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>
This commit is contained in:
Dimitris Papastamos 2018-01-19 16:58:29 +00:00
parent 201ca5b6b4
commit 3a1b0676c7
4 changed files with 100 additions and 2 deletions

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@ -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_SOURCES += bl31/bl31_main.c \
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} \

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@ -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))

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@ -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__ */

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@ -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
);