On Tue, Apr 18, 2023 at 09:44:07AM -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 <stefanb@xxxxxxxxxxxxx>
> Cc: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> Cc: Jason Gunthorpe <jgg@xxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: Frank Rowand <frowand.list@xxxxxxxxx>
> Reviewed-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
> Tested-by: Nageswara R Sastry <rnsastry@xxxxxxxxxxxxx>
> Tested-by: Coiby Xu <coxu@xxxxxxxxxx>
> Acked-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
>
Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
> ---
> v9:
> - Rebased on 6.3-rc7; call tpm_read_log_memory_region if -ENODEV returned
>
> v7:
> - Added original comment back into inlined function
>
> v4:
> - converted to inline function
> ---
> drivers/char/tpm/eventlog/of.c | 30 +++++-----------------------
> include/linux/tpm.h | 36 ++++++++++++++++++++++++++++++++++
> 2 files changed, 41 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/char/tpm/eventlog/of.c b/drivers/char/tpm/eventlog/of.c
> index 930fe43d5daf..41688d9cbd3b 100644
> --- a/drivers/char/tpm/eventlog/of.c
> +++ b/drivers/char/tpm/eventlog/of.c
> @@ -51,11 +51,10 @@ static int tpm_read_log_memory_region(struct tpm_chip *chip)
> 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)
> @@ -66,30 +65,11 @@ 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)
> + ret = of_tpm_get_sml_parameters(np, &base, &size);
> + if (ret == -ENODEV)
> return tpm_read_log_memory_region(chip);
> - 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;
> - }
> + 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 4dc97b9f65fb..dd9a376a1dbb 100644
> --- a/include/linux/tpm.h
> +++ b/include/linux/tpm.h
> @@ -461,4 +461,40 @@ 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
> --
> 2.38.1
>
