Subject: [PATCH v2 3/4] arm64: add implementation for arm-smccc

From: [email-masked] (Will Deacon)
Date: Mon, 23 Nov 2015 13:28:56 +0000

On Wed, Nov 11, 2015 at 11:04:25AM +0100, Jens Wiklander wrote:
> Adds implementation for arm-smccc and enables CONFIG_HAVE_SMCCC.
> 
> Signed-off-by: Jens Wiklander <[email-masked]>
> ---
>  arch/arm64/Kconfig              |  1 +
>  arch/arm64/kernel/Makefile      |  1 +
>  arch/arm64/kernel/asm-offsets.c |  3 +++
>  arch/arm64/kernel/smccc-call.S  | 43 +++++++++++++++++++++++++++++++++++++++++
>  arch/arm64/kernel/smccc.c       | 18 +++++++++++++++++
>  5 files changed, 66 insertions(+)
>  create mode 100644 arch/arm64/kernel/smccc-call.S
>  create mode 100644 arch/arm64/kernel/smccc.c
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 07d1811..a7332ca 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -89,6 +89,7 @@ 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 22dc9bc..c61d758 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_ARM_SMCCC)	+= smccc-call.o smccc.o

I think you can just stick these in arm64-obj-y, since that option will
never be turned off.

>  obj-y					+= $(arm64-obj-y) vdso/
>  obj-m					+= $(arm64-obj-m)
> diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
> index 8d89cf8..cfa0885 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)
> diff --git a/arch/arm64/kernel/smccc.c b/arch/arm64/kernel/smccc.c
> new file mode 100644
> index 0000000..7941210
> --- /dev/null
> +++ b/arch/arm64/kernel/smccc.c
> @@ -0,0 +1,18 @@
> +/*
> + * 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(arm_smccc_smc);
> +EXPORT_SYMBOL_GPL(arm_smccc_hvc);

You can just put these in arch/arm64/kernel/arm64ksyms.c, which is where
the rest of the EXPORTs for asm symbols live.

With those changes:

  Acked-by: Will Deacon <[email-masked]>

Will