[U-Boot] [PATCH v2 1/2] x86: Add efi runtime reset

[Heinrich Schuchardt]

On 1/28/19 4:42 PM, Alexander Graf wrote:
> Our selftest will soon test the actual runtime reset function rather than
> the boot time one. For this, we need to ensure that the runtime version
> actually succeeds on x86 to keep our travis tests work.
> 
> So this patch implements an x86 runtime reset function. It is missing
> shutdown functionality today, but OSs usually implement that via ACPI
> and this function does more than the stub from before, so it's at least
> an improvement.
> 
> Signed-off-by: Alexander Graf <agraf at suse.de>
> ---
>  drivers/sysreset/sysreset_x86.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/drivers/sysreset/sysreset_x86.c b/drivers/sysreset/sysreset_x86.c
> index 20b958cfd4..efed45ccb7 100644
> --- a/drivers/sysreset/sysreset_x86.c
> +++ b/drivers/sysreset/sysreset_x86.c
> @@ -10,6 +10,29 @@
>  #include <sysreset.h>
>  #include <asm/io.h>
>  #include <asm/processor.h>
> +#include <efi_loader.h>
> +
> +#ifdef CONFIG_EFI_LOADER
> +void __efi_runtime EFIAPI efi_reset_system(
> +			enum efi_reset_type reset_type,
> +			efi_status_t reset_status,
> +			unsigned long data_size, void *reset_data)
> +{
> +	u32 value = 0;
> +
> +	if (reset_type == EFI_RESET_COLD)
> +		value = SYS_RST | RST_CPU | FULL_RST;
> +	else if (reset_type == EFI_RESET_WARM)
> +		value = SYS_RST | RST_CPU;

It would preferable to do a reset for EFI_RESET_PLATFORM_SPECIFIC
instead of falling in to a loop.

For EFI_RESET_SHUTDOWN this patch only puts a single CPU core into an
endless loop but does not do anything for the remaining cores. Resetting
the whole CPU would be an alternative.

> +
> +	/* TODO EFI_RESET_PLATFORM_SPECIFIC and EFI_RESET_SHUTDOWN */
> +
> +	if (value)
> +		outb(value, IO_PORT_RESET);
Best regards

Heinrich

> +
> +	while (1) { }
> +}
> +#endif
>  
>  static int x86_sysreset_request(struct udevice *dev, enum sysreset_t type)
>  {
>