Re: [PATCH] powerpc/pseries: detect secure and trusted boot state of the system.

[Michael Ellerman]

Nayna Jain <nayna@xxxxxxxxxxxxx> writes:
> The device-tree property to check secure and trusted boot state is
> different for guests(pseries) compared to baremetal(powernv).
>
> This patch updates the existing is_ppc_secureboot_enabled() and
> is_ppc_trustedboot_enabled() function to add support for pseries.
>
> Signed-off-by: Nayna Jain <nayna@xxxxxxxxxxxxx>
> ---
>  arch/powerpc/kernel/secure_boot.c | 31 +++++++++++++++++++++++++------
>  1 file changed, 25 insertions(+), 6 deletions(-)
>
> diff --git a/arch/powerpc/kernel/secure_boot.c b/arch/powerpc/kernel/secure_boot.c
> index 4b982324d368..43fc6607c7a5 100644
> --- a/arch/powerpc/kernel/secure_boot.c
> +++ b/arch/powerpc/kernel/secure_boot.c
> @@ -6,6 +6,7 @@
>  #include <linux/types.h>
>  #include <linux/of.h>
>  #include <asm/secure_boot.h>
> +#include <asm/machdep.h>
>  
>  static struct device_node *get_ppc_fw_sb_node(void)
>  {
> @@ -23,11 +24,20 @@ bool is_ppc_secureboot_enabled(void)
>  {
>  	struct device_node *node;
>  	bool enabled = false;
> +	const u32 *secureboot;
>  
> -	node = get_ppc_fw_sb_node();
> -	enabled = of_property_read_bool(node, "os-secureboot-enforcing");
> +	if (machine_is(powernv)) {
> +		node = get_ppc_fw_sb_node();
> +		enabled =
> +		    of_property_read_bool(node, "os-secureboot-enforcing");
> +		of_node_put(node);
> +	}

We generally try to avoid adding new machine_is() checks if we can.

In a case like this I think you can just check for both properties
regardless of what platform you're on.
  
> -	of_node_put(node);
> +	if (machine_is(pseries)) {
> +		secureboot = of_get_property(of_root, "ibm,secure-boot", NULL);
> +		if (secureboot)
> +			enabled = (*secureboot > 1) ? true : false;
> +	}

Please don't use of_get_property() in new code. Use one of the properly
typed accessors that handles endian conversion for you.

cheers