Re: [PATCH v2 5/7] powerpc/secvar: Handle max object size in the consumer

[Andrew Donnellan]

On Fri, 2022-12-30 at 15:20 +1100, Russell Currey wrote:
> Currently the max object size is handled in the core secvar code with
> an
> entirely OPAL-specific implementation, so create a new max_size() op
> and
> move the existing implementation into the powernv platform.  Should
> be
> no functional change.
> 
> Signed-off-by: Russell Currey <ruscur@xxxxxxxxxx>

LGTM

Reviewed-by: Andrew Donnellan <ajd@xxxxxxxxxxxxx>

> ---
>  arch/powerpc/include/asm/secvar.h            |  1 +
>  arch/powerpc/kernel/secvar-sysfs.c           | 17 +++--------------
>  arch/powerpc/platforms/powernv/opal-secvar.c | 19
> +++++++++++++++++++
>  3 files changed, 23 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/secvar.h
> b/arch/powerpc/include/asm/secvar.h
> index 3b7e5a3625bd..92d2c051918b 100644
> --- a/arch/powerpc/include/asm/secvar.h
> +++ b/arch/powerpc/include/asm/secvar.h
> @@ -21,6 +21,7 @@ struct secvar_operations {
>         int (*set)(const char *key, uint64_t key_len, u8 *data,
>                    uint64_t data_size);
>         ssize_t (*format)(char *buf);
> +       int (*max_size)(uint64_t *max_size);
>  };
>  
>  #ifdef CONFIG_PPC_SECURE_BOOT
> diff --git a/arch/powerpc/kernel/secvar-sysfs.c
> b/arch/powerpc/kernel/secvar-sysfs.c
> index 190238f51335..aa1daec480e1 100644
> --- a/arch/powerpc/kernel/secvar-sysfs.c
> +++ b/arch/powerpc/kernel/secvar-sysfs.c
> @@ -122,27 +122,16 @@ static struct kobj_type secvar_ktype = {
>  static int update_kobj_size(void)
>  {
>  
> -       struct device_node *node;
>         u64 varsize;
> -       int rc = 0;
> +       int rc = secvar_ops->max_size(&varsize);
>  
> -       node = of_find_compatible_node(NULL, NULL, "ibm,secvar-
> backend");
> -       if (!of_device_is_available(node)) {
> -               rc = -ENODEV;
> -               goto out;
> -       }
> -
> -       rc = of_property_read_u64(node, "max-var-size", &varsize);
>         if (rc)
> -               goto out;
> +               return rc;
>  
>         data_attr.size = varsize;
>         update_attr.size = varsize;
>  
> -out:
> -       of_node_put(node);
> -
> -       return rc;
> +       return 0;
>  }
>  
>  static int secvar_sysfs_load(void)
> diff --git a/arch/powerpc/platforms/powernv/opal-secvar.c
> b/arch/powerpc/platforms/powernv/opal-secvar.c
> index 5e9de06b2533..07260460e966 100644
> --- a/arch/powerpc/platforms/powernv/opal-secvar.c
> +++ b/arch/powerpc/platforms/powernv/opal-secvar.c
> @@ -125,11 +125,30 @@ static ssize_t opal_secvar_format(char *buf)
>         return rc;
>  }
>  
> +static int opal_secvar_max_size(uint64_t *max_size)
> +{
> +       int rc;
> +       struct device_node *node;
> +
> +       node = of_find_compatible_node(NULL, NULL, "ibm,secvar-
> backend");
> +       if (!of_device_is_available(node)) {
> +               rc = -ENODEV;
> +               goto out;
> +       }
> +
> +       rc = of_property_read_u64(node, "max-var-size", max_size);
> +
> +out:
> +       of_node_put(node);
> +       return rc;
> +}
> +
>  static const struct secvar_operations opal_secvar_ops = {
>         .get = opal_get_variable,
>         .get_next = opal_get_next_variable,
>         .set = opal_set_variable,
>         .format = opal_secvar_format,
> +       .max_size = opal_secvar_max_size,
>  };
>  
>  static int opal_secvar_probe(struct platform_device *pdev)

-- 
Andrew Donnellan    OzLabs, ADL Canberra
ajd@xxxxxxxxxxxxx   IBM Australia Limited