replace spinlock by QemuMutex.

spinlock is only used in two cases:
  * cpu-exec.c: to protect TranslationBlock
  * mem_helper.c: for lock helper in target-i386 (which seems broken).

It's a pthread_mutex_t in user-mode, so we can use QemuMutex directly,
with an #ifdef.  The #ifdef will be removed when multithreaded TCG
will need the mutex as well.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Message-Id: <1439220437-23957-5-git-send-email-fred.konrad@greensocs.com>
Signed-off-by: Emilio G. Cota <cota@braap.org>
[Merge Emilio G. Cota's patch to remove volatile. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 22 insertions, 3 deletions

diff --git a/target-i386/mem_helper.c b/target-i386/mem_helper.c
index 1aec8a5f19..8bf0da2433 100644
--- a/target-i386/mem_helper.c
+++ b/target-i386/mem_helper.c
@@ -23,18 +23,37 @@
 
 /* broken thread support */
 
-static spinlock_t global_cpu_lock = SPIN_LOCK_UNLOCKED;
+#if defined(CONFIG_USER_ONLY)
+QemuMutex global_cpu_lock;
 
 void helper_lock(void)
 {
-    spin_lock(&global_cpu_lock);
+    qemu_mutex_lock(&global_cpu_lock);
 }
 
 void helper_unlock(void)
 {
-    spin_unlock(&global_cpu_lock);
+    qemu_mutex_unlock(&global_cpu_lock);
 }
 
+void helper_lock_init(void)
+{
+    qemu_mutex_init(&global_cpu_lock);
+}
+#else
+void helper_lock(void)
+{
+}
+
+void helper_unlock(void)
+{
+}
+
+void helper_lock_init(void)
+{
+}
+#endif
+
 void helper_cmpxchg8b(CPUX86State *env, target_ulong a0)
 {
     uint64_t d;