tcg: Introduce tcg_splitwx_to_{rx,rw}

Add two helper functions, using a global variable to hold
the displacement.  The displacement is currently always 0,
so no change in behaviour.

Begin using the functions in tcg common code only.

Reviewed-by: Joelle van Dyne <j@getutm.app>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

4 files changed, 24 insertions, 8 deletions

diff --git a/include/disas/disas.h b/include/disas/disas.h
index 36c33f6..d363e95 100644
--- a/include/disas/disas.h
+++ b/include/disas/disas.h
@@ -7,7 +7,7 @@
 #include "cpu.h"
 
 /* Disassemble this for me please... (debugging). */
-void disas(FILE *out, void *code, unsigned long size);
+void disas(FILE *out, const void *code, unsigned long size);
 void target_disas(FILE *out, CPUState *cpu, target_ulong code,
                   target_ulong size);
 
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index fab573d..2e5b4bb 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -448,7 +448,7 @@ int probe_access_flags(CPUArchState *env, target_ulong addr,
  * Note: the address of search data can be obtained by adding @size to @ptr.
  */
 struct tb_tc {
-    void *ptr;    /* pointer to the translated code */
+    const void *ptr;    /* pointer to the translated code */
     size_t size;
 };
 
diff --git a/include/exec/log.h b/include/exec/log.h
index e02fff5..3c7fa65 100644
--- a/include/exec/log.h
+++ b/include/exec/log.h
@@ -56,7 +56,7 @@ static inline void log_target_disas(CPUState *cpu, target_ulong start,
     rcu_read_unlock();
 }
 
-static inline void log_disas(void *code, unsigned long size)
+static inline void log_disas(const void *code, unsigned long size)
 {
     QemuLogFile *logfile;
     rcu_read_lock();
diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
index ef571b6..b769e86 100644
--- a/include/tcg/tcg.h
+++ b/include/tcg/tcg.h
@@ -678,6 +678,7 @@ struct TCGContext {
 extern TCGContext tcg_init_ctx;
 extern __thread TCGContext *tcg_ctx;
 extern void *tcg_code_gen_epilogue;
+extern uintptr_t tcg_splitwx_diff;
 extern TCGv_env cpu_env;
 
 static inline bool in_code_gen_buffer(const void *p)
@@ -691,6 +692,21 @@ static inline bool in_code_gen_buffer(const void *p)
     return (size_t)(p - s->code_gen_buffer) <= s->code_gen_buffer_size;
 }
 
+#ifdef CONFIG_DEBUG_TCG
+const void *tcg_splitwx_to_rx(void *rw);
+void *tcg_splitwx_to_rw(const void *rx);
+#else
+static inline const void *tcg_splitwx_to_rx(void *rw)
+{
+    return rw ? rw + tcg_splitwx_diff : NULL;
+}
+
+static inline void *tcg_splitwx_to_rw(const void *rx)
+{
+    return rx ? (void *)rx - tcg_splitwx_diff : NULL;
+}
+#endif
+
 static inline size_t temp_idx(TCGTemp *ts)
 {
     ptrdiff_t n = ts - tcg_ctx->temps;
@@ -1111,7 +1127,7 @@ static inline TCGLabel *arg_label(TCGArg i)
  * correct result.
  */
 
-static inline ptrdiff_t tcg_ptr_byte_diff(void *a, void *b)
+static inline ptrdiff_t tcg_ptr_byte_diff(const void *a, const void *b)
 {
     return a - b;
 }
@@ -1125,9 +1141,9 @@ static inline ptrdiff_t tcg_ptr_byte_diff(void *a, void *b)
  * to the destination address.
  */
 
-static inline ptrdiff_t tcg_pcrel_diff(TCGContext *s, void *target)
+static inline ptrdiff_t tcg_pcrel_diff(TCGContext *s, const void *target)
 {
-    return tcg_ptr_byte_diff(target, s->code_ptr);
+    return tcg_ptr_byte_diff(target, tcg_splitwx_to_rx(s->code_ptr));
 }
 
 /**
@@ -1233,9 +1249,9 @@ static inline unsigned get_mmuidx(TCGMemOpIdx oi)
 #define TB_EXIT_REQUESTED 3
 
 #ifdef CONFIG_TCG_INTERPRETER
-uintptr_t tcg_qemu_tb_exec(CPUArchState *env, void *tb_ptr);
+uintptr_t tcg_qemu_tb_exec(CPUArchState *env, const void *tb_ptr);
 #else
-typedef uintptr_t tcg_prologue_fn(CPUArchState *env, void *tb_ptr);
+typedef uintptr_t tcg_prologue_fn(CPUArchState *env, const void *tb_ptr);
 extern tcg_prologue_fn *tcg_qemu_tb_exec;
 #endif