[U-Boot] [RESEND PATCH v2 15/15] riscv: Move do_reset() to a common place

[Auer, Lukas]

Hi Bin,

On Mon, 2018-09-10 at 21:54 -0700, Bin Meng wrote:
> We don't have a reset method on any RISC-V board yet. Instead of
> adding the same 'unsupported' message for each CPU variant it might
> make more sense to add a generic do_reset function for all CPU
> variants to lib/, similar to the one for ARM (arch/arm/lib/reset.c).
> 
> Suggested-by: Lukas Auer <lukas.auer at aisec.fraunhofer.de>
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> 
> ---
> 
> Changes in v2:
> - new patch to move do_reset() to a common place
> 
>  arch/riscv/cpu/ax25/cpu.c |  9 ---------
>  arch/riscv/cpu/qemu/cpu.c |  8 --------
>  arch/riscv/lib/Makefile   |  1 +
>  arch/riscv/lib/reset.c    | 14 ++++++++++++++
>  4 files changed, 15 insertions(+), 17 deletions(-)
>  create mode 100644 arch/riscv/lib/reset.c
> 
> diff --git a/arch/riscv/cpu/ax25/cpu.c b/arch/riscv/cpu/ax25/cpu.c
> index ab05b57..fddcc15 100644
> --- a/arch/riscv/cpu/ax25/cpu.c
> +++ b/arch/riscv/cpu/ax25/cpu.c
> @@ -6,9 +6,6 @@
>  
>  /* CPU specific code */
>  #include <common.h>
> -#include <command.h>
> -#include <watchdog.h>
> -#include <asm/cache.h>
>  
>  /*
>   * cleanup_before_linux() is called just before we call linux
> @@ -24,9 +21,3 @@ int cleanup_before_linux(void)
>  
>  	return 0;
>  }
> -
> -int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const
> argv[])
> -{
> -	disable_interrupts();
> -	panic("ax25-ae350 wdt not support yet.\n");
> -}
> diff --git a/arch/riscv/cpu/qemu/cpu.c b/arch/riscv/cpu/qemu/cpu.c
> index a064639..6c7a327 100644
> --- a/arch/riscv/cpu/qemu/cpu.c
> +++ b/arch/riscv/cpu/qemu/cpu.c
> @@ -4,7 +4,6 @@
>   */
>  
>  #include <common.h>
> -#include <command.h>
>  
>  /*
>   * cleanup_before_linux() is called just before we call linux
> @@ -20,10 +19,3 @@ int cleanup_before_linux(void)
>  
>  	return 0;
>  }
> -
> -int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const
> argv[])
> -{
> -	printf("reset unsupported yet\n");
> -
> -	return 0;
> -}
> diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
> index cc562f9..b58db89 100644
> --- a/arch/riscv/lib/Makefile
> +++ b/arch/riscv/lib/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_CMD_BOOTM) += bootm.o
>  obj-$(CONFIG_CMD_GO) += boot.o
>  obj-y	+= cache.o
>  obj-y	+= interrupts.o
> +obj-y	+= reset.o
>  obj-y   += setjmp.o
>  
>  # For building EFI apps
> diff --git a/arch/riscv/lib/reset.c b/arch/riscv/lib/reset.c
> new file mode 100644
> index 0000000..5d9b99c
> --- /dev/null
> +++ b/arch/riscv/lib/reset.c
> @@ -0,0 +1,14 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2018, Bin Meng <bmeng.cn at gmail.com>
> + */
> +
> +#include <common.h>
> +#include <command.h>
> +
> +int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char * const
> argv[])
> +{
> +	printf("reset unsupported yet\n");
> +
> +	return 0;
> +}

Thanks for adding this patch!
I see one possible problem with it. The way you implemented it, arch /
board code can't overwrite the function to add a reset method. How
about something like this?

- do_reset() only prints "resetting..." and then calls cpu_reset()
- reset.c includes a weak cpu_reset() function that prints the warning
you currently have in this patch (by the way, it should say "reset not
supported yet"). It might also make sense to print the warning with the
panic() function and define PANIC_HANG, so that u-boot is halted on
resets. cpu_reset() can then be defined by boards that have an actual
reset method.

Thanks,
Lukas