[PATCH v4 08/22] efi_loader: add MM SP status mapping for FF-A variables

Define the MM SP status values as an enum and add a runtime-safe helper
for translating MM SP notification results to U-Boot errno values.

The FF-A notification path uses the same mapping during boot and after
ExitBootServices(), so keep the mapping table in EFI runtime rodata.

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 | 50 ++++++++++++++++++++++++++-----
 1 file changed, 43 insertions(+), 7 deletions(-)

diff --git a/lib/efi_loader/efi_variable_tee.c b/lib/efi_loader/efi_variable_tee.c
index 6a1fa39bb6f..8a75da414f7 100644
--- a/lib/efi_loader/efi_variable_tee.c
+++ b/lib/efi_loader/efi_variable_tee.c
@@ -4,7 +4,7 @@
  *
  *  Copyright (C) 2019 Linaro Ltd. <[email protected]>
  *  Copyright (C) 2019 Linaro Ltd. <[email protected]>
- *  Copyright 2022-2023 Arm Limited and/or its affiliates <[email protected]>
+ *  Copyright 2022-2026 Arm Limited and/or its affiliates <[email protected]>
  *
  *  Authors:
  *    Abdellatif El Khlifi <[email protected]>
@@ -21,18 +21,32 @@
 #include <efi_api.h>
 #include <efi_loader.h>
 #include <efi_variable.h>
+#include <linux/kernel.h>
 #include <malloc.h>
 #include <mapmem.h>
 #include <mm_communication.h>
 #include <tee.h>
 
 #if CONFIG_IS_ENABLED(ARM_FFA_TRANSPORT)
-/* MM return codes */
-#define MM_SUCCESS (0)
-#define MM_NOT_SUPPORTED (-1)
-#define MM_INVALID_PARAMETER (-2)
-#define MM_DENIED (-3)
-#define MM_NO_MEMORY (-5)
+enum mm_sp_status {
+	MM_SUCCESS = 0,
+	MM_NOT_SUPPORTED = -1,
+	MM_INVALID_PARAMETER = -2,
+	MM_DENIED = -3,
+	MM_NO_MEMORY = -5,
+};
+
+/*
+ * MM_* return codes are negative. Use -MM_* as sparse positive indices so
+ * ffa_map_sp_event() can look up mm_sp_errmap[-sp_event_ret]. Unassigned
+ * slots remain 0 and are treated as unmapped MM return codes.
+ */
+static const int __efi_runtime_rodata mm_sp_errmap[] = {
+	[-MM_NOT_SUPPORTED]	 = -EINVAL,
+	[-MM_INVALID_PARAMETER]	 = -EPERM,
+	[-MM_DENIED]		 = -EACCES,
+	[-MM_NO_MEMORY]		 = -EBUSY,
+};
 
 static const char *mm_sp_svc_uuid = MM_SP_UUID;
 static u16 mm_sp_id;
@@ -169,6 +183,28 @@ static efi_status_t optee_mm_communicate(void *comm_buf, ulong dsize)
 }
 
 #if CONFIG_IS_ENABLED(ARM_FFA_TRANSPORT)
+/**
+ * ffa_map_sp_event() - Map MM SP response to errno
+ * @sp_event_ret: MM SP return code from MM SP notification
+ *
+ * Convert the MM SP return code into a standard U-Boot errno. This helper
+ * is marked __efi_runtime so it can be shared by both the boot and runtime
+ * FF-A notification paths.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+static int __efi_runtime ffa_map_sp_event(int sp_event_ret)
+{
+	int idx = -sp_event_ret;
+
+	if (sp_event_ret == MM_SUCCESS)
+		return 0;
+	if (idx > 0 && idx < (int)ARRAY_SIZE(mm_sp_errmap) &&
+	    mm_sp_errmap[idx])
+		return mm_sp_errmap[idx];
+	return -EACCES;
+}
+
 /**
  * ffa_notify_mm_sp() - Announce there is data in the shared buffer
  *
-- 
2.34.1