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>
diff --git a/bl31/bl31.mk b/bl31/bl31.mk
index 2db4856..886d301 100644
--- a/bl31/bl31.mk
+++ b/bl31/bl31.mk
@@ -1,5 +1,5 @@
#
-# Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
#
@@ -23,6 +23,7 @@
bl31/bl31_context_mgmt.c \
common/runtime_svc.c \
plat/common/aarch64/platform_mp_stack.S \
+ services/arm_arch_svc/arm_arch_svc_setup.c \
services/std_svc/std_svc_setup.c \
${PSCI_LIB_SOURCES} \
${SPM_SOURCES} \
diff --git a/include/lib/smcc.h b/include/lib/smcc.h
index 13b1e7a..a273b3a 100644
--- a/include/lib/smcc.h
+++ b/include/lib/smcc.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -67,6 +67,11 @@
#include <cassert.h>
#include <stdint.h>
+#define SMCCC_MAJOR_VERSION U(1)
+#define SMCCC_MINOR_VERSION U(1)
+
+#define MAKE_SMCCC_VERSION(_major, _minor) (((_major) << 16) | (_minor))
+
/* Various flags passed to SMC handlers */
#define SMC_FROM_SECURE (U(0) << 0)
#define SMC_FROM_NON_SECURE (U(1) << 0)
@@ -78,6 +83,10 @@
#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) & U(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 0000000..2961601
--- /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 U(0x80000000)
+#define SMCCC_ARCH_FEATURES U(0x80000001)
+#define SMCCC_ARCH_WORKAROUND_1 U(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 0000000..eedac86
--- /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
+);