[PATCH v4 10/22] efi_loader: make FF-A MM SP notification runtime-safe

Make the FF-A MM SP notification helper usable after ExitBootServices().
The boot path continues to use the FF-A driver-model operation, while
the runtime path uses the resident FF-A runtime transport.

This keeps the notification path shared while avoiding driver-model
access from EFI runtime code.

Reviewed-by: Simon Glass <[email protected]>
Reviewed-by: Abdellatif El Khlifi <[email protected]>
Signed-off-by: Harsimran Singh Tungal <[email protected]>
---
 lib/efi_loader/efi_variable_tee.c | 53 +++++++++++--------------------
 1 file changed, 18 insertions(+), 35 deletions(-)

diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
index 72055b36bba..4ebba83036c 100644
--- a/lib/efi_loader/efi_variable_tee.c
+++ b/lib/efi_loader/efi_variable_tee.c
@@ -14,6 +14,7 @@
 
 #if CONFIG_IS_ENABLED(ARM_FFA_TRANSPORT)
 #include <arm_ffa.h>
+#include <arm_ffa_runtime.h>
 #endif
 #include <cpu_func.h>
 #include <dm.h>
@@ -49,7 +50,7 @@ static const int __efi_runtime_rodata mm_sp_errmap[] = {
 };
 
 static const char *mm_sp_svc_uuid = MM_SP_UUID;
-static u16 mm_sp_id;
+static u16 __efi_runtime_data mm_sp_id;
 #endif
 
 extern struct efi_var_file __efi_runtime_data *efi_var_buf;
@@ -229,52 +230,34 @@ static int __efi_runtime ffa_map_sp_event(int sp_event_ret)
  * This is a blocking call during which trusted world has exclusive access
  * to the MM shared buffer.
  *
- * Return:
- *
- * 0 on success
+ * Return: 0 on success
  */
-static int ffa_notify_mm_sp(void)
+static int __efi_runtime ffa_notify_mm_sp(void)
 {
 	struct ffa_send_direct_data msg = {0};
 	int ret;
 	int sp_event_ret;
-	struct udevice *dev;
+	bool at_runtime = efi_at_runtime();
 
-	ret = uclass_first_device_err(UCLASS_FFA, &dev);
-	if (ret) {
-		log_err("EFI: Cannot find FF-A bus device, notify MM SP failure\n");
-		return ret;
-	}
+	msg.data0 = CONFIG_FFA_SHARED_MM_BUF_OFFSET;
 
-	msg.data0 = CONFIG_FFA_SHARED_MM_BUF_OFFSET; /* x3 */
+	if (at_runtime) {
+		ret = ffa_sync_send_receive_runtime(mm_sp_id, &msg, 1);
+	} else {
+		struct udevice *dev;
 
-	ret = ffa_sync_send_receive(dev, mm_sp_id, &msg, 1);
+		ret = uclass_first_device_err(UCLASS_FFA, &dev);
+		if (ret)
+			return ret;
+
+		ret = ffa_sync_send_receive(dev, mm_sp_id, &msg, 1);
+	}
 	if (ret)
 		return ret;
 
-	sp_event_ret = msg.data0; /* x3 */
+	sp_event_ret = msg.data0;
 
-	switch (sp_event_ret) {
-	case MM_SUCCESS:
-		ret = 0;
-		break;
-	case MM_NOT_SUPPORTED:
-		ret = -EINVAL;
-		break;
-	case MM_INVALID_PARAMETER:
-		ret = -EPERM;
-		break;
-	case MM_DENIED:
-		ret = -EACCES;
-		break;
-	case MM_NO_MEMORY:
-		ret = -EBUSY;
-		break;
-	default:
-		ret = -EACCES;
-	}
-
-	return ret;
+	return ffa_map_sp_event(sp_event_ret);
 }
 
 /**
-- 
2.34.1