Re: [PATCH v5 1/5] arm/arm64: add smccc ARCH32

[Yury <yury.norov@gmail.com>]

On 19.08.2015 11:40, Jens Wiklander wrote:
 >
 > 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.wiklander@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      | 79 
++++++++++++++++++++++++++++++++++++++++++
 >  9 files changed, 184 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..9b8d775
 > --- /dev/null
 > +++ b/include/linux/arm-smccc.h
 > @@ -0,0 +1,79 @@
 > +/*
 > + * 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

typos here?

 > + * Convention as specified in
 > + * http://infocenter.arm.com/help/topic/com.arm.doc.den0028a/index.html
 > + */
 > +
 > +#define SMCCC_SMC_32			(0 << 30)

0 << 30 is just 0, and so meaningless.
It's better to introduce SMCCC_IS_32() macro instead.

 > +#define SMCCC_SMC_64			(1 << 30)
 > +#define SMCCC_FAST_CALL			(1 << 31)
 > +#define SMCCC_STD_CALL			(0 << 31)

The same

 > +
 > +#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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