trusty: Select api version

Select api version in probe, and store it in trusty_state.
This enables new return codes from trusty, and will later be used
to enable a nop stdcall that does not take smc_lock.

Change-Id: Ib0c41b8b14e0638851d5236f83677c25507a2db6
Signed-off-by: Michael Ryleev <gmar@google.com>

2 files changed, 20 insertions, 0 deletions

diff --git a/include/linux/trusty/smcall.h b/include/linux/trusty/smcall.h
index a2be2e357..cdb4eccd7 100644
--- a/include/linux/trusty/smcall.h
+++ b/include/linux/trusty/smcall.h
@@ -78,6 +78,25 @@
 #define SMC_FC_AARCH_SWITCH     SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 9)
 #define SMC_FC_GET_VERSION_STR  SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 10)
 
+/**
+ * SMC_FC_API_VERSION - Find and select supported API version.
+ *
+ * @r1: Version supported by client.
+ *
+ * Returns version supported by trusty.
+ *
+ * If multiple versions are supported, the client should start by calling
+ * SMC_FC_API_VERSION with the largest version it supports. Trusty will then
+ * return a version it supports. If the client does not support the version
+ * returned by trusty and the version returned is less than the version
+ * requested, repeat the call with the largest supported version less than the
+ * last returned version.
+ *
+ * This call must be made before any calls that are affected by the api version.
+ */
+#define TRUSTY_API_VERSION_CURRENT      (0)
+#define SMC_FC_API_VERSION      SMC_FASTCALL_NR (SMC_ENTITY_SECURE_MONITOR, 11)
+
 /* TRUSTED_OS entity calls */
 #define SMC_SC_VIRTIO_GET_DESCR SMC_STDCALL_NR(SMC_ENTITY_TRUSTED_OS, 20)
 #define SMC_SC_VIRTIO_START     SMC_STDCALL_NR(SMC_ENTITY_TRUSTED_OS, 21)
diff --git a/include/linux/trusty/trusty.h b/include/linux/trusty/trusty.h
index d084d9d68..24fe2101a 100644
--- a/include/linux/trusty/trusty.h
+++ b/include/linux/trusty/trusty.h
@@ -56,6 +56,7 @@ int trusty_call_notifier_register(struct device *dev,
 int trusty_call_notifier_unregister(struct device *dev,
                                     struct notifier_block *n);
 const char *trusty_version_str_get(struct device *dev);
+u32 trusty_get_api_version(struct device *dev);
 
 struct ns_mem_page_info {
         uint64_t attr;