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

This does not look ACPI compliant. Shouldn't we read the ACPI table to
identify the reset register?

When we do the reset CPUs in several sockets may be running multiple
cores each. Are all of these stopped via this register? Or do we first
have to halt all but one core before doing the reset?

Best regards

Heinrich


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