targets/mips-linux-user.mak
+++ b/configs/targets/mips-linux-user.mak
@@ -3,3 +3,4 @@ TARGET_ABI_MIPSO32=y
 TARGET_SYSTBL_ABI=o32
 TARGET_SYSTBL=syscall_o32.tbl
 TARGET_BIG_ENDIAN=y
+CONFIG_NATIVE_CALL=y
diff --git a/configs/targets/mips64-linux-user.mak 
b/configs/targets/mips64-linux-user.mak
index d2ff509a11..ecfe6bcf73 100644
--- a/configs/targets/mips64-linux-user.mak
+++ b/configs/targets/mips64-linux-user.mak
@@ -4,3 +4,4 @@ TARGET_BASE_ARCH=mips
 TARGET_SYSTBL_ABI=n64
 TARGET_SYSTBL=syscall_n64.tbl
 TARGET_BIG_ENDIAN=y
+CONFIG_NATIVE_CALL=y
diff --git a/target/mips/tcg/translate.c b/target/mips/tcg/translate.c
index 74af91e4f5..fa58f9e12f 100644
--- a/target/mips/tcg/translate.c
+++ b/target/mips/tcg/translate.c
@@ -36,6 +36,7 @@
 #include "exec/helper-info.c.inc"
 #undef  HELPER_H
 
+#include "native/native.h"
 
 /*
  * Many sysemu-only helpers are not reachable for user-only.
@@ -13484,10 +13485,38 @@ static void decode_opc_special_legacy(CPUMIPSState 
*env, DisasContext *ctx)
     }
 }
 
+static void gen_native_call(DisasContext *ctx, CPUMIPSState *env)
+{
+#ifdef CONFIG_USER_ONLY
+    char *func_name;
+    TCGv arg1 = tcg_temp_new();
+    TCGv arg2 = tcg_temp_new();
+    TCGv arg3 = tcg_temp_new();
+    TCGv ret = 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]);
+#if defined(TARGET_MIPS64)
+    uint64_t func_tmp =
+        translator_ldq(env, &ctx->base, ctx->base.pc_next + 8);
+    ctx->base.pc_next += 12;
+    func_name = g2h(env_cpu(env), func_tmp);
+    gen_native_call_i64(func_name, ret, arg1, arg2, arg3);
+#else
+    uint32_t func_tmp =
+        translator_ldl(env, &ctx->base, ctx->base.pc_next + 4);
+    ctx->base.pc_next += 4;
+    func_name = g2h(env_cpu(env), func_tmp);
+    gen_native_call_i32(func_name, ret, arg1, arg2, arg3);
+#endif
+    tcg_gen_mov_tl(cpu_gpr[2], ret);
+#endif
+}
+
 static void decode_opc_special(CPUMIPSState *env, DisasContext *ctx)
 {
     int rs, rt, rd, sa;
-    uint32_t op1;
+    uint32_t op1, sig;
 
     rs = (ctx->opcode >> 21) & 0x1f;
     rt = (ctx->opcode >> 16) & 0x1f;
@@ -13583,6 +13612,11 @@ static void decode_opc_special(CPUMIPSState *env, 
DisasContext *ctx)
 #endif
         break;
     case OPC_SYSCALL:
+        sig = (ctx->opcode) >> 6;
+        if ((sig == 0xffff) && native_bypass_enabled()) {
+            gen_native_call(ctx, env);
+            break;
+        }
         generate_exception_end(ctx, EXCP_SYSCALL);
         break;
     case OPC_BREAK:
-- 
2.34.1