[PATCH v8 0/4] ARM SMC Calling Convention interface

[PATCH v8 0/4] ARM SMC Calling Convention interface

[Jens Wiklander]

Hi,

This is hopefully the final version of this patch set. Russel, please let
me know if you are OK with this and I'll upload them into your patch
system.

This patch set is based on the Generic TEE subsystem v6 patchset
(https://lwn.net/Articles/662495/) sent out a some time ago. By isolating
the ARM SMC Calling Convention patches that are useful for other purposes
than to support the Generic TEE subsystem some complexity is removed from
that patch set.

This patch set adds a common interface to do an SMC or HVC following ARM
SMC Calling Convention. The interface is implemented for both the arm and
arm64 architectures and updates the PSCI driver to use this interface
instead for firmware communication.

v8:
* Moved HAVE_ARM_SMCCC from arch/Kconfig to drivers/firmware/Kconfig

v7:
* Use shift macros for all fields supplied to ARM_SMCCC_CALL_VAL()
* Move "select HAVE_ARM_SMCCC if CPU_V7" from "select HAVE_ARM_SMCCC if CPU_V7"
* arm: "config ARM_PSCI" now depends on HAVE_ARM_SMCCC instead of CPU_V7

v6:
* Move HAVE_ARM_SMCCC from init/Kconfig

v5:
* Fixes compile errors for Thumb-2 kernels reported by Kevin Hilman
* drivers: psci: replace psci firmware calls
  Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
  Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

v4:
* Rebased on v4.4-rc3 to resolve a PSCI conflict
* drivers: psci: replace psci firmware calls
  Reviewed-by: Mark Rutland <mark.rutland@arm.com>
  Tested-by: Mark Rutland <mark.rutland@arm.com>

v3:
* Moved the export of arm_smccc_{smc,hvc} to armksyms.c for both arm and arm64
* arm: add implementation for arm-smccc
  Reviewed-by: Lars Persson <lars.persson@axis.com>
* arm64: add implementation for arm-smccc
  drivers: psci: replace psci firmware calls
  Acked-by: Will Deacon <will.deacon@arm.com>

v2:
* Added unwinding support in the assembly functions

Thanks,
Jens

Jens Wiklander (4):
  arm/arm64: add arm-smccc
  arm: add implementation for arm-smccc
  arm64: add implementation for arm-smccc
  drivers: psci: replace psci firmware calls

 arch/arm/Kconfig                |   3 +-
 arch/arm/kernel/Makefile        |   3 +-
 arch/arm/kernel/armksyms.c      |   6 +++
 arch/arm/kernel/psci-call.S     |  31 ------------
 arch/arm/kernel/smccc-call.S    |  62 ++++++++++++++++++++++++
 arch/arm64/Kconfig              |   1 +
 arch/arm64/kernel/Makefile      |   4 +-
 arch/arm64/kernel/arm64ksyms.c  |   5 ++
 arch/arm64/kernel/asm-offsets.c |   3 ++
 arch/arm64/kernel/psci-call.S   |  28 -----------
 arch/arm64/kernel/smccc-call.S  |  43 +++++++++++++++++
 drivers/firmware/Kconfig        |   3 ++
 drivers/firmware/psci.c         |  23 ++++++++-
 include/linux/arm-smccc.h       | 104 ++++++++++++++++++++++++++++++++++++++++
 14 files changed, 254 insertions(+), 65 deletions(-)
 delete mode 100644 arch/arm/kernel/psci-call.S
 create mode 100644 arch/arm/kernel/smccc-call.S
 delete mode 100644 arch/arm64/kernel/psci-call.S
 create mode 100644 arch/arm64/kernel/smccc-call.S
 create mode 100644 include/linux/arm-smccc.h

-- 
1.9.1

[PATCH v8 1/4] arm/arm64: add arm-smccc

[Jens Wiklander]

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

This patch doesn't provide an implementation of the declared functions.
Later patches will bring in implementations and set
CONFIG_HAVE_ARM_SMCCC for ARM and ARM64 respectively.

Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 drivers/firmware/Kconfig  |   3 ++
 include/linux/arm-smccc.h | 104 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 107 insertions(+)
 create mode 100644 include/linux/arm-smccc.h

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index cf478fe..49a3a11 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -173,6 +173,9 @@ config QCOM_SCM_64
 	def_bool y
 	depends on QCOM_SCM && ARM64
 
+config HAVE_ARM_SMCCC
+	bool
+
 source "drivers/firmware/broadcom/Kconfig"
 source "drivers/firmware/google/Kconfig"
 source "drivers/firmware/efi/Kconfig"
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
new file mode 100644
index 0000000..b5abfda
--- /dev/null
+++ b/include/linux/arm-smccc.h
@@ -0,0 +1,104 @@
+/*
+ * 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/linkage.h>
+#include <linux/types.h>
+
+/*
+ * This file provides common defines for ARM SMC Calling Convention as
+ * specified in
+ * http://infocenter.arm.com/help/topic/com.arm.doc.den0028a/index.html
+ */
+
+#define ARM_SMCCC_STD_CALL		0
+#define ARM_SMCCC_FAST_CALL		1
+#define ARM_SMCCC_TYPE_SHIFT		31
+
+#define ARM_SMCCC_SMC_32		0
+#define ARM_SMCCC_SMC_64		1
+#define ARM_SMCCC_CALL_CONV_SHIFT	30
+
+#define ARM_SMCCC_OWNER_MASK		0x3F
+#define ARM_SMCCC_OWNER_SHIFT		24
+
+#define ARM_SMCCC_FUNC_MASK		0xFFFF
+
+#define ARM_SMCCC_IS_FAST_CALL(smc_val)	\
+	((smc_val) & (ARM_SMCCC_FAST_CALL << ARM_SMCCC_TYPE_SHIFT))
+#define ARM_SMCCC_IS_64(smc_val) \
+	((smc_val) & (ARM_SMCCC_SMC_64 << ARM_SMCCC_CALL_CONV_SHIFT))
+#define ARM_SMCCC_FUNC_NUM(smc_val)	((smc_val) & ARM_SMCCC_FUNC_MASK)
+#define ARM_SMCCC_OWNER_NUM(smc_val) \
+	(((smc_val) >> ARM_SMCCC_OWNER_SHIFT) & ARM_SMCCC_OWNER_MASK)
+
+#define ARM_SMCCC_CALL_VAL(type, calling_convention, owner, func_num) \
+	(((type) << ARM_SMCCC_TYPE_SHIFT) | \
+	((calling_convention) << ARM_SMCCC_CALL_CONV_SHIFT) | \
+	(((owner) & ARM_SMCCC_OWNER_MASK) << ARM_SMCCC_OWNER_SHIFT) | \
+	((func_num) & ARM_SMCCC_FUNC_MASK))
+
+#define ARM_SMCCC_OWNER_ARCH		0
+#define ARM_SMCCC_OWNER_CPU		1
+#define ARM_SMCCC_OWNER_SIP		2
+#define ARM_SMCCC_OWNER_OEM		3
+#define ARM_SMCCC_OWNER_STANDARD	4
+#define ARM_SMCCC_OWNER_TRUSTED_APP	48
+#define ARM_SMCCC_OWNER_TRUSTED_APP_END	49
+#define ARM_SMCCC_OWNER_TRUSTED_OS	50
+#define ARM_SMCCC_OWNER_TRUSTED_OS_END	63
+
+/**
+ * struct arm_smccc_res - Result from SMC/HVC call
+ * @a0-a3 result values from registers 0 to 3
+ */
+struct arm_smccc_res {
+	unsigned long a0;
+	unsigned long a1;
+	unsigned long a2;
+	unsigned long a3;
+};
+
+/**
+ * arm_smccc_smc() - make SMC calls
+ * @a0-a7: arguments passed in registers 0 to 7
+ * @res: result values from registers 0 to 3
+ *
+ * This function is used to make SMC calls following SMC Calling Convention.
+ * The content of the supplied param are copied to registers 0 to 7 prior
+ * to the SMC instruction. The return values are updated with the content
+ * from register 0 to 3 on return from the SMC instruction.
+ */
+asmlinkage void arm_smccc_smc(unsigned long a0, unsigned long a1,
+			unsigned long a2, unsigned long a3, unsigned long a4,
+			unsigned long a5, unsigned long a6, unsigned long a7,
+			struct arm_smccc_res *res);
+
+/**
+ * arm_smccc_hvc() - make HVC calls
+ * @a0-a7: arguments passed in registers 0 to 7
+ * @res: result values from registers 0 to 3
+ *
+ * This function is used to make HVC calls following SMC Calling
+ * Convention.  The content of the supplied param are copied to registers 0
+ * to 7 prior to the HVC instruction. The return values are updated with
+ * the content from register 0 to 3 on return from the HVC instruction.
+ */
+asmlinkage void arm_smccc_hvc(unsigned long a0, unsigned long a1,
+			unsigned long a2, unsigned long a3, unsigned long a4,
+			unsigned long a5, unsigned long a6, unsigned long a7,
+			struct arm_smccc_res *res);
+
+#endif /*__LINUX_ARM_SMCCC_H*/
-- 
1.9.1

[PATCH v8 2/4] arm: add implementation for arm-smccc

[Jens Wiklander]

Adds implementation for arm-smccc and enables CONFIG_HAVE_SMCCC for
architectures that may support arm-smccc. It's the responsibility of the
caller to know if the SMC instruction is supported by the platform.

Reviewed-by: Lars Persson <lars.persson@axis.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 arch/arm/Kconfig             |  1 +
 arch/arm/kernel/Makefile     |  2 ++
 arch/arm/kernel/armksyms.c   |  6 +++++
 arch/arm/kernel/smccc-call.S | 62 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 71 insertions(+)
 create mode 100644 arch/arm/kernel/smccc-call.S

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 34e1569..36b9490 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -37,6 +37,7 @@ config ARM
 	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32
 	select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
 	select HAVE_ARCH_TRACEHOOK
+	select HAVE_ARM_SMCCC if CPU_V7
 	select HAVE_BPF_JIT
 	select HAVE_CC_STACKPROTECTOR
 	select HAVE_CONTEXT_TRACKING
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index af9e59b..d2d0042 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -92,4 +92,6 @@ obj-y				+= psci-call.o
 obj-$(CONFIG_SMP)		+= psci_smp.o
 endif
 
+obj-$(CONFIG_HAVE_ARM_SMCCC)	+= smccc-call.o
+
 extra-y := $(head-y) vmlinux.lds
diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
index f89811f..7e45f69 100644
--- a/arch/arm/kernel/armksyms.c
+++ b/arch/arm/kernel/armksyms.c
@@ -16,6 +16,7 @@
 #include <linux/syscalls.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>
+#include <linux/arm-smccc.h>
 
 #include <asm/checksum.h>
 #include <asm/ftrace.h>
@@ -175,3 +176,8 @@ EXPORT_SYMBOL(__gnu_mcount_nc);
 EXPORT_SYMBOL(__pv_phys_pfn_offset);
 EXPORT_SYMBOL(__pv_offset);
 #endif
+
+#ifdef CONFIG_HAVE_ARM_SMCCC
+EXPORT_SYMBOL(arm_smccc_smc);
+EXPORT_SYMBOL(arm_smccc_hvc);
+#endif
diff --git a/arch/arm/kernel/smccc-call.S b/arch/arm/kernel/smccc-call.S
new file mode 100644
index 0000000..2e48b67
--- /dev/null
+++ b/arch/arm/kernel/smccc-call.S
@@ -0,0 +1,62 @@
+/*
+ * 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>
+#include <asm/opcodes-virt.h>
+#include <asm/unwind.h>
+
+	/*
+	 * Wrap c macros in asm macros to delay expansion until after the
+	 * SMCCC asm macro is expanded.
+	 */
+	.macro SMCCC_SMC
+	__SMC(0)
+	.endm
+
+	.macro SMCCC_HVC
+	__HVC(0)
+	.endm
+
+	.macro SMCCC instr
+UNWIND(	.fnstart)
+	mov	r12, sp
+	push	{r4-r7}
+UNWIND(	.save	{r4-r7})
+	ldm	r12, {r4-r7}
+	\instr
+	pop	{r4-r7}
+	ldr	r12, [sp, #(4 * 4)]
+	stm	r12, {r0-r3}
+	bx	lr
+UNWIND(	.fnend)
+	.endm
+
+/*
+ * void smccc_smc(unsigned long a0, unsigned long a1, unsigned long a2,
+ *		  unsigned long a3, unsigned long a4, unsigned long a5,
+ *		  unsigned long a6, unsigned long a7, struct arm_smccc_res *res)
+ */
+ENTRY(arm_smccc_smc)
+	SMCCC SMCCC_SMC
+ENDPROC(arm_smccc_smc)
+
+/*
+ * void smccc_hvc(unsigned long a0, unsigned long a1, unsigned long a2,
+ *		  unsigned long a3, unsigned long a4, unsigned long a5,
+ *		  unsigned long a6, unsigned long a7, struct arm_smccc_res *res)
+ */
+ENTRY(arm_smccc_hvc)
+	SMCCC SMCCC_HVC
+ENDPROC(arm_smccc_hvc)
-- 
1.9.1

[PATCH v8 3/4] arm64: add implementation for arm-smccc

[Jens Wiklander]

Adds implementation for arm-smccc and enables CONFIG_HAVE_SMCCC.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 arch/arm64/Kconfig              |  1 +
 arch/arm64/kernel/Makefile      |  2 +-
 arch/arm64/kernel/arm64ksyms.c  |  5 +++++
 arch/arm64/kernel/asm-offsets.c |  3 +++
 arch/arm64/kernel/smccc-call.S  | 43 +++++++++++++++++++++++++++++++++++++++++
 5 files changed, 53 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/kernel/smccc-call.S

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 871f217..96513d0 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -92,6 +92,7 @@ config ARM64
 	select SPARSE_IRQ
 	select SYSCTL_EXCEPTION_TRACE
 	select HAVE_CONTEXT_TRACKING
+	select HAVE_ARM_SMCCC
 	help
 	  ARM 64-bit (AArch64) Linux support.
 
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 474691f..0170bea 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -17,7 +17,7 @@ arm64-obj-y		:= debug-monitors.o entry.o irq.o fpsimd.o		\
 			   hyp-stub.o psci.o psci-call.o cpu_ops.o insn.o	\
 			   return_address.o cpuinfo.o cpu_errata.o		\
 			   cpufeature.o alternative.o cacheinfo.o		\
-			   smp.o smp_spin_table.o topology.o
+			   smp.o smp_spin_table.o topology.o smccc-call.o
 
 extra-$(CONFIG_EFI)			:= efi-entry.o
 
diff --git a/arch/arm64/kernel/arm64ksyms.c b/arch/arm64/kernel/arm64ksyms.c
index 3b6d8cc..678f30b0 100644
--- a/arch/arm64/kernel/arm64ksyms.c
+++ b/arch/arm64/kernel/arm64ksyms.c
@@ -26,6 +26,7 @@
 #include <linux/syscalls.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>
+#include <linux/arm-smccc.h>
 
 #include <asm/checksum.h>
 
@@ -68,3 +69,7 @@ EXPORT_SYMBOL(test_and_change_bit);
 #ifdef CONFIG_FUNCTION_TRACER
 EXPORT_SYMBOL(_mcount);
 #endif
+
+	/* arm-smccc */
+EXPORT_SYMBOL(arm_smccc_smc);
+EXPORT_SYMBOL(arm_smccc_hvc);
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index 25de8b2..bb493d4 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -28,6 +28,7 @@
 #include <asm/suspend.h>
 #include <asm/vdso_datapage.h>
 #include <linux/kbuild.h>
+#include <linux/arm-smccc.h>
 
 int main(void)
 {
@@ -161,5 +162,7 @@ int main(void)
   DEFINE(SLEEP_SAVE_SP_PHYS,	offsetof(struct sleep_save_sp, save_ptr_stash_phys));
   DEFINE(SLEEP_SAVE_SP_VIRT,	offsetof(struct sleep_save_sp, save_ptr_stash));
 #endif
+  DEFINE(ARM_SMCCC_RES_X0_OFFS,	offsetof(struct arm_smccc_res, a0));
+  DEFINE(ARM_SMCCC_RES_X2_OFFS,	offsetof(struct arm_smccc_res, a2));
   return 0;
 }
diff --git a/arch/arm64/kernel/smccc-call.S b/arch/arm64/kernel/smccc-call.S
new file mode 100644
index 0000000..ae0496f
--- /dev/null
+++ b/arch/arm64/kernel/smccc-call.S
@@ -0,0 +1,43 @@
+/*
+ * 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>
+#include <asm/asm-offsets.h>
+
+	.macro SMCCC instr
+	.cfi_startproc
+	\instr	#0
+	ldr	x4, [sp]
+	stp	x0, x1, [x4, #ARM_SMCCC_RES_X0_OFFS]
+	stp	x2, x3, [x4, #ARM_SMCCC_RES_X2_OFFS]
+	ret
+	.cfi_endproc
+	.endm
+
+/*
+ * void arm_smccc_smc(unsigned long a0, unsigned long a1, unsigned long a2,
+ *		  unsigned long a3, unsigned long a4, unsigned long a5,
+ *		  unsigned long a6, unsigned long a7, struct arm_smccc_res *res)
+ */
+ENTRY(arm_smccc_smc)
+	SMCCC	smc
+ENDPROC(arm_smccc_smc)
+
+/*
+ * void arm_smccc_hvc(unsigned long a0, unsigned long a1, unsigned long a2,
+ *		  unsigned long a3, unsigned long a4, unsigned long a5,
+ *		  unsigned long a6, unsigned long a7, struct arm_smccc_res *res)
+ */
+ENTRY(arm_smccc_hvc)
+	SMCCC	hvc
+ENDPROC(arm_smccc_hvc)
-- 
1.9.1

[PATCH v8 4/4] drivers: psci: replace psci firmware calls

[Jens Wiklander]

Switch to use a generic interface for issuing SMC/HVC based on ARM SMC
Calling Convention. Removes now the now unused psci-call.S.

Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 arch/arm/Kconfig              |  2 +-
 arch/arm/kernel/Makefile      |  1 -
 arch/arm/kernel/psci-call.S   | 31 -------------------------------
 arch/arm64/kernel/Makefile    |  2 +-
 arch/arm64/kernel/psci-call.S | 28 ----------------------------
 drivers/firmware/psci.c       | 23 +++++++++++++++++++++--
 6 files changed, 23 insertions(+), 64 deletions(-)
 delete mode 100644 arch/arm/kernel/psci-call.S
 delete mode 100644 arch/arm64/kernel/psci-call.S

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 36b9490..2687c93 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1482,7 +1482,7 @@ config HOTPLUG_CPU
 
 config ARM_PSCI
 	bool "Support for the ARM Power State Coordination Interface (PSCI)"
-	depends on CPU_V7
+	depends on HAVE_ARM_SMCCC
 	select ARM_PSCI_FW
 	help
 	  Say Y here if you want Linux to communicate with system firmware
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index d2d0042..80856de 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -88,7 +88,6 @@ obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 
 obj-$(CONFIG_ARM_VIRT_EXT)	+= hyp-stub.o
 ifeq ($(CONFIG_ARM_PSCI),y)
-obj-y				+= psci-call.o
 obj-$(CONFIG_SMP)		+= psci_smp.o
 endif
 
diff --git a/arch/arm/kernel/psci-call.S b/arch/arm/kernel/psci-call.S
deleted file mode 100644
index a78e9e1..0000000
--- a/arch/arm/kernel/psci-call.S
+++ /dev/null
@@ -1,31 +0,0 @@
-/*
- * 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.
- *
- * Copyright (C) 2015 ARM Limited
- *
- * Author: Mark Rutland <mark.rutland@arm.com>
- */
-
-#include <linux/linkage.h>
-
-#include <asm/opcodes-sec.h>
-#include <asm/opcodes-virt.h>
-
-/* int __invoke_psci_fn_hvc(u32 function_id, u32 arg0, u32 arg1, u32 arg2) */
-ENTRY(__invoke_psci_fn_hvc)
-	__HVC(0)
-	bx	lr
-ENDPROC(__invoke_psci_fn_hvc)
-
-/* int __invoke_psci_fn_smc(u32 function_id, u32 arg0, u32 arg1, u32 arg2) */
-ENTRY(__invoke_psci_fn_smc)
-	__SMC(0)
-	bx	lr
-ENDPROC(__invoke_psci_fn_smc)
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 0170bea..27bf1e5 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -14,7 +14,7 @@ CFLAGS_REMOVE_return_address.o = -pg
 arm64-obj-y		:= debug-monitors.o entry.o irq.o fpsimd.o		\
 			   entry-fpsimd.o process.o ptrace.o setup.o signal.o	\
 			   sys.o stacktrace.o time.o traps.o io.o vdso.o	\
-			   hyp-stub.o psci.o psci-call.o cpu_ops.o insn.o	\
+			   hyp-stub.o psci.o cpu_ops.o insn.o	\
 			   return_address.o cpuinfo.o cpu_errata.o		\
 			   cpufeature.o alternative.o cacheinfo.o		\
 			   smp.o smp_spin_table.o topology.o smccc-call.o
diff --git a/arch/arm64/kernel/psci-call.S b/arch/arm64/kernel/psci-call.S
deleted file mode 100644
index cf83e61..0000000
--- a/arch/arm64/kernel/psci-call.S
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * 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.
- *
- * Copyright (C) 2015 ARM Limited
- *
- * Author: Will Deacon <will.deacon@arm.com>
- */
-
-#include <linux/linkage.h>
-
-/* int __invoke_psci_fn_hvc(u64 function_id, u64 arg0, u64 arg1, u64 arg2) */
-ENTRY(__invoke_psci_fn_hvc)
-	hvc	#0
-	ret
-ENDPROC(__invoke_psci_fn_hvc)
-
-/* int __invoke_psci_fn_smc(u64 function_id, u64 arg0, u64 arg1, u64 arg2) */
-ENTRY(__invoke_psci_fn_smc)
-	smc	#0
-	ret
-ENDPROC(__invoke_psci_fn_smc)
diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index d24f35d..f25cd79 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -13,6 +13,7 @@
 
 #define pr_fmt(fmt) "psci: " fmt
 
+#include <linux/arm-smccc.h>
 #include <linux/errno.h>
 #include <linux/linkage.h>
 #include <linux/of.h>
@@ -58,8 +59,6 @@ struct psci_operations psci_ops;
 
 typedef unsigned long (psci_fn)(unsigned long, unsigned long,
 				unsigned long, unsigned long);
-asmlinkage psci_fn __invoke_psci_fn_hvc;
-asmlinkage psci_fn __invoke_psci_fn_smc;
 static psci_fn *invoke_psci_fn;
 
 enum psci_function {
@@ -107,6 +106,26 @@ bool psci_power_state_is_valid(u32 state)
 	return !(state & ~valid_mask);
 }
 
+static unsigned long __invoke_psci_fn_hvc(unsigned long function_id,
+			unsigned long arg0, unsigned long arg1,
+			unsigned long arg2)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_hvc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
+	return res.a0;
+}
+
+static unsigned long __invoke_psci_fn_smc(unsigned long function_id,
+			unsigned long arg0, unsigned long arg1,
+			unsigned long arg2)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(function_id, arg0, arg1, arg2, 0, 0, 0, 0, &res);
+	return res.a0;
+}
+
 static int psci_to_linux_errno(int errno)
 {
 	switch (errno) {
-- 
1.9.1

[PATCH v8 1/4] arm/arm64: add arm-smccc

[Lorenzo Pieralisi]

On Mon, Jan 04, 2016 at 01:54:36PM +0100, Jens Wiklander wrote:
> Adds helpers to do SMC and HVC based on ARM SMC Calling Convention.
> CONFIG_HAVE_ARM_SMCCC is enabled for architectures that may support the
> SMC or HVC instruction. It's the responsibility of the caller to know if
> the SMC instruction is supported by the platform.
> 
> This patch doesn't provide an implementation of the declared functions.
> Later patches will bring in implementations and set
> CONFIG_HAVE_ARM_SMCCC for ARM and ARM64 respectively.
> 
> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> ---
>  drivers/firmware/Kconfig  |   3 ++
>  include/linux/arm-smccc.h | 104 ++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 107 insertions(+)
>  create mode 100644 include/linux/arm-smccc.h
> 
> diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
> index cf478fe..49a3a11 100644
> --- a/drivers/firmware/Kconfig
> +++ b/drivers/firmware/Kconfig
> @@ -173,6 +173,9 @@ config QCOM_SCM_64
>  	def_bool y
>  	depends on QCOM_SCM && ARM64
>  
> +config HAVE_ARM_SMCCC
> +	bool

Nit: It should be added in alphabetical order.

Thanks,
Lorenzo

> +
>  source "drivers/firmware/broadcom/Kconfig"
>  source "drivers/firmware/google/Kconfig"
>  source "drivers/firmware/efi/Kconfig"
> diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
> new file mode 100644
> index 0000000..b5abfda
> --- /dev/null
> +++ b/include/linux/arm-smccc.h
> @@ -0,0 +1,104 @@
> +/*
> + * 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/linkage.h>
> +#include <linux/types.h>
> +
> +/*
> + * This file provides common defines for ARM SMC Calling Convention as
> + * specified in
> + * http://infocenter.arm.com/help/topic/com.arm.doc.den0028a/index.html
> + */
> +
> +#define ARM_SMCCC_STD_CALL		0
> +#define ARM_SMCCC_FAST_CALL		1
> +#define ARM_SMCCC_TYPE_SHIFT		31
> +
> +#define ARM_SMCCC_SMC_32		0
> +#define ARM_SMCCC_SMC_64		1
> +#define ARM_SMCCC_CALL_CONV_SHIFT	30
> +
> +#define ARM_SMCCC_OWNER_MASK		0x3F
> +#define ARM_SMCCC_OWNER_SHIFT		24
> +
> +#define ARM_SMCCC_FUNC_MASK		0xFFFF
> +
> +#define ARM_SMCCC_IS_FAST_CALL(smc_val)	\
> +	((smc_val) & (ARM_SMCCC_FAST_CALL << ARM_SMCCC_TYPE_SHIFT))
> +#define ARM_SMCCC_IS_64(smc_val) \
> +	((smc_val) & (ARM_SMCCC_SMC_64 << ARM_SMCCC_CALL_CONV_SHIFT))
> +#define ARM_SMCCC_FUNC_NUM(smc_val)	((smc_val) & ARM_SMCCC_FUNC_MASK)
> +#define ARM_SMCCC_OWNER_NUM(smc_val) \
> +	(((smc_val) >> ARM_SMCCC_OWNER_SHIFT) & ARM_SMCCC_OWNER_MASK)
> +
> +#define ARM_SMCCC_CALL_VAL(type, calling_convention, owner, func_num) \
> +	(((type) << ARM_SMCCC_TYPE_SHIFT) | \
> +	((calling_convention) << ARM_SMCCC_CALL_CONV_SHIFT) | \
> +	(((owner) & ARM_SMCCC_OWNER_MASK) << ARM_SMCCC_OWNER_SHIFT) | \
> +	((func_num) & ARM_SMCCC_FUNC_MASK))
> +
> +#define ARM_SMCCC_OWNER_ARCH		0
> +#define ARM_SMCCC_OWNER_CPU		1
> +#define ARM_SMCCC_OWNER_SIP		2
> +#define ARM_SMCCC_OWNER_OEM		3
> +#define ARM_SMCCC_OWNER_STANDARD	4
> +#define ARM_SMCCC_OWNER_TRUSTED_APP	48
> +#define ARM_SMCCC_OWNER_TRUSTED_APP_END	49
> +#define ARM_SMCCC_OWNER_TRUSTED_OS	50
> +#define ARM_SMCCC_OWNER_TRUSTED_OS_END	63
> +
> +/**
> + * struct arm_smccc_res - Result from SMC/HVC call
> + * @a0-a3 result values from registers 0 to 3
> + */
> +struct arm_smccc_res {
> +	unsigned long a0;
> +	unsigned long a1;
> +	unsigned long a2;
> +	unsigned long a3;
> +};
> +
> +/**
> + * arm_smccc_smc() - make SMC calls
> + * @a0-a7: arguments passed in registers 0 to 7
> + * @res: result values from registers 0 to 3
> + *
> + * This function is used to make SMC calls following SMC Calling Convention.
> + * The content of the supplied param are copied to registers 0 to 7 prior
> + * to the SMC instruction. The return values are updated with the content
> + * from register 0 to 3 on return from the SMC instruction.
> + */
> +asmlinkage void arm_smccc_smc(unsigned long a0, unsigned long a1,
> +			unsigned long a2, unsigned long a3, unsigned long a4,
> +			unsigned long a5, unsigned long a6, unsigned long a7,
> +			struct arm_smccc_res *res);
> +
> +/**
> + * arm_smccc_hvc() - make HVC calls
> + * @a0-a7: arguments passed in registers 0 to 7
> + * @res: result values from registers 0 to 3
> + *
> + * This function is used to make HVC calls following SMC Calling
> + * Convention.  The content of the supplied param are copied to registers 0
> + * to 7 prior to the HVC instruction. The return values are updated with
> + * the content from register 0 to 3 on return from the HVC instruction.
> + */
> +asmlinkage void arm_smccc_hvc(unsigned long a0, unsigned long a1,
> +			unsigned long a2, unsigned long a3, unsigned long a4,
> +			unsigned long a5, unsigned long a6, unsigned long a7,
> +			struct arm_smccc_res *res);
> +
> +#endif /*__LINUX_ARM_SMCCC_H*/
> -- 
> 1.9.1
> 

[v8,2/4] arm: add implementation for arm-smccc

[Andreas Dannenberg]

On Mon, Jan 04, 2016 at 01:54:37PM +0100, Jens Wiklander wrote:
> Adds implementation for arm-smccc and enables CONFIG_HAVE_SMCCC for
> architectures that may support arm-smccc. It's the responsibility of the
> caller to know if the SMC instruction is supported by the platform.
> 
> Reviewed-by: Lars Persson <lars.persson@axis.com>
> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> 
> ---
> arch/arm/Kconfig             |  1 +
>  arch/arm/kernel/Makefile     |  2 ++
>  arch/arm/kernel/armksyms.c   |  6 +++++
>  arch/arm/kernel/smccc-call.S | 62 ++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 71 insertions(+)
>  create mode 100644 arch/arm/kernel/smccc-call.S
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 34e1569..36b9490 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -37,6 +37,7 @@ config ARM
>  	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32
>  	select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
>  	select HAVE_ARCH_TRACEHOOK
> +	select HAVE_ARM_SMCCC if CPU_V7
>  	select HAVE_BPF_JIT
>  	select HAVE_CC_STACKPROTECTOR
>  	select HAVE_CONTEXT_TRACKING
> diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
> index af9e59b..d2d0042 100644
> --- a/arch/arm/kernel/Makefile
> +++ b/arch/arm/kernel/Makefile
> @@ -92,4 +92,6 @@ obj-y				+= psci-call.o
>  obj-$(CONFIG_SMP)		+= psci_smp.o
>  endif
>  
> +obj-$(CONFIG_HAVE_ARM_SMCCC)	+= smccc-call.o
> +
>  extra-y := $(head-y) vmlinux.lds
> diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
> index f89811f..7e45f69 100644
> --- a/arch/arm/kernel/armksyms.c
> +++ b/arch/arm/kernel/armksyms.c
> @@ -16,6 +16,7 @@
>  #include <linux/syscalls.h>
>  #include <linux/uaccess.h>
>  #include <linux/io.h>
> +#include <linux/arm-smccc.h>
>  
>  #include <asm/checksum.h>
>  #include <asm/ftrace.h>
> @@ -175,3 +176,8 @@ EXPORT_SYMBOL(__gnu_mcount_nc);
>  EXPORT_SYMBOL(__pv_phys_pfn_offset);
>  EXPORT_SYMBOL(__pv_offset);
>  #endif
> +
> +#ifdef CONFIG_HAVE_ARM_SMCCC
> +EXPORT_SYMBOL(arm_smccc_smc);
> +EXPORT_SYMBOL(arm_smccc_hvc);
> +#endif
> diff --git a/arch/arm/kernel/smccc-call.S b/arch/arm/kernel/smccc-call.S
> new file mode 100644
> index 0000000..2e48b67
> --- /dev/null
> +++ b/arch/arm/kernel/smccc-call.S
> @@ -0,0 +1,62 @@
> +/*
> + * 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>
> +#include <asm/opcodes-virt.h>
> +#include <asm/unwind.h>
> +
> +	/*
> +	 * Wrap c macros in asm macros to delay expansion until after the
> +	 * SMCCC asm macro is expanded.
> +	 */
> +	.macro SMCCC_SMC
> +	__SMC(0)
> +	.endm
> +
> +	.macro SMCCC_HVC
> +	__HVC(0)
> +	.endm
> +
> +	.macro SMCCC instr
> +UNWIND(	.fnstart)
> +	mov	r12, sp
> +	push	{r4-r7}
> +UNWIND(	.save	{r4-r7})
> +	ldm	r12, {r4-r7}
> +	\instr

Jens,
out of curiosity, we don't need any dsb/dmb calls here? I've rummaged
through some other code here at TI and see such barriers being included
right before the smc call. However in all fairness I also don't see such
memory calls included in arch/arm/kernel/psci-call.S that your other
patch is removing, so either they are really not needed or I didn't look
right and need to go to have my prescriptions checked.

Regards,

--
Andreas Dannenberg
Texas Instruments Inc

> +	pop	{r4-r7}
> +	ldr	r12, [sp, #(4 * 4)]
> +	stm	r12, {r0-r3}
> +	bx	lr
> +UNWIND(	.fnend)
> +	.endm
> +
> +/*
> + * void smccc_smc(unsigned long a0, unsigned long a1, unsigned long a2,
> + *		  unsigned long a3, unsigned long a4, unsigned long a5,
> + *		  unsigned long a6, unsigned long a7, struct arm_smccc_res *res)
> + */
> +ENTRY(arm_smccc_smc)
> +	SMCCC SMCCC_SMC
> +ENDPROC(arm_smccc_smc)
> +
> +/*
> + * void smccc_hvc(unsigned long a0, unsigned long a1, unsigned long a2,
> + *		  unsigned long a3, unsigned long a4, unsigned long a5,
> + *		  unsigned long a6, unsigned long a7, struct arm_smccc_res *res)
> + */
> +ENTRY(arm_smccc_hvc)
> +	SMCCC SMCCC_HVC
> +ENDPROC(arm_smccc_hvc)

[v8,2/4] arm: add implementation for arm-smccc

[Will Deacon]

On Wed, Mar 02, 2016 at 03:26:28PM -0600, Andreas Dannenberg wrote:
> On Mon, Jan 04, 2016 at 01:54:37PM +0100, Jens Wiklander wrote:
> > diff --git a/arch/arm/kernel/smccc-call.S b/arch/arm/kernel/smccc-call.S
> > new file mode 100644
> > index 0000000..2e48b67
> > --- /dev/null
> > +++ b/arch/arm/kernel/smccc-call.S
> > @@ -0,0 +1,62 @@
> > +/*
> > + * 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>
> > +#include <asm/opcodes-virt.h>
> > +#include <asm/unwind.h>
> > +
> > +	/*
> > +	 * Wrap c macros in asm macros to delay expansion until after the
> > +	 * SMCCC asm macro is expanded.
> > +	 */
> > +	.macro SMCCC_SMC
> > +	__SMC(0)
> > +	.endm
> > +
> > +	.macro SMCCC_HVC
> > +	__HVC(0)
> > +	.endm
> > +
> > +	.macro SMCCC instr
> > +UNWIND(	.fnstart)
> > +	mov	r12, sp
> > +	push	{r4-r7}
> > +UNWIND(	.save	{r4-r7})
> > +	ldm	r12, {r4-r7}
> > +	\instr
> 
> Jens,
> out of curiosity, we don't need any dsb/dmb calls here? I've rummaged
> through some other code here at TI and see such barriers being included
> right before the smc call. However in all fairness I also don't see such
> memory calls included in arch/arm/kernel/psci-call.S that your other
> patch is removing, so either they are really not needed or I didn't look
> right and need to go to have my prescriptions checked.

There are no architectural requirements for a barrier here. My understanding
of the TI code is that it was there to work around buggy firmware.

Will