From 4388f28f0fdbc8deba4e786c776a56ae2c4d4887 Mon Sep 17 00:00:00 2001
From: J-Alves <joao.alves@arm.com>
Date: Tue, 26 May 2020 14:03:05 +0100
Subject: [PATCH] FFA Version interface update

Change handler of FFA version interface:
- Return SPMD's version if the origin of the call is secure;
- Return SPMC's version if origin is non-secure.

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I0d1554da79b72b1e02da6cc363a2288119c32f44
---
 include/services/ffa_svc.h        | 12 +++++++-----
 services/std_svc/spmd/spmd_main.c | 24 +++++++++++++++++-------
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/include/services/ffa_svc.h b/include/services/ffa_svc.h
index fe321750a..728507749 100644
--- a/include/services/ffa_svc.h
+++ b/include/services/ffa_svc.h
@@ -12,13 +12,13 @@
 #include <tools_share/uuid.h>
 
 /* FFA error codes. */
-#define FFA_ERROR_NOT_SUPPORTED	-1
+#define FFA_ERROR_NOT_SUPPORTED		-1
 #define FFA_ERROR_INVALID_PARAMETER	-2
 #define FFA_ERROR_NO_MEMORY		-3
 #define FFA_ERROR_BUSY			-4
 #define FFA_ERROR_INTERRUPTED		-5
 #define FFA_ERROR_DENIED		-6
-#define FFA_ERROR_RETRY		-7
+#define FFA_ERROR_RETRY			-7
 
 /* The macros below are used to identify FFA calls from the SMC function ID */
 #define FFA_FNUM_MIN_VALUE	U(0x60)
@@ -30,13 +30,15 @@
 
 /* FFA_VERSION helpers */
 #define FFA_VERSION_MAJOR		U(1)
-#define FFA_VERSION_MAJOR_SHIFT	16
+#define FFA_VERSION_MAJOR_SHIFT		16
 #define FFA_VERSION_MAJOR_MASK		U(0x7FFF)
 #define FFA_VERSION_MINOR		U(0)
-#define FFA_VERSION_MINOR_SHIFT	0
+#define FFA_VERSION_MINOR_SHIFT		0
 #define FFA_VERSION_MINOR_MASK		U(0xFFFF)
+#define FFA_VERSION_BIT31_MASK 		U(0x1u << 31)
 
-#define MAKE_FFA_VERSION(major, minor) \
+
+#define MAKE_FFA_VERSION(major, minor) 	\
 	((((major) & FFA_VERSION_MAJOR_MASK) <<  FFA_VERSION_MAJOR_SHIFT) | \
 	 (((minor) & FFA_VERSION_MINOR_MASK) << FFA_VERSION_MINOR_SHIFT))
 #define FFA_VERSION_COMPILED		MAKE_FFA_VERSION(FFA_VERSION_MAJOR, \
diff --git a/services/std_svc/spmd/spmd_main.c b/services/std_svc/spmd/spmd_main.c
index a818037cb..4c2b58df2 100644
--- a/services/std_svc/spmd/spmd_main.c
+++ b/services/std_svc/spmd/spmd_main.c
@@ -350,6 +350,7 @@ uint64_t spmd_smc_handler(uint32_t smc_fid,
 	spmd_spm_core_context_t *ctx = spmd_get_context();
 	bool secure_origin;
 	int32_t ret;
+	uint32_t input_version;
 
 	/* Determine which security state this SMC originated from */
 	secure_origin = is_caller_secure(flags);
@@ -375,15 +376,24 @@ uint64_t spmd_smc_handler(uint32_t smc_fid,
 		break; /* not reached */
 
 	case FFA_VERSION:
+		input_version = (uint32_t)(0xFFFFFFFF & x1);
 		/*
-		 * TODO: This is an optimization that the version information
-		 * provided by the SPM Core manifest is returned by the SPM
-		 * dispatcher. It might be a better idea to simply forward this
-		 * call to the SPM Core and wash our hands completely.
+		 * If caller is secure and SPMC was initialized,
+		 * return FFA_VERSION of SPMD.
+		 * If caller is non secure and SPMC was initialized,
+		 * return SPMC's version.
+		 * Sanity check to "input_version".
 		 */
-		ret = MAKE_FFA_VERSION(spmc_attrs.major_version,
-					spmc_attrs.minor_version);
-		SMC_RET8(handle, FFA_SUCCESS_SMC32, FFA_TARGET_INFO_MBZ, ret,
+		if ((input_version & FFA_VERSION_BIT31_MASK) ||
+			(ctx->state == SPMC_STATE_RESET)) {
+			ret = FFA_ERROR_NOT_SUPPORTED;
+		} else if (!secure_origin) {
+			ret = MAKE_FFA_VERSION(spmc_attrs.major_version, spmc_attrs.minor_version);
+		} else {
+			ret = MAKE_FFA_VERSION(FFA_VERSION_MAJOR, FFA_VERSION_MINOR);
+		}
+
+		SMC_RET8(handle, ret, FFA_TARGET_INFO_MBZ, FFA_TARGET_INFO_MBZ,
 			 FFA_PARAM_MBZ, FFA_PARAM_MBZ, FFA_PARAM_MBZ,
 			 FFA_PARAM_MBZ, FFA_PARAM_MBZ);
 		break; /* not reached */