Adds helpers to do SMC based on ARM SMC Calling Convention.
CONFIG_HAVE_SMCCC is enabled for architectures that may support
the SMC instruction. It's the responsibility of the caller to
know if the SMC instruction is supported by the platform.

Signed-off-by: Jens Wiklander <jens.wiklan...@linaro.org>
---
 arch/arm/Kconfig               |  4 +++
 arch/arm/kernel/Makefile       |  2 ++
 arch/arm/kernel/smccc-call.S   | 26 ++++++++++++++
 arch/arm/kernel/smccc.c        | 17 +++++++++
 arch/arm64/Kconfig             |  4 +++
 arch/arm64/kernel/Makefile     |  1 +
 arch/arm64/kernel/smccc-call.S | 34 ++++++++++++++++++
 arch/arm64/kernel/smccc.c      | 17 +++++++++
 include/linux/arm-smccc.h      | 80 ++++++++++++++++++++++++++++++++++++++++++
 9 files changed, 185 insertions(+)
 create mode 100644 arch/arm/kernel/smccc-call.S
 create mode 100644 arch/arm/kernel/smccc.c
 create mode 100644 arch/arm64/kernel/smccc-call.S
 create mode 100644 arch/arm64/kernel/smccc.c
 create mode 100644 include/linux/arm-smccc.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 45df48b..75e4da3 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -221,6 +221,9 @@ config NEED_RET_TO_USER
 config ARCH_MTD_XIP
        bool
 
+config HAVE_SMCCC
+       bool
+
 config VECTORS_BASE
        hex
        default 0xffff0000 if MMU || CPU_HIGH_VECTOR
@@ -324,6 +327,7 @@ config ARCH_MULTIPLATFORM
        select CLKSRC_OF
        select COMMON_CLK
        select GENERIC_CLOCKEVENTS
+       select HAVE_SMCCC if CPU_V7
        select MIGHT_HAVE_PCI
        select MULTI_IRQ_HANDLER
        select SPARSE_IRQ
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 752725d..8cdd25b 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -90,4 +90,6 @@ obj-y                         += psci.o psci-call.o
 obj-$(CONFIG_SMP)              += psci_smp.o
 endif
 
+obj-$(CONFIG_HAVE_SMCCC)       += smccc-call.o smccc.o
+
 extra-y := $(head-y) vmlinux.lds
diff --git a/arch/arm/kernel/smccc-call.S b/arch/arm/kernel/smccc-call.S
new file mode 100644
index 0000000..05bc554
--- /dev/null
+++ b/arch/arm/kernel/smccc-call.S
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2015, Linaro Limited
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/linkage.h>
+
+#include <asm/opcodes-sec.h>
+
+/* void smccc_call32(struct smccc_param32 *param) */
+ENTRY(smccc_call32)
+       push    {r4-r8, lr}
+       mov     r8, r0
+       ldm     r8, {r0-r7}
+       __SMC(0)
+       stm     r8, {r0-r7}
+       pop     {r4-r8, pc}
+ENDPROC(smccc_call32)
diff --git a/arch/arm/kernel/smccc.c b/arch/arm/kernel/smccc.c
new file mode 100644
index 0000000..ba4039e
--- /dev/null
+++ b/arch/arm/kernel/smccc.c
@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2015, Linaro Limited
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/export.h>
+#include <linux/arm-smccc.h>
+
+EXPORT_SYMBOL_GPL(smccc_call32);
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7796af4..b3ea778 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -83,6 +83,7 @@ config ARM64
        select SPARSE_IRQ
        select SYSCTL_EXCEPTION_TRACE
        select HAVE_CONTEXT_TRACKING
+       select HAVE_SMCCC
        help
          ARM 64-bit (AArch64) Linux support.
 
@@ -146,6 +147,9 @@ config KERNEL_MODE_NEON
 config FIX_EARLYCON_MEM
        def_bool y
 
+config HAVE_SMCCC
+       bool
+
 config PGTABLE_LEVELS
        int
        default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 426d076..f7804f7 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -36,6 +36,7 @@ arm64-obj-$(CONFIG_EFI)                       += efi.o 
efi-stub.o efi-entry.o
 arm64-obj-$(CONFIG_PCI)                        += pci.o
 arm64-obj-$(CONFIG_ARMV8_DEPRECATED)   += armv8_deprecated.o
 arm64-obj-$(CONFIG_ACPI)               += acpi.o
+arm64-obj-$(CONFIG_HAVE_SMCCC)         += smccc-call.o smccc.o
 
 obj-y                                  += $(arm64-obj-y) vdso/
 obj-m                                  += $(arm64-obj-m)
diff --git a/arch/arm64/kernel/smccc-call.S b/arch/arm64/kernel/smccc-call.S
new file mode 100644
index 0000000..3ce7fe8
--- /dev/null
+++ b/arch/arm64/kernel/smccc-call.S
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2015, Linaro Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License Version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/linkage.h>
+
+#define SMC_PARAM_W0_OFFS      0
+#define SMC_PARAM_W2_OFFS      8
+#define SMC_PARAM_W4_OFFS      16
+#define SMC_PARAM_W6_OFFS      24
+
+/* void smccc_call32(struct smccc_param32 *param) */
+ENTRY(smccc_call32)
+       stp     x28, x30, [sp, #-16]!
+       mov     x28, x0
+       ldp     w0, w1, [x28, #SMC_PARAM_W0_OFFS]
+       ldp     w2, w3, [x28, #SMC_PARAM_W2_OFFS]
+       ldp     w4, w5, [x28, #SMC_PARAM_W4_OFFS]
+       ldp     w6, w7, [x28, #SMC_PARAM_W6_OFFS]
+       smc     #0
+       stp     w0, w1, [x28, #SMC_PARAM_W0_OFFS]
+       stp     w2, w3, [x28, #SMC_PARAM_W2_OFFS]
+       ldp     x28, x30, [sp], #16
+       ret
+ENDPROC(smccc_call32)
diff --git a/arch/arm64/kernel/smccc.c b/arch/arm64/kernel/smccc.c
new file mode 100644
index 0000000..ba4039e
--- /dev/null
+++ b/arch/arm64/kernel/smccc.c
@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2015, Linaro Limited
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/export.h>
+#include <linux/arm-smccc.h>
+
+EXPORT_SYMBOL_GPL(smccc_call32);
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
new file mode 100644
index 0000000..98b3c3c
--- /dev/null
+++ b/include/linux/arm-smccc.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2015, Linaro Limited
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#ifndef __LINUX_ARM_SMCCC_H
+#define __LINUX_ARM_SMCCC_H
+
+#include <linux/types.h>
+
+/*
+ * This file provideds defines common defines for ARM SMC Calling
+ * Convention as specified in
+ * http://infocenter.arm.com/help/topic/com.arm.doc.den0028a/index.html
+ */
+
+#define SMCCC_SMC_32                   (0 << 30)
+#define SMCCC_SMC_64                   (1 << 30)
+#define SMCCC_FAST_CALL                        (1 << 31)
+#define SMCCC_STD_CALL                 (0 << 31)
+
+#define SMCCC_OWNER_MASK               0x3F
+#define SMCCC_OWNER_SHIFT              24
+
+#define SMCCC_FUNC_MASK                        0xFFFF
+
+#define SMCCC_IS_FAST_CALL(smc_val)    ((smc_val) & SMCCC_FAST_CALL)
+#define SMCCC_IS_64(smc_val)           ((smc_val) & SMCCC_SMC_64)
+#define SMCCC_FUNC_NUM(smc_val)                ((smc_val) & SMCCC_FUNC_MASK)
+#define SMCCC_OWNER_NUM(smc_val) \
+       (((smc_val) >> SMCCC_OWNER_SHIFT) & SMCCC_OWNER_MASK)
+
+#define SMCCC_CALL_VAL(type, calling_convention, owner, func_num) \
+                       ((type) | (calling_convention) | \
+                       (((owner) & SMCCC_OWNER_MASK) << SMCCC_OWNER_SHIFT) | \
+                       ((func_num) & SMCCC_FUNC_MASK))
+
+#define SMCCC_OWNER_ARCH               0
+#define SMCCC_OWNER_CPU                        1
+#define SMCCC_OWNER_SIP                        2
+#define SMCCC_OWNER_OEM                        3
+#define SMCCC_OWNER_STANDARD           4
+#define SMCCC_OWNER_TRUSTED_APP                48
+#define SMCCC_OWNER_TRUSTED_APP_END    49
+#define SMCCC_OWNER_TRUSTED_OS         50
+#define SMCCC_OWNER_TRUSTED_OS_END     63
+
+struct smccc_param32 {
+       u32 a0;
+       u32 a1;
+       u32 a2;
+       u32 a3;
+       u32 a4;
+       u32 a5;
+       u32 a6;
+       u32 a7;
+};
+
+/**
+ * smccc_call32() - make ARCH32 SMC calls
+ * @param: values to pass in registers 0 to 7
+ *
+ * This function is used to make SMC calls following SMC Calling Convention
+ * for ARCH32 calls. The content of the supplied param are copied to
+ * registers 0 to 7 prior to the SMC instruction. Values a0..a3 are updated
+ * with the content from register 0 to 3 on return from the SMC
+ * instruction.
+ */
+void smccc_call32(struct smccc_param32 *param);
+
+#endif /*__LINUX_ARM_SMCCC_H*/
+
-- 
1.9.1

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