Split out the logic to emit a host memory barrier in response to
a guest memory operation. Do not provide a true default for
TCG_GUEST_DEFAULT_MO because the defined() check will still be
useful for determining if a guest has been updated for MTTCG.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
include/tcg/tcg.h | 20 ++++++++++++++++++++
accel/tcg/tcg-all.c | 6 +-----
tcg/tcg-op.c | 8 +-------
3 files changed, 22 insertions(+), 12 deletions(-)
diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h
index a5cf21be83..b76b597878 100644
--- a/include/tcg/tcg.h
+++ b/include/tcg/tcg.h
@@ -1171,6 +1171,26 @@ static inline size_t tcg_current_code_size(TCGContext *s)
return tcg_ptr_byte_diff(s->code_ptr, s->code_buf);
}
+/**
+ * tcg_req_mo:
+ * @type: TCGBar
+ *
+ * Filter @type to the barrier that is required for the guest
+ * memory ordering vs the host memory ordering. A non-zero
+ * result indicates that some barrier is required.
+ *
+ * If TCG_GUEST_DEFAULT_MO is not defined, assume that the
+ * guest requires strict alignment.
+ *
+ * This is a macro so that it's constant even without optimization.
+ */
+#ifdef TCG_GUEST_DEFAULT_MO
+# define tcg_req_mo(type) \
+ ((type) & TCG_GUEST_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO)
+#else
+# define tcg_req_mo(type) ((type) & ~TCG_TARGET_DEFAULT_MO)
+#endif
+
/**
* tcg_qemu_tb_exec:
* @env: pointer to CPUArchState for the CPU
diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c
index 5dab1ae9dd..604efd1b18 100644
--- a/accel/tcg/tcg-all.c
+++ b/accel/tcg/tcg-all.c
@@ -74,11 +74,7 @@ DECLARE_INSTANCE_CHECKER(TCGState, TCG_STATE,
static bool check_tcg_memory_orders_compatible(void)
{
-#if defined(TCG_GUEST_DEFAULT_MO) && defined(TCG_TARGET_DEFAULT_MO)
- return (TCG_GUEST_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO) == 0;
-#else
- return false;
-#endif
+ return tcg_req_mo(TCG_MO_ALL) == 0;
}
static bool default_mttcg_enabled(void)
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index 2721c1cab9..d6faf30c52 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -2930,13 +2930,7 @@ static void gen_ldst_i64(TCGOpcode opc, TCGv_i64 val,
TCGv addr,
static void tcg_gen_req_mo(TCGBar type)
{
-#ifdef TCG_GUEST_DEFAULT_MO
- type &= TCG_GUEST_DEFAULT_MO;
-#endif
- type &= ~TCG_TARGET_DEFAULT_MO;
- if (type) {
- tcg_gen_mb(type | TCG_BAR_SC);
- }
+ tcg_gen_mb(tcg_req_mo(type) | TCG_BAR_SC);
}
static inline TCGv plugin_prep_mem_callbacks(TCGv vaddr)
--
2.34.1
