Merge remote-tracking branch 'remotes/rth-gitlab/tags/pull-tcg-20210613' into staging

Clean up code_gen_buffer allocation.
Add tcg_remove_ops_after.
Fix tcg_constant_* documentation.
Improve TB chaining documentation.
Fix float32_exp2.
Fix arm tcg_out_op function signature.

# gpg: Signature made Mon 14 Jun 2021 02:12:35 BST
# gpg:                using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg:                issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A  05C0 64DF 38E8 AF7E 215F

* remotes/rth-gitlab/tags/pull-tcg-20210613: (34 commits)
  docs/devel: Explain in more detail the TB chaining mechanisms
  softfloat: Fix tp init in float32_exp2
  tcg/arm: Fix tcg_out_op function signature
  tcg: Fix documentation for tcg_constant_* vs tcg_temp_free_*
  tcg: Introduce tcg_remove_ops_after
  tcg: Move tcg_init_ctx and tcg_ctx from accel/tcg/
  tcg: When allocating for !splitwx, begin with PROT_NONE
  tcg: Merge buffer protection and guard page protection
  tcg: Round the tb_size default from qemu_get_host_physmem
  util/osdep: Add qemu_mprotect_rw
  tcg: Sink qemu_madvise call to common code
  tcg: Return the map protection from alloc_code_gen_buffer
  tcg: Allocate code_gen_buffer into struct tcg_region_state
  tcg: Move in_code_gen_buffer and tests to region.c
  tcg: Tidy split_cross_256mb
  tcg: Tidy tcg_n_regions
  tcg: Rename region.start to region.after_prologue
  tcg: Replace region.end with region.total_size
  tcg: Move MAX_CODE_GEN_BUFFER_SIZE to tcg-target.h
  tcg: Introduce tcg_max_ctxs
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 15 insertions, 16 deletions

diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index 4c6f2390be..236a045671 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -512,6 +512,7 @@ void sigaction_invoke(struct sigaction *action,
 #endif
 
 int qemu_madvise(void *addr, size_t len, int advice);
+int qemu_mprotect_rw(void *addr, size_t size);
 int qemu_mprotect_rwx(void *addr, size_t size);
 int qemu_mprotect_none(void *addr, size_t size);
 
diff --git a/include/sysemu/tcg.h b/include/sysemu/tcg.h
index 00349fb18a..53352450ff 100644
--- a/include/sysemu/tcg.h
+++ b/include/sysemu/tcg.h
@@ -8,8 +8,6 @@
 #ifndef SYSEMU_TCG_H
 #define SYSEMU_TCG_H
 
-void tcg_exec_init(unsigned long tb_size, int splitwx);
-
 #ifdef CONFIG_TCG
 extern bool tcg_allowed;
 #define tcg_enabled() (tcg_allowed)
diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
index 74cb345308..064dab383b 100644
--- a/include/tcg/tcg.h
+++ b/include/tcg/tcg.h
@@ -689,22 +689,12 @@ static inline bool temp_readonly(TCGTemp *ts)
     return ts->kind >= TEMP_FIXED;
 }
 
-extern TCGContext tcg_init_ctx;
 extern __thread TCGContext *tcg_ctx;
 extern const 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)
-{
-    const TCGContext *s = &tcg_init_ctx;
-    /*
-     * Much like it is valid to have a pointer to the byte past the
-     * end of an array (so long as you don't dereference it), allow
-     * a pointer to the byte past the end of the code gen buffer.
-     */
-    return (size_t)(p - s->code_gen_buffer) <= s->code_gen_buffer_size;
-}
+bool in_code_gen_buffer(const void *p);
 
 #ifdef CONFIG_DEBUG_TCG
 const void *tcg_splitwx_to_rx(void *rw);
@@ -873,7 +863,6 @@ void *tcg_malloc_internal(TCGContext *s, int size);
 void tcg_pool_reset(TCGContext *s);
 TranslationBlock *tcg_tb_alloc(TCGContext *s);
 
-void tcg_region_init(void);
 void tb_destroy(TranslationBlock *tb);
 void tcg_region_reset_all(void);
 
@@ -906,7 +895,7 @@ static inline void *tcg_malloc(int size)
     }
 }
 
-void tcg_context_init(TCGContext *s);
+void tcg_init(size_t tb_size, int splitwx, unsigned max_cpus);
 void tcg_register_thread(void);
 void tcg_prologue_init(TCGContext *s);
 void tcg_func_start(TCGContext *s);
@@ -1082,6 +1071,16 @@ void tcg_op_remove(TCGContext *s, TCGOp *op);
 TCGOp *tcg_op_insert_before(TCGContext *s, TCGOp *op, TCGOpcode opc);
 TCGOp *tcg_op_insert_after(TCGContext *s, TCGOp *op, TCGOpcode opc);
 
+/**
+ * tcg_remove_ops_after:
+ * @op: target operation
+ *
+ * Discard any opcodes emitted since @op.  Expected usage is to save
+ * a starting point with tcg_last_op(), speculatively emit opcodes,
+ * then decide whether or not to keep those opcodes after the fact.
+ */
+void tcg_remove_ops_after(TCGOp *op);
+
 void tcg_optimize(TCGContext *s);
 
 /* Allocate a new temporary and initialize it with a constant. */
@@ -1096,7 +1095,8 @@ TCGv_vec tcg_const_ones_vec_matching(TCGv_vec);
 
 /*
  * Locate or create a read-only temporary that is a constant.
- * This kind of temporary need not and should not be freed.
+ * This kind of temporary need not be freed, but for convenience
+ * will be silently ignored by tcg_temp_free_*.
  */
 TCGTemp *tcg_constant_internal(TCGType type, int64_t val);