Implement support for SMCCC v1.1

SMCCC v1.1 comes with a relaxed calling convention for AArch64
callers.  The caller only needs to save x0-x3 before doing an SMC
call.

This patch adds support for SMCCC_VERSION and SMCCC_ARCH_FEATURES.

Refer to "Firmware Interfaces for mitigating CVE_2017_5715 System
Software on Arm Systems"[0] for more information.

[0] https://developer.arm.com/-/media/developer/pdf/ARM%20DEN%200070A%20Firmware%20interfaces%20for%20mitigating%20CVE-2017-5715_V1.0.pdf

Change-Id: If5b1c55c17d6c5c7cb9c2c3ed355d3a91cdad0a9
Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
Reviewed-on: http://vgitil04.il.marvell.com:8080/52576
Tested-by: Kostya Porotchkin <kostap@marvell.com>
Reviewed-by: Kostya Porotchkin <kostap@marvell.com>

4 files changed, 102 insertions, 52 deletions

diff --git a/bl31/bl31.mk b/bl31/bl31.mk
index 9f6de041..934ea22a 100644
--- a/bl31/bl31.mk
+++ b/bl31/bl31.mk
@@ -1,31 +1,7 @@
 #
-# Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
 #
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are met:
-#
-# Redistributions of source code must retain the above copyright notice, this
-# list of conditions and the following disclaimer.
-#
-# Redistributions in binary form must reproduce the above copyright notice,
-# this list of conditions and the following disclaimer in the documentation
-# and/or other materials provided with the distribution.
-#
-# Neither the name of ARM nor the names of its contributors may be used
-# to endorse or promote products derived from this software without specific
-# prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
-# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
-# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-# POSSIBILITY OF SUCH DAMAGE.
+# SPDX-License-Identifier: BSD-3-Clause
 #
 
 include lib/psci/psci_lib.mk
@@ -37,6 +13,7 @@ BL31_SOURCES		+=	bl31/bl31_main.c				\
 				bl31/aarch64/crash_reporting.S			\
 				bl31/bl31_context_mgmt.c			\
 				common/runtime_svc.c				\
+				services/arm_arch_svc/arm_arch_svc_setup.c	\
 				services/std_svc/std_svc_setup.c		\
 				${PSCI_LIB_SOURCES}
 
diff --git a/include/lib/smcc.h b/include/lib/smcc.h
index 7bd9ce39..e7402353 100644
--- a/include/lib/smcc.h
+++ b/include/lib/smcc.h
@@ -1,31 +1,7 @@
 /*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * Redistributions of source code must retain the above copyright notice, this
- * list of conditions and the following disclaimer.
- *
- * Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- *
- * Neither the name of ARM nor the names of its contributors may be used
- * to endorse or promote products derived from this software without specific
- * prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
+ * SPDX-License-Identifier: BSD-3-Clause
  */
 
 #ifndef __SMCC_H__
@@ -86,6 +62,11 @@
 #include <cassert.h>
 #include <stdint.h>
 
+#define SMCCC_MAJOR_VERSION (1)
+#define SMCCC_MINOR_VERSION (1)
+
+#define MAKE_SMCCC_VERSION(_major, _minor) (((_major) << 16) | (_minor))
+
 /* Various flags passed to SMC handlers */
 #define SMC_FROM_SECURE		(0 << 0)
 #define SMC_FROM_NON_SECURE	(1 << 0)
@@ -97,6 +78,10 @@
 #define is_std_svc_call(_fid)		((((_fid) >> FUNCID_OEN_SHIFT) & \
 					   FUNCID_OEN_MASK) == OEN_STD_START)
 
+/* The macro below is used to identify a Arm Architectural Service SMC call */
+#define is_arm_arch_svc_call(_fid)	((((_fid) >> FUNCID_OEN_SHIFT) & \
+					   FUNCID_OEN_MASK) == OEN_ARM_START)
+
 /* The macro below is used to identify a valid Fast SMC call */
 #define is_valid_fast_smc(_fid)		((!(((_fid) >> 16) & 0xff)) && \
 					   (GET_SMC_TYPE(_fid) == SMC_TYPE_FAST))
diff --git a/include/services/arm_arch_svc.h b/include/services/arm_arch_svc.h
new file mode 100644
index 00000000..2d46a87b
--- /dev/null
+++ b/include/services/arm_arch_svc.h
@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __ARM_ARCH_SVC_H__
+#define __ARM_ARCH_SVC_H__
+
+#define SMCCC_VERSION			(0x80000000)
+#define SMCCC_ARCH_FEATURES		(0x80000001)
+#define SMCCC_ARCH_WORKAROUND_1		(0x80008000)
+
+#endif /* __ARM_ARCH_SVC_H__ */
diff --git a/services/arm_arch_svc/arm_arch_svc_setup.c b/services/arm_arch_svc/arm_arch_svc_setup.c
new file mode 100644
index 00000000..eedac869
--- /dev/null
+++ b/services/arm_arch_svc/arm_arch_svc_setup.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arm_arch_svc.h>
+#include <debug.h>
+#include <runtime_svc.h>
+#include <smcc.h>
+#include <smcc_helpers.h>
+
+static int32_t smccc_version(void)
+{
+	return MAKE_SMCCC_VERSION(SMCCC_MAJOR_VERSION, SMCCC_MINOR_VERSION);
+}
+
+static int32_t smccc_arch_features(u_register_t arg)
+{
+	switch (arg) {
+	case SMCCC_VERSION:
+	case SMCCC_ARCH_FEATURES:
+		return SMC_OK;
+#if WORKAROUND_CVE_2017_5715
+	case SMCCC_ARCH_WORKAROUND_1:
+		return SMC_OK;
+#endif
+	default:
+		return SMC_UNK;
+	}
+}
+
+/*
+ * Top-level Arm Architectural Service SMC handler.
+ */
+uintptr_t arm_arch_svc_smc_handler(uint32_t smc_fid,
+	u_register_t x1,
+	u_register_t x2,
+	u_register_t x3,
+	u_register_t x4,
+	void *cookie,
+	void *handle,
+	u_register_t flags)
+{
+	switch (smc_fid) {
+	case SMCCC_VERSION:
+		SMC_RET1(handle, smccc_version());
+	case SMCCC_ARCH_FEATURES:
+		SMC_RET1(handle, smccc_arch_features(x1));
+#if WORKAROUND_CVE_2017_5715
+	case SMCCC_ARCH_WORKAROUND_1:
+		/*
+		 * The workaround has already been applied on affected PEs
+		 * during entry to EL3.  On unaffected PEs, this function
+		 * has no effect.
+		 */
+		SMC_RET0(handle);
+#endif
+	default:
+		WARN("Unimplemented Arm Architecture Service Call: 0x%x \n",
+			smc_fid);
+		SMC_RET1(handle, SMC_UNK);
+	}
+}
+
+/* Register Standard Service Calls as runtime service */
+DECLARE_RT_SVC(
+		arm_arch_svc,
+		OEN_ARM_START,
+		OEN_ARM_END,
+		SMC_TYPE_FAST,
+		NULL,
+		arm_arch_svc_smc_handler
+);