On Fri, Aug 12, 2022 at 12:43:03PM -0400, Stefan Berger wrote:
> Simplify tpm_read_log_of() by moving reusable parts of the code into
> an inline function that makes it commonly available so it can be
> used also for kexec support. Call the new of_tpm_get_sml_parameters()
> function from the TPM Open Firmware driver.
> 
> Signed-off-by: Stefan Berger <stef...@linux.ibm.com>
> Cc: Jarkko Sakkinen <jar...@kernel.org>
> Cc: Jason Gunthorpe <j...@ziepe.ca>
> Cc: Rob Herring <robh...@kernel.org>
> Cc: Frank Rowand <frowand.l...@gmail.com>
> Reviewed-by: Mimi Zohar <zo...@linux.ibm.com>
> Tested-by: Nageswara R Sastry <rnsas...@linux.ibm.com>
> 
> ---
> v7:
>  - Added original comment back into inlined function
> 
> v4:
>  - converted to inline function
> ---
>  drivers/char/tpm/eventlog/of.c | 31 +++++------------------------
>  include/linux/tpm.h            | 36 ++++++++++++++++++++++++++++++++++
>  2 files changed, 41 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/char/tpm/eventlog/of.c b/drivers/char/tpm/eventlog/of.c
> index a9ce66d09a75..f9462d19632e 100644
> --- a/drivers/char/tpm/eventlog/of.c
> +++ b/drivers/char/tpm/eventlog/of.c
> @@ -12,6 +12,7 @@
>  
>  #include <linux/slab.h>
>  #include <linux/of.h>
> +#include <linux/tpm.h>
>  #include <linux/tpm_eventlog.h>
>  
>  #include "../tpm.h"
> @@ -20,11 +21,10 @@
>  int tpm_read_log_of(struct tpm_chip *chip)
>  {
>       struct device_node *np;
> -     const u32 *sizep;
> -     const u64 *basep;
>       struct tpm_bios_log *log;
>       u32 size;
>       u64 base;
> +     int ret;
>  
>       log = &chip->log;
>       if (chip->dev.parent && chip->dev.parent->of_node)
> @@ -35,30 +35,9 @@ int tpm_read_log_of(struct tpm_chip *chip)
>       if (of_property_read_bool(np, "powered-while-suspended"))
>               chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
>  
> -     sizep = of_get_property(np, "linux,sml-size", NULL);
> -     basep = of_get_property(np, "linux,sml-base", NULL);
> -     if (sizep == NULL && basep == NULL)
> -             return -ENODEV;
> -     if (sizep == NULL || basep == NULL)
> -             return -EIO;
> -
> -     /*
> -      * For both vtpm/tpm, firmware has log addr and log size in big
> -      * endian format. But in case of vtpm, there is a method called
> -      * sml-handover which is run during kernel init even before
> -      * device tree is setup. This sml-handover function takes care
> -      * of endianness and writes to sml-base and sml-size in little
> -      * endian format. For this reason, vtpm doesn't need conversion
> -      * but physical tpm needs the conversion.
> -      */
> -     if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
> -         of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
> -             size = be32_to_cpup((__force __be32 *)sizep);
> -             base = be64_to_cpup((__force __be64 *)basep);
> -     } else {
> -             size = *sizep;
> -             base = *basep;
> -     }
> +     ret = of_tpm_get_sml_parameters(np, &base, &size);
> +     if (ret < 0)
> +             return ret;
>  
>       if (size == 0) {
>               dev_warn(&chip->dev, "%s: Event log area empty\n", __func__);
> diff --git a/include/linux/tpm.h b/include/linux/tpm.h
> index dfeb25a0362d..6356baaa1393 100644
> --- a/include/linux/tpm.h
> +++ b/include/linux/tpm.h
> @@ -460,4 +460,40 @@ static inline struct tpm_chip *tpm_default_chip(void)
>       return NULL;
>  }
>  #endif
> +
> +#ifdef CONFIG_OF
> +static inline int of_tpm_get_sml_parameters(struct device_node *np,
> +                                         u64 *base, u32 *size)
> +{
> +     const u32 *sizep;
> +     const u64 *basep;
> +
> +     sizep = of_get_property(np, "linux,sml-size", NULL);
> +     basep = of_get_property(np, "linux,sml-base", NULL);
> +     if (sizep == NULL && basep == NULL)
> +             return -ENODEV;
> +     if (sizep == NULL || basep == NULL)
> +             return -EIO;
> +
> +     /*
> +      * For both vtpm/tpm, firmware has log addr and log size in big
> +      * endian format. But in case of vtpm, there is a method called
> +      * sml-handover which is run during kernel init even before
> +      * device tree is setup. This sml-handover function takes care
> +      * of endianness and writes to sml-base and sml-size in little
> +      * endian format. For this reason, vtpm doesn't need conversion
> +      * but physical tpm needs the conversion.
> +      */
> +     if (of_property_match_string(np, "compatible", "IBM,vtpm") < 0 &&
> +         of_property_match_string(np, "compatible", "IBM,vtpm20") < 0) {
> +             *size = be32_to_cpup((__force __be32 *)sizep);
> +             *base = be64_to_cpup((__force __be64 *)basep);
> +     } else {
> +             *size = *sizep;
> +             *base = *basep;
> +     }
> +     return 0;
> +}
> +#endif
> +
>  #endif
> -- 
> 2.35.1
> 

Reviewed-by: Jarkko Sakkinen <jar...@kernel.org>

BR, Jarkkko

Reply via email to