[PATCH v2] ARM: ARMv7-M: implement restart routine common to all v7-M machines
Jonathan Austin
jonathan.austin at arm.com
Thu Aug 15 11:50:09 EDT 2013
On 15/08/13 16:45, Uwe Kleine-König wrote:
> The newly introduced function is to be used as .restart callback for
> ARMv7-M machines. The used register is architecturally defined, so it
> should work for all M-class machines.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
> ---
>
> Changes since v1, sent with Message-Id:
> 1376494625-25496-1-git-send-email-u.kleine-koenig at pengutronix.de:
>
> - add a more verbose change log
> - rename arch/arm/kernel/common-v7m.c to arch/arm/kernel/v7m.c
>
Thanks Uwe, this looks good now - assuming Russell's happy with
arch/arm/kernel/v7m.c :)
FWIW,
Acked-by: Jonathan Austin <jonathan.austin at arm.com>
> arch/arm/include/asm/v7m.h | 12 ++++++++++++
> arch/arm/kernel/Makefile | 2 +-
> arch/arm/kernel/v7m.c | 19 +++++++++++++++++++
> 3 files changed, 32 insertions(+), 1 deletion(-)
> create mode 100644 arch/arm/kernel/v7m.c
>
> diff --git a/arch/arm/include/asm/v7m.h b/arch/arm/include/asm/v7m.h
> index fa88d09..615781c 100644
> --- a/arch/arm/include/asm/v7m.h
> +++ b/arch/arm/include/asm/v7m.h
> @@ -15,6 +15,10 @@
>
> #define V7M_SCB_VTOR 0x08
>
> +#define V7M_SCB_AIRCR 0x0c
> +#define V7M_SCB_AIRCR_VECTKEY (0x05fa << 16)
> +#define V7M_SCB_AIRCR_SYSRESETREQ (1 << 2)
> +
> #define V7M_SCB_SCR 0x10
> #define V7M_SCB_SCR_SLEEPDEEP (1 << 2)
>
> @@ -42,3 +46,11 @@
> */
> #define EXC_RET_STACK_MASK 0x00000004
> #define EXC_RET_THREADMODE_PROCESSSTACK 0xfffffffd
> +
> +#ifndef __ASSEMBLY__
> +
> +enum reboot_mode;
> +
> +void armv7m_restart(enum reboot_mode mode, const char *cmd);
> +
> +#endif /* __ASSEMBLY__ */
> diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
> index 86d10dd..5140df5f 100644
> --- a/arch/arm/kernel/Makefile
> +++ b/arch/arm/kernel/Makefile
> @@ -24,7 +24,7 @@ obj-$(CONFIG_ATAGS_PROC) += atags_proc.o
> obj-$(CONFIG_DEPRECATED_PARAM_STRUCT) += atags_compat.o
>
> ifeq ($(CONFIG_CPU_V7M),y)
> -obj-y += entry-v7m.o
> +obj-y += entry-v7m.o v7m.o
> else
> obj-y += entry-armv.o
> endif
> diff --git a/arch/arm/kernel/v7m.c b/arch/arm/kernel/v7m.c
> new file mode 100644
> index 0000000..4d2cba9
> --- /dev/null
> +++ b/arch/arm/kernel/v7m.c
> @@ -0,0 +1,19 @@
> +/*
> + * Copyright (C) 2013 Uwe Kleine-Koenig for Pengutronix
> + *
> + * 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.
> + */
> +#include <linux/io.h>
> +#include <linux/reboot.h>
> +#include <asm/barrier.h>
> +#include <asm/v7m.h>
> +
> +void armv7m_restart(enum reboot_mode mode, const char *cmd)
> +{
> + dsb();
> + __raw_writel(V7M_SCB_AIRCR_VECTKEY | V7M_SCB_AIRCR_SYSRESETREQ,
> + BASEADDR_V7M_SCB + V7M_SCB_AIRCR);
> + dsb();
> +}
>
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