Move key_slot_mutex to threading.h
Make this a global mutex so that we don't have to init and free it.
Also rename the mutex to follow the convention
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
diff --git a/include/mbedtls/threading.h b/include/mbedtls/threading.h
index b504233..b4e0502 100644
--- a/include/mbedtls/threading.h
+++ b/include/mbedtls/threading.h
@@ -100,6 +100,20 @@
extern mbedtls_threading_mutex_t mbedtls_threading_gmtime_mutex;
#endif /* MBEDTLS_HAVE_TIME_DATE && !MBEDTLS_PLATFORM_GMTIME_R_ALT */
+#if defined(MBEDTLS_PSA_CRYPTO_C)
+/*
+ * A mutex used to make the PSA subsystem thread safe.
+ *
+ * key_slot_mutex protects the registered_readers and
+ * state variable for all key slots in &global_data.key_slots.
+ *
+ * This mutex must be held when any read from or write to a state or
+ * registered_readers field is performed, i.e. when calling functions:
+ * psa_key_slot_state_transition(), psa_register_read(), psa_unregister_read(),
+ * psa_key_slot_has_readers() and psa_wipe_key_slot(). */
+extern mbedtls_threading_mutex_t mbedtls_threading_key_slot_mutex;
+#endif
+
#endif /* MBEDTLS_THREADING_C */
#ifdef __cplusplus