1 files changed, 65 insertions, 0 deletions
diff --git a/accel/tcg/tb-jmp-cache.h b/accel/tcg/tb-jmp-cache.h
new file mode 100644
index 0000000..ff5ffc8
--- /dev/null
+++ b/accel/tcg/tb-jmp-cache.h
@@ -0,0 +1,65 @@
+/*
+ * The per-CPU TranslationBlock jump cache.
+ *
+ *  Copyright (c) 2003 Fabrice Bellard
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef ACCEL_TCG_TB_JMP_CACHE_H
+#define ACCEL_TCG_TB_JMP_CACHE_H
+
+#define TB_JMP_CACHE_BITS 12
+#define TB_JMP_CACHE_SIZE (1 << TB_JMP_CACHE_BITS)
+
+/*
+ * Accessed in parallel; all accesses to 'tb' must be atomic.
+ * For TARGET_TB_PCREL, accesses to 'pc' must be protected by
+ * a load_acquire/store_release to 'tb'.
+ */
+struct CPUJumpCache {
+    struct {
+        TranslationBlock *tb;
+#if TARGET_TB_PCREL
+        target_ulong pc;
+#endif
+    } array[TB_JMP_CACHE_SIZE];
+};
+
+static inline TranslationBlock *
+tb_jmp_cache_get_tb(CPUJumpCache *jc, uint32_t hash)
+{
+#if TARGET_TB_PCREL
+    /* Use acquire to ensure current load of pc from jc. */
+    return qatomic_load_acquire(&jc->array[hash].tb);
+#else
+    /* Use rcu_read to ensure current load of pc from *tb. */
+    return qatomic_rcu_read(&jc->array[hash].tb);
+#endif
+}
+
+static inline target_ulong
+tb_jmp_cache_get_pc(CPUJumpCache *jc, uint32_t hash, TranslationBlock *tb)
+{
+#if TARGET_TB_PCREL
+    return jc->array[hash].pc;
+#else
+    return tb_pc(tb);
+#endif
+}
+
+static inline void
+tb_jmp_cache_set(CPUJumpCache *jc, uint32_t hash,
+                 TranslationBlock *tb, target_ulong pc)
+{
+#if TARGET_TB_PCREL
+    jc->array[hash].pc = pc;
+    /* Use store_release on tb to ensure pc is written first. */
+    qatomic_store_release(&jc->array[hash].tb, tb);
+#else
+    /* Use the pc value already stored in tb->pc. */
+    qatomic_set(&jc->array[hash].tb, tb);
+#endif
+}
+
+#endif /* ACCEL_TCG_TB_JMP_CACHE_H */